SerialVersionUID question

I'm trying to understand something about the use of serialVersionUID. I understand that the basic purpose of the field is to allow the JVM to compare incoming serialized objects to the local definition of the class, to ensure that no changes have occurred that may affect serialization/deserialization. What I don't get is why the examples I have seen use such wierd numbers ... for example, private static final long serialVersionUID = 7526472295622776147L. Also, why is the default serialVersionUID created using SHA-1 ... is there some security purpose behind the apparent complexity of this number, and the method of generating default values?
It seems that it would be adequate, for the first purpose, to set the value to 1 for the first version of the class, and increment it when changes affecting serialization are made. Are there any namespace conflicts? I would assume that only classes with the same package, name, and class loader will have their serialVersionUIDs compared.
Any small amount of enlightenment will be appreciated.
¦ {Þ

ejp wrote:
Or better still, don't make any changes that affect serialization: use the various advanced facilities of Serialization to ensure compatibility with serializations of the previous version(s).I'm not sure what you mean by the various advanced facilities of Serialization. How can you always avoid making changes that affect serialization?
I've been looking at (not yet reading-in-depth) the Java Object Serialization Specification, but I am a slow learner, and will have to beat my head against it for awhile.
Thanks for the insights you've given me.
¦ {Þ

Similar Messages

Noob Question: Problem with Persistence in First Entity Bean

Hey folks,
I have started with EJB3 just recently. After reading several books on the topic I finally started programming myself. I wanted to develop a little application for getting a feeling of the technology. So what I did is to create a AppClient, which calls a Stateless Session Bean. This Stateless Bean then adds an Entity to the Database. For doing this I use Netbeans 6.5 and the integrated glassfish. The problem I am facing is, that the mapping somehow doesnt work, but I have no clue why it doesn't work. I just get an EJBException.
I would be very thankfull if you guys could help me out of this. And don't forget this is my first ejb project - i might need a very detailed answer ... I know - noobs can be a real ....
So here is the code of the application. I have a few methods to do some extra work there, you can ignore them, there are of no use at the moment. All that is really implemented is testConnection() and testAddCompany(). The testconnection() Methode works pretty fine, but when it comes to the testAddCompany I get into problems.
Edit:As I found out just now, there is the possibility of Netbeans to add a Facade pattern to an Entity bean. If I use this, everythings fine and it works out to be perfect, however I am still curious, why the approach without the given classes by netbeans it doesn't work.
public class Main {
    private EntryRemote entryPoint = null;
    public static void main(String[] args) throws NamingException {
        Main main = new Main();
        main.runApplication();
    private void runApplication()throws NamingException{
        this.getContext();
        this.testConnection();
        this.testAddCompany();
        this.testAddShipmentAddress(1);
        this.testAddBillingAddress(1);
        this.testAddEmployee(1);
        this.addBankAccount(1);
    private void getContext() throws NamingException{
        InitialContext ctx = new InitialContext();
        this.entryPoint = (EntryRemote) ctx.lookup("Entry#ejb.EntryRemote");
    private void testConnection()
        System.err.println("Can Bean Entry be reached: " + entryPoint.isAlive());
    private void testAddCompany(){
        Company company = new Company();
        company.setName("JavaFreaks");
        entryPoint.addCompany(company);
        System.err.println("JavaFreaks has been placed in the db");
    }Here is the Stateless Session Bean. I added the PersistenceContext, and its also mapped in the persistence.xml file, however here the trouble starts.
import javax.ejb.Stateless;
import javax.persistence.EntityManager;
import javax.persistence.PersistenceContext;
@Stateless(mappedName="Entry")
public class EntryBean implements EntryRemote {
    @PersistenceContext(unitName="PersistenceUnit") private EntityManager manager;
    public boolean isAlive() {
        return true;
    public boolean addCompany(Company company) {
        manager.persist(company);
        return true;
    public boolean addShipmentAddress(long companyId) {
        return false;
    public boolean addBillingAddress(long companyId) {
        return false;
    public boolean addEmployee(long companyId) {
        return false;
    public boolean addBankAccount(long companyId) {
        return false;
}That you guys and gals will have a complete overview of whats really going on, here is the Entity as well.
package ejb;
import java.io.Serializable;
import javax.persistence.*;
@Entity
@Table(name="COMPANY")
public class Company implements Serializable {
    private static final long serialVersionUID = 1L;
    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private Long id;
    @Column(name="COMPANY_NAME")
    private String name;
    public Long getId() {
        return id;
    public void setId(Long id) {
        this.id = id;
   public String getName() {
        return name;
    public void setName(String name) {
        this.name = name;
        System.err.println("SUCCESS: CompanyName SET");
    @Override
    public int hashCode() {
        int hash = 0;
        hash += (id != null ? id.hashCode() : 0);
        return hash;
    @Override
    public boolean equals(Object object) {
        // TODO: Warning - this method won't work in the case the id fields are not set
        if (!(object instanceof Company)) {
            return false;
        Company other = (Company) object;
        if ((this.id == null && other.id != null) || (this.id != null && !this.id.equals(other.id))) {
            return false;
        return true;
    @Override
    public String toString() {
        return "ejb.Company[id=" + id + "]";
}And the persistence.xml file
<?xml version="1.0" encoding="UTF-8"?>
<persistence version="1.0" xmlns="http://java.sun.com/xml/ns/persistence" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_1_0.xsd">
<persistence-unit name="PersistenceUnit" transaction-type="JTA">
    <provider>oracle.toplink.essentials.PersistenceProvider</provider>
    <jta-data-source>jdbc/sample</jta-data-source>
    <exclude-unlisted-classes>false</exclude-unlisted-classes>
    <properties>
      <property name="toplink.ddl-generation" value="create-tables"/>
    </properties>
</persistence-unit>
</persistence>And this is the error message
08.06.2009 10:30:46 com.sun.enterprise.appclient.MainWithModuleSupport <init>
WARNUNG: ACC003: Ausnahmefehler bei Anwendung.
javax.ejb.EJBException: nested exception is: java.rmi.ServerException: RemoteException occurred in server thread; nested exception is:
        java.rmi.RemoteException: Transaction aborted; nested exception is: javax.transaction.RollbackException: Transaktion für Zurücksetzung markiert.; nested exception is:
        javax.transaction.RollbackException: Transaktion für Zurücksetzung markiert.
java.rmi.ServerException: RemoteException occurred in server thread; nested exception is:
        java.rmi.RemoteException: Transaction aborted; nested exception is: javax.transaction.RollbackException: Transaktion für Zurücksetzung markiert.; nested exception is:
        javax.transaction.RollbackException: Transaktion für Zurücksetzung markiert.
        at com.sun.corba.ee.impl.javax.rmi.CORBA.Util.mapSystemException(Util.java:243)
        at com.sun.corba.ee.impl.presentation.rmi.StubInvocationHandlerImpl.privateInvoke(StubInvocationHandlerImpl.java:205)
        at com.sun.corba.ee.impl.presentation.rmi.StubInvocationHandlerImpl.invoke(StubInvocationHandlerImpl.java:152)
        at com.sun.corba.ee.impl.presentation.rmi.bcel.BCELStubBase.invoke(BCELStubBase.java:225)
        at ejb.__EntryRemote_Remote_DynamicStub.addCompany(ejb/__EntryRemote_Remote_DynamicStub.java)I spend half the night figuring out whats wrong, however I couldnt find any solution.
If you have any idea pls let me know
Best regards and happy coding
Taggert
Edited by: Taggert_77 on Jun 8, 2009 2:27 PM

Well I don't understand this. If Netbeans created a Stateless Session Bean as a facade then it works -and it is implemented as a CMP, not as a BMP as you suggested.
I defenitely will try you suggestion, just for curiosity and to learn the technology, however I dont have see why BMP will work and CMP won't.
I also don't see why a stateless bean can not be a CMP. As far as I read it should not matter. Also on the link you sent me, I can't see anything related to that.
Maybe you can help me answering these questions.
I hope the above lines don't sound harsh. I really appreciate your input.
Best regards
Taggert

How does the Java card simulator work? and other misc questions

First, I have a class inherited from Applet. Okay, I did that.
How do I convert this class to a CAP file? I mean I have a class file which is compiled by javac, do I use this file to convert into a CAP file? What is an AID? Do I make up this AID?
In this .scr file (APDU Script), I understand the first 4 bytes, it means to create an Applet, but what about the rest? I know there are some intermixes of lengths and AIDs, I just can't decipher this.
// create wallet applet
0x80 0xB8 0x00 0x00 0x14 0x0a 0xa0 0x0 0x0 0x0 0x62 0x3 0x1 0xc 0x6 0x1 0x08 0 0 0x05 0x01 0x02 0x03 0x04 0x05 0x7F;
And here comes the main question?
How does the simulator work? How do I generate the data that mimics what the card reader reads?
Thanks
Jack

At first blush,
I have these when executing the RMIPurse sample according to the user guide
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Skel: unsupported type long of field interfaceHash.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Skel: unsupported bytecode anewarray in clinit method.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Skel: unsupported bytecode new in clinit method.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Skel: unsupported bytecode invokespecial in clinit method.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Skel: unsupported parameter type String of invoked method <init>(java.lang.String) of class java.rmi.server.Operation.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Skel: unsupported bytecode aastore in clinit method.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Skel: unsupported bytecode new in clinit method.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Skel: unsupported bytecode invokespecial in clinit method.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Skel: unsupported parameter type String of invoked method <init>(java.lang.String) of class java.rmi.server.Operation.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Skel: unsupported bytecode aastore in clinit method.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Skel: unsupported bytecode new in clinit method.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Skel: unsupported bytecode invokespecial in clinit method.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Skel: unsupported parameter type String of invoked method <init>(java.lang.String) of class java.rmi.server.Operation.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Skel: unsupported bytecode aastore in clinit method.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Skel: unsupported bytecode new in clinit method.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Skel: unsupported bytecode invokespecial in clinit method.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Skel: unsupported parameter type String of invoked method <init>(java.lang.String) of class java.rmi.server.Operation.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Skel: unsupported bytecode aastore in clinit method.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Skel: unsupported bytecode new in clinit method.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Skel: unsupported bytecode invokespecial in clinit method.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Skel: unsupported parameter type String of invoked method <init>(java.lang.String) of class java.rmi.server.Operation.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Skel: unsupported bytecode aastore in clinit method.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Skel: unsupported parameter type long of method dispatch.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Skel: unsupported long type constant.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Skel: unsupported long type constant.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Skel: unsupported long type constant.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Skel: unsupported long type constant.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Skel: unsupported long type constant.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Skel: unsupported String type constant.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Skel: unsupported parameter type String of invoked method <init>(java.lang.String) of class java.rmi.UnmarshalException.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Skel: unsupported long type constant.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Skel: unsupported String type constant.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Skel: unsupported parameter type String of invoked method <init>(java.lang.String) of class java.rmi.server.SkeletonMismatchException.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Skel: unsupported String type constant.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Skel: unsupported parameter type String of invoked method <init>(java.lang.String, java.lang.Exception) of class java.rmi.UnmarshalException.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Skel: unsupported String type constant.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Skel: unsupported parameter type String of invoked method <init>(java.lang.String, java.lang.Exception) of class java.rmi.MarshalException.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Skel: unsupported String type constant.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Skel: unsupported parameter type String of invoked method <init>(java.lang.String, java.lang.Exception) of class java.rmi.UnmarshalException.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Skel: unsupported String type constant.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Skel: unsupported parameter type String of invoked method <init>(java.lang.String, java.lang.Exception) of class java.rmi.MarshalException.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Skel: unsupported String type constant.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Skel: unsupported parameter type String of invoked method <init>(java.lang.String, java.lang.Exception) of class java.rmi.MarshalException.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Skel: unsupported String type constant.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Skel: unsupported parameter type String of invoked method <init>(java.lang.String, java.lang.Exception) of class java.rmi.MarshalException.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Skel: unsupported String type constant.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Skel: unsupported parameter type String of invoked method <init>(java.lang.String, java.lang.Exception) of class java.rmi.UnmarshalException.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Skel: unsupported String type constant.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Skel: unsupported parameter type String of invoked method <init>(java.lang.String, java.lang.Exception) of class java.rmi.UnmarshalException.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Skel: unsupported String type constant.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Skel: unsupported parameter type String of invoked method <init>(java.lang.String, java.lang.Exception) of class java.rmi.MarshalException.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Skel: unsupported String type constant.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Skel: unsupported parameter type String of invoked method <init>(java.lang.String) of class java.rmi.UnmarshalException.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported type long of field interfaceHash.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported type long of field serialVersionUID.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported bytecode anewarray in clinit method.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported bytecode new in clinit method.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported bytecode invokespecial in clinit method.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported parameter type String of invoked method <init>(java.lang.String) of class java.rmi.server.Operation.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported bytecode aastore in clinit method.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported bytecode new in clinit method.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported bytecode invokespecial in clinit method.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported parameter type String of invoked method <init>(java.lang.String) of class java.rmi.server.Operation.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported bytecode aastore in clinit method.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported bytecode new in clinit method.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported bytecode invokespecial in clinit method.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported parameter type String of invoked method <init>(java.lang.String) of class java.rmi.server.Operation.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported bytecode aastore in clinit method.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported bytecode new in clinit method.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported bytecode invokespecial in clinit method.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported parameter type String of invoked method <init>(java.lang.String) of class java.rmi.server.Operation.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported bytecode aastore in clinit method.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported bytecode new in clinit method.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported bytecode invokespecial in clinit method.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported parameter type String of invoked method <init>(java.lang.String) of class java.rmi.server.Operation.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported bytecode aastore in clinit method.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unhandled bytecode ifnull in clinit method, try a different compiler.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unhandled bytecode goto in clinit method, try a different compiler.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported bytecode invokestatic in clinit method.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported parameter type String of invoked method class$(java.lang.String) of class com.sun.jcclassic.samples.rmi.PurseImpl_Stub.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported bytecode anewarray in clinit method.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unhandled bytecode ifnull in clinit method, try a different compiler.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unhandled bytecode goto in clinit method, try a different compiler.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported bytecode invokestatic in clinit method.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported parameter type String of invoked method class$(java.lang.String) of class com.sun.jcclassic.samples.rmi.PurseImpl_Stub.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported bytecode aastore in clinit method.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unhandled bytecode ifnull in clinit method, try a different compiler.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unhandled bytecode goto in clinit method, try a different compiler.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported bytecode invokestatic in clinit method.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported parameter type String of invoked method class$(java.lang.String) of class com.sun.jcclassic.samples.rmi.PurseImpl_Stub.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported bytecode aastore in clinit method.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unhandled bytecode ifnull in clinit method, try a different compiler.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unhandled bytecode goto in clinit method, try a different compiler.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported bytecode invokestatic in clinit method.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported parameter type String of invoked method class$(java.lang.String) of class com.sun.jcclassic.samples.rmi.PurseImpl_Stub.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported bytecode aastore in clinit method.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported bytecode aastore in clinit method.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported bytecode invokevirtual in clinit method.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported parameter type String of invoked method getMethod(java.lang.String, java.lang.Class[]) of class java.lang.Class.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unhandled bytecode pop in clinit method, try a different compiler.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unhandled bytecode ifnull in clinit method, try a different compiler.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unhandled bytecode goto in clinit method, try a different compiler.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported bytecode invokestatic in clinit method.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported parameter type String of invoked method class$(java.lang.String) of class com.sun.jcclassic.samples.rmi.PurseImpl_Stub.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported bytecode anewarray in clinit method.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported bytecode aastore in clinit method.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported bytecode invokevirtual in clinit method.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported parameter type String of invoked method getMethod(java.lang.String, java.lang.Class[]) of class java.lang.Class.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unhandled bytecode ifnull in clinit method, try a different compiler.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unhandled bytecode goto in clinit method, try a different compiler.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported bytecode invokestatic in clinit method.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported parameter type String of invoked method class$(java.lang.String) of class com.sun.jcclassic.samples.rmi.PurseImpl_Stub.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported bytecode anewarray in clinit method.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported bytecode aastore in clinit method.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported bytecode invokevirtual in clinit method.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported parameter type String of invoked method getMethod(java.lang.String, java.lang.Class[]) of class java.lang.Class.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unhandled bytecode ifnull in clinit method, try a different compiler.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unhandled bytecode goto in clinit method, try a different compiler.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported bytecode invokestatic in clinit method.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported parameter type String of invoked method class$(java.lang.String) of class com.sun.jcclassic.samples.rmi.PurseImpl_Stub.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported bytecode anewarray in clinit method.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported bytecode invokevirtual in clinit method.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported parameter type String of invoked method getMethod(java.lang.String, java.lang.Class[]) of class java.lang.Class.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unhandled bytecode ifnull in clinit method, try a different compiler.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unhandled bytecode goto in clinit method, try a different compiler.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported bytecode invokestatic in clinit method.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported parameter type String of invoked method class$(java.lang.String) of class com.sun.jcclassic.samples.rmi.PurseImpl_Stub.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported bytecode anewarray in clinit method.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported bytecode invokevirtual in clinit method.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported parameter type String of invoked method getMethod(java.lang.String, java.lang.Class[]) of class java.lang.Class.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unhandled bytecode ifnull in clinit method, try a different compiler.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unhandled bytecode goto in clinit method, try a different compiler.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported bytecode invokestatic in clinit method.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported parameter type String of invoked method class$(java.lang.String) of class com.sun.jcclassic.samples.rmi.PurseImpl_Stub.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported bytecode anewarray in clinit method.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unhandled bytecode ifnull in clinit method, try a different compiler.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unhandled bytecode goto in clinit method, try a different compiler.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported bytecode invokestatic in clinit method.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported parameter type String of invoked method class$(java.lang.String) of class com.sun.jcclassic.samples.rmi.PurseImpl_Stub.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported bytecode aastore in clinit method.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported bytecode invokevirtual in clinit method.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported parameter type String of invoked method getMethod(java.lang.String, java.lang.Class[]) of class java.lang.Class.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unhandled bytecode goto in clinit method, try a different compiler.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unhandled bytecode pop in clinit method, try a different compiler.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported parameter type String of method class$.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported parameter type String of invoked method forName(java.lang.String) of class java.lang.Class.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported return type String of invoked method getMessage() of class java.lang.Throwable.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported parameter type String of invoked method <init>(java.lang.String) of class java.lang.NoClassDefFoundError.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported long type constant.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported parameter type long of invoked method invoke(java.rmi.Remote, java.lang.reflect.Method, java.lang.Object[], long) of class java.rmi.server.RemoteRef.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported long type constant.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported parameter type long of invoked method newCall(java.rmi.server.RemoteObject, java.rmi.server.Operation[], int, long) of class java.rmi.server.RemoteRef.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported String type constant.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported parameter type String of invoked method <init>(java.lang.String, java.lang.Exception) of class java.rmi.MarshalException.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported String type constant.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported parameter type String of invoked method <init>(java.lang.String, java.lang.Exception) of class java.rmi.UnexpectedException.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported long type constant.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported parameter type long of invoked method invoke(java.rmi.Remote, java.lang.reflect.Method, java.lang.Object[], long) of class java.rmi.server.RemoteRef.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported long type constant.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported parameter type long of invoked method newCall(java.rmi.server.RemoteObject, java.rmi.server.Operation[], int, long) of class java.rmi.server.RemoteRef.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported String type constant.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported parameter type String of invoked method <init>(java.lang.String, java.lang.Exception) of class java.rmi.MarshalException.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported String type constant.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported parameter type String of invoked method <init>(java.lang.String, java.lang.Exception) of class java.rmi.UnexpectedException.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported long type constant.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported parameter type long of invoked method invoke(java.rmi.Remote, java.lang.reflect.Method, java.lang.Object[], long) of class java.rmi.server.RemoteRef.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported long type constant.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported parameter type long of invoked method newCall(java.rmi.server.RemoteObject, java.rmi.server.Operation[], int, long) of class java.rmi.server.RemoteRef.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported String type constant.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported parameter type String of invoked method <init>(java.lang.String, java.lang.Exception) of class java.rmi.UnmarshalException.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported String type constant.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported parameter type String of invoked method <init>(java.lang.String, java.lang.Exception) of class java.rmi.UnmarshalException.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported String type constant.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported parameter type String of invoked method <init>(java.lang.String, java.lang.Exception) of class java.rmi.UnexpectedException.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported long type constant.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported parameter type long of invoked method invoke(java.rmi.Remote, java.lang.reflect.Method, java.lang.Object[], long) of class java.rmi.server.RemoteRef.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported long type constant.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported parameter type long of invoked method newCall(java.rmi.server.RemoteObject, java.rmi.server.Operation[], int, long) of class java.rmi.server.RemoteRef.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported String type constant.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported parameter type String of invoked method <init>(java.lang.String, java.lang.Exception) of class java.rmi.UnmarshalException.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported String type constant.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported parameter type String of invoked method <init>(java.lang.String, java.lang.Exception) of class java.rmi.UnexpectedException.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported long type constant.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported parameter type long of invoked method invoke(java.rmi.Remote, java.lang.reflect.Method, java.lang.Object[], long) of class java.rmi.server.RemoteRef.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported long type constant.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported parameter type long of invoked method newCall(java.rmi.server.RemoteObject, java.rmi.server.Operation[], int, long) of class java.rmi.server.RemoteRef.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported String type constant.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported parameter type String of invoked method <init>(java.lang.String, java.lang.Exception) of class java.rmi.MarshalException.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported String type constant.
[convert] error: com.sun.jcclassic.samples.rmi.PurseImpl_Stub: unsupported parameter type String of invoked method <init>(java.lang.String, java.lang.Exception) of class java.rmi.UnexpectedException.At the first command prompt, I typed cref -o demoee
and at the next command prompt, I typed ant all, and I got those error messages.
Thanks, you are so nice to help :)
Jack

Stupid Question: Suppress Warnings vs Fixing What Ain't Broken

Hey all,
I'm getting about 70 warnings in my code, mostly because I'm using anonymous classes to set up Actions as shown in the code snip below. This generates the warning "The serializable class does not declare a static final serialVersionUID field of type long" every time I create an Action this way:
final Action defaultUpAction = am.get(im.get(KeyStroke.getKeyStroke("control UP")));
          Action upAction = new AbstractAction(){ //warning generated here
               public void actionPerformed(ActionEvent e){
                    defaultUpAction.actionPerformed(e);
                    lastAction = "UP";
          };I understand what's causing the warning, and I even know how to fix it (or ignore the warning).
My question is, which is less of a hack? Do I just throw in a few SuppressWarnings annotations, or should I add a default serialVersionUID in each anonymous class? I'm not using the serialization functionality, but I might want to sometime in the future in which case suppressing the warnings would be a bad idea. Both solutions (adding a field I don't need or suppressing warnings instead of fixing them) seem a bit kludgey to me. Am I just being too touchy, or is there a better way?
Thanks

Thanks for the input, that does make quite a bit of sense. I suppose my hesitation comes from the feeling that although I was told by the higher-ups to "fix those warnings", all I'm doing is concealing them. I guess I shouldn't look at it that way, especially since I don't use serialization at all in any of my code (nobody else does, either). So in this case, simply suppressing the warnings probably makes more sense than adding fixes that won't be used anyway (and in fact may mislead future developers into thinking I'm using serialization somewhere).

SerialVersionUID and inner classes

Hello All
A quick question about serialVersionUID in inner classes.
If an inner class can't have any static members, how come it's legal to define
static final long serialVersionUID = 123L;
in an inner class ? Is there something special about serialization that allows this ?

there is nothing special about the serialVersionUID defintion -
you can define static datamember of inner class as long as it is final or the inner class is static :
public class Out {
public Out() {
private class In {
static final int i1 = 1; //legal
static int i2 = 2; //** illegal
private static class InStatic{
static final int i1 = 1; //legal
static int i2 = 2; //legal
}

General JPA query question

Hello world,
I'm new to JPA 2.0 and there are few things I don't understand.
BTW: I can't figure out the keywords to search for this question, so please pardon me if it's one of the most asked.
Using the Preview, I've seen that alignment went straight to Hell, so I tried to make this as readable as I could using pipes in place of white spaces in the result sets.
I have a couple of tables:
CUST table (for customers):
CUST_ID (pk, integer)
CUST_NAME (varchar)
ORD table (for orders):
ORD_ID (pk, integer)
ORD_STATUS (char) can be: N for new, S for shipped, D for delivered
CUST_ID (fk, integer)
The relationship is, of course, a "one to many" (every customer can place many orders).
Content of the tables:
CUST_ID|CUST_NAME
1|elcaro
2|tfosorcim
3|elppa
ORD_ID|ORD_STATUS|CUST_ID
2|N|1
3|N|1
4|N|1
5|S|1
6|S|1
7|D|1
8|D|1
9|D|1
10|D|2
11|N|2
12|S|3
13|S|3
Here's how I annotated my classes:
Customer.java:
@Entity(name = "Customer")
@Table(name = "CUST")
public class Customer implements Serializable
private static final long serialVersionUID = 1L;
@Id
@Column(name = "CUST_ID")
private Integer id;
@Column(name = "CUST_NAME")
private String name;
@OneToMany(mappedBy = "customer")
private List<Order> orders;
// Default constructor, getters and setters (no annotations on these)
Order.java:
@Entity(name = "Order")
@Table(name = "ORD")
public class Order implements Serializable
private static final long serialVersionUID = 1L;
@Id
@Column(name = "ORD_ID")
private Integer id;
@Column(name = "ORD_STATUS")
private Character status;
@ManyToOne
@JoinColumns
@JoinColumn(name = "CUST_ID", referencedColumnName = "CUST_ID")
private Customer customer;
// Default constructor, getters and setters (no annotations on these)
Everything works just fine, the following JPQL query yields the results I expected:
select c from Customer c
it returns three objects of type Customer, each of which contains the orders that belong to that customer.
But now, I want to extract the list of customers that have orders in status 'N', along with the associated orders (only the status 'N' orders, of course).
Back in the good ol' days I would have written an SQL query like this:
select c.cust_id, c.cust_name, o.ord_id, o.ord_status
from cust c
inner join ord o on (o.cust_id = c.cust_id)
where o.ord_status = 'N'
and it would have returned the following result set:
CUST_ID|CUST_NAME|ORD_ID|ORD_STATUS
1|elcaro|2|N
1|elcaro|3|N
1|elcaro|4|N
2|tfosorcim|11|N
The following JPQL query, however, doesn't yield the expected results:
select distinct c from Customer c join c.orders o where o.status = 'N'
it returns the correct set of customers (customer 'elppa' doesn't have any status 'N' order and is correctly excluded), but each customer contains the full set of orders, regardless of the status.
It seems that the 'where' clause is only evaluated to determine which set of customers has to be extracted and then the persistence provider starts to navigate the relationship to extract the full set of orders.
Thinking a little about it, I must admit that it makes sense.
I then tried out another JPQL query:
select c, o from Customer c join c.orders o where o.status = 'N'
this JPA query yields results that are similar to the ones produced by the previous SQL query: each result (4 results as expected) is a 2-object array, the first object is of type Customer and the second object is of type Order. But, again, the objects of type Customer contain the full set of related orders (as I expected, this time). Not to mention the fact that now the orders are not contained in the Customer objects, but are returned separately, just as in an SQL result set.
Now the question is:
Is it possible to write a JPA query that filters out, not only the customers that don't have an order in status 'N', but the related orders (fetched during relationship navigation) that are not in status 'N' as well?
What I'd like to be able to get is a 2-customer result where each customer contains only its status 'N' orders.
I read the Java EE 6 Tutorial and one of the examples (the Order Application) has a schema that is similar to mine, but I couldn't find a query like this (in the downloaded source code).
Although I think the above is standard behavior, I use an Oracle Weblogic 12c server (through its Eclipse adapter) and the persistence provider appears to be EclipseLink.
Thanks in advance.
Best regards,
Stefano
Edited by: user11265230 on 17-apr-2012 14.11

Hello,
When returning an entity from JPQL, it gives you the entity as it is in the database. Your "select distinct c from Customer c join c.orders o where o.status = 'N'" is asking for all customers that have an order with a status of 'N', so that is what it gives you. There is no condition to filter anything on the relationship when building the Customer object in JPA - doing so would mean returning a managed entity that does not reflect what is in the database. This would affect other queries, since JPA requires that queries return the same instance of an entity regardless of the query that is used to bring it back. So a query using your "where o.status = 'N'" would cause conflicting results when used with a query using "where o.status = 'Y'". And these queries would make the EntityManager unable to determine what has changed on the returned objects.
EclipseLink does have the ability to filter over relationships, it is just not available through standard JPA and I would strongly discourage it. Instead of querying for Customers, why not change the query to get Orders instead -
"select o from Customer c join c.orders o where o.status = 'N'". Assuming Orders have a ManyToOne back reference to their Customer, this will mean you do not need to travers the Customer-> order relationship. If using
"select c, o from Customer c join c.orders o where o.status = 'N'"
I am not sure why you would use the orders from the returned customers instead of the orders returned in the results though.
You could also return "select c.id, c.name, o.id, o.status from Customer c join c.orders o where o.status = 'N'" which is the equivalent of what you would get from the SQL you initially posted.
Regards,
Chris

Order of execution of static { } statements question

Hi,
I have a question about the order of execution of static statements. Let's imagine the following Class B inheriting of Class A:
public class A {
    static { // My static code for A };
public class B extends A {
    static { // My static code for B; };
}I know that static statements are executed when classes are loaded, but does Java guarantee an order of execution of static statements between inherited classed (like for constructors) or is it 'random' in that it depends which class is loaded first?
Thanks,
J.

Jrm,
My advise with this and all such questions is "Suck it and see"...
Have compiler, will travail ;-)
Cheers. Keith.
PS:
package forums;
import java.util.List;
import java.util.ArrayList;
public class InitBlocksTesterpator
private List<String> list = new ArrayList<String>() {
      add("This hack uses an anonymous inner-class to populate the list.");
      add("It causes serialization problems");
C:\\Java\\home\\src\\forums\\InitBlocksTesterpator.java:8: warning: [serial] serializable class <anonymous forums.InitBlocksTesterpator$1> has no definition of serialVersionUID
private List<String> list = new ArrayList<String>() {
                                                      ^
1 warning
static {
    System.out.println("this is a static initialiser block above the main method.");
    System.out.println("this is a instance initialiser block above the main method.");
public static void main(String[] args) {
    // static { System.out.println("this is a static initialiser block inside the main method."); } // won't compile
    { // this is hardly ever used. just use a method FFS!
      int n = 0; // n is lexically scoped... i.e. it only exists in this code block
      System.out.println("this is a code block inside the main method.");
    new InitBlocksTesterpator().moreBeer();
    System.out.println("this is a instance initialiser block below the main method.");
static {
    System.out.println("this is a static initialiser block below the main method.");
public void moreBeer() {
      System.out.println("this is a code block in the moreBeer instance method.");
    // static { System.out.println("this is a static initialiser block in an instance method"); } // won't compile
    System.out.println(list);
}... just to save you some time ...

Question with Struts ActionServlet

Hi,everybody.
I have written a simple application using Struts.The program is used to validate a user who login to the system.I have added all *.jar library file of Struts 1.2.6 to the Tomcat project,But after I accessed to Login page,enter username and password,and then click "Login" button,It popup the following exception:
Error loading WebappClassLoader
delegate: false
repositories:
/WEB-INF/classes/
----------> Parent Classloader:
org.apache.catalina.loader.StandardClassLoader@fe315d
org.apache.struts.action.ActionServlet
java.lang.ClassNotFoundException: org.apache.struts.action.ActionServlet
     at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1355)
     at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1201)
     at org.apache.catalina.core.StandardWrapper.loadServlet(StandardWrapper.java:1034)
     at org.apache.catalina.core.StandardWrapper.allocate(StandardWrapper.java:757)
     at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:130)
     at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:178)
     at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:126)
     at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:105)
     at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:107)
     at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:148)
     at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:869)
     at org.apache.coyote.http11.Http11BaseProtocol$Http11ConnectionHandler.processConnection(Http11BaseProtocol.java:664)
     at org.apache.tomcat.util.net.PoolTcpEndpoint.processSocket(PoolTcpEndpoint.java:527)
     at org.apache.tomcat.util.net.LeaderFollowerWorkerThread.runIt(LeaderFollowerWorkerThread.java:80)
     at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:684)
     at java.lang.Thread.run(Unknown Source)
and the web.xml file is list as following:
<?xml version="1.0" encoding="ISO-8859-1"?>
<!DOCTYPE web-app
PUBLIC "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN"
"http://java.sun.com/dtd/web-app_2_3.dtd">
<web-app>

<servlet>
<servlet-name>actionServlet</servlet-name>
<servlet-class>org.apache.struts.action.ActionServlet</servlet-class>
</servlet>

<servlet-mapping>
<servlet-name>actionServlet</servlet-name>
<url-pattern>*.do</url-pattern>
</servlet-mapping>

<welcome-file-list>
<welcome-file>login.jsp</welcome-file>
</welcome-file-list>
</web-app>
struts-config.xml is listed as following:
<?xml version="1.0" encoding="ISO-8859-1" ?>
<!DOCTYPE struts-config PUBLIC
     "-//Apache Software Foundation//DTD Struts Configuration 1.1//EN"
     "http://jakarta.apache.org/struts/dtds/struts-config_1_1.dtd">
<struts-config>
     <form-beans>
          <form-bean name="formBean1" type="classmate.UserForm"/>
     </form-beans>
     <global-forwards>
          <forward name="failed" path="/error.jsp"/>
          <forward name="successed" path="/right.jsp"/>
     </global-forwards>
     <action-mappings>
          <action path="/login" type="classmate.LoginAction" name="formBean1" scope="request" input="/login.jsp" />
          <action path="/regist" forward="/regist.jsp"/>
     </action-mappings>
</struts-config>
if anybody can help me to resovle this question? Please Reply .
Besides this,I also have another question I want to ask,it is that how to install Struts plugin to Eclipse,I have tried to unziped the download EasyStruts plugin to the Eclipse plugins directory,but after click Window->Preference ,I have not found the EasyStruts item in the left of the pop-up panel,the Eclipse version is 3.1.2 and have installed lomboz in it.if anybody have practice in such installation? Please response to help me.
Thank you and Regards.

Hi,
Thank you for response.I have modified the program as what you told me.it can startup now,But it suspended at LoginAction,the running message is printed as following:
LoginAction.execute(ActionMapping, ActionForm, HttpServletRequest, HttpServletResponse) line: 18
RequestProcessor.processActionPerform(HttpServletRequest, HttpServletResponse, Action, ActionForm, ActionMapping) line: 419
RequestProcessor.process(HttpServletRequest, HttpServletResponse) line: 224
ActionServlet.process(HttpServletRequest, HttpServletResponse) line: 1192
ActionServlet(HttpServlet).service(HttpServletRequest, HttpServletResponse) line: 709
when I click on the information "RequestProcessor.processActionPerform",it popup a message that show "Source not found ,The jar file Struts.jar has no source attachment",Does it need to attach the source of struts.jar?
I list the LoginAction.java as following:
package classmate;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.struts.action.Action;
import org.apache.struts.action.ActionForm;
import org.apache.struts.action.ActionForward;
import org.apache.struts.action.ActionMapping;
public final class LoginAction extends Action{
public ActionForward execute(
     ActionMapping mapping,
     ActionForm form,
     HttpServletRequest request,
     HttpServletResponse response) throws Exception {
     UserForm userform = (UserForm) form;
     String name = userform.getName();
     String psw = userform.getPsw();
     if("jenny".equals(name) && "hi".equals(psw)){
          UserLoginLog ul = new UserLoginLog();
          ul.save(name,psw);
          return mapping.findForward("successed");
     }else{
          return mapping.findForward("failed");
as I debuged the program,the breakpoint line "UserForm userform = (UserForm) form; "
and the UseForm.java is listed as following:
package classmate;
import org.apache.struts.action.ActionForm;
public class UserForm extends ActionForm{
     private static final long serialVersionUID = 1L;
     private String name = null;
     private String psw = null;
     public UserForm(){}
     public void setName(String name) {
          this.name = name;
     public String getName() {
          return name;
     public void setPsw(String psw) {
          this.psw = psw;
     public String getPsw() {
          return psw;
and I have written the web.xml and struts-config.xml in above message.
how can I run through the breakpoint line so that I can access the ActionForm's Data? if anybody can tell me how to resovle it ,Please reply to help me. Thanks you.
Message was edited by:
Devemor

Question on Generics

Consider a type-parameterized class declared as follows
public class Box<T> {
}Is there any way to get the Class object for whatever type was passed into T?
For instance I would like to be able to use something like the following code:
Box<Integer> box = new Box<Integer>();
Class<?> myClass = box.getParameterizedType();...where myClass would then be the same as what is returned by a call to Integer.class.
For the record, this is part of a reworking of a genetic programming suite I've been developing. The parametrized type in question is the return type of a node of a tree, and I am verifying if it fits the signature of some application element.

Well the Box class doesn't exist, it's merely a simplification of the problem at hand. If you want to see the body of the actual code I have written, it's something like the following:
package darwin.applicationObjects;
import java.io.Serializable;
public abstract class Node<returnType> implements Serializable {
     private static final long serialVersionUID = -1550106950846205458L;
     protected Class<?>[] childTypes;
     protected Node<?>[] childNodes;
     protected int arity;
     protected Node<?> parent;
     protected int birthOrder;
      * Instantiate a new terminal
     public Node() {
          arity = 0;
          childTypes = new Class<?>[0];
          childNodes = new Node<?>[0];
      * Instantiate a new node with child types specified
      * @param childTypes array of types of child nodes
     public Node(Class<?>[] childTypes) {
          arity = childTypes.length;
          this.childTypes = childTypes;
          childNodes = new Node<?>[arity];
      * Instantiate a new node with child nodes specified
      * @param childNodes array of child nodes
     public Node(Node<?>[] childNodes) {
          arity = childTypes.length;
          childTypes = new Class<?>[childNodes.length];
          for(int i = 0; i < childNodes.length; i++) {
               Node<?> node = childNodes;
               node.setParent(i, this);
               childTypes[i] = node.getReturnType();
          this.childNodes = childNodes;
     * Set the parent and birth order of this node to reflect the tree
     * @param birthOrder index of childNodes array to which this node is assigned
     * @param parent     reference to the parent node
     private void setParent(int birthOrder, Node<?> parent) {
          this.parent = parent;
          this.birthOrder = birthOrder;
     public Class<?> getReturnType() {
          //MAKE THIS WORK!
          return null;
     public abstract returnType getValue(Parameters p);

SerialversionUID Changes in JAVA 5

I have an application which has Serializable classes. The application works in a cluster environment where these classes get serialized and deserialized. None of the classes declare an serialVersionUID variable explicitly.
My question is: Based on the changes in Serialization changes in JAVA 5, how do I decide whether I really need to declare serialVersionUID field explicitly for my classes?

I am a colleague of Puneet's. The serialization is not something we do; it is something that a Servlet Container does for (to?) us. There is persistence of these objects, but it's "temporary persistence" in that it will not span any versions of anything. The persistence will never last more than a few hours.
I think this explains why this has not been an issue for us, and why we have not been interested in it. It sounds like we should go ahead and use serialver to populate this attribute and forget about it. I understand that if our application were managing the persistence of these objects, we would be interested in the version, because we would need to key off it for "upgrading" older persistent objects that are read by a newer version of software. None of that applies in this case, which is the source of confusion here, I'm pretty sure.
Hope this helps.

Question about argument marshalling with RMI.

Hello guys,
I recently started an RMI-related project and successfully implemented this technology, but at some point I created this interface on the server
package xyz;
import somePackage.SomeClass ;
public interface A extends Remote{
public void methodA( SomeClass x ) throws RemoteEx; //SomeClass is implementing interface A
and exported it to the RemoteReg folowing standard RMI procedure.
The problem came when i tried to pass a instance of SomeClass to methodA from the corresponding object retrived from the registry, got myself a nice
java.rmi.MarshalException: error marshalling arguments; nested exception is:
java.io.NotSerializableException: somePackage.SomeClass
The question is: can't RMI pass arguments as shown previously or it's my implementation faulty?
//ofc i could send the vars needed and create the SomeClass instance on the server but maybe it can be done this way too.

Well the .class on the client implemented Serialize, while the .class from the server didn't(this being the only difference).So in other words 'yes, I had different versions of the .class file at the server and the client'.
So in theory they might get different serialVersionsUID due to this discrepancyNo, in theory one of them isn't Serializable, so either the sender or the receiver is going to throw an exception of some kind.
You have to deploy the same .class file at both ends (until you get into Versioning), and they certainly both have to implement Serializable. They also both have to have the same serialVersionUID, which you should hard-code into the class now.

SerialVersionUID in abstract classes

Hi,
i have a Question about the serialVersionUID for abstract classes.
first i will describe a simple example to show my problem.
abstract class A implements Serializable {
    private int value;
    public A(int value) {
        this.value = value;
    protected abstract void doSomething();
class B extends A {
    private static final serialVersionUID = 8373629029L;
    public B(int value) {
           super(value);
    protected void doSomething() {
     //do something
} B is a ValueObjects on a Server and transmitted to a Client Application.
When i change the abstract super class A i get an exception on the client because the serialVersionUID does not mathc to the Client anymore
So i changed the " implements Serializable" Statement down to B. And tried the same. Then i get an InvalidClassException because with following hint "no valid constructor". So i also have to make A Serializable and also need a defined serialVersionUID for A.
I think there is something i don't unterstand in the serialization Mechanism in Java.
Why does it makes sense to adda serialVersionUID to an abstract class? And how do i generate the UID with the "serialver" tool deliversd with the JDK form a class which i cannot instanciate?
Edited by: kbj on Jan 23, 2009 7:14 AM

kbj wrote:
So i would like to know what is the best practise in such a case?Classes designed for inheritance should rarely implement Serializable, and interfaces should rarely extend it. If a class or interface exists primarily to participate in a framework that requires all participants to implement Serializable then it makes sense to violate this rule.
So in your case you may want to provide a protected parameterless constructor and a protected initialization method if a client provided invariant is required ("value" in your case). Then all public or protected instance methods need to call a private method that checks that the class has been initialized (i.e. the subclass has been written so that it calls the protected initialization method and passes in the "value" invariant). If not then you should throw an IllegalStateException. The field you use to flag that the object has been initialized should be of type java.util.concurrent.atomic.AtomicReference.
The above is taken pretty much verbatim from chapter 11 of effective java second edition. The book also provides an example of the above you could use as a template.

SerialVersionUID warnings

I have started to use Eclipse as a development platform and receive a warning message on all of my Serializable classes that I have not declared "static final long serialVersionUID".
I have read articles and understand why/what the serialVersionUID is all about in regards to a single class. My question is, does this value have to be different for every class? Or can I simply create a value for each class starting at 1 and simply modify the value whenever I add/remove data values from the class?
I know the default value is a hash value, so that leads me to believe that they should be unique, but I also know that is it possible for hash values to collide, so am not 100% certain.

does this value have to be different for every class? No.
Or can I simply create a value for each class starting at 1 and simply modify
the value whenever I add/remove data values from the class?Not quite. Everytime you make a significant change in the class as far as serialization goes.
It's hard to define, but ask yourself if the new version of the class could correctly
read in a serialized instance from the previous version of the class and interpret it
correctly. For example, you could have a class with x,y values that you're reinterpreting
to be relative to something else, versus absolute. The fields haven't changed
and neither have the serialized data for the class, but you've made a significant change.
I know the default value is a hash value, so that leads me to believe that they should be uniqueThe hashing was just a automatic way to generate an id that would, in all likelyhood
detect even minute changes in the class.

Deserializing Object which had different SerialVersionUID than current One?

Hi guys,
Please help me on this topic. i ll explain what i have done as a newbie to Serialization.
I have a Class A with serialVersionUID = 5L.
I have serialized this class and stored in DB.
I can deserialize that class and use it using same class.
Now i want to change some fields (add modify and delete ) in class which accordingly ask me to change my serialVersionUID.
If i deserialize using new class i cannot deserialize it.
Now my questions are:-
How should i check my SerialVersionUID of object stored in DB?
How can i deserialize old Object?
Please ppl help.................

Hi ejp thanks for replying...........
Well i read the Serialization specification doc from Sun.And its really gud.Thanks for the same.
Now why would i want to add new fields ......The product i m working now is still evolving and we are focussing on performance through Serialization. Though we dont know what new features in our product might ask us to add some more fields..So we want to handle this by knowing SerialVersionUID and handling the changes in previous and current classes while readObject() written by us......
So i would like to know SerialVersionUID from the stream.......
There is a method in ObjectInputStream readObjectClassDescriptor() but that one is protected from which i can access serialVersionUID.
The problem i m facing is that readObjectClassDescriptor() method requires to know that next in the stream is ObjectClassDescriptor...
Help my language might not be informative but i have tried to sum up ......
Waiting for ur reply.....!!

Questions on Print Quote report

Hi,
I'm fairly new to Oracle Quoting and trying to get familiar with it. I have a few questions and would appreciate if anyone answers them
1) We have a requirement to customize the Print Quote report. I searched these forums and found that this report can be defined either as a XML Publisher report or an Oracle Reports report depending on a profile option. Can you please let me know what the name of the profile option is?
2) When I select the 'Print Quote' option from the Actions drop down in the quoting page and click Submit I get the report printed and see the following URL in my browser.
http://<host>:<port>/dev60cgi/rwcgi60?PROJ03_APPS+report=/proj3/app/appltop/aso/11.5.0/reports/US/ASOPQTEL.rdf+DESTYPE=CACHE+P_TCK_ID=23731428+P_EXECUTABLE=N+P_SHOW_CHARGES=N+P_SHOW_CATG_TOT=N+P_SHOW_PRICE_ADJ=Y+P_SESSION_ID=c-RAuP8LOvdnv30grRzKqUQs:S+P_SHOW_HDR_ATTACH=N+P_SHOW_LINE_ATTACH=N+P_SHOW_HDR_SALESUPP=N+P_SHOW_LN_SALESUPP=N+TOLERANCE=0+DESFORMAT=RTF+DESNAME=Quote.rtf
Does it mean that the profile in our case is set to call the rdf since it has reference to ASOPQTEL.rdf in the above url?
3) When you click on submit button do we have something like this in the jsp code: On click call ASOPQTEL.rdf. Is the report called using a concurrent program? I want to know how the report is getting invoked?
4) If we want to customize the jsp pages can you please let me know the steps involved in making the customizations and testing them.
Thanks and Appreciate your patience
-PC

1) We have a requirement to customize the Print Quote report. I searched these forums and found that this report can be defined either as a XML Publisher report or an Oracle Reports report depending on a profile option. Can you please let me know what the name of the profile option is?
I think I posted it in one of the threads2) When I select the 'Print Quote' option from the Actions drop down in the quoting page and click Submit I get the report printed and see the following URL in my browser.
http://<host>:<port>/dev60cgi/rwcgi60?PROJ03_APPS+report=/proj3/app/appltop/aso/11.5.0/reports/US/ASOPQTEL.rdf+DESTYPE=CACHE+P_TCK_ID=23731428+P_EXECUTABLE=N+P_SHOW_CHARGES=N+P_SHOW_CATG_TOT=N+P_SHOW_PRICE_ADJ=Y+P_SESSION_ID=c-RAuP8LOvdnv30grRzKqUQs:S+P_SHOW_HDR_ATTACH=N+P_SHOW_LINE_ATTACH=N+P_SHOW_HDR_SALESUPP=N+P_SHOW_LN_SALESUPP=N+TOLERANCE=0+DESFORMAT=RTF+DESNAME=Quote.rtf
Does it mean that the profile in our case is set to call the rdf since it has reference to ASOPQTEL.rdf in the above url?
Yes, your understanding is correct.3) When you click on submit button do we have something like this in the jsp code: On click call ASOPQTEL.rdf. Is the report called using a concurrent program? I want to know how the report is getting invoked?
No, there is no conc program getting called, you can directly call a report in a browser window, Oracle reports server will execute the report and send the HTTP response to the browser.4) If we want to customize the jsp pages can you please let me know the steps involved in making the customizations and testing them.
This is detailed in many threads.Thanks
Tapash

SerialVersionUID question

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