Instantiation access to other java classes

Hello,
I have a public Java file in my package.
I want to grant access to only classes of my choice to instantiate my class, irrespective of any package(my constructor is public itself).
Is there any way?
eg:
I have MyJava.java in com.abc;
I want to give access only to 2 classes even though other classes exist in the same package:
YourJava1.java in com.abc; (there are other classes in this package)
YourJava2.java in com.xyz; (there are other classes in this package)
Thanks.

Hi,
I'm not sure about your depths in java knowledge... however, I'm gonna try to help you based on my knowledge...
whenever "public" modifier will be used any case( doesn't matter if it is Class, method or attributes), it will be visible from any package level. That is the Rule. If you make your constructor as public, then it always be accessible for any class regardless the package level. Otherwise, it would defeat the purpose of "public" modifier.
Its depends on your business logic why you are trying to do this scenario. But, there are couple of ways to solve the problem...
Make "MyJava.java"constructor as "protected" AND move whichever class needs to have handle on it into the same package(in this case: "YourJava1.java" and "YourJava2.java"). Thats how only those classes will be able to instantiate "MyJava.java". you may have multiple constructor and one of them can be "public" so that this object also can be accessed from outside of the package...
Another option might be - make "MyJava.java" as an Interface or an abstract class. So that you can implement it whichever class needs it. This is how you can restrict it someway...
Hope it helps...

Similar Messages

How can I compile and run other java classes from within an application?

Hello there everyone! I really hope that someone can help me. I am writing a program that must be able to compile and run other java classes that are in different files, much like development environments like Kawa or Forte allow you to do.
There has to be a way of doing this ( I hope!! ), but i can't seem to find it!!
I have tried using this command to compile:
Runtime.getRuntime().exec ("c:\\programs\\javac className.java");
...and this one to run:
Runtime.getRuntime().exec ("c:\\programs\\java className");
...but neither works!!! I can compile and run classes that are in the same file as my application, but I can't get it to work at all for files in different directories or files.
PLEASE, PLEASE, PLEASE help me - i've run out of ideas, and i need this to be working in 3 days!!!
Thank you very much for any help anyone can give me, I really appreciate it!! Thanks again!!
Adrian ( ...in distress!! )

public class JavaCompiler{
   public static void main(String[] args)throws Exception{ //sorry bout the laziness
      if(args == null || args.length != 1){
         System.out.println("Usage: java JavaCompiler MyClass.java");
         System.exit(0);
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      p.waitFor();
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Accessing ServletContext from Java class Data Control

I'm writing some business service classes as plain old java classes that will be bound to a JSP using ADF and STRUTS. The business logic requires the real path of the servlet context to access a file. How do I call servletContext.getRealPath("/WEB-INF/test.xml")?
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Thanks in advance...

Ok, it looks like I'll have to define my own action class and pass the pathname on to the data control class.

Access a normal java class from EJB

how can i access normal java class from an EJB.
I do not want to write the business logic inside the EJB. How can I achieve this.

There's no special API for doing this. Just use normal java. E.g.
@Stateless
public class FooBean implements Foo {
public void foo() {
// access non-EJB utility class Bar
Bar b = new Bar();
b.bar();
}

Problem accessing servlet from java class which uses Basic Authentication

"Hi,
I am using weblogic 6.1 server. I am calling a servlet file from a class file using HttpURLConnection. This is the code below.
          String theUsername="B1A1Z1T2";
          String thePassword="hlladmin";
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               int it = 0;
               while ((it = encoding.indexOf('\n')) != -1
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                         encoding = encoding.substring(0, it)
                         encoding.substring(it 1);
               uc.setRequestProperty("Authorization","BASIC " encoding);
               uc.setRequestProperty("SOAPAction", url.toString());
               System.out.println(uc.getResponseCode());
               System.out.println(uc.getResponseMessage());
          catch(Exception io)
               io.printStackTrace();
               System.out.println("error message........" io.getMessage());
In web.xml I have d

Hello,
Could you post the stack trace?
Thanks,
Bruce
Vijay Babu wrote:
>
"Hi,
I am using weblogic 6.1 server. I am calling a servlet file from a class file using HttpURLConnection. This is the code below.
String theUsername="B1A1Z1T2";
String thePassword="hlladmin";
String urlString="http://rsnetserver:113/hll/servlet/CallSSRUpload";
String userPassword = theUsername ":" thePassword;
String encoding = new sun.misc.BASE64Encoder().encode (userPassword.getBytes());
try
URL url = new URL (urlString);
HttpURLConnection uc=(HttpURLConnection)url.openConnection();
int it = 0;
while ((it = encoding.indexOf('\n')) != -1
|| (it = encoding.indexOf('\r')) != -1) {
encoding = encoding.substring(0, it)
encoding.substring(it 1);
uc.setRequestProperty("Authorization","BASIC " encoding);
uc.setRequestProperty("SOAPAction", url.toString());
System.out.println(uc.getResponseCode());
System.out.println(uc.getResponseMessage());
catch(Exception io)
io.printStackTrace();
System.out.println("error message........" io.getMessage());
In web.xml I have d

JCX access from java class

Is it possible to access jcx from java class ?
from jpf i am calling java class which inturn calls jcx and
i am getting nullpointer exception at jcx call in java class
waiting for solution...
thanks,
sridhar

Shrishar,
Unfortunately in the current release controls cannot be accessed from stand
alone java classes. You can create a custom control which can invoke the jcx
and be invoked from within the jpf.
Regards,
Raj Alagumalai
Backline Workshop Support
"sridhar" <[email protected]> wrote in message
news:4083d449$[email protected]..
>
Is it possible to access jcx from java class ?
from jpf i am calling java class which inturn calls jcx and
i am getting nullpointer exception at jcx call in java class
waiting for solution...
thanks,
sridhar

Error in accessing Java Class?

I got an error when accessing JavaClass,
The Java Class is following,
packages mypack;
public class myParentClass{
public myParentClass{
public String doAct(String act){
return act;
public static act class {
public static final String ADD="ADD";
public static final String DELETE="DELETE";
And I am using JavaBean as the following,
<%@ page import="mypack.*"%>
<jsp:useBean id="mybean" scope="page" class="myParentClass"/>
<%
String act=mybean.doAct(mybean.act.ADD);
%>
The error I got is "No variable act defined in class myParentClass"
I don't know why! How can I solve it?
Thanks in advance!

hi, you lose a semicolon ";" .
you should add ";" at the end of the definition of "act" as:
public class myParentClass{
public myParentClass{
public String doAct(String act){
return act;
public static act class {
public static final String ADD="ADD";
public static final String DELETE="DELETE";
}; // this is the error .

Accessing managed-beans property from simple java class

I have managed bean that is registered in faces-config.xml:
<managed-bean>
<managed-bean-name>documentReportsBean</managed-bean-name>
<managed-bean-class>[myApp].beans.DocumentReportsBean</managed-bean-class>
<managed-bean-scope>session</managed-bean-scope>
</managed-bean>
I want to access property of documentReportsBean from other java class without registering managed-property in faces-config. How can I do that?

Thank you, what I needed was someone saying the right word. "ValueBinding" in this case.. :)
Two lines:
ValueBinding vb = FacesContext.getCurrentInstance().getApplication().createValueBinding("#{documentReportsBean}");
DocumentReportsBean pbean = (DocumentReportsBean) vb.getValue(FacesContext.getCurrentInstance());
gives my full control. Nice

Using java class and variables declared in java file in jsp

hi everyone
i m trying to seperate business logic form web layer. i don't know i am doing in a right way or not.
i wanted to access my own java class and its variables in jsp.
for this i created java file like this
package ris;
import java.sql.*;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
public class NewClass{
    public static void main(String args[]){
        Connection con = null;
        ResultSet rs=null;
        Statement smt=null;
        try{
            Class.forName("com.mysql.jdbc.Driver").newInstance();
            con=DriverManager.getConnection("jdbc:mysql:///net","root", "anthony111");
            smt=con.createStatement();
           rs= smt.executeQuery("SELECT * FROM emp");
           while(rs.next()){
            String str = rs.getString("Name");
            }catch( Exception e){
                String msg="Exception:"+e.getMessage();
            }finally {
      try {
        if(con != null)
          con.close();
      } catch(SQLException e) {}
}next i created a jsp where i want to access String str defined in java class above.
<%--
    Document   : fisrt
    Created on : Jul 25, 2009, 3:00:38 PM
    Author     : REiSHI
--%>
<%@page import="ris.NewClass"%>
<%@page contentType="text/html" pageEncoding="UTF-8"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
   "http://www.w3.org/TR/html4/loose.dtd">
<html>
    <head>
        <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
        <title>JSP Page</title>
    </head>
    <body>
        <h1><%=str%></h1>
    </body>
</html>I wanted to print the name field extracted from database by ResultSet.
but it gives error cannot find symbol str.
please help me to find right way to do this.
i am using netbeans ide.

Very bad approach
1) Think if your table contains more than one NAMEs then you will get only the last one with your code.
2) Your String is declared as local variable in the method.
3) You have not created any object of NewClass nor called the method in JSP page. Then who will call the method to run sql?
4) Your NewClass contains main method which will not work in web application, it's not standalone desktop application so remove main.
Better create an ArrayList and then call the method of NewClass and then store the data into ArrayList and return the ArrayList.
It should look like
{code:java}
package ris;
import java.sql.*;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
public class NewClass{
    public static ArrayList getNames(){
        Connection con = null;
        ResultSet rs=null;
        Statement smt=null;
        ArrayList nameList = new ArrayList();
        try{
            Class.forName("com.mysql.jdbc.Driver").newInstance();
            con=DriverManager.getConnection("jdbc:mysql:///net","root", "anthony111");
            smt=con.createStatement();
           rs= smt.executeQuery("SELECT * FROM emp");
           while(rs.next()){
            nameList.add(rs.getString("Name"));
           return nameList;
            }catch( Exception e){
                String msg="Exception:"+e.getMessage();
               </code><code class="jive-code jive-java"><font>return nameList;</code><code class="jive-code jive-java">
            }finally {
      try {
        if(con != null)
          con.close();
      } catch(SQLException e) {}
      </code><code>return nameList;</code>
<code class="jive-code jive-java">    }

AES Algorithm error when trying to encrypt using stored Java class.

Dear All,
We have a specific reuirement where in we cannot use DBMS_CRYPTO package to encrypt/decrypt data using AES Algorithm
So I am trying to use a stored Java class and I am getting "AES algorithm not available".
I am using Oracle 10gR2 standard edition.
Below is my code
1. Stored Java class
2. Stored function to access the above Java class.
3. Test anonymus PL/SQL to test above code.
Please help me finding the problem why I am getting "AES algorithm not available" error when I call stored Java class in Oracle.?
**** If I use "DES" algorithm, it works. Also the Java code works well if I execute it as normal Java class from Eclipse.
I verified the java.security file in jre/lib/security and I see that there is provider entry for SunJCE.
The jre version in Oracle is 1.4.2.
I appreciate your help.
Thanks,
Priyanka
Step1: Stored java class to encrypt and decrypt data
CREATE OR REPLACE AND RESOLVE JAVA SOURCE NAMED "EncryptUtil" AS
import java.security.Key;
import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
import javax.crypto.SecretKey;
import javax.crypto.spec.SecretKeySpec;
public class EncryptUtil
     public static String encrypt(String inStr)
     String outStr = "Test data 123";
try
KeyGenerator kgen = KeyGenerator.getInstance("AES");
kgen.init(128);
SecretKey skey = kgen.generateKey();
byte[] raw = skey.getEncoded();
SecretKeySpec skeySpec = new SecretKeySpec(raw, "AES");
Cipher cipher = Cipher.getInstance("AES");
cipher.init(Cipher.ENCRYPT_MODE, skeySpec);
byte[] encrypted =
cipher.doFinal(inStr.getBytes());
outStr =new String(encrypted);
catch (Exception e)
     outStr = outStr + "exception thrown::" + e.getMessage();
e.printStackTrace();
return outStr;
Step2: Stored function to access above stored java class.
CREATE OR REPLACE FUNCTION SF_ENCRYPTUTIL(
pKey1 VARCHAR2
) RETURN VARCHAR2 AS
LANGUAGE JAVA NAME 'EncryptUtil.encrypt(java.lang.String ) return java.lang.String';
Step3: Test encryption and descryption
DECLARE
outstr VARCHAR2(2000);
BEGIN
DBMS_OUTPUT.PUT_LINE('outstr-->' || SF_ENCRYPTUTIL('12345'));
END;
Below code example using DBMS_CRYPTO. This works, but we do not want to use this.
declare
l_in_val varchar2(2000) := 'Test data 123';
l_mod number := dbms_crypto.ENCRYPT_AES128
+ dbms_crypto.CHAIN_CBC
+ dbms_crypto.PAD_PKCS5;
l_enc raw (2000);
l_enc_key raw (2000);
l_dec raw (2000);
begin
l_enc := dbms_crypto.encrypt
UTL_I18N.STRING_TO_RAW (l_in_val, 'AL32UTF8'),
l_mod,
HEXTORAW('156ae12300ccfbeb48e43aa016febb36'),
HEXTORAW('001122230405060708090a0b0c0d0e0f')
dbms_output.put_line ('Encrypted='||l_enc);
end;
Edited by: user5092433 on Sep 10, 2009 12:26 AM

I guess I'd be a bit curious about why you can't use a DBMS_CRYPTO solution that provides identical output. It seems odd to want to have a procedure running inside Oracle and then dictate that it has to be Java and not PL/SQL...
I verified the java.security file in jre/lib/security and I see that there is provider entry for SunJCE.
The jre version in Oracle is 1.4.2.Which java.security file are you talking about? The JVM that is inside the Oracle database does not and can not use configuration files that are outside the database. I suspect when you talk about files and paths that you're looking at a JVM outside the database, which is not the JVM that your Java stored procedure would be using.
Looking at the error, my assumption is that some JAR file needs to be loaded into the internal JVM in order for the AES algorithm to be available. But I'm unfortunately not familiar enough with these classes to say what that would be.
Justin

Java Class Mapping Program in BPM process

I have a scenario where I'm receiving an IDOC I then use a JAVA mapping program in my first transformation step. Immediately following I have a switch step but there is not data in from the mapping program.
1) Receive Step
2) Transformation IDOC to Table using Java class
3) Switch step based on Table field value
Problem is there is no values in the table.
This java class was not developed within NetWeaver but was used in our old process. We simply imported the jar file for accessing our existing java classes. Is there something else we need to do to utilize our java modules within the BPM process?

Hi,
You must to have in the java class:
- You java have to be like:
import java.io.InputStream;
import java.io.OutputStream;
import java.util.Map;
import java.util.HashMap;
import com.sap.aii.mapping.api. AbstractTrace;
import com.sap.aii.mapping.api.StreamTransformation;
import com.sap.aii.mapping.api.StreamTransformationConstants;
public class JavaMapping implements StreamTransformation {
   private Map           param = null;
   private AbstractTrace trace = null;
   public void setParameter (Map param) {
      this.param = param;
      if (param == null) {
         this.param = new HashMap();
   public void execute(InputStream in, OutputStream out) {
try {
         trace = (AbstractTrace)param.get(
                   StreamTransformationConstants.MAPPING_TRACE );
         trace.addInfo(...);
         String receiverName = (String)param.get(
                   StreamTransformationConstants.RECEIVER_NAME);
The method execute take the InputStream with the XML source. The out (OutputStream) have to be an XML like the IDOC structure.
Regards.

Re: Using simple java class in an .war file.

Hi All,
I have a simple question,
Can I access an simple java class from a jsp file that I have written by putting it in the "classes" folder?? What entry should go in the web.xml file?
Here is my directory structure:
sample.war
|
----test.jsp <file>
|
----WEB-INF <folder>
| |
| ----classes<folder>
| | |
| | ----simpleJavaClass.class<file>
| |
| ----lib<folder>
| |
| ----web.xml
I want to access the simpleJavaClass.class from the jsp test.jsp.
Please suggest.
Thanks and regards
Ayusman

It is possible to access the class in u r classes folder from u r jsp file.
For example
<%@ page import="com.test.service.PricingSolution,
com.test.core.PhoneNumber
%>
<% PricingSolution solution = (PricingSolution)session.getAttribute("solution"); %>
This is a simple scriplet example. You do the same using jstl tags also.
--Shinoy

Audit of Java Class, Resource, and Source

We are currently at 10.1.0.5 on Win@K3 server, and are implementing DIACAP requirements. One of the finding states we need to add auditing of objects and they gave us the script to implement this:
AUDIT ALL BY ACCESS;
AUDIT ALL PRIVILEGES BY ACCESS;
AUDIT ALTER JAVA CLASS BY ACCESS;
AUDIT ALTER JAVA RESOURCE BY ACCESS;
AUDIT ALTER JAVA SOURCE BY ACCESS;
When we try to run this in sqlplus, it gives us an error on the Java lines (Ora-00969: Missing ON keyword). According to the documentation I found on line, which was limited, this is the correct syntax. Anyone know why this is failing?
Thanks!

We are currently at 10.1.0.5 on Win@K3 server, and are implementing DIACAP requirements. One of the finding states we need to add auditing of objects and they gave us the script to implement this:
AUDIT ALL BY ACCESS;
AUDIT ALL PRIVILEGES BY ACCESS;
AUDIT ALTER JAVA CLASS BY ACCESS;
AUDIT ALTER JAVA RESOURCE BY ACCESS;
AUDIT ALTER JAVA SOURCE BY ACCESS;
When we try to run this in sqlplus, it gives us an error on the Java lines (Ora-00969: Missing ON keyword). According to the documentation I found on line, which was limited, this is the correct syntax. Anyone know why this is failing?
Thanks!

Standard Java class communicating with a servlet

Hey,
I am trying to access a standard java classes member via a servlet class however the data is never received even though the member is visible on compilation. is there something Im doing wrong ?
public class Start {
//lots of stuff
     static List<Plug> plugList = Collections.synchronizedList(new LinkedList<Plug>());
//lots more stuff
public class wah extends HttpServlet{
        public void doGet( HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException{
                doPost(request, response);
    public void doPost(HttpServletRequest request,
                                HttpServletResponse res)throws ServletException, IOException{
                res.setContentType("text/html");
                PrintWriter out = res.getWriter();
                out.println("wahwahwah");
                synchronized(Start.plugList){
                        out.println("pluglist");
                        Iterator i1 = Start.plugList.iterator();
                        while (i1.hasNext()) {
                                Plug oldPlug = (Plug)i1.next();
                                out.println("PLug : " + oldPlug.getaddress64());
        }//doPost
}

Don't post all your code. Instead, make a simplified version of the code that demonstrates what your problem is and that we could compile and see what is going on. Make it as simple as possible but still demonstrating the problem.
Who knows, when you make the SSCCP (small, self contained, compileable program) you will find your mistake as well.
But without seeing any code all I can say is that the date you are accessing in the list has not been made available when you try to get it from the servlet. Perhaps the servlet call is blocking the other threads from accessing the list to put data into it, perhaps the other threads haven't begun working yet, perhaps the list you give to the servlet isn't the same list (but instead a copy of the list) that the data is being entered into, or many other reasons.
One thing I would assume you need to do, since the Servlet is the data consumer, you need to make sure the data has been entered before the servlet tries to read it. The best way to do that is to put a wait() in the servlet code so that it knows it can't do anything until the producers are finished. Then the producers would add a notify() to tell the servlet to go ahead and display the data.
So some modification might be:
public class Start {
//lots of stuff
     static List<Plug> plugList = Collections.synchronizedList(new LinkedList<Plug>());
        //marker to let servlet know that it can consume data
        private static boolean done = false;
        //producers call this method when list is ready for use
        static void setReadyToConsume() { done = true; }
        //servlet calls this to check if the list is ready
        public static boolean isReadyToConsume() { return done; }
//lots more stuff
    public void doPost(HttpServletRequest request,
                                HttpServletResponse res)throws ServletException, IOException{
                res.setContentType("text/html");
                PrintWriter out = res.getWriter();
                out.println("wahwahwah");
                synchronized(Start.plugList){
                       //Hold off trying to use list until list is ready
                        while (!Start.isReadyToConsume()) {
                              try {
                                      Start.plugList.wait();
                              } catch (InterruptedException ie) {
                                      log("Waiting for Plugs to be ready interrupted. Continuing to wait.");
                                      log(ie.getMessage(), ie);
                        out.println("pluglist");
                        Iterator i1 = Start.plugList.iterator();
                        while (i1.hasNext()) {
                                Plug oldPlug = (Plug)i1.next();
                                out.println("PLug : " + oldPlug.getaddress64());
        }//doPostAnd don't forget to add a Start.plugList.notify() or Start.plugList().notifyAll() in the producer code after it calls the setReadyToConsume() method.

How can I locate EBS FND security java classes being referenced from packages?

Hi All,
I need to load few java classes in database whose methods are being called from SQL packages. For example, package FND_WEB_SEC calls methods from java class "oracle.apps.fnd.security.WebSessionManagerProc"
Which means I need to load this class on my db for it to be used correctly.
I am unable to locate this and few other java classes.
Can anyone suggest where can I find these?
Thanks,
Ishwar

Hi Ishwar,
Please have a look at the forum search, as it would be of assistance..
Forum Search: Where are Java classess
Best Regards,

Instantiation access to other java classes

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