Compiler Class in Extended RTSJ

Hello Friends,
For my real time application i am using following options at the start of the VM.
-XX:+ITCRT -XX:+ITCJLT -XX:+CompilePreLoaded -Drtsj.precompile=nhrt.precompile -Drtjs.preload=itc.preload -Drtsj.preinit=itc.preinit
But i want to give the compile list of method and class list for the pre initialization, programatically at the run time.For this i found methods in the RTJ Documentation. According to documentation we can do this by using mark(), preinit() and preload() method of the Compiler Class. when i tried to find this compiler class in the library of the RTJ i m unable to ...............i am able to find only api of the Compiler class but at the time of implementation class is not present in the jar files.......................
please tell me where i can find this Compiler class for RTJ or in which jar file this class is present
Also tell me if Compiler class is not present then how i can do the above step.............
Thanks

This Error occurs:
cannot find symbol
symbol: method preinit()
location: class *java.lang.*Compiler
You want com.sun.rtsjx.Compiler. I'll get the Compilation Guide fixed to make that clear.
And myRealtimeThread is not compiled, so that I can't use the VM afterwards (with the parameters: -XX:+RTSJBuildClassInitializationList) to create the list out of my myRealtimeThread.class code.
Maybe I have missunderstood the usage of Compiler.preinit()!? Maybe someone can explain its correct usage or give a short example for compiling this correctly.I think you have misunderstood. ITC can perform pre-initialization based on the -Drtsj.preinit=<filename> option passed at VM startup. This will cause the listed file to be read and for each class listed there to be pre-initialized. This list can be generated for you by using the -XX:+RTSJBuildClassInitializationList runtime option - which creates a list of all classes that were compiled-at-initialization time (ie those classes compiled because of the precompile list.) Alternatively you can use the com.sun.rtsjx.Compiler class to perform dynamic "pre-initialization" at runtime by passing it a URL to a file that contains the list of classes to be immediately initialized - the idea being that you would have created the contents of this file at runtime based on information that only became available to you at runtime.
Hope this clarifies things.
David Holmes

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    please be gentle with your anwsers im still kinda new to java, but know enough to understand most things.
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    That's not a subclass, it doesn't extend anything (except Object of course). However the problem is either that you didn't compile it, or if you did, then the compiled class (which is a file named loadercontent.class) isn't in the classpath when you compile the "main" class.
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        public void mouseExited(MouseEvent e) {}
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    Don't really understand what the posted code does and I can't execute the code so I don't have much to offer.
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    thats right, i mounted C:\divelog at first and thats
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    import data.UserPassword;     //Is this right?
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    import java.util.*;
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    import javax.servlet.*;
    import javax.servlet.http.*;
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       private static PreparedStatement pstmt1;
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    import java.sql.*;
    import java.util.*;
    import javax.sql.*;
    import javax.servlet.*;
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         private String username;
         private String password;
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              this.username = username;
              this.password = password;
              this.level = level;
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    4.1\webapps\HRM\WEB-INF\classes\core\data\UserPassword.class
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    import javax.servlet.http.*;
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    import javax.servlet.http.*;
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    C:\Program Files\Apache Group\Tomcat
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                                             ^
    C:\Program Files\Apache Group\Tomcat
    4.1\work\Standalone\localhost\HRM\CreateAcc_jsp.java:69: non-static method
    verifyUsername(java.lang.String) cannot be referenced from a static context
         if(UserAccManager.verifyUsername(username)){
                             ^
    C:\Program Files\Apache Group\Tomcat
    4.1\work\Standalone\localhost\HRM\CreateAcc_jsp.java:70: cannot resolve symbol
    symbol  : variable empno
    location: class org.apache.jsp.CreateAcc_jsp
              if(UserAccManager.createAcc(empno, username,password,level)) nextPage
    ="MsgAcc.jsp";
                                                ^
    C:\Program Files\Apache Group\Tomcat
    4.1\work\Standalone\localhost\HRM\CreateAcc_jsp.java:70: cannot resolve symbol
    symbol  : variable username
    location: class org.apache.jsp.CreateAcc_jsp
              if(UserAccManager.createAcc(empno, username,password,level)) nextPage
    ="MsgAcc.jsp";
                                                       ^
    C:\Program Files\Apache Group\Tomcat
    4.1\work\Standalone\localhost\HRM\CreateAcc_jsp.java:70: cannot resolve symbol
    symbol  : variable password
    location: class org.apache.jsp.CreateAcc_jsp
              if(UserAccManager.createAcc(empno, username,password,level)) nextPage
    ="MsgAcc.jsp";
                                                                ^
    C:\Program Files\Apache Group\Tomcat
    4.1\work\Standalone\localhost\HRM\CreateAcc_jsp.java:70: cannot resolve symbol
    symbol  : variable level
    location: class org.apache.jsp.CreateAcc_jsp
              if(UserAccManager.createAcc(empno, username,password,level)) nextPage
    ="MsgAcc.jsp";
                                                                         ^
    C:\Program Files\Apache Group\Tomcat
    4.1\work\Standalone\localhost\HRM\CreateAcc_jsp.java:70: non-static method
    createAcc(int,java.lang.String,java.lang.String,int) cannot be referenced from a static
    context
              if(UserAccManager.createAcc(empno, username,password,level)) nextPage
    ="MsgAcc.jsp";
                                     ^
    8 errorsTo solve the problem non-static method,I goto the UserAccManager.java file and do these
    things.
    package com;
    import java.io.*;
    import java.sql.*;
    import java.util.*;
    import javax.sql.*;
    //import javax.servlet.*;               //otherwise it tells an error.(package           
                                  //javax.servlet does not exist)
    //import javax.servlet.http.*;
    public  class UserAccManager {
       private static final String DRIVER = "com.mysql.jdbc.Driver";
       private static final String URL = "jdbc:mysql://localhost:3306/superfine";
       private static Connection connection;
       private static PreparedStatement pstmt1;
        private static PreparedStatement pstmt2;
          private static PreparedStatement pstmt3;
       private UserAccManager() {
       // Initializes the connection and statements
       private static void initConnection() {
             //same
       // Closes the connection and statements
       // Method to be called by main class when finished with DB
       public static void closeConnection() {
         //same
       public static boolean verifyEmpno(int empno) {
          // same.
       public static boolean verifyUsername(String username) {
         //same.
         public static boolean createAcc(int empno, String username, String password, int      
    level){
              //same
    package com;
    import java.io.*;
    import java.sql.*;
    import java.util.*;
    import javax.sql.*;
    //import javax.servlet.*;
    //import javax.servlet.http.*;
    public class UserPassword {
         // same
    Again compile those files and put .class filses into the WEB-INF/classes/com directory.
    When i submits the data via the form it generates an error:
    org.apache.jasper.JasperException: Unable to compile class for JSP
    An error occurred at line: 9 in the jsp file: /CreateAcc.jsp
    Generated servlet error:
        [javac] Compiling 1 source file
    C:\Program Files\Apache Group\Tomcat
    4.1\work\Standalone\localhost\HRM\CreateAcc_jsp.java:68: cannot resolve symbol
    symbol  : variable empno
    location: class org.apache.jsp.CreateAcc_jsp
    if(UserAccManager.verifyEmpno(empno)){
                                  ^
    An error occurred at line: 9 in the jsp file: /CreateAcc.jsp
    Generated servlet error:
    C:\Program Files\Apache Group\Tomcat
    4.1\work\Standalone\localhost\HRM\CreateAcc_jsp.java:69: cannot resolve symbol
    symbol  : variable username
    location: class org.apache.jsp.CreateAcc_jsp
         if(UserAccManager.verifyUsername(username)){
                                             ^
    An error occurred at line: 9 in the jsp file: /CreateAcc.jsp
    Generated servlet error:
    C:\Program Files\Apache Group\Tomcat
    4.1\work\Standalone\localhost\HRM\CreateAcc_jsp.java:70: cannot resolve symbol
    symbol  : variable empno
    location: class org.apache.jsp.CreateAcc_jsp
              if(UserAccManager.createAcc(empno, username,password,level)) nextPage
    ="MsgAcc.jsp";
                                                ^
    An error occurred at line: 9 in the jsp file: /CreateAcc.jsp
    Generated servlet error:
    C:\Program Files\Apache Group\Tomcat
    4.1\work\Standalone\localhost\HRM\CreateAcc_jsp.java:70: cannot resolve symbol
    symbol  : variable username
    location: class org.apache.jsp.CreateAcc_jsp
              if(UserAccManager.createAcc(empno, username,password,level)) nextPage
    ="MsgAcc.jsp";
                                                       ^
    An error occurred at line: 9 in the jsp file: /CreateAcc.jsp
    Generated servlet error:
    C:\Program Files\Apache Group\Tomcat
    4.1\work\Standalone\localhost\HRM\CreateAcc_jsp.java:70: cannot resolve symbol
    symbol  : variable password
    location: class org.apache.jsp.CreateAcc_jsp
              if(UserAccManager.createAcc(empno, username,password,level)) nextPage
    ="MsgAcc.jsp";
                                                                ^
    An error occurred at line: 9 in the jsp file: /CreateAcc.jsp
    Generated servlet error:
    C:\Program Files\Apache Group\Tomcat
    4.1\work\Standalone\localhost\HRM\CreateAcc_jsp.java:70: cannot resolve symbol
    symbol  : variable level
    location: class org.apache.jsp.CreateAcc_jsp
              if(UserAccManager.createAcc(empno, username,password,level)) nextPage
    ="MsgAcc.jsp";
                                                                         ^
    6 errorshere is the CreateAcc.jsp file
    <%@ page language="java" %>
    <%@ page import="com.UserAccManager" %>
    <%@ page import="com.UserPassword" %>
    <jsp:useBean id="userPassword" class="com.UserPassword" scope="request"/>
    <jsp:setProperty name="userPassword" property="*" />
    <%
    String nextPage ="MainForm.jsp";
    if(UserAccManager.verifyEmpno(empno)){
         if(UserAccManager.verifyUsername(username)){
              if(UserAccManager.createAcc(empno, username,password,level)) nextPage
    ="MsgAcc.jsp";
          }else{
               nextPage="UserNameExist.jsp";
          else{
              nextPage="UserAccError.jsp";
    %>
    <jsp:forward page="<%=nextPage%>"/>Please, anyone know how to send these parameters to the java file.
    Thanks.

  • ?Is it possible to create a javafx class without extending Application class ? If yes, how

    Is it possible to create a javafx class without extending Application class ? If yes, how ?

      There is no  such thing as a javafx  class.  It is a regular  java class.  The Aapplication class is  the entry
    point  for JavaFX application.  You have to extend the Application class to create Javafx  application .

  • LoadClass    (error loading a class which extends other class  at run-time)

    Hey!
    I'm using the Reflection API
    I load a class called 'SubClass' which exists in a directory called 'subdir' at run-time from my program
    CustomClassLoader loader = new CustomClassLoader();
    Class classRef = loader.loadClass("SubClass");
    class CustomClassLoader extends ClassLoader. I have defined 'findClass(String className)' method in CustomClassLoader.
    This is what 'findClass(String className)' returns:
    defineClass (className,byteArray,0,byteArray.length);
    'byteArray' is of type byte[] and has the contents of subdir/SubClass.
    the problem:
    The program runs fine if SubClass does not extend any class.
    If however, SubClass extends another class, the program throws a NoClassDefFoundError. How is it conceptually different?
    Help appreciated in Advance..
    Thanks!

    Because i'm a newbie to the Reflection thing, i'm notI don't see reflection anywhere. All I see is class loading.
    sure what role does the superclass play when i'm
    trying to load the derived class and how to get away
    with the errorWell... hint: all the superclass's stuff is not copied into the subclass.
    I am quite sure it fails to load the superclass because of classpath issues.

  • Calls to methods in a class that extends Thread

    Hello,
    I have some code that I am initiating from within an ActionListener that is part of my programs GUI. The code is quite long winded, at least in terms of how long it takes to perform. The code runs nicely, however once it is running the GUI freezes completely until operations have completed. This is unacceptable as the code can take up to hours to complete. After posting a message on this forum in regard to the freezing of the GUI it was kindly suggested that I use multi-threading to avoid the unwelcome program behaviour.
    The code to my class is as follows:
    public class FullURLAddress
      private boolean success_flag = true;
      private BufferedReader iN;
      private Document dT;
      private EditorKit kT;
      private Element lmNt;
      private ElementIterator lmIterate;
      private XURL[] compAddress;
      private int countX = 0;           //Tracks Vector vT's size.
      private int countY = 0;           //Tracks Vector vS's size.
      private int xURLcount = 0;        //Tracks XURL objects instantiated by this FullURLAddress object.
      private SimpleAttributeSet simpAtSet;
      private String aURL;              //Contains original (Xtended) URL!
      private String fileType;
      private String indexContent;
      private String[] parseURL;
      private String[] finalStrings;
      private String[] sortStrings;
      private URL indexConnect;
      private URLConnection iconn;
      private Vector vT;            //Stores href information, from targeted URL's HTML souce code.
      private Vector vS;            //Stores sorted HREF info ".jpg" and ".gif" only (no: png, tiff, etc).
      public FullURLAddress(String aURL)
        this.aURL = aURL;
        try{
          indexConnect = new URL(aURL);
          iconn = indexConnect.openConnection();
          iN = new BufferedReader(new InputStreamReader(iconn.getInputStream()));
            /* Document creation, analysis objects instantiated */
          vT = new Vector();
          vS = new Vector();
          kT = new HTMLEditorKit();
          dT = kT.createDefaultDocument();
          dT.putProperty("IgnoreCharsetDirective", Boolean.TRUE);
            /* Iterate through document and store all HREF values */
          kT.read(iN, dT, 0);
          lmIterate = new ElementIterator(dT);
          while((lmNt = lmIterate.next()) != null)
            simpAtSet = (SimpleAttributeSet)lmNt.getAttributes().getAttribute(HTML.Tag.A);
            if(simpAtSet != null)         //As long as there are A tags to be read...
              vT.addElement(simpAtSet.getAttribute(HTML.Attribute.HREF));
              countX++;//Tracks number of HREF occurences occur, giving better control of the Vector.
        }catch(MalformedURLException e){
          success_flag = false;
          System.out.println("FullURLAddress object has encountered a "+
                             "MalformedURLException at: "+aURL);
        }catch(IOException e){
          e.getMessage();
          success_flag = false;
        }catch(BadLocationException e){
          e.getMessage();
          success_flag = false;
        /* Searches through all HREF attributes that are now stored in Vector
           vT for occurences of the character string ".htm" */
        sortStrings = new String[countX];
        for(int i=0;i<countX;i++)
          sortStrings[i] = (String)vT.elementAt(i); //Vector Strings transfered into array.
          if(sortStrings.endsWith("gif")) // Does href value end with ".jpg"?
    vS.addElement(sortStrings[i]); // If so add it to the sorted Vector vS.
    countY++;
    if(sortStrings[i].endsWith("GIF"))
    vS.addElement(sortStrings[i]);
    countY++;
    if(sortStrings[i].endsWith("jpg")) // Does href value end with ".jpg"?
    vS.addElement(sortStrings[i]); // If so add it to the sorted Vector vS.
    countY++;
    if(sortStrings[i].endsWith("JPG"))
    vS.addElement(sortStrings[i]);
    countY++;
    finalStrings = new String[countY];
    for(int j=0;j<countY;j++)
    finalStrings[j] = (String)vS.elementAt(j);
    public int getCount()
    return countY; //Returns number of instances of htm strings
    } //ending with either "jpg" or "gif".
    public String[] xurlAddressDetails()
    return finalStrings;
    I have changed the above code to make use of multithreading by making this class extend Thread and implementing the run() method as follows:
    public class FullURLAddress extends Thread
      private boolean success_flag = true;
      private BufferedReader iN;
      private Document dT;
      private EditorKit kT;
      private Element lmNt;
      private ElementIterator lmIterate;
      private XURL[] compAddress;
      private int countX = 0;           //Tracks Vector vT's size.
      private int countY = 0;           //Tracks Vector vS's size.
      private int xURLcount = 0;        //Tracks XURL objects instantiated by this FullURLAddress object.
      private SimpleAttributeSet simpAtSet;
      private String aURL;              //Contains original (Xtended) URL!
      private String fileType;
      private String indexContent;
      private String[] parseURL;
      private String[] finalStrings;
      private String[] sortStrings;
      private URL indexConnect;
      private URLConnection iconn;
      private Vector vT;            //Stores href information, from targeted URL's HTML souce code.
      private Vector vS;            //Stores sorted HREF info ".jpg" and ".gif" only (no: png, tiff, etc).
      public FullURLAddress(String aURL)
        this.aURL = aURL;
      public void run()
        try{
          indexConnect = new URL(aURL);
          iconn = indexConnect.openConnection();
          iN = new BufferedReader(new InputStreamReader(iconn.getInputStream()));
            /* Document creation, analysis objects instantiated */
          vT = new Vector();
          vS = new Vector();
          kT = new HTMLEditorKit();
          dT = kT.createDefaultDocument();
          dT.putProperty("IgnoreCharsetDirective", Boolean.TRUE);
            /* Iterate through document and store all HREF values */
          kT.read(iN, dT, 0);
          lmIterate = new ElementIterator(dT);
          while((lmNt = lmIterate.next()) != null)
            simpAtSet = (SimpleAttributeSet)lmNt.getAttributes().getAttribute(HTML.Tag.A);
            if(simpAtSet != null)         //As long as there are A tags to be read...
              vT.addElement(simpAtSet.getAttribute(HTML.Attribute.HREF));
              countX++;//Tracks number of HREF occurences occur, giving better control of the Vector.
        }catch(MalformedURLException e){
          success_flag = false;
          System.out.println("FullURLAddress object has encountered a "+
                             "MalformedURLException at: "+aURL);
        }catch(IOException e){
          e.getMessage();
          success_flag = false;
        }catch(BadLocationException e){
          e.getMessage();
          success_flag = false;
        /* Searches through all HREF attributes that are now stored in Vector
           vT for occurences of the character string ".htm" */
        sortStrings = new String[countX];
        for(int i=0;i<countX;i++)
          sortStrings[i] = (String)vT.elementAt(i); //Vector Strings transfered into array.
          if(sortStrings.endsWith("gif")) // Does href value end with ".jpg"?
    vS.addElement(sortStrings[i]); // If so add it to the sorted Vector vS.
    countY++;
    if(sortStrings[i].endsWith("GIF"))
    vS.addElement(sortStrings[i]);
    countY++;
    if(sortStrings[i].endsWith("jpg")) // Does href value end with ".jpg"?
    vS.addElement(sortStrings[i]); // If so add it to the sorted Vector vS.
    countY++;
    if(sortStrings[i].endsWith("JPG"))
    vS.addElement(sortStrings[i]);
    countY++;
    finalStrings = new String[countY];
    for(int j=0;j<countY;j++)
    finalStrings[j] = (String)vS.elementAt(j);
    /* What happens with these methods, will they need to have their
    own treads also? */
    public int getCount()
    return countY; //Returns number of instances of htm strings
    } //ending with either "jpg" or "gif".
    public String[] xurlAddressDetails()
    return finalStrings;
    Are there any special things that I need to do in regard to the variables returned by the getCount() and xurlAddressDetails() methods. These methods are called by the code that started the run method from within my GUI. I don't understand which thread these methods are running in, obviously there is an AWT thread for my GUI and then a seperate thread for my FullURLAddress objects, but does this new thread also encompass the getCount() and xurlAddressDetails() methods?
    Please explain.
    This probably sounds a little wack, but I don't understand what thread is responisble for the methods in my FullURLAddress class aside of course from the run() method which is obvious. Any help will be awesome.
    Thanks
    Davo

    Threads are part of code that allows you to run multiple operations "simultaneously". "Simultaneously", because threads are not run actually simultaneously in any one-CPU machine. Since you most propably have only one CPU in your system, you can only execute one CPU instruction at time. Basically this means that your CPU can handle only one java-operation at time. It does not matter if you put some code in thread and start it, it will still take up all CPU time as long as the thread runs.
    So you would need a way to let other threads run also, for that purpose thread contains a yield feature that allows you to give time for other threads to run.
    http://java.sun.com/j2se/1.4.1/docs/api/java/lang/Thread.html#yield()
    You need to use thread's yield() method in your thread code, in a place you want to give other threads time to run. Also bear in mind that if you yield your first thread run to allow second thread to run, you also need to add yield to the second thread also. If you don't, after yielding the first thread, the second thread will eat up all CPU time until it finishes, thus meaning the rest of your first thread will be run after second thread is done.
    One good place to execute yield() is usually at the end of a loop, for example 'for' or 'while' loop. This way you prevent for example while-deadlocks.
    Here is a java thread tutorial, worthy reading:
    http://java.sun.com/docs/books/tutorial/essential/threads/

  • Unable to compile class for JSP. apache-tomcat-6. What could be wrong?

    Hello, I am new to JSP and I am trying a very basic jsp and class file on Windows XP. I get the Unable to compile class for JSP.
    Steps that I have done:
    javac ch06_01.java , placed the ch06_01.class under
    C:\Apps\apache-tomcat-6.0.16\webapps\ch06\WEB-INF\classes
    Then grabbed the ch06_02.jsp and placed it under
    C:\Apps\apache-tomcat-6.0.16\webapps\ch06\
    When I run it (by placing this into Explorer or Firefox URL
    http://localhost:8080/ch06/ch06_02.jsp) I get the error further
    below. Things I have done and made sure they are in place are:
    set up JAVA_HOME to C:\Apps\jdk1.6.0_06
    Using CATALINA_BASE: C:\Apps\apache-tomcat-6.0.16
    Using CATALINA_HOME: C:\Apps\apache-tomcat-6.0.16
    Using CATALINA_TMPDIR: C:\Apps\apache-tomcat-6.0.16\temp
    Using JRE_HOME: C:\Apps\jre1.6.0_06
    I did a google on the error and I found people saying to place the
    tools.jar from the jsk into the lib directory under CATALINA_HOME. But
    the examples still don't work. What step could I be missing? Your help is greatly
    appreciated.
    This is the simple jsp file:
    <%@ page import="ch06_01" %>
    <HTML>
    <HEAD>
    <TITLE>Using a JavaBean</TITLE>
    </HEAD>
    <BODY>
    <H1>Using a JavaBean</H1>
    <% ch06_01 messager = new ch06_01(); %>
    The message is: <%= messager.msg() %>
    </BODY>
    </HTML>
    this is the simple ch6_01 java file:
    public class ch06_01
    public ch06_01()
    public String msg()
    return "Hello from JSP!";
    HTTP Status 500 -
    type Exception report
    message
    description The server encountered an internal error () that prevented
    it from fulfilling this request.
    exception
    org.apache.jasper.JasperException: Unable to compile class for JSP:
    An error occurred at line: 6 in the generated java file
    The import ch06_01 cannot be resolved
    An error occurred at line: 9 in the jsp file: /ch06_02.jsp
    ch06_01 cannot be resolved to a type
    6: <BODY>
    7: <H1>Using a JavaBean</H1>
    8:
    9: <% ch06_01 messager = new ch06_01(); %>
    10:
    11: The message is: <%= messager.msg() %>
    12:
    An error occurred at line: 9 in the jsp file: /ch06_02.jsp
    ch06_01 cannot be resolved to a type
    6: <BODY>
    7: <H1>Using a JavaBean</H1>
    8:
    9: <% ch06_01 messager = new ch06_01(); %>
    10:
    11: The message is: <%= messager.msg() %>
    12:
    Stacktrace:
    org.apache.jasper.compiler.DefaultErrorHandler.javacError(DefaultErrorHandler.java:92)
    org.apache.jasper.compiler.ErrorDispatcher.javacError(ErrorDispatcher.java:330)
    org.apache.jasper.compiler.JDTCompiler.generateClass(JDTCompiler.java:423)
    org.apache.jasper.compiler.Compiler.compile(Compiler.java:316)
    org.apache.jasper.compiler.Compiler.compile(Compiler.java:294)
    org.apache.jasper.compiler.Compiler.compile(Compiler.java:281)
    org.apache.jasper.JspCompilationContext.compile(JspCompilationContext.java:566)
    org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:317)
    org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:337)
    org.apache.jasper.servlet.JspServlet.service(JspServlet.java:266)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
    Edited by: indikon1 on Jun 12, 2008 1:18 PM
    I just updated the directories of the variables to reflect the current status of my system.

    What is wrong is that you are using an "old" jsp tutorial :-)
    Since Java 1.4, JSPs have been unable to access classes in the "default" package.
    What you need to do:
    Put the java class ch06_01 in a package.
    Steps to do this
    - Edit ch06_01 and add the following to the very top of the file (without the quotes): "package mypackage;"
    - create a folder "mypackage"
    - move ch06_01.java into that folder
    - compile that class (now in the mypackage package)
    - place ch06_01.class under C:\Apps\apache-tomcat-6.0.16\webapps\ch06\WEB-INF\classes\mypackage
    In your jsp:
    <%@ page import="mypackage.ch06_01" %>
    I would suggest using a more up-to-date tutorial that uses JSTL.
    Take a look at this [Apache Tomcat tutorial|http://www.coreservlets.com/Apache-Tomcat-Tutorial/index.html]

  • Unable to compile class for JSP--- help me plz!!!!!

    hi friends;
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    <HTML>
    <BODY>
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    <jsp:useBean id="user" class="UserData" scope="session">
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    <HTML>
    <BODY>
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    </BODY>
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    public class UserData {
    String username;
    String email;
    int age;
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    public void setUsername( String value )
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    public void setEmail( String value )
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    public void setAge( int value )
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    public String getEmail() { return email; }
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    <HTML>
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    Email: <%= user.getEmail() %><BR>
    Age: <%= user.getAge() %><BR>
    </BODY>
    </HTML>
    url: http://localhost:8080/test3/GetName.html
    is it related to context path??
    HTTP Status 500 -
    type Exception report
    message
    description The server encountered an internal error () that prevented it from fulfilling this request.
    exception
    org.apache.jasper.JasperException: Unable to compile class for JSP
    An error occurred at line: 2 in the jsp file: /SaveName.jsp
    Generated servlet error:
    C:\Program Files\Apache Software Foundation\Tomcat 5.0\work\Catalina\localhost\test3\org\apache\jsp\SaveName_jsp.java:44: cannot find symbol
    symbol : class UserData
    location: class org.apache.jsp.SaveName_jsp
    UserData user = null;
    ^
    An error occurred at line: 2 in the jsp file: /SaveName.jsp
    Generated servlet error:
    C:\Program Files\Apache Software Foundation\Tomcat 5.0\work\Catalina\localhost\test3\org\apache\jsp\SaveName_jsp.java:46: cannot find symbol
    symbol : class UserData
    location: class org.apache.jsp.SaveName_jsp
    user = (UserData) jspxpage_context.getAttribute("user", PageContext.SESSION_SCOPE);
    ^
    An error occurred at line: 2 in the jsp file: /SaveName.jsp
    Generated servlet error:
    C:\Program Files\Apache Software Foundation\Tomcat 5.0\work\Catalina\localhost\test3\org\apache\jsp\SaveName_jsp.java:48: cannot find symbol
    symbol : class UserData
    location: class org.apache.jsp.SaveName_jsp
    user = new UserData();
    ^
    3 errors
    org.apache.jasper.compiler.DefaultErrorHandler.javacError(DefaultErrorHandler.java:84)
    org.apache.jasper.compiler.ErrorDispatcher.javacError(ErrorDispatcher.java:332)
    org.apache.jasper.compiler.Compiler.generateClass(Compiler.java:437)
    org.apache.jasper.compiler.Compiler.compile(Compiler.java:497)
    org.apache.jasper.compiler.Compiler.compile(Compiler.java:476)
    org.apache.jasper.compiler.Compiler.compile(Compiler.java:464)
    org.apache.jasper.JspCompilationContext.compile(JspCompilationContext.java:511)
    org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:295)
    org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:292)
    org.apache.jasper.servlet.JspServlet.service(JspServlet.java:236)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
    note The full stack trace of the root cause is available in the Apache Tomcat/5.0.30 logs.
    Apache Tomcat/5.0.30
    please Reply me ASAP
    i'll be glad if you reply. please

    I am using Tomcat 6.0.
    I have put my UserData class in user package and
    used in below jsp(SaveName.jsp)
    <%@ page import="user.UserData" %>
    <jsp:useBean id="user" class="user.UserData" scope="session"/>
    <jsp:setProperty name="user" property="*"/>
    <HTML>
    <BODY>
    Continue
    </BODY>
    </HTML>
    I have already set my classpath as C:\Documents and Settings\user\My Documents\Java\apache-tomcat-6.0.16\apache-tomcat-6.0.16\webapps\ROOT\WEB-INF\classes;
    UserData class is in C:\Documents and Settings\user\My Documents\Java\apache-tomcat-6.0.16\apache-tomcat-6.0.16\webapps\ROOT\WEB-INF\classes\user
    My UserData class is
    package user;
    public class UserData {
    String username;
    String email;
    int age;
         public UserData(){
              this("","",0);
              System.out.println("najn thanne puli");
         public UserData(String username,String email,int age){
              this.username=username;
              this.email=email;
              this.age=age;
    public void setUsername( String value )
    username = value;
    public void setEmail( String value )
    email = value;
    public void setAge( int value )
    age = value;
    public String getUsername() { return username; }
    public String getEmail() { return email; }
    public int getAge() { return age; }
    But running SaveName.jsp shows exception
    org.apache.jasper.JasperException: /SaveName.jsp(2,0) The value for the useBean class attribute user.UserData is invalid.
         org.apache.jasper.compiler.DefaultErrorHandler.jspError(DefaultErrorHandler.java:40)
         org.apache.jasper.compiler.ErrorDispatcher.dispatch(ErrorDispatcher.java:407)
         org.apache.jasper.compiler.ErrorDispatcher.jspError(ErrorDispatcher.java:148)
         org.apache.jasper.compiler.Generator$GenerateVisitor.visit(Generator.java:1200)
         org.apache.jasper.compiler.Node$UseBean.accept(Node.java:1160)
         org.apache.jasper.compiler.Node$Nodes.visit(Node.java:2343)
         org.apache.jasper.compiler.Node$Visitor.visitBody(Node.java:2393)
         org.apache.jasper.compiler.Node$Visitor.visit(Node.java:2399)
         org.apache.jasper.compiler.Node$Root.accept(Node.java:489)
         org.apache.jasper.compiler.Node$Nodes.visit(Node.java:2343)
         org.apache.jasper.compiler.Generator.generate(Generator.java:3372)
         org.apache.jasper.compiler.Compiler.generateJava(Compiler.java:198)
         org.apache.jasper.compiler.Compiler.compile(Compiler.java:314)
         org.apache.jasper.compiler.Compiler.compile(Compiler.java:294)
         org.apache.jasper.compiler.Compiler.compile(Compiler.java:281)
         org.apache.jasper.JspCompilationContext.compile(JspCompilationContext.java:566)
         org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:317)
         org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:337)
         org.apache.jasper.servlet.JspServlet.service(JspServlet.java:266)
         javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
    Please help me.thanks in advance.

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