Apr 12, 2008

Writing a Java Concurrent Program

Steps in writing Java Concurrent Program

Template Program:

Copy the template Java Concurrent Program from $FND_TOP/java/cp/request/Template.java to your directory and start coding according to your requirement. Change file name and class name to your required name as Java Concurrent Program name.
================= Template.java===========================
package oracle.apps.fnd.cp.request;
// Change the package name to the required one.
// import all the other required classes/packages.
import oracle.apps.fnd.util.*;
import oracle.apps.fnd.cp.request.*;
// Change the name of the class from Template to your
// concurrent program class name
public class Template implements JavaConcurrentProgram
{
   /** Optionally provide class constructor without any arguments.
    *  If you provide any arguments to the class constructor then while
    *  running the program will fail.
    */
   public void runProgram(CpContext pCpContext)
   {
        ReqCompletion lRC = pCpContext.getReqCompletion();
        String CompletionText = "";
        /* Code your program logic here.
         * Use getJDBCConnection method to get the connection
* object for any JDBC operations.
         * Use CpContext provided commit,rollback methods to
* commit/rollback data base transactions.
         * Don't forget to release the connection before returning
* from this method.
         */
        /* Call setCompletion method to set the request completion
* status and completion text.
         * Status values are ReqCompletion.NORMAL,ReqCompletion.WARNING,
         * ReqCompletion.ERROR.
         * Use Completion text message of length 240 characters.
* If it is more than 240 then full string will appear in
* log file and truncated 240 characters will be used as
* request completion text.
         */
         lRC.setCompletion(ReqCompletion.NORMAL, CompletionText);
    }
}
==================End of Template.java===========================

program Logic


Implement the runProgram with your Java Concurrent Program business logic. runProgram() gets the CpContext .  CpContext is a subclass of AOL/J AppsContext which provides the request specific member classes LogFile to write to request log file, OutFile to write to request output file and ReqCompletion to set the completion status of the request. 
Program Parameters 
CpContext uses the AOL/J utility Parameter List to pass the parameters to the Java Concurrent Program.
Please refer AOL/J Parameter list to get the Parameter List name, value pairs. You will be referring parameter list name as the parameter name and corresponding value as the parameter value in the Java Concurrent Program. You have to register the parameter names as token name in the register concurrent program form Parameter screen. 

Database Operations 
Use getJDBCConnection method to get the connection object for any JDBC operations within program and release the connection to the AppsContext connection pool. Use CpContext's commit(), rollback() methods to commit or rollback the transactions in the database. These methods will set the program proffered rollback segments after commit or rollback segments for the rest of the database transaction in the Java Concurrent Program. 
Setting request Completion Status 
Call setCompletion() method of the ReqCompletion object which is a member of CpContext before returning from your Java Concurrent Program to set the completion status for the program and optional completion text. 

Register executable

Register your Java Concurrent Program class name as execution_file_name and package name in execution_file_path in register concurrent executables form

Register Concurrent Program

Register you Java Concurrent Program as concurrent program in the register concurrent program form. Register all the parameters that you want to pass to the program in the parameter screen of this form. Register the Parameter List names referred in the program as the token names in the parameter screen.

Test Program from OS Prompt

You can test your Java Concurrent Program from OS prompt by using the following syntax: 

jre -Ddbcfile= 
            [ -Drequest.logfile=
            [ -Drequest.requestid=
            [ -Drequest.outfile=
            [ -Drequest.userid=  ] 
            [ -Drequest.respapplid=
            [ -Drequest.respid=
            [ -Drequest.secgrpid=
            [ -Drequest.enabletrace=
            oracle.apps.fnd.cp.request.Run  
            [

     Example: 
     jre -Ddbcfile=/d2/fnd/secure/appsnode_appdb.dbc 
          -Dreqeust.requestid=23453 -Drequest.logfile=./myreq.log 
           oracle.apps.fnd.cp.request.Run oracle.apps.wip.program.MyProg 
           "TOKEN1=value1:TOKEN2=value2"
If you don't specify the 'request.logfile' with -D option then the all the log file information will be printed to the standard output. Specify the 'request.requestid' to rerun already completed request. You can specify the all the application user specific context values with -D to get the specific user context to the program when run from the OS prompt. Pass all the parameters if any by using the AOL/J Parameter list syntax.

Sample Program

package oracle.apps.fnd.cp.request;
import java.io.*;
import java.sql.*;
import oracle.apps.fnd.util.*;
public class AvailableProg implements JavaConcurrentProgram
{
   String applName;
   public AvailableProg()
   {
        // if no parameter value is specified for
// APPLNAME then use FND as default value
        applName = "FND";
   }
   public void runProgram(CpContext pCpContext)
   {
        // get the JDBC connection object
        Connection mJConn = pCpContext.getJDBCConnection();
        // get parameter list object from CpContext
        ParameterList lPara = pCpContext.getParameterList();
        // get ReqCompletion object from CpContext
        ReqCompletion lRC = pCpContext.getReqCompletion();
        String lQuery =
                " select substr(user_concurrent_program_name,1,70) , " +
                " decode(enabled_flag,'Y','Enabled','N','Disabled') " +
                " from fnd_concurrent_programs_vl cp, fnd_application_vl a " +
                " where cp.application_id        = a.application_id " +
                " and a.application_short_name = ? " +
                " order by 1 " ;
        // check for the APPLNAME parameter token name and if it there get
        // value and use it as the application short name in the query
        while (lPara.hasMoreElements())
        {
                NameValueType aNVT = lPara.nextParameter();
                if ( aNVT.getName().equals("APPLNAME") )
                        applName = aNVT.getValue();
        }
        try
        {
           PreparedStatement lStmt = mJConn.prepareStatement(lQuery);
           lStmt.setString(1, applName );
           ResultSet lRs = lStmt.executeQuery();
           // get OutFile object from CpContext
           OutFile lOF = pCpContext.getOutFile();
           // get LogFile object from CpContext
           LogFile lLF = pCpContext.getLogFile();
           lLF.writeln("Generating Programs for Application : "  + applName,
                      LogFile.STATEMENT);
           lOF.writeln(
           "                Available Concurrent Programs for Application " +
                         applName );
           lOF.writeln(
           "Concurrent Program Name                             Enabled");
          lOF.writeln(
           "----------------------------------------------" );
         while( lRs.next() )
           {
                lOF.writeln(lRs.getString(1) + "   " + lRs.getString(2) );
           }
           lLF.writeln("Generated Programs for Application : " + applName,
                     LogFile.STATEMENT);
           lStmt.close();
           lRC.setCompletion(ReqCompletion.NORMAL, "Request Completed Normal");
        }
        catch (SQLException e)
        {
              lRC.setCompletion(ReqCompletion.ERROR, e.toString());
        }
        finally
        {
pCpContext.releaseJDBCConnection();
    }
    }
}
NOTE: If you're creating a BC4J Application Module in a concurrent program and are passing CpContext object to it, you should NOT call releaseJDBCConnection() on CpContext while it is still in use by the BC4J AM. You should clean up after the AM properly by calling am.remove().

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