Re: JPA Problem

Hi,

I got past the above error but experiencing some strange results as follows.

In the BankBean.java, I have the following method.

*********
   public void deposit(int accountNumber, int amount) {
            Account account = manager.find(Account.class, accountNumber);
            account.balance += amount;
            System.out.println("New balance="+account.balance);
            System.out.println("Merging the account");
            manager.merge(account);
        }
*********

I have the Account.java as follows.
**********************************************************************
package sample.jpa;

import java.io.Serializable;

import javax.persistence.Entity;
import javax.persistence.Id;
import javax.persistence.NamedQuery;
import javax.persistence.PostLoad;
import javax.persistence.PostUpdate;
import javax.persistence.PrePersist;
import javax.persistence.PreUpdate;
import javax.persistence.Version;
import javax.persistence.Table;

/**
 * This demo entity represents a Bank Account.
 * <p>
 * The entity is not a remote object and can only be accessed locally by
 * clients. However, it is made serializable so that instances can be passed by
 * value to remote clients for local inspection.
 * <p>
 * Access to persistent state is by direct field access.
 */
@Entity
@Table(name = "ACCOUNT")
@NamedQuery(name="findThem", query="SELECT a FROM Account a")
public class Account implements Serializable {

    /** The account number is the primary key for the persistent object */
    @Id
    public int accountNumber;

    public String ownerName;

    public int balance;
   
    @Version
    public int version;

    /**
     * Entity beans must have a public no-arg constructor
     */
    public Account() {
        // our own primary key generation, workaround for the
        // time being as persistence does not support
        // auto-generation
        accountNumber = (int) System.nanoTime();
    }

    public String toString() {
        return "Acc.# " + accountNumber + ", owner" + ownerName + ", balance: " + balance
                + " $";
    }

    @PrePersist
    void prepersist() {
        System.out.println("pre persist!!");
    }
   
    @PreUpdate
    void preupdate() {
        System.out.println("pre update!!");
    }
   
    @PostUpdate
    void postupdate() {
        System.out.println("post update!!");
    }
   
    @PostLoad
    void postload() {
        System.out.println("post load!!");
    }
   
}
**********************************************************************

In the servlet I have the following code

**********************************************************************

 bank = (Bank)ctx.lookup("BankBeanRemote");
 account = bank.findAccount(Integer.parseInt(request.getParameter("accNo")));
                
               out.println("account Number = "+account.accountNumber+"<br/>");
               out.println("ownerName = "+account.ownerName+"<br/>");
               out.println("balance = "+account.balance+"<br/>");
               out.println("version = "+account.version+"<br/>");
               
                
                accountNumber = account.accountNumber;
                
                out.println("Depositing Rs.100"+"<br/>");
                
                bank.deposit(accountNumber,100);
               
**********************************************************************

When I run the servlet, it is able to load the account values from the "account = bank.findAccount(Integer.parseInt(request.getParameter("accNo")));" statement. However, the "bank.deposit(accountNumber,100);" is not updating the "balance" field.

What is the problem?? I have the following persistence.xml file
*****************************************************************************************************
<?xml version="1.0" encoding="UTF-8"?>
<persistence    xmlns="http://java.sun.com/xml/ns/persistence"
                xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" version="1.0"
                xsi:schemaLocation="http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_1_0.xsd">
    <persistence-unit name="BankPU">
        <description>Bank example</description>
        <provider>org.apache.openjpa.persistence.PersistenceProviderImpl</provider>
        <class>sample.jpa.Account</class>
        <properties>
            <property name="openjpa.ConnectionURL" value="jdbc:derby:BankDB" />
            <property name="openjpa.ConnectionDriverName" value="org.apache.derby.jdbc.EmbeddedDriver" />
            <property name="ConnectionUserName" value="app" />
            <property name="openjpa.jdbc.SynchronizeMappings" value="false" />
        </properties>
    </persistence-unit>
    <!--
    <jta-data-source>PhoneBookPool</jta-data-source>
    <non-jta-data-source>PhoneBookPool</non-jta-data-source>
    -->
</persistence>

**********************************************************************************************************