Question

Today I came across one situation, here it is.

I have a db object to persist. I use SampleBean.add method. Inside that method, I’m getting primary key from a sequence, setting it to db object’s id property and persisting it to db (using PreparedStatement). But I could not get the db object’s id property (it comes as 0, even though it got set in persisting method) from the method I’am calling that bean method.

Please clarify me this.

DB Object

public class LogRow implements Serializable {
     public long cardLogId;
     public String data;
}

Persist method

public void insertLogRow(LogRow logRow) {
        Connection con = null;
        PreparedStatement ps = null;        
        try {
            String insertSql = LogRow.INSERT_LOG;
            con = global.getConnection();
            if (logger.isEnabled(IMessage.DEBUG1)) {
                logger.println(IMessage.DEBUG1, CLASS_NAME + "insertLogRow():: insertSql " + insertSql);
            }
            ps = con.prepareStatement(insertSql);
            logRow.setLogId(seq.getNextVal());
            ps.executeUpdate(); 
        } catch (SQLException sqe) {          
            logger.println("insertLogRow():: SQLException occurred");
            throw new ProcessingErrorException(sqe.getMessage());
        } 
}

I am able to see the persisted id value here in persist method.

Calling method

RemoteLookup.getSampleBean().insertLogRow(logRow);
log.println("log id " + logRow.logId());

This calling method prints 0

Answer 1

This is not an Answer:
Since the question is very difficult to understand I have tried to rephrase it, cant edit the question without understanding it.

I have an object say User to be saved in database, In my SampleBean.add method I fetch the id by getting the next val of some sequence say userSequence.

The same value (fetched from userSequence is set as the id of User object.

Now while persisting the object I am not getting the value of id which I have already set in SampleBean.add method.

For Persistence I am using PreparedStatement. Can you help me in understanding why is this happening ?

This part is Answer

Your are doing a RemoteLookup, and in Java Remote objects are not sent given copy instead it serializes it and sends it, if you want to see the changes done to your object in remove service then you will have to send your object back

So the code changes required:

1. Change your insertLogRow method and make it return the object which it has persisted like:

     public LogRow insertLogRow(LogRow logRow) {
        //Do all database operation
        return logRow;
     }
   

2. Now change the caller code:

    logRow = RemoteLookup.getSampleBean().insertLogRow(logRow);
    log.println("log id " + logRow.logId());
   

Rebuild, deploy and run.

Now you should see your id which has been set on the object inside insertLogRow method.