I'm trying to use selectBatch and selectNext in a query manager that I am developing. When I call selectNext, I get a StackOverflowError.

Code Example:
foundVector = dataSource.selectBlock(state,
"aces.dataAccess.queries.cashIssuance.CashIssuance",
blockSize);
foundVector = dataSource.selectNext(foundVector, state,
"aces.dataAccess.queries.cashIssuance.CashIssuance");

foundVector: A vector for the results of the query
dataSource: An instance of CocoDriverInterface that has an open database connection.
state: A state object that implements CBProp
blockSize: 1000

The selectNext() method causes:
java.lang.StackOverflowError
at thought.CocoBase.CocoPowder.selectNext(CocoPowder.java, Compiled Code)
at thought.CocoBase.CocoPowderPlugin20.selectNext(CocoPowderPlugin20.java, Compiled Code)
at thought.CocoBase.CocoPowder.selectNext(CocoPowder.java, Compiled Code)
at thought.CocoBase.CocoPowderPlugin20.selectNext(CocoPowderPlugin20.java, Compiled Code)
at thought.CocoBase.CocoPowder.selectNext(CocoPowder.java, Compiled Code)
at thought.CocoBase.CocoPowderPlugin20.selectNext(CocoPowderPlugin20.java, Compiled Code)
.
.
.
at thought.CocoBase.CocoPowder.selectNext(CocoPowder.java, Compiled Code)
at thought.CocoBase.CocoPowderPlugin20.selectNext(CocoPowderPlugin20.java, Compiled Code)
at thought.CocoBase.CocoPowder.selectNext(CocoPowder.java, Compiled Code)
at thought.CocoBase.CocoPowderPlugin20.selectNext(CocoPowderPlugin20.java, Compiled Code)
at thought.CocoBase.CocoPowder.selectNext(CocoPowder.java, Compiled Code)
at thought.CocoBase.CocoPowderPlugin20.selectNext(CocoPowderPlugin20.java, Compiled Code)
at aces.dataAccess.queries.cashIssuanceBatch.CashIssuanceQuery.findByState(CashIssuanceQuery.java, Compiled Code)
at aces.dataAccess.queries.cashIssuanceBatch.CashIssuanceTest.main(CashIssuanceTest.java, Compiled Code)

Any ideas?

Wow,

This sounds like an out of memory or some such error.

Without having the program involved in this it would be
difficult to determine if that's the problem.

You might also consider enabling debug on the runtime and
disabling the JIT so you can get some valid line numbers in
the backtrace. That might help you to debug this better.

The debug option in the runtime is initiated through a call
such as:
cocoDataSource.setDebug(true)

Hope that helps!

THOUGHT Support

I've created a very simple test client that recreates this problem. You should be able to perform the same test using any simple state class.

Debug does not display anything for the selectNext call. Looking at the stack trace, it appears that there is an infinite loop between CocoPowder.selectNext() and CocoPowderPlugin20.selectNext().

Here is my test client. I could email this to you if you prefer.

package aces.selectNextTest;

import java.util.Enumeration;
import java.util.Vector;
import thought.CocoBase.CocoDriver;
import thought.CocoBase.CocoDriverInterface;

/**
* Test Client for demonstrating a bug in selectNext.
*
* @author ***************
*/

public class TestClient extends Object {

/**
* Constructor
*/
public TestClient() {
}

/**
* main
* @param args
*/
public static void main(String[] args) {

String mapname = "aces.selectNextTest.SelectNextTest";
int blockSize = 10;
Vector results;
CocoDriverInterface dataSource = null;

try {

// get a connection
dataSource = CocoDriver.getCocoDriver(
"thought.CocoBase.CocoPowderPlugin20",
"oracle.jdbc.driver.OracleDriver",
"jdbc:oracle:thin:@NNN.NNN.NNN.NNN:1521:MYINSTANCE"
+ ";cocoprop=primarykey.lookup=false,dynamic.querying=true",
"***", "***");
dataSource.setDebug(false);
dataSource.connect();

// instantiate a state class to set query parameters
// (just get all records for this test)
SelectNextTest state = new SelectNextTest();

// perform initial query
results = dataSource.selectBlock(state, mapname, blockSize);
display(results);

// perform selectNext
dataSource.setDebug(true);
results = dataSource.selectNext(results, state, mapname);
display(results);

} finally {
// close connection
if(dataSource != null) {
dataSource.close();
}
}

}

/**
* quick & dirty method for displaying returned data
*/
private static void display(Vector results) {
Enumeration resultsEnum = results.elements();
while(resultsEnum.hasMoreElements()) {
System.out.println(resultsEnum.nextElement());
}
}

}

Thanks for the test.

We'll have someone take a closer look at this and get back to you. Your code looks great, so we're suspicious as to what
might be causing it...

THOUGHT Support

Do you have any estimate on when I can expect to hear back on this?

It's on the hot queue, it should be in the next day or so...

THOUGHT Support

It's been a few more days. Just wondering what the status of this issue is.

We tested this locally and haven't been able to reproduce it
yet. Our selectNext tests work perfectly.

Can you email the support all of the java classes you used and
export your map(s) as XML and send the DDL used to create the
test and populate the database tables. That might give us
a better chance of reproducing this...

THOUGHT Support