2.1.0 CR1 - Issue in getResultList

[sanghakanwar]

Hi,

The getResultList() is throwing exceptions in the latest build of seam (2.1.0 CR1).

[#|2008-10-02T09:23:26.013+0530|WARNING|sun-appserver9.1|javax.enterprise.system.stream.err|_ThreadID=21;_ThreadName=httpSSLWorkerThread-8080-0;_RequestID=c0bc8b99-c91f-4770-9991-babdad503395;|

java.lang.ClassCastException: java.lang.String

     at org.jboss.seam.framework.Query.parseEjbql(Query.java:220)

     at org.jboss.seam.framework.EntityQuery.createQuery(EntityQuery.java:169)

     at org.jboss.seam.framework.EntityQuery.initResultList(EntityQuery.java:73)

     at org.jboss.seam.framework.EntityQuery.getResultList(EntityQuery.java:65)

     at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)

     at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)

     at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)

     at java.lang.reflect.Method.invoke(Method.java:585)

     at org.jboss.seam.util.Reflections.invoke(Reflections.java:22)

Another exception thrown if result set is empty. These conditions were working fine in the previous version -

Caused by: java.lang.IndexOutOfBoundsException: Index: 0, Size: 0

     at java.util.ArrayList.RangeCheck(ArrayList.java:546)

     at java.util.ArrayList.get(ArrayList.java:321)

     at org.jboss.seam.framework.Query.getRenderedEjbql(Query.java:240)

     at org.jboss.seam.framework.EntityQuery.createQuery(EntityQuery.java:175)

     at org.jboss.seam.framework.EntityQuery.initResultList(EntityQuery.java:73)

     at org.jboss.seam.framework.EntityQuery.getResultList(EntityQuery.java:65)

     at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)

     at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)

     at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)

     at java.lang.reflect.Method.invoke(Method.java:585)

     at org.jboss.seam.util.Reflections.invoke(Reflections.java:22)

[nickarls]

Details, details. Show code, tell versions (sun-appserver9.1?)

[sanghakanwar]

we are extending EntityQuery and overriding

@Override
    public List getResultList() {
          edList = super.getResultList();
          return edList;
    }

Sun-appserver 9.1
mysql version - 6.0
Seam - 2.1.0.CR1

exception

Caused by: java.lang.IndexOutOfBoundsException: Index: 0, Size: 0

     at java.util.ArrayList.RangeCheck(ArrayList.java:546)

     at java.util.ArrayList.get(ArrayList.java:321)

     at org.jboss.seam.framework.Query.getRenderedEjbql(Query.java:240)

     at org.jboss.seam.framework.EntityQuery.createQuery(EntityQuery.java:175)

     at org.jboss.seam.framework.EntityQuery.initResultList(EntityQuery.java:73)

     at org.jboss.seam.framework.EntityQuery.getResultList(EntityQuery.java:65)

     at com.prod.sps.session.EventdefinitionList.getResultList(EventdefinitionList.java:44)

[pmuir]

Please file an issue in JIRA, with a simple example we can use to reproduce asap so we can get the fix in for the next release.

[sanghakanwar]

earlier version had this in the generated entityList.java file which was causing the issue -

@Override
public List<String> getRestrictions() {
return Arrays.asList(RESTRICTIONS);
}

New version generates the following-

@Override
public List getRestrictions() {
// TODO Auto-generated method stub
return super.getRestrictions();
} 

[jkronegg]

Hi kanwar,
I got the same issue using Seam 2.1.1-SNAPSHOT #340.

This is not a bug, but a Seam 2.0.x->2.1.x migration issue, as the seam21migration.txt file state the following:

Seam Application Framework Changes
----------------------------------

Seam now expects value expressions for a number of properties 
(entityHome.createdMessage, entityHome.updatedMessage, entityHome.deletedMessage
and entityQuery.restrictions); if you are using components.xml to configure your
objects, you don't need to make any changes. If you are extending the objects in
Java, you just need to create a value expression; for example:

public ValueExpression getCreatedMessage() { return createValueExpression("New person #{person.firstName} #{person.lastName} created"); }

As me, you probably had the following RESTRICTIONS in your subclass of EntityQuery:

public class MyobjectList extends EntityQuery {
  private static final String[] RESTRICTIONS = {"lower(myobject.name) like concat(lower(#{myobjectList.myobject.name}),'%')",};
  ...
  public List<String> getRestrictions() { return Arrays.asList(RESTRICTIONS); }
}

You must convert the RESTRICTIONS String[] to a org.jboss.seam.core.Expressions.ValueExpression[] (and getRestrictions() must return a List<ValueExpression>). Even simpler, you can use the following convenience method:

import org.jboss.seam.core.Expressions.ValueExpression;
public class MyobjectList extends EntityQuery {
  ...
  public List<ValueExpression> getRestrictions() {
    setRestrictionExpressionStrings(Arrays.asList(RESTRICTIONS));
    return super.getRestrictions();
  }
}

I did it, it worked like a charm.

By the way, the IndexOutOfBoundException may be a different problem, as the org.jboss.seam.framework.Query.getRenderedEjbql() source code states at line 240:

  for (int i=0; i<getRestrictions().size(); i++)
  {
    Object parameterValue = restrictionParameters.get(i).getValue();

Notice the for's i<getRestrictions().size() boundary and the restrictionParameters.get(i) which may cause the problem.

Could you correct the restrictions migration problem and retry to see if the IndexOutOfBoundException can be reproduced?

[joblini]

Hi Julien,

Thanks so much for posting this, I am converting my EntityQuery classes as you suggested:

@Override
public List<ValueExpression> getRestrictions()
{
     setRestrictionExpressionStrings(Arrays.asList(RESTRICTIONS));
     return super.getRestrictions();
}

The only thing is that I get a warning :

Expressions.ValueExpression is a raw type. References to generic type Expressions.ValueExpression<T> should be parameterized     

Oddly enough, this warning is not issued for the getRestrictions method in the base class, Query.

[joblini]

Calling setRestrictionExpressionStrings) does not work for me, it causes parsedRestrictions to be set to null, resulting in a NullPointerException

Line 240 in Query class:

getRestrictions calls setRestrictionExpressionStrings, which calls setRestrictions, which sets parsedRestrictions to null;

  for (int i=0; i<getRestrictions().size(); i++)

   (snip)
           builder.append( parsedRestrictions.get(i) );
 

Here is what works for me:

 
@Override
public List<ValueExpression> getRestrictions()
{
     return toValueExpressionList(Arrays.asList(RESTRICTIONS));
}

public List<ValueExpression> toValueExpressionList(List<String> expressionStrings)
{
   List<ValueExpression> expressionList = new ArrayList<ValueExpression>(expressionStrings.size());
   for (String expressionString : expressionStrings) {
        expressionList.add(Expressions.instance().createValueExpression(expressionString));
   }
   return expressionList;
}

[joblini]

Correct implementation is posted here (call setRestrictionExpressionStrings from constructor, not from getRestrictions)

GetRestrictionsInSeam21