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Home » Eclipse Projects » EclipseLink » EclipseLink 2.7.4 mixed approach - Native TopLinkProject and JPA approaches don't work together
EclipseLink 2.7.4 mixed approach - Native TopLinkProject and JPA approaches don't work together [message #1824273] Sat, 11 April 2020 23:45 Go to next message
krishna Mising name is currently offline krishna Mising nameFriend
Messages: 16
Registered: July 2009
Junior Member
Sample project to prove that EL Mixed Approach Native EL + JPA fails for complex selection criteria mappings

Stack (3 maven dependencies):
org.eclipse.persistence:eclipselink:jar:2.6.4:compile com.microsoft.sqlserver:mssql-jdbc:jar:6.1.0.jre8:compile org.springframework.data:spring-data-jpa:jar:1.11.3.RELEASE:compile


Bug: ReadAllQueries are cached by name and reuse common expressions SQL by caching such as ObjectKeyExpression hasMapping and when they are evaluated in a mixed approach, they fail to find the mappings.

Steps to reproduce: Run com.mixed.AppRunner class to see exception However, when you comment out CompanyRepo activeEmployees(), it works fine:

Reasoning: on App startup, EntityManager sets up the EL ServerSession from com.mixed.domain.data.SampleTOPLinkProject ORM configuration with custom mapping com.mixed.domain.data.SampleCompany#addToDescriptor that adds the right selection criteria for m_Employees collection

However, when the com.mixed.data.repo.CompanyRepo.activeEmployees() JPQL query select c.m_Employees from com.mixed.domain.data.SampleCompany c where c.id = ?1 is evaluated during org.eclipse.persistence.internal.queries.ExpressionQueryMechanism#prepareReportQuerySelectAllRows, it seems to prepare the SQL correctly after setSQLStatement(statement) is done:

One of the QueryKeyExpressions for key firstName sets up the mapping with hasMapping=true: Query Key firstName Query Key m_Employees Base com.mixed.domain.data.SampleCompany mapping = {DirectToFieldMapping@3721} "org.eclipse.persistence.mappings.DirectToFieldMapping[firstName-->Employees.FirstName]" hasMapping = true

The SQL statement is prepared correctly: SQLSelectStatement(SELECT t0.Id, t0.FirstName, t0.LastName, t0.MiddleInitial, t0.Version, t0.CompanyID FROM {oj Companies t1 LEFT OUTER JOIN Employees t0 ON ((t0.CompanyID = t1.Id) AND (((t0.FirstName = ?) OR ((t0.LastName = ?) OR (t0.MiddleInitial IS NULL))) AND NOT ((t0.Version IS NULL))))} WHERE ((t1.Id = ?) AND (t1.Type = ?)))


The next method setCallFromStatement() seems to set the QueryKeyExpression for firstName sets hasMapping=false in the printSQL(printer) flows

And when we do get the Company and access Employees "Natively",

    CompanyRepo companyRepo = context.getBean(CompanyRepo.class);
    SampleCompany company = (SampleCompany) companyRepo.findOne(COMPANY_ID);
    try {
        List<SampleEmployee> employees = company.getEmployees(); 
        System.out.println(employees.size()); <<<<< here, again accessing m_Employees collection natively >>>>
When you put a breakpoint in org.eclipse.persistence.internal.queries.ExpressionQueryMechanism#buildNormalSelectStatement, you can see that the cached/cloned QueryKeyExpression

Query Key firstName
   Base com.mixed.domain.data.SampleEmployee
 name = "firstName"
...
mapping = null
hasMapping = false <<<
Does not find org.eclipse.persistence.internal.expressions.QueryKeyExpression#validateNode

    if ((queryKey == null) && (mapping == null)) {
        throw QueryException.invalidQueryKeyInExpression(getName());
    }


Solution: It looks like if we use both EL natively and via JPA queries and access the same collection sub graphs, it throws an exception as hasMapping and isAttributeExpression etc., seemed to be cached for the Query Key clones.

    fixClonedQueryKeyExpressions(clonedExpressions); <<< 
    selectStatement.normalize(getSession(), getDescriptor(), clonedExpressions);

private void fixClonedQueryKeyExpressions(Map clonedExpressions) {
clonedExpressions.values().stream()
    .filter(e -> e instanceof QueryKeyExpression)
    .forEach(expression -> {
	QueryKeyExpression queryKeyExpression = (QueryKeyExpression) expression;
	Expression baseExpression = queryKeyExpression.getBaseExpression();
	if(baseExpression != null && baseExpression instanceof  DataExpression){
	    ClassDescriptor descriptor = ((DataExpression) baseExpression).getDescriptor();
	    if(descriptor != null){
		Field field = com.paycycle.util.Helper.getField(QueryKeyExpression.class.getName(), "hasMapping");
		if (field != null) {
		    field.setAccessible(true);
		}
		try {
		    field.setBoolean(expression, true);
		} catch (IllegalAccessException e) {
		    throw new RuntimeException(e);
		}
	    }
	}
    });
}


Failure StackTrace: [EL Warning]: 2020-04-08 17:03:31.165--ServerSession(951221468)--Thread(Thread[main,5,main])--Exception [EclipseLink-6015] (Eclipse Persistence Services - 2.6.4.v20160829-44060b6): org.eclipse.persistence.exceptions.QueryException Exception Description: Invalid query key [firstName] in expression. Query: ReadAllQuery(name="m_Employees" referenceClass=SampleEmployee ) 17:03:31.167 [main] ERROR com.mixed.AppRunner - >>>>>>> Exception accessing employees subgraph in a mixed approach TopLinkProject Native way and JPA way <<<<<< org.eclipse.persistence.exceptions.QueryException: Exception Description: Invalid query key [firstName] in expression. Query: ReadAllQuery(name="m_Employees" referenceClass=SampleEmployee ) at org.eclipse.persistence.exceptions.QueryException.invalidQueryKeyInExpression(QueryException.java:697) at org.eclipse.persistence.internal.expressions.QueryKeyExpression.validateNode(QueryKeyExpression.java:1011) at org.eclipse.persistence.expressions.Expression.normalize(Expression.java:3291) at org.eclipse.persistence.internal.expressions.DataExpression.normalize(DataExpression.java:369) at org.eclipse.persistence.internal.expressions.QueryKeyExpression.normalize(QueryKeyExpression.java:758) at org.eclipse.persistence.internal.expressions.QueryKeyExpression.normalize(QueryKeyExpression.java:671) at org.eclipse.persistence.internal.expressions.RelationExpression.normalize(RelationExpression.java:841) at org.eclipse.persistence.internal.expressions.CompoundExpression.normalize(CompoundExpression.java:224) at org.eclipse.persistence.internal.expressions.CompoundExpression.normalize(CompoundExpression.java:224) at org.eclipse.persistence.internal.expressions.CompoundExpression.normalize(CompoundExpression.java:232) at org.eclipse.persistence.internal.expressions.SQLSelectStatement.normalize(SQLSelectStatement.java:1521) at org.eclipse.persistence.internal.queries.ExpressionQueryMechanism.buildNormalSelectStatement(ExpressionQueryMechanism.java:550) at org.eclipse.persistence.internal.queries.ExpressionQueryMechanism.prepareSelectAllRows(ExpressionQueryMechanism.java:1722) at org.eclipse.persistence.queries.ReadAllQuery.prepareSelectAllRows(ReadAllQuery.java:885) at org.eclipse.persistence.queries.ReadAllQuery.prepare(ReadAllQuery.java:816) at org.eclipse.persistence.queries.DatabaseQuery.checkPrepare(DatabaseQuery.java:666) at org.eclipse.persistence.queries.ObjectLevelReadQuery.checkPrepare(ObjectLevelReadQuery.java:911) at org.eclipse.persistence.queries.DatabaseQuery.checkPrepare(DatabaseQuery.java:615) at org.eclipse.persistence.queries.DatabaseQuery.execute(DatabaseQuery.java:872) at org.eclipse.persistence.queries.ObjectLevelReadQuery.execute(ObjectLevelReadQuery.java:1134) at org.eclipse.persistence.queries.ReadAllQuery.execute(ReadAllQuery.java:460) at org.eclipse.persistence.internal.sessions.AbstractSession.internalExecuteQuery(AbstractSession.java:3271) at org.eclipse.persistence.internal.sessions.AbstractSession.executeQuery(AbstractSession.java:1857) at org.eclipse.persistence.internal.sessions.AbstractSession.executeQuery(AbstractSession.java:1839) at org.eclipse.persistence.internal.indirection.QueryBasedValueHolder.instantiate(QueryBasedValueHolder.java:133) at org.eclipse.persistence.internal.indirection.QueryBasedValueHolder.instantiate(QueryBasedValueHolder.java:120) at org.eclipse.persistence.internal.indirection.DatabaseValueHolder.getValue(DatabaseValueHolder.java:89) at org.eclipse.persistence.internal.indirection.UnitOfWorkValueHolder.instantiateImpl(UnitOfWorkValueHolder.java:173) at org.eclipse.persistence.internal.indirection.UnitOfWorkValueHolder.instantiate(UnitOfWorkValueHolder.java:234) at org.eclipse.persistence.internal.indirection.DatabaseValueHolder.getValue(DatabaseValueHolder.java:89) at org.eclipse.persistence.indirection.IndirectList.buildDelegate(IndirectList.java:271) at org.eclipse.persistence.indirection.IndirectList.getDelegate(IndirectList.java:455) at org.eclipse.persistence.indirection.IndirectList.size(IndirectList.java:829) at com.mixed.AppRunner.runAssertions(AppRunner.java:46) at com.mixed.AppRunner.main(AppRunner.java:25) 17:03:31.168 [main] DEBUG org.springframework.beans.factory.support.DefaultListableBeanFactory - Returning cached instance of singleton bean 'entityManager'

Process finished with exit code 0

Success stacktrace: [EL Fine]: sql: 2020-04-08 17:06:25.418--ServerSession(209429254)--Connection(1278616846)--Thread(Thread[main,5,main])--SELECT Id, FirstName, LastName, MiddleInitial, Version, CompanyID FROM Employees WHERE ((CompanyID = ?) AND (((FirstName = ?) OR ((LastName = ?) OR (MiddleInitial IS NULL))) AND NOT ((Version IS NULL)))) ORDER BY LastName ASC, FirstName ASC bind => [2, I, AM] 0 17:06:25.424 [main] INFO com.mixed.AppRunner - >>>>>>> Successfully accessed employees subgraph in a mixed approach TopLinkProject Native way and JPA way <<<<<< 17:06:25.424 [main] DEBUG org.springframework.beans.factory.support.DefaultListableBeanFactory - Returning cached instance of singleton bean 'entityManager'


Dependency list: $ mvn dependency:list
[INFO] The following files have been resolved:
[INFO]    com.microsoft.azure:adal4j:jar:1.0.0:compile
[INFO]    net.jcip:jcip-annotations:jar:1.0:compile
[INFO]    com.microsoft.azure:azure-keyvault:jar:0.9.3:compile
[INFO]    com.sun.jersey:jersey-json:jar:1.13:compile
[INFO]    org.codehaus.jackson:jackson-jaxrs:jar:1.9.2:compile
[INFO]    org.springframework.data:spring-data-commons:jar:1.13.3.RELEASE:compile
[INFO]    com.sun.xml.bind:jaxb-impl:jar:2.2.3-1:compile
[INFO]    org.springframework:spring-tx:jar:4.3.8.RELEASE:compile
[INFO]    org.codehaus.jackson:jackson-mapper-asl:jar:1.9.2:compile
[INFO]    org.apache.httpcomponents:httpclient:jar:4.3.6:compile
[INFO]    org.glassfish:javax.json:jar:1.0.4:compile
[INFO]    org.springframework:spring-beans:jar:4.3.8.RELEASE:compile
[INFO]    ch.qos.logback:logback-classic:jar:1.2.3:compile
[INFO]    org.eclipse.persistence:javax.persistence:jar:2.1.1:compile
[INFO]    com.nimbusds:oauth2-oidc-sdk:jar:4.5:compile
[INFO]    org.springframework:spring-expression:jar:4.3.8.RELEASE:compile
[INFO]    org.eclipse.persistence:eclipselink:jar:2.6.4:compile
[INFO]    org.springframework:spring-aop:jar:4.3.8.RELEASE:compile
[INFO]    com.nimbusds:nimbus-jose-jwt:jar:3.1.2:compile
[INFO]    javax.validation:validation-api:jar:1.1.0.Final:compile
[INFO]    com.sun.jersey:jersey-client:jar:1.13:compile
[INFO]    org.bouncycastle:bcprov-jdk15on:jar:1.51:compile
[INFO]    com.google.code.gson:gson:jar:2.2.4:compile
[INFO]    org.springframework.data:spring-data-jpa:jar:1.11.3.RELEASE:compile
[INFO]    com.microsoft.sqlserver:mssql-jdbc:jar:6.1.0.jre8:compile
[INFO]    org.apache.httpcomponents:httpcore:jar:4.3.3:compile
[INFO]    org.codehaus.jackson:jackson-xc:jar:1.9.2:compile
[INFO]    com.nimbusds:lang-tag:jar:1.4:compile
[INFO]    org.slf4j:slf4j-api:jar:1.7.24:compile
[INFO]    org.slf4j:jcl-over-slf4j:jar:1.7.24:runtime
[INFO]    javax.xml.bind:jaxb-api:jar:2.2.2:compile
[INFO]    javax.mail:mail:jar:1.4.5:compile
[INFO]    org.aspectj:aspectjrt:jar:1.8.10:compile
[INFO]    commons-lang:commons-lang:jar:2.6:compile
[INFO]    javax.activation:activation:jar:1.1:compile
[INFO]    net.minidev:json-smart:jar:1.1.1:compile
[INFO]    ch.qos.logback:logback-core:jar:1.2.3:compile
[INFO]    org.springframework:spring-orm:jar:4.3.8.RELEASE:compile
[INFO]    commons-codec:commons-codec:jar:1.10:compile
[INFO]    org.apache.commons:commons-lang3:jar:3.3.1:compile
[INFO]    org.eclipse.persistence:commonj.sdo:jar:2.1.1:compile
[INFO]    com.h2database:h2:jar:1.4.200:compile
[INFO]    com.microsoft.azure:azure-core:jar:0.9.3:compile
[INFO]    javax.inject:javax.inject:jar:1:compile
[INFO]    com.sun.jersey:jersey-core:jar:1.13:compile
[INFO]    org.springframework:spring-jdbc:jar:4.3.8.RELEASE:compile
[INFO]    org.codehaus.jettison:jettison:jar:1.1:compile
[INFO]    javax.xml.stream:stax-api:jar:1.0-2:compile
[INFO]    org.springframework:spring-context:jar:4.3.8.RELEASE:compile
[INFO]    org.springframework:spring-core:jar:4.3.8.RELEASE:compile
[INFO]    commons-logging:commons-logging:jar:1.1.3:compile
[INFO]    org.codehaus.jackson:jackson-core-asl:jar:1.9.2:compile
[INFO]    stax:stax-api:jar:1.0.1:compile
Re: EclipseLink 2.7.4 mixed approach - Native TopLinkProject and JPA approaches don't work together [message #1824274 is a reply to message #1824273] Sat, 11 April 2020 23:49 Go to previous messageGo to next message
krishna Mising name is currently offline krishna Mising nameFriend
Messages: 16
Registered: July 2009
Junior Member
This looks like a bug to me.

Posted EL JPA bugs for both versions and a small patch to fix the bug, as it seems the queries are cached on startup and should not impact us, and we can either patch or aspect this like other EL bugs
https://bugs.eclipse.org/bugs/show_bug.cgi?id=561968

Can some one please take a look at this bug and its patch?
https://bugs.eclipse.org/bugs/attachment.cgi?id=282403

https://github.com/krishna81m/eclipselink-mixed-approach-fails-github
patch:
Re: EclipseLink 2.7.4 mixed approach - Native TopLinkProject and JPA approaches don't work together [message #1824376 is a reply to message #1824274] Tue, 14 April 2020 15:41 Go to previous messageGo to next message
Chris Delahunt is currently offline Chris DelahuntFriend
Messages: 1388
Registered: July 2009
Senior Member
I'm not exactly sure of the problem this is trying to solve, but it is entirely avoiding code meant to avoid having to call "super.getMapping()" on every QueryKeyExpression.getMapping() call. This would cause performance degradation for any query keys that don't have a mapping behind them, as they will constantly be looking for one that isn't there.

This code defaults the hasMapping to true and then sets it to false only when "super.getMapping()" returns null, so a fix should be to figure out where/why hasMapping is being set to false when there is or should be a mapping tied to the query key. If calling "super.getMapping()" eventually returns a mapping it means there is something else that wasn't set, and this needs to be set earlier in the code path - not doing so just means there is an issue in the code, you just don't have an obvious Exception being thrown to detect it.

[Updated on: Tue, 14 April 2020 15:44]

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Re: EclipseLink 2.7.4 mixed approach - Native TopLinkProject and JPA approaches don't work together [message #1824380 is a reply to message #1824376] Tue, 14 April 2020 16:02 Go to previous messageGo to next message
Chris Delahunt is currently offline Chris DelahuntFriend
Messages: 1388
Registered: July 2009
Senior Member
I looked a bit further, and this isn't an issue with JPA interactions, but the expression added via setSelectionCriteria on the mapping itself. A bit of a pain to solve as JPA and other test complexities hide these aspects and it has become less used so there aren't many examples explaining it as well as they should.
What you've done is similar to the first example in:
https://wiki.eclipse.org/EclipseLink/Examples/JPA/MappingSelectionCriteria

It works there because that example is just using database fields directly - not mappings. It creates query keys and ties them entirely to database columns, and has nothing to do with the object model or mappings.

What you are doing is to reuse mappings and query keys defined in the model object. For that, you need to follow the second example on that page, and either set the class in the ExpressionBuilder you create, or reuse the one tied to the existing one within the mappings.getSelectionQuery query to build your expression:
exp = new ExpressionBuilder(mapping.getReferenceClass());


Best Regards,
Chris
Re: EclipseLink 2.7.4 mixed approach - Native TopLinkProject and JPA approaches don't work together [message #1826247 is a reply to message #1824380] Wed, 22 April 2020 01:04 Go to previous messageGo to next message
krishna Mising name is currently offline krishna Mising nameFriend
Messages: 16
Registered: July 2009
Junior Member
Sorry Chris, that seems to not throw the exception, but gives wrong results as discussed in https://bugs.eclipse.org/bugs/show_bug.cgi?id=561968#c11

Your suggested patch is returning wrong results: https://github.com/krishna81m/eclipselink-mixed-approach-fails-github/tree/el-2.6.4-bug

https://github.com/krishna81m/eclipselink-mixed-approach-fails-github/blob/el-2.6.4-bug/src/main/java/com/mixed/AppRunner.java#L54
            ReadObjectQuery readObjectQuery = new ReadObjectQuery();    // Contains common behavior for all read queries using objects
            readObjectQuery.setReferenceClass(SampleCompany.class);
            readObjectQuery.setSelectionId(COMPANY_ID);
            SampleCompany companyByEL = (SampleCompany) jpaServerSession.executeQuery(readObjectQuery);
            List<SampleEmployee> elEmployees = companyByEL.getEmployees();
            // WRONG: returns 12 records

            // returns a null vector of size 0
            List<SampleEmployee> jpaEmpList = companyRepo.activeEmployees(COMPANY_ID);
            logger.info("JPA employee list size: " + jpaEmpList.size());
           // RIGHT: returns 2 records

            // access via JPA!!! using same JPA ServerSession
            SampleCompany company = (SampleCompany) companyRepo.findOne(COMPANY_ID);
            List<SampleEmployee> employees = company.getEmployees();
            logger.info("EL Native employee list size: " + employees.size());
            // WRONG: returns 12 records


Your suggested patch:

Index: src/main/java/com/mixed/domain/data/SampleCompany.java
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
--- src/main/java/com/mixed/domain/data/SampleCompany.java	(revision 1c415df09ca36969bf54bc77dbe23fc1b8ce7925)
+++ src/main/java/com/mixed/domain/data/SampleCompany.java	(date 1587529514000)
@@ -12,7 +12,7 @@
 
         // Only read object attributes of type company
         mapping = (OneToManyMapping) descriptor.getMappingForAttributeName("m_Employees");
-        exp = new ExpressionBuilder();
+        exp = new ExpressionBuilder(mapping.getReferenceClass());
 
         // complex EL selection criteria
         mapping.setSelectionCriteria(mapping.buildSelectionCriteria()

[Updated on: Wed, 22 April 2020 05:24]

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Re: EclipseLink 2.7.4 mixed approach - Native TopLinkProject and JPA approaches don't work together [message #1826276 is a reply to message #1826247] Wed, 22 April 2020 15:32 Go to previous messageGo to next message
Chris Delahunt is currently offline Chris DelahuntFriend
Messages: 1388
Registered: July 2009
Senior Member
Looks like your new expression is causing a Cartesian product, with the new filter only applying to the unattached table.

The example I posted to you in https://wiki.eclipse.org/EclipseLink/Examples/JPA/MappingSelectionCriteria is completely redefining the join, not reusing it. If you want to reuse the existing mapping expression ( the mapping.buildSelectionCriteria().and(...) stuff), you are going to need to get the expression builder from the existing criteria and reuse that to build your new additions. You should be able to get it from the mapping.buildSelectionCriteria() expression using getBuilder() and be more along the lines of:

  Expression previousCriteriaExpression = mapping.buildSelectionCriteria();
  exp = previousCriteria.getBuilder();
mapping.setSelectionCriteria(previousCriteriaExpression
            .and(exp.get("firstName")
                .equal("First1")
                    .or(
                        exp.get("lastName").equal("Last1")
                        .or(exp.get("middleInitial").isNull())
                    )
                    .and(
                        exp.get("version").isNull().not())
                    )
                );
Re: EclipseLink 2.7.4 mixed approach - Native TopLinkProject and JPA approaches don't work together [message #1826629 is a reply to message #1826276] Tue, 28 April 2020 01:33 Go to previous message
krishna Mising name is currently offline krishna Mising nameFriend
Messages: 16
Registered: July 2009
Junior Member
All of our cases were reusing the previous critiera, so, we have to take the expression builder from the existing criteria and reuse that to build your new additions.

But, this was not enough for some reason, we also had to explicitly add query class again.

        Expression previousCriteria = mapping.buildSelectionCriteria();
        ExpressionBuilder exp = previousCriteria.getBuilder();
        exp.setQueryClass(mapping.getReferenceClass()); <<< EXTRA


Also, see the updated response, I included a diff in the Expression with both approaches: https://bugs.eclipse.org/bugs/show_bug.cgi?id=561968#c15

[Updated on: Tue, 28 April 2020 17:24]

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