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Difference between revisions of "EclipseLink/Development/JPA 2.0/weblogic"

m (DI 1: Alternative 4: Global Level Shared Library)
m (Running JPA 2.0 API on WebLogic 10.3)
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=Running JPA 2.0 API on WebLogic 10.3=
 
=Running JPA 2.0 API on WebLogic 10.3=
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==Problem==
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*'''''We want a way for end users to override the JPA 1.0 library shipped with WebLogic Server 10.3.2.0 without modifying the server and affecting other applications.'''''
 +
 
*This document details a solution for enabling JPA 2.0 API functionality for various enterprise application use cases involving application managed EntityManagers.
 
*This document details a solution for enabling JPA 2.0 API functionality for various enterprise application use cases involving application managed EntityManagers.
 
*The page is geared to both end users and internal ''eclipselink.jpa.test'' server test implementors.
 
*The page is geared to both end users and internal ''eclipselink.jpa.test'' server test implementors.

Revision as of 11:12, 4 December 2009

Running JPA 2.0 API on WebLogic 10.3

Problem

  • We want a way for end users to override the JPA 1.0 library shipped with WebLogic Server 10.3.2.0 without modifying the server and affecting other applications.
  • This document details a solution for enabling JPA 2.0 API functionality for various enterprise application use cases involving application managed EntityManagers.
  • The page is geared to both end users and internal eclipselink.jpa.test server test implementors.
    • 1) End users of WebLogic 10.3.2.0
      • This involves configuring the server for JPA 1.0 permanently or per-deployment
      • Note: This procedure is for application managed deployments - container managed injection will still default to JPA 1.0 for servers that do not ship with 2.0 out of the box
    • 2) EclipseLink JPA test users on WebLogic 10.3.2.0
      • This involves temporarily configuring the server per-test-deployment

Analysis

  • EclipseLink 1.2 and 2.0+ fully implement the JPA 2.0 specification via enhancement # 248291 and are the RI for the GlassFish V3 JEE6 server. In order to use this functionality the 2.0 version of the JPA specification jar - javax.persistence.jar must be added higher in the WebLogic server classpath see enhancement # 296271.
  • Now, you may have noticed that the modules/org.eclipse.persistence_1.0.0.0_1-2-0.jar jar contains JPA 2.0 API implementation classes such as org.eclipse.persistence.internal.jpa.metamodel - however this API is not available through interface classes (because only the javax.persistence 1.0 jar is present) and we also are missing the services file for Criteria/Metamodel - in any case a predeploy should fail where the EAR contains JPA 2.0 API out of the box.

Use Cases

  • Use case partitioning criteria
    • Container managed EM
      • @PersistenceUnit EMF and/or @PersistenceContext EM injection on session bean
        • Global scoped datasource
          • JTA global scoped datasource
          • non-JTA global scoped datasource
          • RESOURCE_LOCAL jdbc connector
        • Application scoped datasource
          • JTA global scoped datasource
          • non-JTA global scoped datasource
          • RESOURCE_LOCAL jdbc connector
    • Application managed EM
      • @PersistenceUnit EMF or static bootstrap Persistence.createEntityManagerFactory EMF
        • Global scoped datasource
          • JTA global scoped datasource
          • non-JTA global scoped datasource
          • RESOURCE_LOCAL jdbc connector
        • Application scoped datasource
          • JTA global scoped datasource
          • non-JTA global scoped datasource
          • RESOURCE_LOCAL jdbc connector

UC1: Application managed EM

  • List incomplete

Design

Design Issue 1: JSR-317 JPA 2.0 EJB 3.1 Support

DI 1: Problem

  • The modules currently shipped with WebLogic 10.3.2.0 (Patch Set 1) in are the following JPA 1.0 compatible versions - these must be overriden in order to run JPA 2.0 API.
    • modules/org.eclipse.persistence_1.0.0.0_1-2-0.jar
    • modules/javax.persistence_1.0.0.0_1-0-2.jar

DI 1: Alternative 1: Manual overwrite of eclipselink and javax.persistence libraries in modules

  • Current solution - this should be deprecated.

DI 1: Alternative 2: Reference higher in the server classpath via commEnv.cmd

  • Workable solution but it has issues
    • The server now runs a single version of the two libraries for all applications - this may not be compatible with older applications or other JPA providers running on the server.
DI 1: Solution
  • In <WEBLOGIC_HOME>\wlserver_10.3\common\bin\commEnv.cmd
    • change
      • set WEBLOGIC_CLASSPATH=%JAVA_HOME%\lib\tools.jar...
    • To
      • set WEBLOGIC_CLASSPATH=F:/view_w35d/jpa/plugins/javax.persistence_2.0.0.*.jar;%JAVA_HOME%\lib\tools.jar...
      • where F:/view_w35d == %SVN_TRUNK
  • Note: do not use the javax.persistence_2.0_preview.jar - the dated javax.persistence_2.0.0.*.jar one is the final PFD version for the JPA 2.0 specification.

DI 1: Alternative 3: Application Level Shared Library - In Use

  • 20091202 working standalone Eclipse EAR (WAR only) prototype attached bug 296271 - this procedure has been verified on 2 separate servers on separate machines (in order to filter out any possible leftover configuration experimentation that could skew results)
  • The following artifacts and modifications are required (failure of any one of these will result in a Persistence Unit not found during deployment or runtime)
  • 1) Start with an EAR project containing only a WAR (no ejb-jar) - Eclipse can generate one for you after you install the WebLogic Eclipse Plugin
  • 2) Ship EclipseLink 2.0 and JPA 2.0 in the EAR project (not the WAR)
    • 2a) Add eclipselink.jar V2 (OSGI version is org.eclipse.persistence_1.0.0.0_2-0-0.jar) to EarContent\APP-INF\lib - this will override org.eclipse.persistence_1.0.0.0_1-2-0.jar in the modules dir on the server
    • 2b) Add the JPA 2.0 specification jar - this will override javax.persistence_1.0.0.0_1-0-2.jar.
  • 3) Update the .MANIFEST where the root of the classes that use the EntityManager reside (here the src\META-INF' off the WAR) to point to the these included jars (relative paths not required if they are in the classpath - which they are)
    • Class-Path: javax.persistence_2.0.0.v200911041116.jar eclipselink.jar
  • 4) Place your persistence.xml jar as usual for an application managed entitymanager in the WAR also at the classes root in src\META-INF - this will be exported to the server as classes
    • 4a) make sure to modify the entity package paths as we are dealing with an SE persistence unit here
  • 5) Add the prefer-application-packages element to weblogic-application.xml so the internal WebLogic API FilteredClassLoader places our library ahead of the modules directory.
    <wls:prefer-application-packages>
        <wls:package-name>javax.persistence.*</wls:package-name>
        <wls:package-name>org.eclipse.persistence.*</wls:package-name>
    </wls:prefer-application-packages>
  • 6) The EMF is either injected or obtained via a static call
    @PersistenceUnit(unitName="example")
    private EntityManagerFactory emf;
or
    private EntityManagerFactory emf;
    emf  = Persistence.createEntityManagerFactory("example);
  • Note: at this time there is no requirement to add WebLogic platform specific handling for the FilteredClassLoader - we are ok with the XML EAR deployment descriptor change.
Output 3

Weblogic app managed em ear jpa2 server classpath override browser output 296271.JPG

DI 1: Alternative 4: Global Level Shared Library

Weblogic shared libraries in eclipse preferences.jpg

DI 1: Alternative 5: Domain Extension Template

  • 20091202 - This one suggested by Doug - similar to what is done for other vendor libraries.
  • This method involves copying the JPA 2.0 libraries to the lib directory off the current domain
    • example: %WEBLOGIC_HOME%\user_projects\domains\base_domain\lib
    • is below
    • %WEBLOGIC_HOME%\modules
  • The domain lib override alternative will not work because this lib is below the server classpath and has no effect after 10.3.0.
  • Our current weblogic.xml test script copies the xdb, spatial, jdbc, junit, xmlparserv2 and trunk eclipselink.jar to the domain lib - however this only works if no library is in modules that will override these domain libs.

Since 10.3.1 the user still needs to apply a patch to override modules libs in these lib cases. Therefore this option is deprecated for 10.3.1 and 10.3.2 since we started shipping with the eclipselink jar.

  • Potential modification to weblogic.xml:weblogic-install is (without $ variable prefix)
  <copy file="F:/view_w35d/jpa/plugins/javax.persistence_2.0.0.v200911041116.jar" todir="${weblogic.domain}/lib"/>
  • Another issue to solve is the absence of OSGI functionality - fixed by editing the .MANIFEST - see bug# 296733
<2-Dec-2009 1:09:45 o'clock PM EST> <Notice> <WebLogicServer> <BEA-000395> <Following extensions directory contents added to the end of the classpath:
C:\opt\wls10320\user_projects\domains\base_domain\lib\eclipselink.jar;C:\opt\wls10320\user_projects\domains\base_domain\lib\javax.persistence_2.0.0.v200911041116.jar;F:\view_w35d\jpa\plugins\javax.persistence_2.0.0.v200911041116.jar> 
<2-Dec-2009 1:09:45 o'clock PM EST> <Critical> <WebLogicServer> <BEA-000386> <Server subsystem failed. Reason: 
java.lang.NoClassDefFoundError: org/osgi/framework/BundleActivator
java.lang.NoClassDefFoundError: org/osgi/framework/BundleActivator

DI 1: Alternative 6: Use -Dweblogic.ext.dirs override

  • Like alternative #5 - this one is also appended to the end of the server classpath - so is not of use.


Implementation

Application Managed Clients

  • The shared-library approach has been prototyped as Alternative #3 and functions fine for EARs that utilize application managed entitymanagers - the Eclipse 1.2 and JPA 1.0 libraries shipped with WebLogic 10.3.2.0 are overriden by the supplied EclipseLink 2.0 and JPA 2.0 libraries in the EAR.
  • See the development bug #296271 for attached EAR test archives.

Container Managed Clients

  • Support for container managed applications is as-is with out of the box JPA 1.0 API functionality - however the alternatives above give WebLogic server administratiors options for setting the JPA 2.0 specification library ahead of the shipped 1.0 jar in the server classpath.

Log

  • 20091201: Start investigation
  • 20091202: Scope of this issue has been reduced to the application managed EAR level - @PersistenceContext injection of a 2.0 EM is not supported for EE servers that do not support JPA 2.0 out of the box.
    • The example used for EAR testing uses a container-managed EM via the following injected bean - this will be modified
@Local @Stateless
public class ApplicationService implements ApplicationServiceLocal {
	@PersistenceContext(unitName="example", type=PersistenceContextType.TRANSACTION)	
	private EntityManager entityManager;

Resources

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