wsenhancer command

The entity enhancer tool for Java Persistence API (JPA) applications inserts bytecode into an entity class file that supports the JPA provider to manage the state of an entity. Use this command-line tool to enhance entities under the Java Persistence API (JPA) 2.0 specification provider, WSJPA/OpenJPA, for WebSphere Application Server.

JPA with the application server requires that all entity classes be enhanced to manage their state. In a container-managed environment, automated enhancement is provided by the containers. In a Java SE environment, though, there are no containers to manage persistence and we might use this command frequently before packaging application files for testing. After we have created the JPA entities, we can run the wsenhancer tool to inject bytecode into the entities before packaging the JAR file into the EAR file for the application.

Syntax

Before running the command, we must have a copy of the persistence.xml file on the classpath, or specify it as a properties file in the -p [path_to_persistence.xml] argument. Issue the command from the bin subdirectory of the profile_root directory.

The command syntax is as follows:

(UNIX) (ZOS)

wsenhancer.sh [parameters][arguments]

(iSeries)

wsenhancer [parameters][arguments]

(Windows)

wsenhancer.bat [parameters][arguments]

Parameters

The enhancer accepts the standard set of command-line arguments defined by the configuration framework along with the following:

• -directory/-d <output directory>: Path to the output directory.

  If the directory does not match the enhanced class package, the package structure is created beneath the directory. By default, the enhancer overwrites the original .class file.

• -enforcePropertyRestrictions/-epr <true/t | false/f>: Specifies whether to generate an exception when a property access entity is not obeying the restrictions that are placed on property access.

  The default is set to false.

• -addDefaultConstructor/-adc <true/t | false/f>: That all of the persistent classes define a no-argument constructor. This flag informs the enhancer to add a protected no-arg constructor to any persistent classes in which the constructor is not already present.
• -tmpClassLoader/-tcl <true/t | false/f>: Specifies whether the enhancer should load persistent classes with a temporary class loader.

  This function supports other code to load the enhanced version of the class afterward within the same JVM. The default is set to true.

  If we are encountering class loading problems when running the enhancer, we can set this flag to false as a debugging step.

• For class name, specify one of the following:

  • The full name of a class.

  • The .java name for a class.

  • The .class file of a class.

If we do not provide arguments to the enhancer, it runs on the classes in your persistent class list.

To use the wsenhancer tool we need entities defined to the JPA specifications, and the entities must be compiled. Run the wsenhancer tool against the entities before packaging them into a JAR file. If the entities are already packaged, you extract the entity class files, run the enhancer, and recreate the JAR file.

To enhance your entities:

• Verify that your entities are in the class path, if they are not, add them.

• Run the wsenhancer command. It is found in profile_root/bin directory.

Messages and errors are logged to the administrative console as specified in the log settings. After starting the wsenhancer command, the files are enhanced.

Examples

To enhance all entities on the class path:

(UNIX) (ZOS)

$ cd build
/home/user/myproject/build $ ${profile_root}/bin/wsenhancer.sh

(iSeries)

$ cd build
/home/user/myproject/build $ ${profile_root}/bin/wsenhancer

(Windows)

C:\myproject\cd build
C:\myproject\build>%profile_root%\bin\wsenhancer.bat 

All entities in myproject are enhanced.

To enhance a specific entity when we have the source files:

(UNIX) (ZOS)

$ cd build
/home/user/myproject/build $ ${profile_root}/bin/wsenhancer.sh Magazine.java

(iSeries)

$ cd build
/home/user/myproject/build $ ${profile_root}/bin/wsenhancer Magazine.java

(Windows)

C:\myproject\cd build
C:\myproject\build>%profile_root%\bin\wsenhancer.bat Magazine.java

To enhance a specific entity when we have the compiled class files:

(UNIX) (ZOS)

$ export CLASSPATH=target/classes
$ ${profile_root}/bin/wsenhancer.sh /bin/wsenhancer.sh target/classes/jpa/example/MyEntity.class

(iSeries)

$ export CLASSPATH=target/classes
$ ${profile_root}/bin/wsenhancer target/classes/jpa/example/MyEntity.class

(Windows)

C:> cd build
C:\build> SET CLASSPATH=target\classes
C:\build>%profile_root%\bin\wsenhancer.bat \bin\wsenhancer.bat target\classes\jpa\example\Magazine.class

The entity, Magazine.java, located in project are enhanced.

Additional information

For more information about enhancement tools, see the section on persistent classes in the Apache OpenJPA documentation.

Developing JPA 2.x applications for a Java EE environment

Developing JPA 2.x applications for a Java SE environment

Apache OpenJPA User's Guide