Section 9.6. Developing Enterprise JavaBeans

9.6. Developing Enterprise JavaBeans

Ant provides a number of optional tasks for developing EJBs. Generally, these tasks are specific to the particular vendor's EJB Server. Currently, these tasks support these servers:

• Borland Application Server 4.5

• IBM WebSphere 4.0

• iPlanet Application Server 6.0

• JBoss 2.1 and above EJB servers

• JOnAS 2.4.x and 2.5 Open Source EJB server

• Weblogic 4.5.1 through to 7.0 EJB servers

The Ant EJB tasks and the servers they target appear in Table 9-14.

Table 9-14. The Ant EJB tasks

Task	Does this	Application servers
blgenclient	Specifies you want to create a client .jar file corresponding to an EJB .jar file	Borland Application Server 4.5 and 5.x
ddcreator	Specifies you want to compile Weblogic text-based deployment descriptors into an EJB deployment descriptor	Weblogic 4.5.1
ejbc	Lets you run Weblogic's ejbc tool	Weblogic 4.5.1
ejbjar	Supports creation of EJB .jar files (EJB 1.1 & 2.0)	Borland Application Server 4.5 and 5.x, iPlanet Application Server 6.0, JBoss, JOnAS 2.4.x and 2.5, Weblogic 5.1 to 7.0, and IBM WebSphere 4.0
iplanet-ejbc	Supports compilation of EJB stubs and skeletons for iPlanet Application Server 6.0	iPlanet Application Server 6.0
wlrun	Lets you start a Weblogic server	Weblogic 4.5.1 to 7.0
wlstop	Lets you stop a Weblogic server	Weblogic 4.5.1 to 7.0

9.6.1. JARing Files

The largest and most general of the EJB tasks is the ejbjar task. This task works by scanning directories; for each deployment descriptor found, ejbjar will parse it to determine the necessary .class files which implement the bean. These files are assembled along with the deployment descriptors into a well-formed EJB .jar file. (Any support files which should be included in the created .jar file can be added with the support nested element.) For each class included in the .jar file, ejbjar will scan for any super classes or super interfaces, which will be added to the generated .jar file. The attributes of this task appear in Table 9-15.

Table 9-15. The Ant ejbjar task's attribute

Attribute	Description	Required	Default
basejarname	Specifies the base name you want used for the generated .jar files.	No
classpath	Specifies the classpath you wnt used when resolving classes that are to be added to the .jar.	No
cmpversion	Specifies the CMP version. Possible values are 1.0 or 2.0.	No	1.0
dependency	Specifies which classes and interfaces are added to the .jar.	No
descriptordir	Specifies the directory under which the task shoulc scan for EJB deployment descriptors.	No
destdir	Specifies the directory into which you want generated JAR files to be placed.	Yes, unless you use vendor-specific deployment elements.
flatdestdir	Specifies you want to store all generated JARs in the root of the destdir, rather than the location specified by the deployment descriptor. Set to true/false.	No
genericjarsuffix	Specifies a string that you want appended to the deployment descriptor in order to create the filename of a generic EJB JAR file.	No	-generic.jar
naming	Specifies the naming convention you want to use to name generated EJB jars.	No
srcdir	Specifies the base directory containing the .class files that make up the generated bean.	Yes

You can nest classpath elements to set the classpath in the ejbjar task, and you can use nested dtd elements to specify the local location of DTDs to be used when parsing the EJB deployment descriptor (see Table 9-2 for the dtd element's attributes).

You can use nested support elements to specify additional .class files to be included in the generated .jar files. The support element is a fileset, so it can reference a fileset declared elsewhere or it can be defined with the appropriate include and exclude nested elements. The ejbjar task supports vendor-specific nested elements, which let you use the vendors' deployment tools.

Vendor-specific nested elements provide support for various vendor deployment tools. (If no nested vendor-specific deployment elements are present, the task will create a generic EJB .jar file.) For each nested deployment element, the vendor-specific deployment tool is run to generate a .jar file for deployment to that vendor's EJB server. Here are the legal vendor-specific nested elements:

borland

For Borland Application Server 4.5 and 5.x

iPlanet

For iPlanet Application Server 6.0

jboss

For JBoss

jonas

For JOnAS 2.4.x and 2.5

weblogic

For Weblogic 5.1 to 7.0

websphere

For IBM WebSphere 4.0

These vendor-specific elements can become involved. For example, the attributes of the weblogic element, used to control the weblogic.ejbc compiler for generating Weblogic EJB .jar files, appear in Table 9-16.

Table 9-16. The weblogic element's attribute

Attribute	Description	Required	Default
args	Specifies any additional arguments you want to pass to the weblogic.ejbc tool.	No
classpath	Specifies the classpath that should be used when the task runs the weblogic.ejbc tool.	No
compiler	Specifies a different compiler to be used for compiling the generated Java files.	No
destdir	Specifies the directory where the generated JAR files should be stored.	Yes
ejbcclass	Specifies the classname of the ejbc compiler. When used with Version 7, this attribute should be set to "weblogic.ejbc" to avoid a deprecation warning.	No
genericjarsuffix	Specifies the suffix used for the generic JAR file. This JAR file is generated as an intermediate step in building the weblogic deployment JAR.	No	-generic.jar
jvmargs	Specifies any additional arguments you want passed to the JVM running the weblogic.ejbc tool.	No
jvmdebuglevel	Specifies the debug level for messages. Set to 16 to avoid warnings about EJB Home and Remotes in the classpath.	No
keepgenerated	Specifies if Weblogic will preserve the Java files it generates.	No	false
keepgeneric	Specifies if you want the generic file used for input to ejbc to be preserved.	No	false
newCMP	Specifies ejbjar should parse the Weblogic deployment descriptor to find the CMP descriptors. Set to true/false.	No	false
noEJBC	Specifies you don't want Weblogic's ejbc to be run on the EJB .jar file.	No
outputdir	Specifies this directory as the output directory instead of a .jar file.	No
rebuild	Specifies if weblogic.ejbc should always be used to build the .jar file.	No	TRue
suffix	Specifies the string that should be added to the deployment descriptor to create the WebLogic JAR filename.	No	.jar
wlclasspath	Specifies the classpath for the Weblogic classes to avoid a warning when the home and remote interfaces of a bean are on the classpath used by weblogic.ejbc.	No

The weblogic nested element supports nested classpath and wlclasspath nested elementsthe wlclasspath element holds the classpath used by the Weblogic Server as detailed by the wlclasspath attribute in Table 9-16, and it takes the same attributes and nested elements as classpath. The weblogic element supports nested sysproperty elements to allow Java system properties to be set.

Investigating them all would take us many pages deep into the mechanics of these six EJB servers, and far from Ant. If you're interested, you can find the details for using various vendor-specific tools in the Ant EJB Tasks User Manual at ${ant-home}/docs/manual/OptionalTasks/ejb.html.