Appendix A. Reference Material

A.1. Jakarta Enterprise Beans Java Naming and Directory Interface Reference

The Java Naming and Directory Interface lookup name for a session bean uses the following syntax:

ejb:<appName>/<moduleName>/<distinctName>/<beanName>!<viewClassName>?stateful
  • <appName>: If the session bean’s JAR file has been deployed within an enterprise archive (EAR) then the appName is the name of the respective EAR. By default, the name of an EAR is its file name without the .ear suffix. The application name can be overridden in its application.xml file. If the session bean is not deployed in an EAR, then leave the appName blank.
  • <moduleName>: The moduleName is the name of the JAR file in which the session bean is deployed. The default name of the JAR file is its file name without the .jar suffix. The module name can be overridden in the JAR’s ejb-jar.xml file.
  • <distinctName>: JBoss EAP allows each deployment to specify an optional distinct name. If the deployment does not have a distinct name, then leave the distinctName blank.
  • <beanName>: The beanName is the simple class name of the session bean to be invoked.
  • <viewClassName>: The viewClassName is the fully qualified class name of the remote interface. This includes the package name of the interface.
  • ?stateful: The ?stateful suffix is required when the Java Naming and Directory Interface name refers to a stateful session bean. It is not included for other bean types.

For example, if we deployed hello.jar having a stateful bean org.jboss.example.HelloBean that exposed a remote interface org.jboss.example.Hello, then the Java Naming and Directory Interface lookup name would be:

ejb:/hello/HelloBean!org.jboss.example.Hello?stateful"

A.2. Jakarta Enterprise Beans Reference Resolution

This section covers how JBoss EAP implements @EJB and @Resource. Please note that XML always overrides annotations but the same rules apply.

Rules for the @EJB annotation
  • The @EJB annotation also has a mappedName() attribute. The specification leaves this as vendor specific metadata, but JBoss EAP recognizes mappedName() as the global Java Naming and Directory Interface name of the Jakarta Enterprise Beans you are referencing. If you have specified a mappedName(), then all other attributes are ignored and this global Java Naming and Directory Interface name is used for binding.
  • If you specify @EJB with no attributes defined:

    @EJB
    ProcessPayment myEjbref;

    Then the following rules apply:

    • The Jakarta Enterprise Beans JAR of the referencing bean is searched for Jakarta Enterprise Beans with the interface used in the @EJB injection. If there are more than one Jakarta Enterprise Beans that publishes same business interface, then an exception is thrown. If there is only one bean with that interface then that one is used.
    • Search the EAR for Jakarta Enterprise Beans that publish that interface. If there are duplicates, then an exception is thrown. Otherwise the matching bean is returned.
    • Search globally in JBoss EAP runtime for an Jakarta Enterprise Beans of that interface. Again, if duplicates are found, an exception is thrown.
  • @EJB.beanName() corresponds to <ejb-link>. If the beanName() is defined, then use the same algorithm as @EJB with no attributes defined except use the beanName() as a key in the search. An exception to this rule is if you use the ejb-link # syntax: it allows you to put a relative path to a JAR in the EAR where the Jakarta Enterprise Beans you are referencing is located. Refer to the Jakarta Enterprise Beans 3.2 specification for more details.

A.3. Project Dependencies for Remote Jakarta Enterprise Beans Clients

Maven projects that include the invocation of session beans from remote clients require the following dependencies from the JBoss EAP Maven repository. There are two ways to declare Jakarta Enterprise Beans client dependencies, as described in the sub-sections below.

Note

The artifactId versions are subject to change. See the JBoss EAP Maven Repository for the latest versions.

Maven Dependencies for Remote Jakarta Enterprise Beans Clients

The jboss-eap-jakartaee8 Bill of Materials (BOM) packages the correct version of many of the artifacts commonly required by a JBoss EAP application. The BOM dependency is specified in the <dependencyManagement> section of the pom.xml with the scope of import.

Example: POM File <dependencyManagement> Section

<dependencyManagement>
   <dependencies>
      <dependency>
      <groupId>org.jboss.bom</groupId>
        <artifactId>jboss-eap-jakartaee8</artifactId>
        <version>7.4.0.GA</version>
        <type>pom</type>
        <scope>import</scope>
      </dependency>
   </dependencies>
</dependencyManagement>

The remaining dependencies are specified in the <dependencies> section of the pom.xml file.

Example: POM File <dependencies> Section

<dependencies>
    <!-- Include the Enterprise Java Bean client JARs -->
    <dependency>
        <groupId>org.jboss.eap</groupId>
        <artifactId>wildfly-ejb-client-bom</artifactId>
        <type>pom</type>
    </dependency>

    <!-- Include any additional dependencies required by the application
        ...
    -->

</dependencies>

The ejb-remote quickstart that ships with JBoss EAP provides a complete working example of remote Jakarta Enterprise Beans client application. See the client/pom.xml file located in root directory of that quickstart for a complete example of dependency configuration for remote session bean invocation.

Single artifactID for jboss-ejb-client Dependencies

You can use the wildfly-ejb-client-bom artifactID and add the jboss-ejb-client library to include all the required dependencies for Jakarta Enterprise Beans clients:

<dependencyManagement>
    <dependencies>
        <dependency>
            <groupId>org.jboss.eap</groupId>
            <artifactId>wildfly-ejb-client-bom</artifactId>
            <version>JAKARTA_ENTERPRISE_BEANS_CLIENT_BOM_VERSION</version>
            <type>pom</type>
            <scope>import</scope>
        </dependency>
    </dependencies>
</dependencyManagement>
<dependencies>
    <dependency>
        <groupId>org.jboss</groupId>
        <artifactId>jboss-ejb-client</artifactId>
    </dependency>
</dependencies>

You must use the JAKARTA_ENTERPRISE_BEANS_CLIENT_BOM_VERSION that is available in the JBoss EAP Maven repository.

A.4. jboss-ejb3.xml Deployment Descriptor Reference

jboss-ejb3.xml is a custom deployment descriptor that can be used in either Jakarta Enterprise Beans JAR or WAR archives. In a Jakarta Enterprise Beans JAR archive it must be located in the META-INF/ directory. In a WAR archive it must be located in the WEB-INF/ directory.

The format is similar to ejb-jar.xml, using some of the same namespaces and providing some other additional namespaces. The contents of jboss-ejb3.xml are merged with the contents of ejb-jar.xml, with the jboss-ejb3.xml items taking precedence.

This document only covers the additional non-standard namespaces used by jboss-ejb3.xml. See http://xmlns.jcp.org/xml/ns/javaee/ for documentation on the standard namespaces.

The root namespace is http://xmlns.jcp.org/xml/ns/javaee.

Assembly descriptor namespaces
The following namespaces can all be used in the <assembly-descriptor> element. They can be used to apply their configuration to a single bean, or to all beans in the deployment by using a wildcard (*) as the ejb-name.
The security namespace (urn:security)
xmlns:s="urn:security"

This allows you to set the security-domain and the run-as-principal for an Jakarta Enterprise Beans.

<s:security>
  <ejb-name>*</ejb-name>
  <s:security-domain>myDomain</s:security-domain>
  <s:run-as-principal>myPrincipal</s:run-as-principal>
</s:security>
The resource adapter namespace: urn:resource-adapter-binding
xmlns:r="urn:resource-adapter-binding"

This allows you to set the resource adapter for a Message-Driven Bean.

<r:resource-adapter-binding>
  <ejb-name>*</ejb-name>
  <r:resource-adapter-name>myResourceAdapter</r:resource-adapter-name>
</r:resource-adapter-binding>
The IIOP namespace: urn:iiop
xmlns:u="urn:iiop"

The IIOP namespace is where IIOP settings are configured.

The pool namespace: urn:ejb-pool:1.0
xmlns:p="urn:ejb-pool:1.0"

This allows you to select the pool that is used by the included stateless session beans or Message-Driven Beans. Pools are defined in the server configuration.

<p:pool>
   <ejb-name>*</ejb-name>
   <p:bean-instance-pool-ref>my-pool</p:bean-instance-pool-ref>
</p:pool>
The cache namespace: urn:ejb-cache:1.0
xmlns:c="urn:ejb-cache:1.0"

This allows you to select the cache that is used by the included stateful session beans. Caches are defined in the server configuration.

<c:cache>
   <ejb-name>*</ejb-name>
   <c:cache-ref>my-cache</c:cache-ref>
</c:cache>
<?xml version="1.1" encoding="UTF-8"?>
<jboss:ejb-jar xmlns:jboss="http://www.jboss.com/xml/ns/javaee"
    xmlns="http://xmlns.jcp.org/xml/ns/javaee"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://www.jboss.com/xml/ns/javaee http://www.jboss.org/j2ee/schema/jboss-ejb3-2_0.xsd"
    version="3.1"
    impl-version="2.0">
  <enterprise-beans>
     <message-driven>
        <ejb-name>ReplyingMDB</ejb-name>
        <ejb-class>org.jboss.as.test.integration.ejb.mdb.messagedestination.ReplyingMDB</ejb-class>
        <activation-config>
           <activation-config-property>
              <activation-config-property-name>destination</activation-config-property-name>
              <activation-config-property-value>java:jboss/mdbtest/messageDestinationQueue
              </activation-config-property-value>
           </activation-config-property>
        </activation-config>
     </message-driven>
  </enterprise-beans>
 </jboss:ejb-jar>
Note

There are known issues with the jboss-ejb3-spec-2_0.xsd file that may result in schema validation errors. You can ignore these errors. For more information, see https://bugzilla.redhat.com/show_bug.cgi?id=1192591.

A.5. Configure a Jakarta Enterprise Beans Thread Pool

You can create an Jakarta Enterprise Beans thread pool using the management console or the management CLI.

A.5.1. Configuring an Jakarta Enterprise Beans Thread Pool Using the Management Console

Procedure

  1. Log in to the management console.
  2. Navigate to ConfigurationSubsystemsEJB and click View.
  3. Select ContainerThread Pool.
  4. Click Add and specify the Name and Max Threads values.
  5. Click Save.

A.5.2. Configure an Jakarta Enterprise Beans Thread Pool Using the Management CLI

Procedure

  1. Use the add operation with the following syntax:

    /subsystem=ejb3/thread-pool=THREAD_POOL_NAME:add(max-threads=MAX_SIZE)
    1. Replace THREAD_POOL_NAME with the required name for the thread pool.
    2. Replace MAX_SIZE with the maximum size of the thread pool.
  2. Use the read-resource operation to confirm the creation of the thread pool:

    /subsystem=ejb3/thread-pool=THREAD_POOL_NAME:read-resource
    1. To reconfigure all the services in the ejb3 subsystem to use a new thread pool, use the following commands:

      /subsystem=ejb3/thread-pool=bigger:add(max-threads=100, core-threads=10)
      /subsystem=ejb3/service=async:write-attribute(name=thread-pool-name, value="bigger")
      /subsystem=ejb3/service=remote:write-attribute(name=thread-pool-name, value="bigger")
      /subsystem=ejb3/service=timer-service:write-attribute(name=thread-pool-name, value="bigger")
      reload

      XML Configuration Sample:

      <subsystem xmlns="urn:jboss:domain:ejb3:5.0">
          ...
          <async thread-pool-name="bigger"/>
          ...
          <timer-service thread-pool-name="bigger" default-data-store="default-file-store">
          ...
          <remote connectors="http-remoting-connector" thread-pool-name="bigger"/>
          ...
          <thread-pools>
              <thread-pool name="default">
                  <max-threads count="10"/>
                  <core-threads count="5"/>
                  <keepalive-time time="100" unit="milliseconds"/>
              </thread-pool>
              <thread-pool name="bigger">
                  <max-threads count="100"/>
                  <core-threads count="5"/>
              </thread-pool>
          </thread-pools>
          ...

A.5.3. Jakarta Enterprise Beans Thread Pool Attributes

Jakarta Enterprise Beans thread pools can be configured using attributes to run more efficiently for specific configuration needs.

  • The max-threads attribute determines the total or maximum number of threads that the executor supports.
/subsystem=ejb3/thread-pool=default:write-attribute(name=max-threads, value=9)
{"outcome" => "success"}
  • The core-threads attribute determines the number of threads that are kept in the executor’s pool. This includes idle threads. If the core-threads attribute is not specified, it will default to the value of max-threads.
/subsystem=ejb3/thread-pool=default:write-attribute(name=core-threads, value=3)
{"outcome" => "success"}
  • The keepalive-time attribute determines the amount of time that a non-core thread will be allowed to remain idle. After this time, the non-core thread is removed.
/subsystem=ejb3/thread-pool=default:write-attribute(name=keepalive-time, value={time=5, unit=MINUTES})
{"outcome"=> "success"}
  • To change the time without changing the units of time for the keepalive-time attribute, use the following command:
/subsystem=ejb3/thread-pool=default:write-attribute(name=keepalive-time.time, value=10)
{"outcome"=> "success"}





Revised on 2024-01-17 05:24:45 UTC