2 Replies Latest reply on May 12, 2004 10:00 AM by nusa

    An MBean invoke another MBean

    nusa Novice

      Hi all,

      I'm using JBOSS3.2.4RC2.
      I have an MBean A which depends on MBean B and MBean C, as defined in my jboss-service.xml :
      ...
      <!--
      | A depend on B and C
      -->

      <depends optional-attribute-name="BManager">nusa:service=B
      <depends optional-attribute-name="CManager">nusa:service=C


      <!--
      | BMBean
      -->

      false


      <!--
      | CBMBean
      -->

      false

      ...

      A, B, and C has the usual getter/setter method.

      If a method within A calls a method in B, as shown below :

      ...
      public ObjectName getBManager() {
      return this.bManager;
      }

      public void setBManager(ObjectName obj) {
      this.bManager = obj;
      }
      ...
      public void methodA1() {
      try {
      log.info("=== A.methodA1() invoke methodB1() ");
      server.invoke(bManager ,"methodB1" ,null ,null);
      } catch ( Exception e) {
      log.debug( "=== Exception in A.methodA1 : " + e);
      }
      }

      public void methodA2(String s) {
      try {
      log.info("=== A.methodA2() invoke methodB2() ");
      Object[] params = new Object[] { s };
      String[] signature = new String[] { "java.lang.String" };
      server.invoke ( bManager, "methodB2", params, signature );
      } catch ( Exception e) {
      log.debug( "=== Exception in A.methodA2 : " + e);
      }
      }
      ...
      and the methods in B are :

      ...
      public void methodB1() {
      log.info("=== B.methodB1()");
      }

      public void methodB2(String s) {
      log.info("=== B.methodB2() : " + s);
      }
      ...

      I got this error :

      ...
      10:26:36,849 INFO [example.jmx.A] === A.startService()

      10:26:36,849 INFO [example.jmx.A] === A.methodA1()

      10:26:36,849 DEBUG [example.jmx.A] === Exception in A.methodA1 : ReflectionException: null
      Cause: java.lang.IllegalArgumentException: Unable to find operation methodB1()

      10:26:36,849 INFO [example.jmx.A] === A.methodA2()

      10:26:36,849 DEBUG [example.jmx.A] === Exception in A.methodA2 : ReflectionException: null
      Cause: java.lang.IllegalArgumentException: Unable to find operation methodB2(java.lang.String)
      ...


      How to use invoke ? What's wrong with the syntax above ?

      The C class has a method which return an instance of C :

      ...
      public Object getInstance() {
      return this;
      }
      ...

      If a method within A calls a method in C, as shown below :

      ...
      public ObjectName getCManager() {
      return this.cManager;
      }

      public void setCManager(ObjectName obj) {
      this.cManager = obj;
      }
      ...
      public void methodA1() {
      try {
      log.info("=== A.methodA1() invoke methodC1() ");
      C obj = (C)server.getAttribute(cManager ,"Instance");
      obj.methodC1();
      } catch ( Exception e) {
      log.debug( "=== Exception in A.methodA1 : " + e);
      }
      }

      public void methodA2(String s) {
      try {
      log.info("=== A.methodA2() invoke methodC2() ");
      C obj = (C)server.getAttribute(cManager ,"Instance");
      obj.methodC2(s);
      } catch ( Exception e) {
      log.debug( "=== Exception in A.methodA2 : " + e);
      }
      }
      ...

      I got this error :
      ...
      12:08:28,634 INFO [example.jmx.A] === A.startService()

      12:08:28,634 INFO [example.jmx.A] === A.methodA1() invoke methodC1()

      12:08:28,634 DEBUG [example.jmx.A] === Exception in A.methodA1 : javax.management.AttributeNotFoundException: not found: Instance

      12:08:28,634 INFO [example.jmx.A] === A.methodA2() invoke methodC2()

      12:08:28,634 DEBUG [example.jmx.A] === Exception in A.methodA2 : javax.management.AttributeNotFoundException: not found: Instance

      ...

      Any idea why the getInstance() in C is not recognize ?

      Thanks for any help/suggestion.