Class MBeanServerInvocationHandler

java.lang.Object
javax.management.MBeanServerInvocationHandler
All Implemented Interfaces:
InvocationHandler
public class MBeanServerInvocationHandler extends Object implements InvocationHandler

InvocationHandler that forwards methods in an MBean's management interface through the MBean server to the MBean.

Given an MBeanServerConnection, the ObjectName of an MBean within that MBean server, and a Java interface Intf that describes the management interface of the MBean using the patterns for a Standard MBean or an MXBean, this class can be used to construct a proxy for the MBean. The proxy implements the interface Intf such that all of its methods are forwarded through the MBean server to the MBean.

If the InvocationHandler is for an MXBean, then the parameters of a method are converted from the type declared in the MXBean interface into the corresponding mapped type, and the return value is converted from the mapped type into the declared type. For example, with the method
public List<String> reverse(List<String> list);
and given that the mapped type for List<String> is String[], a call to proxy.reverse(someList) will convert someList from a List<String> to a String[], call the MBean operation reverse, then convert the returned String[] into a List<String>.

The method Object.toString(), Object.hashCode(), or Object.equals(Object), when invoked on a proxy using this invocation handler, is forwarded to the MBean server as a method on the proxied MBean only if it appears in one of the proxy's interfaces. For a proxy created with JMX.newMBeanProxy or JMX.newMXBeanProxy, this means that the method must appear in the Standard MBean or MXBean interface. Otherwise these methods have the following behavior:

  • toString() returns a string representation of the proxy
  • hashCode() returns a hash code for the proxy such that two equal proxies have the same hash code
  • equals(Object) returns true if and only if the Object argument is of the same proxy class as this proxy, with an MBeanServerInvocationHandler that has the same MBeanServerConnection and ObjectName; if one of the MBeanServerInvocationHandlers was constructed with a Class argument then the other must have been constructed with the same Class for equals to return true.
Since:
1.5

  • Constructor Summary

    Constructors
    Constructor
    Description
    MBeanServerInvocationHandler(MBeanServerConnection connection, ObjectName objectName)
    Invocation handler that forwards methods through an MBean server to a Standard MBean.
    MBeanServerInvocationHandler(MBeanServerConnection connection, ObjectName objectName, boolean isMXBean)
    Invocation handler that can forward methods through an MBean server to a Standard MBean or MXBean.

  • Method Summary

    Modifier and Type
    Method
    Description
    MBeanServerConnection
    getMBeanServerConnection()
    The MBean server connection through which the methods of a proxy using this handler are forwarded.
    ObjectName
    getObjectName()
    The name of the MBean within the MBean server to which methods are forwarded.
    Object
    invoke(Object proxy, Method method, Object[] args)
    Processes a method invocation on a proxy instance and returns the result.
    boolean
    isMXBean()
    If true, the proxy is for an MXBean, and appropriate mappings are applied to method parameters and return values.
    static <T> T
    newProxyInstance(MBeanServerConnection connection, ObjectName objectName, Class<T> interfaceClass, boolean notificationBroadcaster)
    Return a proxy that implements the given interface by forwarding its methods through the given MBean server to the named MBean.

    Methods declared in class Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
    Modifier and Type
    Method
    Description
    protected Object
    clone()
    Answers a new instance of the same class as the receiver, whose slots have been filled in with the values in the slots of the receiver.
    boolean
    equals(Object o)
    Compares the argument to the receiver, and answers true if they represent the same object using a class specific comparison.
    protected void
    finalize()
    Deprecated, for removal: This API element is subject to removal in a future version.
    May cause performance issues, deadlocks and hangs.
    final Class<? extends Object>
    getClass()
    Answers the unique instance of java.lang.Class which represents the class of the receiver.
    int
    hashCode()
    Answers an integer hash code for the receiver.
    final void
    notify()
    Causes one thread which is waiting on the receiver to be made ready to run.
    final void
    notifyAll()
    Causes all threads which are waiting on the receiver to be made ready to run.
    String
    toString()
    Answers a string containing a concise, human-readable description of the receiver.
    final void
    wait()
    Causes the thread which sent this message to be made not ready to run pending some change in the receiver (as indicated by notify or notifyAll).
    final void
    wait(long time)
    Causes the thread which sent this message to be made not ready to run either pending some change in the receiver (as indicated by notify or notifyAll) or the expiration of the timeout.
    final void
    wait(long time, int frac)
    Causes the thread which sent this message to be made not ready to run either pending some change in the receiver (as indicated by notify or notifyAll) or the expiration of the timeout.

  • Constructor Details

    • MBeanServerInvocationHandler

      public MBeanServerInvocationHandler(MBeanServerConnection connection, ObjectName objectName)

      Invocation handler that forwards methods through an MBean server to a Standard MBean. This constructor may be called instead of relying on JMX.newMBeanProxy, for instance if you need to supply a different ClassLoader to Proxy.newProxyInstance.

      This constructor is not appropriate for an MXBean. Use MBeanServerInvocationHandler(MBeanServerConnection, ObjectName, boolean) for that. This constructor is equivalent to new MBeanServerInvocationHandler(connection, objectName, false).

      Parameters:
      connection - the MBean server connection through which all methods of a proxy using this handler will be forwarded.
      objectName - the name of the MBean within the MBean server to which methods will be forwarded.

    • MBeanServerInvocationHandler

      public MBeanServerInvocationHandler(MBeanServerConnection connection, ObjectName objectName, boolean isMXBean)

      Invocation handler that can forward methods through an MBean server to a Standard MBean or MXBean. This constructor may be called instead of relying on JMX.newMXBeanProxy, for instance if you need to supply a different ClassLoader to Proxy.newProxyInstance.

      Parameters:
      connection - the MBean server connection through which all methods of a proxy using this handler will be forwarded.
      objectName - the name of the MBean within the MBean server to which methods will be forwarded.
      isMXBean - if true, the proxy is for an MXBean, and appropriate mappings will be applied to method parameters and return values.
      Since:
      1.6

  • Method Details

    • getMBeanServerConnection

      public MBeanServerConnection getMBeanServerConnection()

      The MBean server connection through which the methods of a proxy using this handler are forwarded.

      Returns:
      the MBean server connection.
      Since:
      1.6

    • getObjectName

      public ObjectName getObjectName()

      The name of the MBean within the MBean server to which methods are forwarded.

      Returns:
      the object name.
      Since:
      1.6

    • isMXBean

      public boolean isMXBean()

      If true, the proxy is for an MXBean, and appropriate mappings are applied to method parameters and return values.

      Returns:
      whether the proxy is for an MXBean.
      Since:
      1.6

    • newProxyInstance

      public static <T> T newProxyInstance(MBeanServerConnection connection, ObjectName objectName, Class<T> interfaceClass, boolean notificationBroadcaster)

      Return a proxy that implements the given interface by forwarding its methods through the given MBean server to the named MBean. As of 1.6, the methods JMX.newMBeanProxy(MBeanServerConnection, ObjectName, Class) and JMX.newMBeanProxy(MBeanServerConnection, ObjectName, Class, boolean) are preferred to this method.

      This method is equivalent to Proxy.newProxyInstance(interfaceClass.getClassLoader(), interfaces, handler). Here handler is the result of new MBeanServerInvocationHandler(connection, objectName), and interfaces is an array that has one element if notificationBroadcaster is false and two if it is true. The first element of interfaces is interfaceClass and the second, if present, is NotificationEmitter.class.

      Type Parameters:
      T - allows the compiler to know that if the interfaceClass parameter is MyMBean.class, for example, then the return type is MyMBean.
      Parameters:
      connection - the MBean server to forward to.
      objectName - the name of the MBean within connection to forward to.
      interfaceClass - the management interface that the MBean exports, which will also be implemented by the returned proxy.
      notificationBroadcaster - make the returned proxy implement NotificationEmitter by forwarding its methods via connection. A call to NotificationBroadcaster.addNotificationListener(NotificationListener, NotificationFilter, Object) on the proxy will result in a call to MBeanServerConnection.addNotificationListener(ObjectName, NotificationListener, NotificationFilter, Object), and likewise for the other methods of NotificationBroadcaster and NotificationEmitter.
      Returns:
      the new proxy instance.
      See Also:

    • invoke

      public Object invoke(Object proxy, Method method, Object[] args) throws Throwable
      Description copied from interface: InvocationHandler
      Processes a method invocation on a proxy instance and returns the result. This method will be invoked on an invocation handler when a method is invoked on a proxy instance that it is associated with.
      Specified by:
      invoke in interface InvocationHandler
      Parameters:
      proxy - the proxy instance that the method was invoked on
      method - the Method instance corresponding to the method invoked on the proxy instance; the declaring class of the Method object may be a proxy interface, one of their superinterfaces, or the Object class
      args - an array of objects containing the values of the arguments passed in the method invocation on the proxy instance, or null if the invoked method takes no arguments. Arguments of primitive types are wrapped in instances of the appropriate primitive wrapper class, such as java.lang.Integer or java.lang.Boolean.
      Returns:
      the value to return from the method invocation on the proxy instance. If the declared return type of the invoked method is a primitive type, then the value returned by this method must be an instance of the corresponding primitive wrapper class; otherwise, it must be a type assignable to the declared return type. If the value returned by this method is null and the invoked method's return type is primitive, then a NullPointerException will be thrown by the method invocation on the proxy instance. If the value returned by this method is otherwise not compatible with the invoked method's declared return type as described above, a ClassCastException will be thrown by the method invocation on the proxy instance.
      Throws:
      Throwable - the exception to throw from the method invocation on the proxy instance. The exception's type must be assignable either to any of the exception types declared in the throws clause of the invoked method or to the unchecked exception types java.lang.RuntimeException or java.lang.Error. If a checked exception is thrown by this method that is not assignable to any of the exception types declared in the throws clause of the invoked method, then an UndeclaredThrowableException containing the exception that was thrown by this method will be thrown by the method invocation on the proxy instance.
      See Also: