Class CompositeDataInvocationHandler
- java.lang.Object
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- javax.management.openmbean.CompositeDataInvocationHandler
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- All Implemented Interfaces:
- InvocationHandler
public class CompositeDataInvocationHandler extends Object implements InvocationHandler
An
InvocationHandlerthat forwards getter methods to aCompositeData. If you have an interface that contains only getter methods (such asString getName()orboolean isActive()) then you can use this class in conjunction with theProxyclass to produce an implementation of the interface where each getter returns the value of the corresponding item in aCompositeData.For example, suppose you have an interface like this:
and apublic interface NamedNumber { public int getNumber(); public String getName(); }CompositeDataconstructed like this:
then you can construct an object implementingCompositeData cd = newCompositeDataSupport( someCompositeType, new String[] {"number", "name"}, new Object[] {5, "five"} );NamedNumberand backed by the objectcdlike this:
A call toInvocationHandler handler = new CompositeDataInvocationHandler(cd); NamedNumber nn = (NamedNumber) Proxy.newProxyInstance(NamedNumber.class.getClassLoader(), new Class[] {NamedNumber.class}, handler);nn.getNumber()will then return 5.If the first letter of the property defined by a getter is a capital, then this handler will look first for an item in the
CompositeDatabeginning with a capital, then, if that is not found, for an item beginning with the corresponding lowercase letter or code point. For a getter calledgetNumber(), the handler will first look for an item calledNumber, then fornumber. If the getter is calledgetnumber(), then the item must be callednumber.If the method given to
invokeis the methodboolean equals(Object)inherited fromObject, then it will return true if and only if the argument is aProxywhoseInvocationHandleris also aCompositeDataInvocationHandlerand whose backingCompositeDatais equal (not necessarily identical) to this object's. If the method given toinvokeis the methodint hashCode()inherited fromObject, then it will return a value that is consistent with this definition ofequals: if two objects are equal according toequals, then they will have the samehashCode.- Since:
- 1.6
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Constructor Summary
Constructors Constructor and Description CompositeDataInvocationHandler(CompositeData compositeData)Construct a handler backed by the givenCompositeData.
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method and Description CompositeDatagetCompositeData()Return theCompositeDatathat was supplied to the constructor.Objectinvoke(Object proxy, Method method, Object[] args)Processes a method invocation on a proxy instance and returns the result.
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Constructor Detail
CompositeDataInvocationHandler
public CompositeDataInvocationHandler(CompositeData compositeData)
Construct a handler backed by the given
CompositeData.- Parameters:
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compositeData- theCompositeDatathat will supply information to getters. - Throws:
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IllegalArgumentException- ifcompositeDatais null.
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Method Detail
getCompositeData
public CompositeData getCompositeData()
Return theCompositeDatathat was supplied to the constructor.- Returns:
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the
CompositeDatathat this handler is backed by. This is never null.
invoke
public Object invoke(Object proxy, Method method, Object[] args) throws Throwable
Description copied from interface:InvocationHandlerProcesses 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:
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invokein interfaceInvocationHandler - Parameters:
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proxy- the proxy instance that the method was invoked on -
method- theMethodinstance corresponding to the interface method invoked on the proxy instance. The declaring class of theMethodobject will be the interface that the method was declared in, which may be a superinterface of the proxy interface that the proxy class inherits the method through. -
args- an array of objects containing the values of the arguments passed in the method invocation on the proxy instance, ornullif interface method takes no arguments. Arguments of primitive types are wrapped in instances of the appropriate primitive wrapper class, such asjava.lang.Integerorjava.lang.Boolean. - Returns:
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the value to return from the method invocation on the proxy instance. If the declared return type of the interface 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
nulland the interface method's return type is primitive, then aNullPointerExceptionwill be thrown by the method invocation on the proxy instance. If the value returned by this method is otherwise not compatible with the interface method's declared return type as described above, aClassCastExceptionwill be thrown by the method invocation on the proxy instance. - Throws:
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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 thethrowsclause of the interface method or to the unchecked exception typesjava.lang.RuntimeExceptionorjava.lang.Error. If a checked exception is thrown by this method that is not assignable to any of the exception types declared in thethrowsclause of the interface method, then anUndeclaredThrowableExceptioncontaining the exception that was thrown by this method will be thrown by the method invocation on the proxy instance. - See Also:
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UndeclaredThrowableException
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