Groovy Documentation

org.codehaus.groovy.runtime
[Java] Class ConversionHandler

java.lang.Object
  org.codehaus.groovy.runtime.ConversionHandler
All Implemented Interfaces:
java.lang.reflect.InvocationHandler, java.io.Serializable

public abstract class ConversionHandler
extends java.lang.Object

This class is a general adapter to map a call to a Java interface to a given delegate.

Authors:
Ben Yu
Jochen Theodorou


Constructor Summary
ConversionHandler(java.lang.Object delegate)

Creates a ConversionHandler with an delegate.

 
Method Summary
protected boolean checkMethod(java.lang.reflect.Method method)

boolean equals(java.lang.Object obj)

Indicates whether some other object is "equal to" this one.

java.lang.Object getDelegate()

Returns the delegate.

int hashCode()

Returns a hash code value for the delegate.

java.lang.Object invoke(java.lang.Object proxy, java.lang.reflect.Method method, java.lang.Object[] args)

This method is a default implementation for the invoke method given in InvocationHandler.

java.lang.Object invokeCustom(java.lang.Object proxy, java.lang.reflect.Method method, java.lang.Object[] args)

This method is called for all Methods not defined on Object.

static boolean isCoreObjectMethod(java.lang.reflect.Method method)

Checks whether a method is a core method from java.lang.Object.

java.lang.String toString()

Returns a String version of the delegate.

 
Methods inherited from class java.lang.Object
java.lang.Object#wait(long, int), java.lang.Object#wait(long), java.lang.Object#wait(), java.lang.Object#equals(java.lang.Object), java.lang.Object#toString(), java.lang.Object#hashCode(), java.lang.Object#getClass(), java.lang.Object#notify(), java.lang.Object#notifyAll()
 

Constructor Detail

ConversionHandler

public ConversionHandler(java.lang.Object delegate)
Creates a ConversionHandler with an delegate.
throws:
IllegalArgumentException if the given delegate is null
Parameters:
delegate - the delegate


 
Method Detail

checkMethod

protected boolean checkMethod(java.lang.reflect.Method method)


equals

public boolean equals(java.lang.Object obj)
Indicates whether some other object is "equal to" this one. The delegate is used if the class of the parameter and the current class are equal. In other cases the method will return false. The exact class is here used, if inheritance is needed, this method must be overwritten.
See Also:
java.lang.Object#equals(java.lang.Object)


getDelegate

public java.lang.Object getDelegate()
Returns the delegate.
Returns:
the delegate


hashCode

public int hashCode()
Returns a hash code value for the delegate.
See Also:
java.lang.Object#hashCode()


invoke

public java.lang.Object invoke(java.lang.Object proxy, java.lang.reflect.Method method, java.lang.Object[] args)
This method is a default implementation for the invoke method given in InvocationHandler. Any call to a method with a declaring class that is not Object, excluding toString(), is redirected to invokeCustom. Methods like equals and hashcode are called on the class itself instead of the delegate because they are considered fundamental methods that should not be overwritten. The toString() method gets special treatment as it is deemed to be a method that you might wish to override when called from Groovy.

In many scenarios, it is better to overwrite the invokeCustom method where the core Object related methods are filtered out.

throws:
Throwable if caused by the delegate or the method
Parameters:
proxy - the proxy
method - the method
args - the arguments
Returns:
the result of the invocation by method or delegate
See Also:
invokeCustom(Object, Method, Object[])
InvocationHandler#invoke(java.lang.Object, java.lang.reflect.Method, java.lang.Object[])


invokeCustom

public java.lang.Object invokeCustom(java.lang.Object proxy, java.lang.reflect.Method method, java.lang.Object[] args)
This method is called for all Methods not defined on Object. The delegate should be called here.
throws:
Throwable any exception causes by the delegate
Parameters:
proxy - the proxy
method - the method
args - the arguments
Returns:
the result of the invocation of the delegate
See Also:
invoke(Object, Method, Object[])
InvocationHandler#invoke(java.lang.Object, java.lang.reflect.Method, java.lang.Object[])


isCoreObjectMethod

public static boolean isCoreObjectMethod(java.lang.reflect.Method method)
Checks whether a method is a core method from java.lang.Object. Such methods often receive special treatment because they are deemed fundamental enough to not be tampered with.
Parameters:
method - the method to check
Returns:
true if the method is deemed to be a core method


toString

public java.lang.String toString()
Returns a String version of the delegate.
See Also:
java.lang.Object#toString()


 

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