[Java] Class ConversionHandler

public abstract class ConversionHandler
extends Object
implements InvocationHandler, Serializable

Constructor Detail

public ConversionHandler(Object delegate)

Creates a ConversionHandler with an delegate.

throws:

IllegalArgumentException if the given delegate is null

Parameters:

delegate - the delegate

Method Detail

protected boolean checkMethod(Method method)

public boolean equals(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:

Object.equals

public Object getDelegate()

Returns the delegate.

Returns:

the delegate

public int hashCode()

Returns a hash code value for the delegate.

See Also:

Object.hashCode

public Object invoke(Object proxy, Method method, 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() and default methods 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. Interface default methods from Java 8 on the other hand are considered being default implementations you don't normally want to change. So they are called directly too

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[])

public abstract Object invokeCustom(Object proxy, Method method, 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[])

public static boolean isCoreObjectMethod(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

protected boolean isDefaultMethod(Method method)

public String toString()

Returns a String version of the delegate.

See Also:

Object.toString