org.apache.river.proxy

Class ConstrainableProxyUtil

java.lang.Object

org.apache.river.proxy.ConstrainableProxyUtil

public class ConstrainableProxyUtil
extends Object

A collection of utility methods for use in implementing constrainable proxies. This class cannot be instantiated.

Since:

2.0

Author:

Sun Microsystems, Inc.

Method Summary

Modifier and Type	Method and Description
static boolean	equivalentConstraints(MethodConstraints methodConstraints1, MethodConstraints methodConstraints2, Method[] mappings) Test to see if two MethodConstraints instances are equivalent given a method-to-method mapping.
static MethodConstraints	translateConstraints(MethodConstraints methodConstraints, Method[] mappings) Creates a MethodConstraints using the constraints in methodConstraints, but with the methods remapped according to mappings, where the first element of each pair of elements is mapped to the second.
static void	verifyConsistentConstraints(MethodConstraints methodConstraints, Object proxy, Method[] mappings) Verify that an object, proxy, is an instance of RemoteMethodControl its MethodConstraints are equivalent to another MethodConstraints instance, methodConstraints once a mapping has been applied.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

translateConstraints

public static MethodConstraints translateConstraints(MethodConstraints methodConstraints,
                                                     Method[] mappings)

Creates a MethodConstraints using the constraints in methodConstraints, but with the methods remapped according to mappings, where the first element of each pair of elements is mapped to the second. For example, if methodConstraints returns constraints C1 for method M1, and the elements of mappings are methods M1 and M2, then the resulting method constraints return C1 for method M2.

Parameters:

methodConstraints - the method constraints whose methods should be translated, or null for empty constraints

mappings - the method mappings

Returns:

the translated method constraints

Throws:

NullPointerException - if mappings is null or contains null elements

IllegalArgumentException - if mappings contains an odd number of elements

equivalentConstraints

public static boolean equivalentConstraints(MethodConstraints methodConstraints1,
                                            MethodConstraints methodConstraints2,
                                            Method[] mappings)

Test to see if two MethodConstraints instances are equivalent given a method-to-method mapping. Only the constraints for methods that appear in the mapping are compared. The mapping is represented by an array, mappings, of 2n Method objects. For all values p less than n the constraints associated with mappings[2p] in methodConstraints1 are compared to the constraints associated with mappings[2p+1] in methodConstraints2. If null is passed in for both instances they are considered equivalent.

Parameters:

methodConstraints1 - the first MethodConstraints object to compare.

methodConstraints2 - the second MethodConstraints object to compare.

mappings - the method-to-method mapping.

Returns:

true if the MethodConstraints instances represent equivalent constraints, returns false otherwise.

Throws:

NullPointerException - if mapping is null contains null elements.

IllegalArgumentException - if mapping contains an odd number of elements

verifyConsistentConstraints

public static void verifyConsistentConstraints(MethodConstraints methodConstraints,
                                               Object proxy,
                                               Method[] mappings)
                                        throws InvalidObjectException

Verify that an object, proxy, is an instance of RemoteMethodControl its MethodConstraints are equivalent to another MethodConstraints instance, methodConstraints once a mapping has been applied. If proxy does not implement RemoteMethodControl or the associated constraints are not equivalent throw an InvalidObjectException. The mapping is represented by an array, mappings, of 2n Method objects. For all values p less than n the constraints associated with mappings[2p] in methodConstraints are compared to the constraints associated with mappings[2p+1] in the MethodConstraints returned by proxy.getConstraints. Will also return normally if both methodConstraints and the value returned by proxy.getConstraints are null.

Parameters:

methodConstraints - the method constraints proxy should have.

proxy - the proxy to test, must implement RemoteMethodControl.

mappings - the method to method mapping

Throws:

NullPointerException - if mappings or proxy is null or if mapping contains null elements

IllegalArgumentException - if mappings contains an odd number of elements

InvalidObjectException - if proxy does not implement RemoteMethodControl, or if the constraints on proxy are not equivalent to methodConstraints.