/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.commons.proxy;
import org.apache.commons.proxy.invoker.NullInvoker;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.HashMap;
/**
* Provides some helpful proxy utility methods.
*
* @author James Carman
* @since 1.0
*/
public class ProxyUtils
{
//----------------------------------------------------------------------------------------------------------------------
// Fields
//----------------------------------------------------------------------------------------------------------------------
public static final Object[] EMPTY_ARGUMENTS = new Object[0];
public static final Class[] EMPTY_ARGUMENT_TYPES = new Class[0];
private static final Map wrapperClassMap = new HashMap();
//----------------------------------------------------------------------------------------------------------------------
// Static Methods
//----------------------------------------------------------------------------------------------------------------------
static
{
wrapperClassMap.put( Integer.TYPE, Integer.class );
wrapperClassMap.put( Character.TYPE, Character.class );
wrapperClassMap.put( Boolean.TYPE, Boolean.class );
wrapperClassMap.put( Short.TYPE, Short.class );
wrapperClassMap.put( Long.TYPE, Long.class );
wrapperClassMap.put( Float.TYPE, Float.class );
wrapperClassMap.put( Double.TYPE, Double.class );
wrapperClassMap.put( Byte.TYPE, Byte.class );
}
/**
* Creates a "null object" which implements the <code>proxyClasses</code>.
*
* @param proxyFactory the proxy factory to be used to create the proxy object
* @param proxyClasses the proxy interfaces
* @return a "null object" which implements the <code>proxyClasses</code>.
*/
public static Object createNullObject( ProxyFactory proxyFactory, Class[] proxyClasses )
{
return proxyFactory.createInvokerProxy( new NullInvoker(), proxyClasses );
}
/**
* Creates a "null object" which implements the <code>proxyClasses</code>.
*
* @param proxyFactory the proxy factory to be used to create the proxy object
* @param classLoader the class loader to be used by the proxy factory to create the proxy object
* @param proxyClasses the proxy interfaces
* @return a "null object" which implements the <code>proxyClasses</code>.
*/
public static Object createNullObject( ProxyFactory proxyFactory, ClassLoader classLoader, Class[] proxyClasses )
{
return proxyFactory.createInvokerProxy( classLoader, new NullInvoker(), proxyClasses );
}
/**
* <p>Gets an array of {@link Class} objects representing all interfaces implemented by the given class and its
* superclasses.</p>
* <p/>
* <p>The order is determined by looking through each interface in turn as declared in the source file and following
* its hierarchy up. Then each superclass is considered in the same way. Later duplicates are ignored, so the order
* is maintained.</p>
* <p/>
* <b>Note</b>: Implementation of this method was "borrowed" from
* <a href="http://commons.apache.org/lang/">Apache Commons Lang</a> to avoid a dependency.</p>
*
* @param cls the class to look up, may be <code>null</code>
* @return an array of {@link Class} objects representing all interfaces implemented by the given class and its
* superclasses or <code>null</code> if input class is null.
*/
public static Class[] getAllInterfaces( Class cls )
{
final List interfaces = getAllInterfacesImpl( cls, new LinkedList() );
return interfaces == null ? null : ( Class[] ) interfaces.toArray( new Class[interfaces.size()] );
}
private static List getAllInterfacesImpl( Class cls, List list )
{
if( cls == null )
{
return null;
}
while( cls != null )
{
Class[] interfaces = cls.getInterfaces();
for( int i = 0; i < interfaces.length; i++ )
{
if( !list.contains( interfaces[i] ) )
{
list.add( interfaces[i] );
}
getAllInterfacesImpl( interfaces[i], list );
}
cls = cls.getSuperclass();
}
return list;
}
/**
* Returns the class name as you would expect to see it in Java code.
* <p/>
* <b>Examples:</b> <ul> <li>getJavaClassName( Object[].class ) == "Object[]"</li> <li>getJavaClassName(
* Object[][].class ) == "Object[][]"</li> <li>getJavaClassName( Integer.TYPE ) == "int"</li> </p>
*
* @param clazz the class
* @return the class' name as you would expect to see it in Java code
*/
public static String getJavaClassName( Class clazz )
{
if( clazz.isArray() )
{
return getJavaClassName( clazz.getComponentType() ) + "[]";
}
return clazz.getName();
}
/**
* Returns the wrapper class for the given primitive type.
* @param primitiveType the primitive type
* @return the wrapper class
*/
public static Class getWrapperClass( Class primitiveType )
{
return ( Class )wrapperClassMap.get( primitiveType );
}
}