com.googlecode.jinahya.commons.codec.EncoderProxy Maven / Gradle / Ivy
/*
* Copyright 2012 Jin Kwon .
*
* Licensed 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 com.googlecode.jinahya.commons.codec;
import java.lang.reflect.Constructor;
import java.lang.reflect.InvocationHandler;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.lang.reflect.Proxy;
/**
*
* @author Jin Kwon
* @param encoder(delegate) type parameter
*/
public abstract class EncoderProxy implements InvocationHandler {
/**
* Class for {@code org.apache.commons.codec.Encoder}.
*/
private static final Class ENCODER;
static {
try {
ENCODER = Class.forName("org.apache.commons.codec.Encoder");
} catch (ClassNotFoundException cnfe) {
throw new InstantiationError(cnfe.getMessage());
}
}
/**
* Method for {@code encode(Ljava/lang/Object;)Ljava/lang/Object;}
*/
private static final Method ENCODE;
static {
try {
ENCODE = ENCODER.getMethod("encode", Object.class);
} catch (NoSuchMethodException nsme) {
throw new InstantiationError(nsme.getMessage());
}
}
/**
* Class for {@code org.apache.commons.codec.EncoderException}.
*/
protected static final Class ENCODER_EXCEPTION;
static {
try {
ENCODER_EXCEPTION = Class.forName(
"org.apache.commons.codec.EncoderException").
asSubclass(Throwable.class);
} catch (ClassNotFoundException cnfe) {
throw new InstantiationError(cnfe.getMessage());
}
}
protected static Throwable newEncoderException()
throws InstantiationException, IllegalAccessException {
return ENCODER_EXCEPTION.newInstance();
}
protected static Throwable newEncoderException(final String message)
throws NoSuchMethodException, InstantiationException,
IllegalAccessException, InvocationTargetException {
return ENCODER_EXCEPTION
.getConstructor(String.class)
.newInstance(message);
}
protected static Throwable newEncoderException(final String message,
final Throwable cause)
throws NoSuchMethodException, InstantiationException,
IllegalAccessException, InvocationTargetException {
return ENCODER_EXCEPTION
.getConstructor(String.class, Throwable.class)
.newInstance(message, cause);
}
protected static Throwable newEncoderException(final Throwable cause)
throws NoSuchMethodException, InstantiationException,
IllegalAccessException, InvocationTargetException {
return ENCODER_EXCEPTION
.getConstructor(Throwable.class)
.newInstance(cause);
}
static , E> Object newInstance(
final ClassLoader loader, final Class[] interfaces,
final Class
proxyType, final Class encoderType, final E encoder) {
if (loader == null) {
throw new NullPointerException("loader");
}
if (interfaces == null) {
throw new NullPointerException("interfaces");
}
if (proxyType == null) {
throw new NullPointerException("proxyType");
}
if (encoderType == null) {
throw new NullPointerException("encoderType");
}
if (encoder == null) {
// ok
}
try {
final Constructor constructor =
proxyType.getDeclaredConstructor(encoderType);
if (!constructor.isAccessible()) {
constructor.setAccessible(true);
}
try {
return Proxy.newProxyInstance(loader, interfaces,
constructor.newInstance(encoder));
} catch (IllegalAccessException iae) {
throw new RuntimeException(iae);
} catch (InstantiationException ie) {
throw new RuntimeException(ie);
} catch (InvocationTargetException ite) {
throw new RuntimeException(ite);
}
} catch (NoSuchMethodException nsme) {
throw new RuntimeException(nsme);
}
}
/**
* Creates a new proxy instance for
* {@code org.apache.commons.codec.Encoder}.
*
* @param
proxy type parameter
* @param encoder type parameter
* @param proxyType proxy type
* @param encoderType encoder type
* @param encoder encoder instance
*
* @return
*
* @throws NoSuchMethodException
* @throws InstantiationException
* @throws IllegalAccessException
* @throws InvocationTargetException
*/
protected static , E> Object newInstance(
final Class
proxyType, final Class encoderType, final E encoder) {
return newInstance(ENCODER.getClassLoader(), new Class[]{ENCODER},
proxyType, encoderType, encoder);
}
/**
* Creates a new instance.
*
* @param encoder the delegate
*/
protected EncoderProxy(final E encoder) {
super();
// if (encoder == null) {
// throw new NullPointerException("null encoder");
// }
this.encoder = encoder;
}
@Override
public Object invoke(final Object proxy, final Method method,
final Object[] args)
throws Throwable {
if (ENCODE.equals(method)) {
return encode(encoder, args[0]);
}
throw new UnsupportedOperationException("unsupported: " + method);
}
protected abstract Object encode(final E encoder, final Object source)
throws Throwable;
/**
* encoder instance.
*/
protected final E encoder;
}