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2010-06-01T07:00:14Z

1 версия

в 18:01, 31 мая 2010

2010-05-31T18:01:46Z

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== Demonstrates a dangerous use of proxy names ==



<source lang="java">
/*
$Proxy0
$Proxy0
*/
import java.lang.reflect.InvocationHandler;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.lang.reflect.Proxy;
/*
*
* This software is granted under the terms of the Common Public License,
* CPL, which may be found at the following URL:
* http://www-124.ibm.ru/developerworks/oss/CPLv1.0.htm
*
* Copyright(c) 2003-2005 by the authors indicated in the @author tags.
* All Rights are Reserved by the various authors.
*
########## DO NOT EDIT ABOVE THIS LINE ########## */
/**
* Demonstrates a dangerous use of proxy names.
*
* <p>
* According to the JDK, the unqualified name of a proxy class is undefined so using it
* in code like this could cause you grief.
* </p>
*
* @author
* @version $Revision: 1.2 $
*
* @see java.lang.reflect.InvocationHandler
*/
class MethodCountingHandler implements InvocationHandler {
/** The implementation object for this proxy. */
private final Object impl;
/** Holds the invocation count. */
private int invocationCount = 0;
/**
* Creates a new MethodCOuntingHandler object.
*
* @param impl
*/
public MethodCountingHandler(final Object impl) {
this.impl = impl;
}
/**
* Gets the value of the property invocationCount.
*
* @return The current value of invocationCount
*/
public int getInvocationCount() {
return invocationCount;
}
/**
* @see java.lang.reflect.InvocationHandler#invoke(java.lang.Object,
* java.lang.reflect.Method, java.lang.Object[])
*/
public Object invoke(Object proxy, Method meth, Object[] args) throws Throwable {
try {
this.invocationCount++;
Object result = meth.invoke(impl, args);
return result;
} catch (final InvocationTargetException ex) {
throw ex.getTargetException();
}
}
}

</source>



== Demonstrates a dynamic proxy ==



<source lang="java">
/*
joeyin
Our Proxy works!
2
*/

/*
*
* This software is granted under the terms of the Common Public License,
* CPL, which may be found at the following URL:
* http://www-124.ibm.ru/developerworks/oss/CPLv1.0.htm
*
* Copyright(c) 2003-2005 by the authors indicated in the @author tags.
* All Rights are Reserved by the various authors.
*
########## DO NOT EDIT ABOVE THIS LINE ########## */
import java.lang.reflect.InvocationHandler;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.lang.reflect.Proxy;
import java.util.logging.Logger;
/**
* Demonstrates a dynamic proxy.
*
* @author
* @version $Revision: 1.2 $
*
* @see java.lang.reflect.InvocationHandler
*/
class MethodCountingHandler implements InvocationHandler {
/** The implementation object for this proxy. */
private final Object impl;
/** Holds the invocation count. */
private int invocationCount = 0;
/**
* Creates a new MethodCOuntingHandler object.
*
* @param impl
*/
public MethodCountingHandler(final Object impl) {
this.impl = impl;
}
/**
* Gets the value of the property invocationCount.
*
* @return The current value of invocationCount
*/
public int getInvocationCount() {
return invocationCount;
}
/**
* @see java.lang.reflect.InvocationHandler#invoke(java.lang.Object,
* java.lang.reflect.Method, java.lang.Object[])
*/
public Object invoke(Object proxy, Method meth, Object[] args) throws Throwable {
try {
this.invocationCount++;
Object result = meth.invoke(impl, args);
return result;
} catch (final InvocationTargetException ex) {
throw ex.getTargetException();
}
}
}

</source>



== Demonstrates the basic concept of proxies generated by clients to the proxies ==



<source lang="java">
/*
Fred
Our Proxy works!
*/
import java.lang.reflect.InvocationHandler;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.lang.reflect.Proxy;
/*
*
* This software is granted under the terms of the Common Public License,
* CPL, which may be found at the following URL:
* http://www-124.ibm.ru/developerworks/oss/CPLv1.0.htm
*
* Copyright(c) 2003-2005 by the authors indicated in the @author tags.
* All Rights are Reserved by the various authors.
*
########## DO NOT EDIT ABOVE THIS LINE ########## */
/**
* Demonstrates the basic concept of proxies generated by clients to the proxies.
*
* @author
* @version $Revision: 1.2 $
*
* @see java.lang.reflect.InvocationHandler
*/
class MethodCountingHandler implements InvocationHandler {
/** The implementation object for this proxy. */
private final Object impl;
/** Holds the invocation count. */
private int invocationCount = 0;
/**
* Creates a new MethodCOuntingHandler object.
*
* @param impl
*/
public MethodCountingHandler(final Object impl) {
this.impl = impl;
}
/**
* Gets the value of the property invocationCount.
*
* @return The current value of invocationCount
*/
public int getInvocationCount() {
return invocationCount;
}
/**
* @see java.lang.reflect.InvocationHandler#invoke(java.lang.Object,
* java.lang.reflect.Method, java.lang.Object[])
*/
public Object invoke(Object proxy, Method meth, Object[] args) throws Throwable {
try {
this.invocationCount++;
Object result = meth.invoke(impl, args);
return result;
} catch (final InvocationTargetException ex) {
throw ex.getTargetException();
}
}
}

</source>



== Demonstrates the usage of a counting proxy ==



<source lang="java">

/*
joeyin
Our Proxy works!
Method Invocation Count = 2
*/
import java.lang.reflect.InvocationHandler;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.lang.reflect.Proxy;
/**
* Demonstrates the usage of a counting proxy.
*
* @author
* @version $Revision: 1.2 $
*
* @see java.lang.reflect.InvocationHandler
*/
class MethodCountingHandler implements InvocationHandler {
/** The implementation object for this proxy. */
private final Object impl;
/** Holds the invocation count. */
private int invocationCount = 0;
/**
* Creates a new MethodCOuntingHandler object.
*
* @param impl
*/
public MethodCountingHandler(final Object impl) {
this.impl = impl;
}
/**
* Gets the value of the property invocationCount.
*
* @return The current value of invocationCount
*/
public int getInvocationCount() {
return invocationCount;
}
/**
* @see java.lang.reflect.InvocationHandler#invoke(java.lang.Object,
* java.lang.reflect.Method, java.lang.Object[])
*/
public Object invoke(Object proxy, Method meth, Object[] args) throws Throwable {
try {
this.invocationCount++;
Object result = meth.invoke(impl, args);
return result;
} catch (final InvocationTargetException ex) {
throw ex.getTargetException();
}
}
}

</source>



== Demonstrates the use of factories to generate proxies ==



<source lang="java">
/*
joeyin
Our Proxy works!
*/
import java.lang.reflect.InvocationHandler;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.lang.reflect.Proxy;
/*
*
* This software is granted under the terms of the Common Public License,
* CPL, which may be found at the following URL:
* http://www-124.ibm.ru/developerworks/oss/CPLv1.0.htm
*
* Copyright(c) 2003-2005 by the authors indicated in the @author tags.
* All Rights are Reserved by the various authors.
*
########## DO NOT EDIT ABOVE THIS LINE ########## */
/**
* Demonstrates the use of factories to generate proxies.
*
* @author
* @version $Revision: 1.2 $
*
* @see java.lang.reflect.InvocationHandler
*/
class MethodCountingHandler implements InvocationHandler {
/** The implementation object for this proxy. */
private final Object impl;
/** Holds the invocation count. */
private int invocationCount = 0;
/**
* Creates a new MethodCOuntingHandler object.
*
* @param impl
*/
public MethodCountingHandler(final Object impl) {
this.impl = impl;
}
/**
* Gets the value of the property invocationCount.
*
* @return The current value of invocationCount
*/
public int getInvocationCount() {
return invocationCount;
}
/**
* @see java.lang.reflect.InvocationHandler#invoke(java.lang.Object,
* java.lang.reflect.Method, java.lang.Object[])
*/
public Object invoke(Object proxy, Method meth, Object[] args) throws Throwable {
try {
this.invocationCount++;
Object result = meth.invoke(impl, args);
return result;
} catch (final InvocationTargetException ex) {
throw ex.getTargetException();
}
}
}

</source>



== Demonstrates the use of interface based proxies ==



<source lang="java">
/*
joeyin
Our Proxy works!
*/
import java.lang.reflect.InvocationHandler;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.lang.reflect.Proxy;
/*
*
* This software is granted under the terms of the Common Public License,
* CPL, which may be found at the following URL:
* http://www-124.ibm.ru/developerworks/oss/CPLv1.0.htm
*
* Copyright(c) 2003-2005 by the authors indicated in the @author tags.
* All Rights are Reserved by the various authors.
*
########## DO NOT EDIT ABOVE THIS LINE ########## */
/**
* Demonstrates the use of interface based proxies.
*
* @author
* @version $Revision: 1.2 $
*
* @see java.lang.reflect.InvocationHandler
*/
class MethodCountingHandler implements InvocationHandler {
/** The implementation object for this proxy. */
private final Object impl;
/** Holds the invocation count. */
private int invocationCount = 0;
/**
* Creates a new MethodCOuntingHandler object.
*
* @param impl
*/
public MethodCountingHandler(final Object impl) {
this.impl = impl;
}
/**
* Gets the value of the property invocationCount.
*
* @return The current value of invocationCount
*/
public int getInvocationCount() {
return invocationCount;
}
/**
* @see java.lang.reflect.InvocationHandler#invoke(java.lang.Object,
* java.lang.reflect.Method, java.lang.Object[])
*/
public Object invoke(Object proxy, Method meth, Object[] args) throws Throwable {
try {
this.invocationCount++;
Object result = meth.invoke(impl, args);
return result;
} catch (final InvocationTargetException ex) {
throw ex.getTargetException();
}
}
}

</source>



== Dynamic Action Hookup Test ==



<source lang="java">
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.lang.reflect.Method;
import java.util.Hashtable;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
public class DynamicHookupTest extends JFrame {
DynamicActionAdapter actionAdapter = new DynamicActionAdapter();
JLabel label = new JLabel("Ready...", JLabel.CENTER);
int count;
public DynamicHookupTest() {
JButton launchButton = new JButton("Launch!");
getContentPane().add(launchButton, "South");
getContentPane().add(label, "Center");
actionAdapter.hookup(launchButton, this, "launchTheMissiles");
}
public void launchTheMissiles() {
label.setText("Launched: " + count++);
}
public static void main(String[] args) {
JFrame f = new DynamicHookupTest();
f.addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent we) {
System.exit(0);
}
});
f.setSize(150, 150);
f.setVisible(true);
}
}
class DynamicActionAdapter implements ActionListener {
Hashtable actions = new Hashtable();
public void hookup(Object sourceObject, Object targetObject, String targetMethod) {
actions.put(sourceObject, new Target(targetObject, targetMethod));
invokeReflectedMethod(sourceObject, "addActionListener", new Object[] { this },
new Class[] { ActionListener.class });
}
public void actionPerformed(ActionEvent e) {
Target target = (Target) actions.get(e.getSource());
if (target == null)
throw new RuntimeException("unknown source");
invokeReflectedMethod(target.object, target.methodName, null, null);
}
private void invokeReflectedMethod(Object target, String methodName, Object[] args,
Class[] argTypes) {
try {
Method method = target.getClass().getMethod(methodName, argTypes);
method.invoke(target, args);
} catch (Exception e) {
throw new RuntimeException("invocation problem: " + e);
}
}
class Target {
Object object;
String methodName;
Target(Object object, String methodName) {
this.object = object;
this.methodName = methodName;
}
}
}

</source>

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Admin: 1 версия

в 18:01, 31 мая 2010