java:代理测试

package nlpr.mmc.v1ch06.ProxyTest;

import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Method;
import java.lang.reflect.Proxy;
import java.util.Arrays;
import java.util.Random;

public class ProxyTest {

public static void main(String[] args) {
// TODO Auto-generated method stub

Object[] elements = new Object[1000];

// fill elements with proxies for the integers 1 ... 1000
for (int i = 0; i < elements.length; i++)
{
Integer value = i + 1;
InvocationHandler handler = new TraceHandler(value);
Object proxy = Proxy.newProxyInstance(null, new Class[] { Comparable.class } , handler);
elements[i] = proxy;
}

// construct a random integer
Integer key = new Random().nextInt(elements.length) + 1;

// search for the key
int result = Arrays.binarySearch(elements, key);

// print match if found
if (result >= 0) System.out.println(elements[result]);

}

}

/**
* An invocation handler that prints out the method name and parameters, then
* invokes the original method
*/
class TraceHandler implements InvocationHandler {

public TraceHandler(Object o){
target = o;
}

@Override
public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
// TODO Auto-generated method stub
// print implicit argument
System.out.print(target);
// print method name
System.out.print("." + method.getName() + "(");
// print explicit arguments
if (args != null){
for(int i=0; i<args.length;i++){
if(i>0) System.out.print(", ");
System.out.print(args[i]);
}
}
System.out.println(")");

return method.invoke(target, args);
}

private Object target;
}