代理类的用法

package chapter6;

import java.lang.reflect.*;
import java.util.*;

public class ProxyTest {
    public static void main(String[] args) {
        var elements = new Object[1000];
        for (int i = 0; i < elements.length; i++) {
            Integer value = i + 1;
            var handler = new TraceHandler(value);
            Object proxy = Proxy.newProxyInstance(
                    ClassLoader.getSystemClassLoader(),
                    new Class[]{Comparable.class}, handler);
            elements[i] = proxy;
        }
        Integer key = new Random().nextInt(elements.length) + 1;

        int result = Arrays.binarySearch(elements, key);

        if (result >=0) System.out.println(elements[result]);
    }
}
class TraceHandler implements InvocationHandler
{
    private Object target;

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

    public Object invoke(Object proxy, Method m,Object[] args) throws Throwable
    {
        System.out.print(target);
// print method name
        System.out.print("." +m.getName() + "(");
// print explicit arguments
        if (args != null)
        {
            for (int i = 0; i <args.length; i++)
            {
                System.out.print(args[i]);
                if (i < args.length - 1) {
                    System.out.print(", ");
                }
            }
        }
        System.out.println(")");
        return m.invoke(target, args);
    }
}

输出结果如下：