SelectingMethods.java

package ch14reflect;//: ch15generic.typeinfo/SelectingMethods.java
// Looking for particular methods in a dynamic proxy.

import java.lang.reflect.*;

import static net.mindview.util.Print.*;

class MethodSelector implements InvocationHandler {
    private Object proxied;

    public MethodSelector(Object proxied) {
        this.proxied = proxied;
    }

    public Object invoke(Object proxy, Method method, Object[] args)
            throws Throwable {
        if (method.getName().equals("interesting"))
            print("Proxy detected the interesting method");
        return method.invoke(proxied, args);
    }
}

interface SomeMethods {
    void boring1();

    void boring2();

    void interesting(String arg);

    void boring3();
}

class Implementation implements SomeMethods {
    public void boring1() {
        print("boring1");
    }

    public void boring2() {
        print("boring2");
    }

    public void interesting(String arg) {
        print("interesting " + arg);
    }

    public void boring3() {
        print("boring3");
    }
}

/**
 * Java中的动态代理，选择方法
 */
public class SelectingMethods {

    /**
     * 选择方法的动态代理
     */
    public void selectMethods() {
        SomeMethods proxy = (SomeMethods) Proxy.newProxyInstance(
                SomeMethods.class.getClassLoader(),
                new Class[]{SomeMethods.class}, new MethodSelector(
                        new Implementation()));
        proxy.boring1();
        proxy.boring2();
        proxy.interesting("bonobo");
        proxy.boring3();
    }
} /*
 * Output: boring1 boring2 Proxy detected the interesting method interesting
 * bonobo boring3
 */// :~