1、定义
代理模式：为其他对象提供一种代理以控制对这个对象访问
写法
公共部分
public interface ILawsuit {
//提交申请
void submit();
//举证
void burden();
//辩护
void defend();
//诉讼完成
void finish();
}
public class XiaoMin implements ILawsuit {
@Override
public void submit() {
//小民申请仲裁
System.out.println( "老板年底拖欠工资，特此申请仲裁！" );
}
@Override
public void burden() {
//小民提交证据
System.out.println( "这是合同书和过去一年的银行工资流水！" );
}
@Override
public void defend() {
//铁证如山
System.out.println( "证据确凿，不需要再说什么！" );
}
@Override
public void finish() {
//结果
System.out.println( "诉讼成功，判决老板即日起七天内结算工资！" );
}
}
1、静态代理
/**
* 代理类
*/
public class Lawyer implements ILawsuit {
private ILawsuit mLawsuit;
public Lawyer(ILawsuit mLawsuit) {
this.mLawsuit = mLawsuit;
}
@Override
public void submit() {
}
@Override
public void burden() {
}
@Override
public void defend() {
}
@Override
public void finish() {
}
}
public class TestMain {
public static void main(String[] args) {
ILawsuit xiaomin = new XiaoMin();
//静态代理
ILawsuit lawyer = new Lawyer( xiaomin );
lawyer.submit();
lawyer.burden();
lawyer.defend();
lawyer.finish();
}
}
2、动态代理
公共部分
public class DynamicProxy implements InvocationHandler {
private Object obj;
public DynamicProxy(Object obj) {
this.obj = obj;
}
@Override
public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
Object result = method.invoke( obj,args );
return result;
}
}
例子1
public class TestMain {
public static void main(String[] args) {
ILawsuit xiaomin = new XiaoMin();
//动态代理
DynamicProxy proxy = new DynamicProxy( xiaomin );
//获取小民的classLoader
ClassLoader loader = xiaomin.getClass().getClassLoader();
//动态代理一个代理律师
ILawsuit lawyer = (ILawsuit) Proxy.newProxyInstance( loader, new Class[]{ILawsuit.class}, proxy );
lawyer.submit();
lawyer.burden();
lawyer.defend();
lawyer.finish();
}
}
2、优化封装
public class SubjectProxy<T> {
//获得动态实例
public T newInstance(Object obj) {
DynamicProxy proxy = new DynamicProxy( obj );
ClassLoader loader = obj.getClass().getClassLoader();
Class superclazz = getSuperclass();
return (T) Proxy.newProxyInstance( loader, new Class[]{superclazz}, proxy );
}
//Java 得到泛型中得到T.class
private Class getSuperclass() {
return (Class<T>) ((ParameterizedType) getClass().getGenericSuperclass()).getActualTypeArguments()[0];
}
}
public class TestMain {
//为其他对象提供一种代理以控制对这个对象的访问
public static void main(String[] args) {
ILawsuit xiaomin = new XiaoMin();
SubjectProxy<ILawsuit> subjectProxy = new SubjectProxy<ILawsuit>();
ILawsuit lawyer = subjectProxy.newInstance( xiaomin );
lawyer.submit();
lawyer.burden();
lawyer.defend();
lawyer.finish();
}
}
