代理模式（Proxy）

基本介绍

静态代理

动态代理

public interface ITeacherDao {
    void teach();
}

public class TeacherDao implements ITeacherDao {
    @Override
    public void teach() {
        System.out.println("teach");
    }
}

public class ProxyFactory {
    private Object target;
    public ProxyFactory(Object target) {
        this.target = target;
    }
    public Object getProxyInstance() {
        return Proxy.newProxyInstance(target.getClass().getClassLoader(),
                target.getClass().getInterfaces(),
                (proxy, method, args) -> {
                    System.out.println("JDK代理开始");
                    Object returnVal = method.invoke(target, args);
                    return returnVal;
                });
    }
}

public class Client {
    public static void main(String[] args) {
        //创建目标对象
        ITeacherDao target = new TeacherDao();
        //给目标对象创建代理对象
        ProxyFactory proxyFactory = new ProxyFactory(target);
        ITeacherDao proxyInstance = (ITeacherDao) proxyFactory.getProxyInstance();
        proxyInstance.teach();
    }
}