SPRING代理模式

Posted 2020-09-30 <烟花易冷>

1.静态代理

主题对象：Student

public interface Student {

    public String add();
}

目标对象：RealStudent

public class RealStudent implements Student {
    public String add() {
        System.out.println("add Ok");
        return null;
    }
}

代理对象：ProxStudent

public class ProxStudent implements Student {
    //对象间交互
    private Student realStudent;

    public Student getRealStudent() {
        return realStudent;
    }

    public void setRealStudent(Student realStudent) {
        this.realStudent = realStudent;
        this.realStudent=realStudent;
    }

    public String add() {
        System.out.println("事务已经开启！");
        return realStudent.add();

    }
}

单测

//静态代理
    @Test
    public void test01(){
        //真实主题对象
        Student student=new RealStudent();
        //代理对象
        ProxStudent proxStudent=new ProxStudent();

        proxStudent.setRealStudent(student);

        proxStudent.add();

    }

2.JDK动态代理

接口：IUserDAO

public interface IUserDAO {
    public String add();

    public String edit();
}

类：UserDAOImpl

public class UserDAOImpl implements IUserDAO {
    public String add() {
        System.out.println("add");
        return "add";
    }

    public String edit() {
        System.out.println("edit");
        return "edit";
    }
}

单测

//JDK动态代理
    @Test
    public void test02(){
        final IUserDAO dao=new UserDAOImpl();
        IUserDAO proxy=(IUserDAO) Proxy.newProxyInstance(dao.getClass().getClassLoader(), dao.getClass().getInterfaces(), new InvocationHandler() {
            public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
                System.out.println("事务已经开启");
                method.invoke(dao,args);
                return null;
            }
        });
        //代理对象 add() edit()
        proxy.add();
        proxy.edit();

    }

3.CGLIB动态代理

public class UserService {
    public void dalete() {
        System.out.println("dalete OK");
    }
}

单测 方式一

//CGLIB 动态代理 一
    @Test
    public void test03(){

        final UserService service=new UserService();

        Enhancer enhancer =new Enhancer();
        //在内存中构建业务类的子类
        enhancer.setSuperclass(service.getClass());
        enhancer.setCallback(new org.springframework.cglib.proxy.InvocationHandler() {
            public Object invoke(Object o, Method method, Object[] objects) throws Throwable {
                System.out.println("事务已经开启");
                method.invoke(service,objects);
                return null;
            }
        });
        UserService proxy=(UserService)enhancer.create();
        proxy.dalete();
    }

单测 方式二

//CGLIB 动态代理 二
    @Test
    public void test04(){
        final UserService service=new UserService();

        Enhancer enhancer =new Enhancer();
        //在内存中构建业务类的子类
        enhancer.setSuperclass(service.getClass());
        enhancer.setCallback(new MethodInterceptor() {
            public Object intercept(Object o, Method method, Object[] objects, MethodProxy methodProxy) throws Throwable {
                System.out.println("事务已经开启");
                methodProxy.invoke(service,objects);
                return null;
            }
        });
        UserService proxy=(UserService)enhancer.create();
        proxy.dalete();

        }