Java 动态代理你真的懂了吗(动态和代理)

public interface ising {

    void sing();

}

/**

* 周杰伦

*/

public class jayimp implements ising {

    @override

    public void sing() {

        system.out.println( "say happy birthday to you girl friend" );

   }

}

/**

* 经纪人

*/

public class jayproxy implements ising{

    ising target;

    /**

     * 初始化的时候，和明星进行签约

     * @param target

     */

    public jayproxy(ising target) {

        this .target = target;

   }

    @override

    public void sing() {

        target.sing();

   }

}

public class moneyowner {

    public static void main(string[] args) {

        jayimp jay = new jayimp();

        // 周杰伦和经纪人进行签约，这一步可以放在内部实现

        jayproxy jayproxy = new jayproxy(jay);

        jayproxy.sing();

   }

}

package org.pdool.dynamic;

/**

* 林俊杰

*/

public class jjimp implements ising {

    @override

    public void sing() {

        system.out.println( "i am jj! happy birthday to you" );

   }

}

import java.lang.reflect.invocationhandler;

import java.lang.reflect.method;

import java.lang.reflect.proxy;

public class jayagentfactory implements invocationhandler {

    object target;

    public jayagentfactory(object target) {

        this .target = target;

   }

    // 生成代理类

    public ising creatproxyedobj() {

        return (ising) proxy.newproxyinstance(target.getclass().getclassloader(), target.getclass().getinterfaces(), this );

   }

    @override

    public object invoke(object proxy, method method, object[] args) throws throwable {

        object invoke = method.invoke(target, args);

        logafter(invoke);

        return invoke;

   }

    public void logafter(object invoke) {

        system.out.println( "结果 " + invoke);

        system.out.println( "收入 ++ " );

   }

}

package org.pdool.dynamic;

import java.lang.reflect.proxy;

public class aain {

    public static void main(string[] args) {

        jayimp jayimp = new jayimp();

        ising subjectproxy=(ising) proxy.newproxyinstance(jayimp.getclass().getclassloader(), jayimp.getclass().getinterfaces(), new jayagentfactory(jayimp));

        subjectproxy.sing();

   }

}

/** parameter types of a proxy class constructor */

    private static final class <?>[] constructorparams =

       { invocationhandler. class };

import sun.misc.proxygenerator;

public class test {

    public static void main(string[] args) {

        //开启保存代码class属性

        system.getproperties().put( "sun.misc.proxygenerator.savegeneratedfiles" , "true" );

        proxygenerator.generateproxyclass( "xiangcai" , jayimp. class .getinterfaces());

   }

}

import java.lang.reflect.invocationhandler;

import java.lang.reflect.method;

import java.lang.reflect.proxy;

import java.lang.reflect.undeclaredthrowableexception;

import org.pdool.dynamic.ising;

public final class xiangcai extends proxy implements ising {

    private static method m1;

    private static method m2;

    private static method m3;

    private static method m0;

    public xiangcai(invocationhandler var1) throws {

        super (var1);

   }

    public final boolean equals(object var1) throws {

        try {

            return ( boolean ) super .h.invoke( this , m1, new object[]{var1});

       } catch (runtimeexception | error var3) {

            throw var3;

       } catch (throwable var4) {

            throw new undeclaredthrowableexception(var4);

       }

   }

    public final string tostring() throws {

        try {

            return (string) super .h.invoke( this , m2, (object[]) null );

       } catch (runtimeexception | error var2) {

            throw var2;

       } catch (throwable var3) {

            throw new undeclaredthrowableexception(var3);

       }

   }

//注意看这里！！！其他的都不重要

    public final void sing() throws {

        try {

            super .h.invoke( this , m3, (object[]) null );

       } catch (runtimeexception | error var2) {

            throw var2;

       } catch (throwable var3) {

            throw new undeclaredthrowableexception(var3);

       }

   }

    public final int hashcode() throws {

        try {

            return (integer) super .h.invoke( this , m0, (object[]) null );

       } catch (runtimeexception | error var2) {

            throw var2;

       } catch (throwable var3) {

            throw new undeclaredthrowableexception(var3);

       }

   }

    static {

        try {

            m1 = class .forname( "java.lang.object" ).getmethod( "equals" , class .forname( "java.lang.object" ));

            m2 = class .forname( "java.lang.object" ).getmethod( "tostring" );

            m3 = class .forname( "org.pdool.dynamic.ising" ).getmethod( "sing" );

            m0 = class .forname( "java.lang.object" ).getmethod( "hashcode" );

       } catch (nosuchmethodexception var2) {

            throw new nosuchmethoderror(var2.getmessage());

       } catch (classnotfoundexception var3) {

            throw new noclassdeffounderror(var3.getmessage());

       }

   }

}

import com.tao.springboot.hibernate.entity.customer;

import org.springframework.data.jpa.repository.jparepository;

public interface customerrepository extends jparepository<customer, long > {

}

public interface jparepository<t, id> extends pagingandsortingrepository<t, id>, querybyexampleexecutor<t> {

    list<t> findall();

    list<t> findall(sort var1);

    list<t> findallbyid(iterable<id> var1);

    <s extends t> list<s> saveall(iterable<s> var1);

    void flush();

    <s extends t> s saveandflush(s var1);

    void deleteinbatch(iterable<t> var1);

    void deleteallinbatch();

    t getone(id var1);

    <s extends t> list<s> findall(example<s> var1);

    <s extends t> list<s> findall(example<s> var1, sort var2);

}

public class simplejparepository<t, id> implements jparepositoryimplementation<t, id> {

    private static final string id_must_not_be_null = "the given id must not be null!" ;

    private final jpaentityinformation<t, ?> entityinformation;

   private final entitymanager em; //看这里！！！

    private final persistenceprovider provider;

    @nullable

    private crudmethodmetadata metadata;

    //具体的实现方法

       @transactional

    public void delete(t entity) {

        assert .notnull(entity, "the entity must not be null!" );

        this .em.remove( this .em.contains(entity) ? entity : this .em.merge(entity));

   }

proxy.newproxyinstance(thread.currentthread().getcontextclassloader(), jparepository. class .getinterfaces(), new simplejparepository(());