基于接口和基于子类的动态代理

Posted 2020-11-24 zou-rong

一：基于接口（JDK1.3之后提供）：

import com.aiitec.service.IAccountService;
import com.aiitec.utils.TransactionManager;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.stereotype.Component;

import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Method;
import java.lang.reflect.Proxy;

public class AccountServiceFactory {
    @Autowired
    @Qualifier("accountService")
    private IAccountService service;//被代理对象，必须实现至少一个接口

    @Autowired
    private TransactionManager transactionManager;//事务控制器

　　

/**
 * 获取代理对象
 * @return
 */

    public IAccountService getProxy() {
        return (IAccountService) Proxy.newProxyInstance(service.getClass().getClassLoader(), service.getClass().getInterfaces(), new InvocationHandler() {
            @Override
            public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
                Object result=null;
                try{
                    transactionManager.beginTransaction();
                    System.out.println("前置通知生效。。。");

                    result=method.invoke(service,args);

                    transactionManager.commit();
                    System.out.println("后置通知生效。。。");
                }catch (Exception e){
                    transactionManager.rollback();
                    System.out.println("异常通知生效。。。");
                    throw new RuntimeException(e);
                }finally {
                    transactionManager.relese();
                    System.out.println("最终通知生效。。。");
                }
                return result;
            }
        });
    }
}

配置spring的IOC：

<!--配置基于接口的动态代理对象，工厂方法创建-->
<bean id="serviceProxy" factory-bean="accountServiceFactory" factory-method="getProxy"></bean>

<bean id="accountServiceFactory" class="com.aiitec.proxy.AccountServiceFactory"></bean>

使用：

    @Autowired
    @Qualifier("serviceProxy")
    private IAccountService ccountService;



一：基于子类（第三方Cglib提供）：
先导包

<!--cglib基于子类的动态代理-->
<dependency>
  <groupId>cglib</groupId>
  <artifactId>cglib</artifactId>
  <version>2.1_3</version>
</dependency>

import com.aiitec.service.impl.AccountServiceCglib;
import com.aiitec.utils.TransactionManager;
import net.sf.cglib.proxy.Enhancer;
import net.sf.cglib.proxy.MethodInterceptor;
import net.sf.cglib.proxy.MethodProxy;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;

import java.lang.reflect.Method;

public class AccountServiceCglibFactory {
    @Autowired
    private AccountServiceCglib accountServiceCglib;//被代理对象，必须不是final类

    @Autowired
    private TransactionManager transactionManager;

/**
 * 获取代理对象
 * @return
 */

    public AccountServiceCglib getProxy() {
        return (AccountServiceCglib) Enhancer.create(accountServiceCglib.getClass(), new MethodInterceptor() {
            @Override
            public Object intercept(Object proxy, Method method, Object[] args, MethodProxy methodProxy) throws Throwable {
                Object result=null;
                try{
                    transactionManager.beginTransaction();
                    System.out.println("cglib前置通知生效。。。");
                    result=method.invoke(accountServiceCglib,args);
                    transactionManager.commit();
                    System.out.println("cglib后置通知生效。。。");
                }catch (Exception e){
                    transactionManager.rollback();
                    System.out.println("cglib异常通知生效。。。");
                    throw new RuntimeException(e);
                }finally {
                    transactionManager.relese();
                    System.out.println("cglib最终通知生效。。。");
                }
                return result;
            }
        });
    }
}

配置spring的IOC：

<!--配置基于子类的动态代理对象，工厂方法创建-->

<bean id="serviceCglib" factory-bean="accountCglibFactory" factory-method="getProxy"></bean>
<bean id="accountCglibFactory" class="com.aiitec.proxy.AccountServiceCglibFactory"></bean>

使用：

@Autowired
@Qualifier("serviceCglib")
private AccountServiceCglib serviceCglibProxy;