Spring 02

AOP 操作的准备
1,Spring框架一般都是基于AspectJ实现AOP操作
什么是AspectJ?
AspectJ 不是Spring组成部分,独立Aop框架,一般把AspectJ 和Spring 框架一起使用,进行AOP操作
基于AspectJ实现AOP操作
1,基于xml配置文件实现
2,基于注解方式实现
3,在项目工程里引入AOP相关依赖
4,切入点表达式
1,切入点表达式作用?
知道对哪个类里的哪个方法进行增强
2,语法结构?
execution([权限修饰符][返回类型][类全路径][方法名称]([参数列表]))

进行通知的配置
1,在SPring 配置文件中,开启扫描注解


"1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:context="http://www.springframework.org/schema/context"
       xmlns:aop="http://www.springframework.org/schema/aop"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
       http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd
       http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop.xsd">
 
    <context:component-scan base-package="test2">context:component-scan>
 
<aop:aspectj-autoproxy>aop:aspectj-autoproxy>
 
beans>

2,使用注解创建User 和UserProxy对象
3,在增强类上面添加注解@Aspect


package test2;
 
import org.springframework.stereotype.Component;
 
@Component
public class User {
    public void add(){
        System.out.println("原方法");
        int a = 10/0;
    }
}
=========================================
package test2;
 
import org.aspectj.lang.ProceedingJoinPoint;
import org.aspectj.lang.annotation.*;
import org.springframework.stereotype.Component;
 
@Component
@Aspect //生成代理对象
public class UserProxy {
    //添加通知类型注解
    @Before(value = "execution(* test2.User.add(..))")
    public void before(){
        System.out.println("原方法之前的功能 before");
    }
// 不管有没有异常都执行
    @After(value =  "execution(* test2.User.add(..))")
    public void after(){
        System.out.println("原方法后的功能 after");
    }
 
    //在方法返回值之后执行
    // 有异常就不执行
    @AfterReturning(value =  "execution(* test2.User.add(..))")
    public void AfterReturning(){
        System.out.println("AfterReturning");
    }
 
    //异常通知
    @AfterThrowing(value =  "execution(* test2.User.add(..))")
    public void AfterThrowing(){
        System.out.println("原方法出现异常时的功能 AfterThrowing");
    }
    //在原方法之前之后都执行
    @Around(value =  "execution(* test2.User.add(..))")
    public void Around(ProceedingJoinPoint prceedingJoinPoint) throws Throwable {
        System.out.println("环绕之前 Around");
 
        prceedingJoinPoint.proceed();
 
 
        System.out.println("环绕之后 Around");
    }
 
}
======================================================

4, 在 Spring 配置文件中开启生成代理对象


package test2;
 
import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
 
public class TestAop {
//    @Test
//    public void test1(){
//        ApplicationContext context = new ClassPathXmlApplicationContext("bean3.xml");
//        User user = context.getBean("user",User.class);
//        user.add();
//    }
 
    public static void main(String[] args) {
        ApplicationContext context = new ClassPathXmlApplicationContext("bean3.xml");
        User user = context.getBean("user",User.class);
        user.add();
    }
}
/*
* 无异常情况
环绕之前 Around
原方法之前的功能 before
原方法
环绕之后 Around
原方法后的功能 after
AfterReturning
 */
/*
* 有异常情况
环绕之前 Around
原方法之前的功能 before
原方法
原方法后的功能 after
原方法出现异常时的功能 AfterThrowing
 */

相同的切入点抽取


   @Pointcut(value = "execution(* test2.User.add(..))")
    public void pointdemo(){}
 
    @Before(value = "pointdemo()")
    public void before(){
        System.out.println("原方法之前的功能 before");
    }

有多个增强类对同一个方法进行增强,设置增强类优先级
在增强类上面添加注解@order(数字类型值) ,数字类型值越小优先级越高


@Component
@Aspect
@Order(1)
public class User2Proxy {
        @Before(value = "execution(* test2.User.add(..))")
    public void before(){
        System.out.println("order=1 before");
    }
}
========================
@Component
@Aspect //生成代理对象
@Order(3)
public class UserProxy {
 
    @Pointcut(value = "execution(* test2.User.add(..))")
    public void pointdemo(){}
 
    @Before(value = "pointdemo()")
    public void before(){
        System.out.println("原方法之前的功能 before");
    }

基于配置方式:


"1.0" encoding="UTF-8"?>
"http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:context="http://www.springframework.org/schema/context"
       xmlns:aop="http://www.springframework.org/schema/aop"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
       http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd
       http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop.xsd">
 
 
    "user" class="test3.User">
    "userProxy" class="test3.UserProxy">
 
    
        "p" expression="execution(* test3.User.buy(..))"/>
 
        "userProxy">
            "before" pointcut-ref="p"/>

完全使用注解开发

jdbcTemplate
1,Spring 框架对jdbc进行封装,使用jdbcTemplate方便实现对数据库操作
2,准备工作
引入相关jar包
在spring配置文件配置数据库连接池

3,配置jdbcTemplate对象,注入DataSource


"1.0" encoding="UTF-8"?>
"http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:context="http://www.springframework.org/schema/context"
       xmlns:aop="http://www.springframework.org/schema/aop"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
       http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd
       http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop.xsd">
 
    package="test3">
 
    "dataSource" class="com.alibaba.druid.pool.DruidDataSource">
        "driverClassName" value="com.mysql.jdbc.Driver">
        "url"  value="jdbc:mysql://localhost:3306/catering_management">
        "username" value="root">
        "password" value="root">
    
 
    "jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate">
        "dataSource" ref="dataSource">

4,创建service,dao类,在dao注入jdbcTemplate对象


**  dao类
=========================
package test3.dao.daoImpl;
 
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.stereotype.Repository;
import test3.entity.Grocers;
@Repository
public class GrocersDaoImpl {
    @Autowired
    private JdbcTemplate jdbcTemplate;
    public void add(Grocers grocers){
        String sql = "INSERT INTO grocers VALUES (?,?,?,?,?)";
        jdbcTemplate.update(sql,grocers.getMerchants_id(),grocers.getMerchants_name(),grocers.getLegalperson_name(),grocers.getLegalperson_phone(),grocers.getState());
    }
}
=====================
** service 类
=====================
package test3.service;
 
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import test3.dao.daoImpl.GrocersDaoImpl;
import test3.entity.Grocers;
 
@Service
public class GrocersService {
    @Autowired
    private GrocersDaoImpl grocersDao;
    public void add(Grocers grocers){
        grocersDao.add(grocers);
    }
}
 
=============================== 
** 测试类
==================
package test3.test.Ch1;
 
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import test3.dao.daoImpl.GrocersDaoImpl;
import test3.entity.Grocers;
 
public class Ch1 {
    public static void main(String[] args) {
        Grocers grocers = new Grocers(6,"2","4","5","2");
        ApplicationContext context = new ClassPathXmlApplicationContext("bean5.xml");
        //名称首字母小写
        GrocersDaoImpl grocersDaoImpl = context.getBean("grocersDaoImpl", GrocersDaoImpl.class);
        grocersDaoImpl.add(grocers);
    }
}
======================================

相关阅读:
文心一言 VS 讯飞星火 VS chatgpt （111）-- 算法导论10.2 2题
 LLM-阿里云 DashVector + ModelScope 多模态向量化实时文本搜图实战总结
 CSS 背景
 C++20 实现字符串类型的转换操作
 QDir（目录）
数据结构红黄树学习笔记
 硬件知识积累 PCIE 接口
 第一章：IDEA使用介绍
 JUC常用
 逆向-破零
原文地址：https://blog.csdn.net/qq_56951318/article/details/126812515