Spring-Study

转载于Kuang shen Spring study in bilibili,仅作为学习备份

1. 简介

spring理念:是现有的技术更加容易使用,本身是一个大杂烩。

  • SSH:Struct2 + Spring + Hibernate
  • SSM: SpringMVC + Spring + Mybatis

官网: https://spring.io/projects/spring-framework#overview

官方下载: https://repo.spring.io/release/org/springframework/spring/

GitHub: https://github.com/spring-projects/spring-framework

Spring Web MVC » 5.2.5.RELEASE

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<!-- https://mvnrepository.com/artifact/org.springframework/spring-webmvc -->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-webmvc</artifactId>
<version>5.2.5.RELEASE</version>
</dependency>

<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-jdbc</artifactId>
<version>5.2.3.RELEASE</version>
</dependency>
  • spring是开源的免费的容器。
  • spring是一个轻量级的,非入侵式的。
  • 控制反转(IOC),面向切面编程 (AOP)。
  • 支持事务处理,对框架整合的支持。

总结:spring是一个轻量级的控制反转(IOC)和面向切面编程(AOP)的框架。

2.IOC理论

  1. UserDao

  2. UserDaoImp

  3. UserSevice

  4. UserServiceImp

在之前,用户的需求可能会影响原来的代码。

使用一个set。

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public void setUserDao(UserDao userDao){
this.userDao = userDao;
}
  • 之前是主动创建对象,控制权在程序员手上。

  • 使用set之后,是被动接受对象。

3. Hello Spring

pojo中

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package com.hou.pojo;

public class Hello {

private String name;

public String getName() {
return name;
}

public void setName(String name) {
this.name = name;
}

@Override
public String toString() {
return "Hello{" +
"name='" + name + '\'' +
'}';
}
}

resource种

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<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.springframework.org/schema/beans
https://www.springframework.org/schema/beans/spring-beans.xsd">

<!--bean = 对象-->
<!--id = 变量名-->
<!--class = new的对象-->
<!--property 相当于给对象中的属性设值-->

<bean id="hello" class="com.hou.pojo.Hello">
<property name="name" value="Spring"/>
</bean>
</beans>

test

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import com.hou.pojo.Hello;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class Mytest {

public static void main(String[] args) {
//获取spring上下文对象
ApplicationContext context = new ClassPathXmlApplicationContext("beans.xml");
//我们的对象下能在都在spring·中管理了,我们要使用,直接取出来就可以了
Hello hello = (Hello) context.getBean("hello");
System.out.println(hello.toString());
}
}

bean = 对象
id = 变量名
class = new的对象
property 相当于给对象中的属性设值

核心用set注入

第一个文件中

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<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.springframework.org/schema/beans
https://www.springframework.org/schema/beans/spring-beans.xsd">

<bean id="userdaomysql" class="com.hou.dao.UserDaoMysqlImpl"></bean>

<bean id="userServiceImpl" class="com.hou.service.UserServiceImp">
<!--ref引用spring中已经创建很好的对象-->
<!--value是一个具体的值-->
<property name="userDao" ref="userdaomysql"/>
</bean>

</beans>

4. IOC创建对象的方式

  1. 使用无参构造创建对象,默认。
  2. 使用有参构造

下标赋值

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<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.springframework.org/schema/beans
https://www.springframework.org/schema/beans/spring-beans.xsd">

<bean id="user" class="com.hou.pojo.User">
<constructor-arg index="0" value="hou"/>
</bean>
</beans>

类型赋值(不建议使用)

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<bean id="user" class="com.hou.pojo.User">
<constructor-arg type="java.lang.String" value="dong"/>
</bean>

直接通过参数名

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<bean id="user" class="com.hou.pojo.User">
<constructor-arg name="name" value="hou"></constructor-arg>
</bean>

Spring类似于婚介网站!

你想不想要,对象都在里面。注册bean之后用不用被实例化。

5. Spring配置

别名

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<bean id="user" class="com.hou.pojo.User">
<constructor-arg name="name" value="hou"></constructor-arg>
</bean>

<alias name="user" alias="user2aaa"/>

Bean的配置

  • id:bean的id标识符
  • class:bean对象所对应的类型
  • name:别名,更高级,可以同时取多个别名。

import

一般用于团队开发,它可以将多个配置文件,导入合并为一个

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<import resource="beans.xml"/>

6. DI依赖注入

构造器注入

set方式注入(重点)

  • 依赖:bean对象的创建依赖于容器
  • 注入:bean对象中的所有属性,由容器来注入

【环境搭建】

  1. 复杂类型
  2. 真实测试对象
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package com.pojo;

import java.util.*;

public class Student {

private String name;
private Address address;

private String[] books;
private List<String> hobbies;

private Map<String, String> card;
private Set<String> game;

private Properties infor;
private String wife;

@Override
public String toString() {
return "Student{" +
"name='" + name + '\'' +
", address=" + address +
", books=" + Arrays.toString(books) +
", hobbies=" + hobbies +
", card=" + card +
", game=" + game +
", infor=" + infor +
", wife='" + wife + '\'' +
'}';
}
}
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public class Address {
private String address;

public String getAddress() {
return address;
}

public void setAddress(String address) {
this.address = address;
}

@Override
public String toString() {
return "Address{" +
"address='" + address + '\'' +
'}';
}
}
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<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.springframework.org/schema/beans
https://www.springframework.org/schema/beans/spring-beans.xsd">

<bean id="address" class="com.pojo.Address">
<property name="address" value="xian"></property>
</bean>

<bean id="student" class="com.pojo.Student">
<property name="name" value="hou"/>
<property name="address" ref="address"/>

<!--数组注入-->
<property name="books">
<array>
<value>三国</value>
<value>西游</value>
<value>水浒</value>
</array>
</property>

<!--list-->
<property name="hobbies">
<list>
<value>eat</value>
<value>drink</value>
<value>play</value>
</list>
</property>

<property name="card">
<map>
<entry key="1" value="12"/>
<entry key="2" value="23"/>
</map>
</property>

<property name="game">
<set>
<value>wangzhe</value>
<value>daota</value>
<value>lol</value>
</set>
</property>

<property name="wife">
<null></null>
</property>

<!--properties-->
<property name="infor">
<props>
<prop key="id">20200405</prop>
<prop key="name">hdk</prop>
</props>
</property>
</bean>

</beans>

第三方

p标签和c标签

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package com.pojo;

public class User {

private String name;
private int age;

public User() {
}

public User(String name, int age) {
this.name = name;
this.age = age;
}

@Override
public String toString() {
return "User{" +
"name='" + name + '\'' +
", age=" + age +
'}';
}

public String getName() {
return name;
}

public void setName(String name) {
this.name = name;
}

public int getAge() {
return age;
}

public void setAge(int age) {
this.age = age;
}
}
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<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:p="http://www.springframework.org/schema/p"
xmlns:c="http://www.springframework.org/schema/c"
xsi:schemaLocation="http://www.springframework.org/schema/beans
https://www.springframework.org/schema/beans/spring-beans.xsd">

<!--p命名空间注入/set注入-->
<bean id="use" class="com.pojo.User" p:name="dong" p:age="10">
</bean>

<!--c命名空间/构造器-->
<bean id="use2" class="com.pojo.User" c:name="kun" c:age="19"></bean>
</beans>

bean的作用域

1586093707060

  1. 单例模式(默认)
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<bean id="use2" class="com.pojo.User" c:name="kun" c:age="19" scope="singleton"></bean>
  1. 原型模式: 每次从容器中get的时候,都产生一个新对象!
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<bean id="use2" class="com.pojo.User" c:name="kun" c:age="19" scope="prototype"></bean>
  1. 其余的request、session、application这些只能在web开放中使用!

7. Bean的自动装配

  • 自动装配是Spring是满足bean依赖的一种方式
  • Spring会在上下文自动寻找,并自动给bean装配属性

在Spring中有三种装配的方式

  1. 在xml中显示配置

  2. 在java中显示配置

  3. 隐式的自动装配bean 【重要】

  4. 环境搭建:一个人有两个宠物

  5. Byname自动装配:byname会自动查找,和自己对象set对应的值对应的id

    保证所有id唯一,并且和set注入的值一致

  6. Bytype自动装配:byType会自动查找,和自己对象属性相同的bean

    保证所有的class唯一

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public class Cat {
public void jiao(){
System.out.println("miao");
}
}
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public class Dog {

public void jiao(){
System.out.println("wow");
}

}
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package com.pojo;


public class People {

private Cat cat;
private Dog dog;
private String name;

@Override
public String toString() {
return "People{" +
"cat=" + cat +
", dog=" + dog +
", name='" + name + '\'' +
'}';
}

public Cat getCat() {
return cat;
}

public void setCat(Cat cat) {
this.cat = cat;
}

public Dog getDog() {
return dog;
}

public void setDog(Dog dog) {
this.dog = dog;
}

public String getName() {
return name;
}

public void setName(String name) {
this.name = name;
}
}

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<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.springframework.org/schema/beans
https://www.springframework.org/schema/beans/spring-beans.xsd">

<bean id="cat11" class="com.pojo.Cat"/>
<bean id="dog" class="com.pojo.Dog"/>
<!--byname会自动查找,和自己对象set对应的值对应的id-->
<!--<bean id="people" class="com.pojo.People" autowire="byName">-->
<!--<property name="name" value="hou"></property>-->
<!--</bean>-->
<!--byType会自动查找,和自己对象属性相同的bean-->
<bean id="people" class="com.pojo.People" autowire="byType">
<property name="name" value="hou"></property>
</bean>

</beans>

使用注解自动装配

jdk1.5支持的注解,spring2.5支持的注解

The introduction of annotation-based configuration raised the question of whether this approach is “better” than XML.

导入context约束

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<?xml version="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"
xsi:schemaLocation="http://www.springframework.org/schema/beans
https://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/context
https://www.springframework.org/schema/context/spring-context.xsd">

<context:annotation-config/>

</beans>

@Autowire

在属性上个使用,也可以在set上使用

我们可以不用编写set方法了

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public class People {
@Autowired
private Cat cat;
@Autowired
private Dog dog;
private String name;
}
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@Nullable 字段标志的注解,说明这个字段可以为null

如果@Autowired自动装配环境比较复杂。自动装配无法通过一个注解完成的时候

我们可以使用@Qualifier(value = “dog”)去配合使用,指定一个唯一的id对象

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public class People {
@Autowired
private Cat cat;
@Autowired
@Qualifier(value = "dog")
private Dog dog;
private String name;
}

@Resource(name=“dog”)也可以

区别:

  • @autowire通过byType实现,而且必须要求这个对象存在

  • @resource默认通过byName实现,如果找不到,通过byType实现

8. 使用注解开发

在spring4之后,必须要保证aop的包导入

使用注解需要导入contex的约束

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<?xml version="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"
xsi:schemaLocation="http://www.springframework.org/schema/beans
https://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/context
https://www.springframework.org/schema/context/spring-context.xsd">

<context:annotation-config/>

</beans>
  1. 属性如何注入
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@Component
public class User {

@Value("dong")
private String name;

public String getName() {
return name;
}

public void setName(String name) {
this.name = name;
}
}
  1. 衍生的注解

@Component有几个衍生注解,会按照web开发中,mvc架构中分层。

  • dao (@Repository)
  • service(@Service)
  • controller(@Controller)

这四个注解功能一样的,都是代表将某个类注册到容器中

  1. 作用域

@Scope(“singleton”)

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@Component
@Scope("prototype")
public class User {

@Value("dong")
private String name;

public String getName() {
return name;
}

public void setName(String name) {
this.name = name;
}
}

小结:

xml与注解

  • xml更加万能,维护简单
  • 注解,不是自己的类,使用不了,维护复杂

最佳实践:

  • xml用来管理bean
  • 注解只用来完成属性的注入
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<?xml version="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"
xsi:schemaLocation="http://www.springframework.org/schema/beans
https://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/context
https://www.springframework.org/schema/context/spring-context.xsd">

<context:annotation-config/>
<!--指定要扫描的包-->
<context:component-scan base-package="com.pojo"/>

</beans>

9. 使用java方式配置spring

JavaConfig

Spring的一个子项目,在spring4之后,,他成为了核心功能

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@Configuration //这个也会被spring容器托管,注册到容器中,因为他本来就是一个@Component
@ComponentScan("com.pojo")
@Import(Config2.class)
public class MyConfig {

@Bean
public User getUser(){
return new User();
}

}
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@Component
public class User {

@Value("dong")
private String name;

public String getName() {
return name;
}

public void setName(String name) {
this.name = name;
}

@Override
public String toString() {
return "User{" +
"name='" + name + '\'' +
'}';
}
}

这种纯java配置方式

在springboot中,随处可见

10. 动态代理

动态代理和静态代理

角色一样

动态代理类是动态生成的,不是我们直接写好的!

动态代理:基于接口,基于类

  • 基于接口:JDK的动态代理【使用】
  • 基于类:cglib
  • java字节码

InvocationHandler

Proxy

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

//会这个类,自动生成代理类
public class ProxyInvocation implements InvocationHandler {

//被代理的接口
private Rent rent;

public void setRent(Rent rent) {
this.rent = rent;
}

//生成代理类
public Object getProxy(){
return Proxy.newProxyInstance(this.getClass().getClassLoader(),rent.getClass().getInterfaces(),this);
}

//处理代理实例,并返回结果
public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
seeHouse();
Object result = method.invoke(rent, args);
fare();
return result;
}

public void seeHouse(){
System.out.println("see house");
}

public void fare(){
System.out.println("fare");
}
}
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public interface Rent {
void rent();
}
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public class Host implements Rent {
public void rent() {
System.out.println("host rent");
}
}
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public class Client {

public static void main(String[] args) {
//真实角色
Host host = new Host();

//代理角色
ProxyInvocation proxyInvocation = new ProxyInvocation();

//通过调用程序处理角色来处理我们要调用的接口对象
proxyInvocation.setRent(host);

Rent proxy = (Rent) proxyInvocation.getProxy(); //这里的proxy是动态生成的

proxy.rent();
}
}

11.AOP

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<dependencies>
<dependency>
<groupId>org.aspectj</groupId>
<artifactId>aspectjweaver</artifactId>
<version>1.9.4</version>
</dependency>
</dependencies>

方法一:使用spring接口【springAPI接口实现】

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<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:aop="http://www.springframework.org/schema/aop"
xsi:schemaLocation="http://www.springframework.org/schema/beanss
https://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/aop
https://www.springframework.org/schema/aop/spring-aop.xsd">

<!--注册bean-->
<bean id="userservice" class="com.service.UserServiceImp"></bean>
<bean id="log" class="com.log.Log"/>
<bean id="afterlog" class="com.log.AfterLog"/>

<!--配置aop-->
<aop:config>
<!--切入点:expression:表达式,execution(要执行的位置)-->
<aop:pointcut id="point" expression="execution(* com.service.UserServiceImp.*(..))"/>
<!--执行环绕-->
<aop:advisor advice-ref="log" pointcut-ref="point"/>
<aop:advisor advice-ref="afterlog" pointcut-ref="point"/>
</aop:config>

</beans>
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public class UserServiceImp implements UserService {


public void add() {
System.out.println("add");
}

public void delete() {
System.out.println("delete");
}

public void query() {
System.out.println("query");
}

public void update() {
System.out.println("update");
}
}
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import org.springframework.aop.MethodBeforeAdvice;

import java.lang.reflect.Method;

public class Log implements MethodBeforeAdvice {
//method:要执行的目标对象的方法
//args:参数
//target:目标对象
public void before(Method method, Object[] args, Object target) throws Throwable {
System.out.println(target.getClass().getName()+method.getName());
}
}
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public class AfterLog implements AfterReturningAdvice {

//returnVaule: 返回值
public void afterReturning(Object returnValue, Method method, Object[] args, Object target) throws Throwable {
System.out.println(method.getName()+returnValue);
}
}
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public class Mytest {
public static void main(String[] args) {
ApplicationContext context = new ClassPathXmlApplicationContext("ApplcationContext.xml");
//动态代理代理的是接口
UserService userService = (UserService) context.getBean("userservice");
userService.add();
}
}

方法二:自定义来实现AOP【主要是切面定义】

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<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:aop="http://www.springframework.org/schema/aop"
xsi:schemaLocation="http://www.springframework.org/schema/beans
https://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/aop
https://www.springframework.org/schema/aop/spring-aop.xsd">

<!--注册bean-->
<bean id="userservice" class="com.service.UserServiceImp"></bean>
<bean id="log" class="com.log.Log"/>
<bean id="afterlog" class="com.log.AfterLog"/>

<bean id="diy" class="com.diy.DiyPointcut">
</bean>
<aop:config>
<!--自定义切面-->
<aop:aspect ref="diy">
<!--切入点-->
<aop:pointcut id="point" expression="execution(* com.service.UserServiceImp.*(..))"/>
<aop:before method="before" pointcut-ref="point"/>
<aop:after method="after" pointcut-ref="point"/>
</aop:aspect>
</aop:config>

</beans>
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public class DiyPointcut {

public void before(){
System.out.println("before");
}

public void after(){
System.out.println("after");
}
}

方法三:注解方式

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<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:aop="http://www.springframework.org/schema/aop"
xsi:schemaLocation="http://www.springframework.org/schema/beans
https://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/aop
https://www.springframework.org/schema/aop/spring-aop.xsd">

<bean id="ann" class="com.diy.Annotation"></bean>
<aop:aspectj-autoproxy/>
<!--注册bean-->
<bean id="userservice" class="com.service.UserServiceImp"></bean>

</beans>
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import org.aspectj.lang.ProceedingJoinPoint;
import org.aspectj.lang.annotation.After;
import org.aspectj.lang.annotation.Around;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Before;

@Aspect //标注这个类是一个切面
public class Annotation {

@Before("execution(* com.service.UserServiceImp.*(..))")
public void before(){
System.out.println("before");
}

@After("execution(* com.service.UserServiceImp.*(..))")
public void after(){
System.out.println("after");
}

//在环绕增强中,我们可以给地暖管一个参数,代表我们要获取切入的点
@Around("execution(* com.service.UserServiceImp.*(..))")
public void around(ProceedingJoinPoint joinPoint) throws Throwable {
System.out.println("around");

Object proceed = joinPoint.proceed();

System.out.println("after around");
}
}

12. 整合mybatis

文档: https://mybatis.org/spring/zh/

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<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<parent>
<artifactId>spring-study</artifactId>
<groupId>com.hou</groupId>
<version>1.0-SNAPSHOT</version>
</parent>
<modelVersion>4.0.0</modelVersion>

<artifactId>spring-10-mybatis</artifactId>

<dependencies>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.47</version>
</dependency>

<dependency>
<groupId>org.mybatis</groupId>
<artifactId>mybatis-spring</artifactId>
<version>2.0.4</version>
</dependency>

<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-jdbc</artifactId>
<version>5.2.3.RELEASE</version>
</dependency>


<dependency>
<groupId>org.mybatis</groupId>
<artifactId>mybatis</artifactId>
<version>3.5.2</version>
</dependency>

<dependency>
<groupId>org.aspectj</groupId>
<artifactId>aspectjweaver</artifactId>
<version>1.9.4</version>
</dependency>

<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<version>1.18.12</version>
</dependency>
</dependencies>

<build>
<resources>
<resource>
<directory>src/main/resources</directory>
<includes>
<include>**/*.properties</include>
<include>**/*.xml</include>
</includes>
</resource>
<resource>
<directory>src/main/java</directory>
<includes>
<include>**/*.properties</include>
<include>**/*.xml</include>
</includes>
<filtering>true</filtering>
</resource>
</resources>
</build>

</project>
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<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE configuration
PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-config.dtd">

<configuration>

<typeAliases>
<package name="com.pojo"/>
</typeAliases>

<environments default="development">
<environment id="development">
<transactionManager type="JDBC"/>
<dataSource type="POOLED">
<property name="driver" value="com.mysql.jdbc.Driver"/>
<property name="url" value="jdbc:mysql://111.230.212.103:3306/mybatis?userSSL=true&amp;
userUnicode=true&amp;characterEncoding=UTF-8"/>
<property name="username" value="root"/>
<property name="password" value="hdk123"/>
</dataSource>
</environment>
</environments>

<mappers>
<mapper class="com.mapper.UserMapper"/>
</mappers>
</configuration>
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<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-mapper.dtd">

<mapper namespace="com.mapper.UserMapper">

<select id="selectUser" resultType="user">
select * from mybatis.user;
</select>

</mapper>
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public interface UserMapper {
List<User> selectUser();
}

整合

方法一:

1586177510119

UserMapperImpl

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package com.mapper;

import com.pojo.User;
import org.mybatis.spring.SqlSessionTemplate;

import java.util.List;

public class UserMapperImpl implements UserMapper {

private SqlSessionTemplate sqlSessionTemplate;

public void setSqlSessionTemplate(SqlSessionTemplate sqlSessionTemplate) {
this.sqlSessionTemplate = sqlSessionTemplate;
}

public List<User> selectUser() {
UserMapper mapper = sqlSessionTemplate.getMapper(UserMapper.class);
return mapper.selectUser();
}
}

mybatis.xml

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<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE configuration
PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-config.dtd">

<configuration>

<typeAliases>
<package name="com.pojo"/>
</typeAliases>

</configuration>

spring.xml

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<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:aop="http://www.springframework.org/schema/aop"
xsi:schemaLocation="http://www.springframework.org/schema/beans
https://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/aop
https://www.springframework.org/schema/aop/spring-aop.xsd">

<!--data source-->
<bean id="datasource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
<property name="driverClassName" value="com.mysql.jdbc.Driver"/>
<property name="url" value="jdbc:mysql://111.230.212.103:3306/mybatis?userSSL=true&amp;
userUnicode=true&amp;characterEncoding=UTF-8"/>
<property name="username" value="root"/>
<property name="password" value="hdk123"/>
</bean>

<!--sqlsession-->
<bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
<property name="dataSource" ref="datasource" />
<!--bound mybatis-->
<property name="configLocation" value="classpath:mybatis-config.xml"/>
<property name="mapperLocations" value="classpath:com/mapper/UserMapper.xml"/>
</bean>

<bean id="sqlSession" class="org.mybatis.spring.SqlSessionTemplate">
<constructor-arg index="0" ref="sqlSessionFactory"/>
</bean>

<bean id="userMapper" class="com.mapper.UserMapperImpl">
<property name="sqlSessionTemplate" ref="sqlSession"></property>
</bean>

</beans>

test

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import com.mapper.UserMapper;
import com.pojo.User;
import org.springframework.context.support.ClassPathXmlApplicationContext;

import java.io.IOException;


public class Mytest {


public static void main(String[] args) throws IOException {

ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext("spring-dao.xml");
UserMapper userMapper = context.getBean("userMapper", UserMapper.class);

for (User user : userMapper.selectUser()) {
System.out.println(user);
}
}
}

方法二:

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<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.springframework.org/schema/beans
https://www.springframework.org/schema/beans/spring-beans.xsd">

<!--data source-->
<bean id="datasource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
<property name="driverClassName" value="com.mysql.jdbc.Driver"/>
<property name="url" value="jdbc:mysql://111.230.212.103:3306/mybatis?userSSL=true&amp;
userUnicode=true&amp;characterEncoding=UTF-8"/>
<property name="username" value="root"/>
<property name="password" value="hdk123"/>
</bean>

<!--sqlsession-->
<bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
<property name="dataSource" ref="datasource" />
<!--bound mybatis-->
<property name="configLocation" value="classpath:mybatis-config.xml"/>
<property name="mapperLocations" value="classpath:com/mapper/UserMapper.xml"/>
</bean>

<!--<bean id="sqlSession" class="org.mybatis.spring.SqlSessionTemplate">-->
<!--<constructor-arg index="0" ref="sqlSessionFactory"/>-->
<!--</bean>-->

<!--<bean id="userMapper" class="com.mapper.UserMapperImpl">-->
<!--<property name="sqlSessionTemplate" ref="sqlSession"></property>-->
<!--</bean>-->

<bean id="userMapper2" class="com.mapper.UserMapperIml2">
<property name="sqlSessionFactory" ref="sqlSessionFactory"></property>
</bean>

</beans>
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package com.mapper;

import com.pojo.User;
import org.apache.ibatis.session.SqlSession;
import org.mybatis.spring.support.SqlSessionDaoSupport;

import java.util.List;

public class UserMapperIml2 extends SqlSessionDaoSupport implements UserMapper {
public List<User> selectUser() {
SqlSession sqlSession = getSqlSession();
UserMapper mapper = sqlSession.getMapper(UserMapper.class);
return mapper.selectUser();
}
}

13. 声明式事务

  • 要么都成功,要么都失败
  • 十分重要,涉及到数据一致性
  • 确保完整性和一致性

事务的acid原则:

  • 原子性

  • 一致性

  • 隔离性

    • 多个业务可能操作一个资源,防止数据损坏
  • 持久性

    • 事务一旦提交,无论系统发生什么问题,结果都不会被影响。

Spring中的事务管理

  • 声明式事务
  • 编程式事务

声明式事务

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<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:tx="http://www.springframework.org/schema/tx"
xmlns:aop="http://www.springframework.org/schema/aop"
xsi:schemaLocation="http://www.springframework.org/schema/beans
https://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/tx
https://www.springframework.org/schema/tx/spring-tx.xsd
http://www.springframework.org/schema/aop
https://www.springframework.org/schema/aop/spring-tx.aop">

<!--data source-->
<bean id="datasource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
<property name="driverClassName" value="com.mysql.jdbc.Driver"/>
<property name="url" value="jdbc:mysql://111.230.212.103:3306/mybatis?userSSL=true&amp;
userUnicode=true&amp;characterEncoding=UTF-8"/>
<property name="username" value="root"/>
<property name="password" value="hdk123"/>
</bean>

<!--sqlsession-->
<bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
<property name="dataSource" ref="datasource" />
<!--bound mybatis-->
<property name="configLocation" value="classpath:mybatis-config.xml"/>
<property name="mapperLocations" value="classpath:com/mapper/*.xml"/>
</bean>

<!--声明式事务-->
<bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
<constructor-arg ref="datasource" />
</bean>

<!--结合aop实现事务置入-->
<!--配置事务的类-->
<tx:advice id="tx1" transaction-manager="transactionManager">
<!--给哪些方法配置事务-->
<!--配置事务的传播特性-->
<tx:attributes>
<tx:method name="add" propagation="REQUIRED"/>
<tx:method name="delete" propagation="REQUIRED"/>
<tx:method name="update" propagation="REQUIRED"/>
<tx:method name="*" propagation="REQUIRED"/>
<tx:method name="query" read-only="true"/>
</tx:attributes>
</tx:advice>

<!--配置事务切入-->
<aop:config>
<aop:pointcut id="txpointxut" expression="execution(* com.mapper.*.*(..))"/>
<aop:advisor advice-ref="tx1" pointcut-ref="txpointxut"/>
</aop:config>

</beans>
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<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.springframework.org/schema/beans
https://www.springframework.org/schema/beans/spring-beans.xsd">

<import resource="spring-dao.xml"/>

<bean id="userMapper2" class="com.mapper.UserMapperIml2">
<property name="sqlSessionFactory" ref="sqlSessionFactory"></property>
</bean>

</beans>

Mapper

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package com.mapper;

import com.pojo.User;

import java.util.List;

public interface UserMapper {
List<User> selectUser();
int addUser(User user);
int delete(int id);
}
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<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-mapper.dtd">

<mapper namespace="com.mapper.UserMapper">
<select id="selectUser" resultType="user">
select * from mybatis.user;
</select>

<insert id="addUser" parameterType="user">
insert into mybatis.user (id, name, pwd) values
(#{id}, #{name}, #{pwd})
</insert>

<delete id="delete" parameterType="int">
delete from mybatis.user where id=#{id}
</delete>
</mapper>
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package com.mapper;

import com.pojo.User;
import org.apache.ibatis.session.SqlSession;
import org.mybatis.spring.support.SqlSessionDaoSupport;

import java.util.List;

public class UserMapperIml2 extends SqlSessionDaoSupport implements UserMapper {

public List<User> selectUser() {
User user = new User(6, "long", "zhi");
SqlSession sqlSession = getSqlSession();
UserMapper mapper = sqlSession.getMapper(UserMapper.class);
mapper.addUser(user);
mapper.delete(6);
return mapper.selectUser();
}

public int addUser(User user) {
return getSqlSession().getMapper(UserMapper.class).addUser(user);
}

public int delete(int id) {
return getSqlSession().getMapper(UserMapper.class).delete(id);
}
}