spring

day 621

spring 学习笔记

1，ioc ##控制反转，依赖注入 demo

控制反转：对象由spring容器创建依赖注入属性方法由spring容器赋值

.1 set注入 ##样例类必须有set方法

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 + '\'' +
                '}';
    }
}

在spring的配置文件中注册

<?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">
    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  
	<import resource="beans.xml"/>
   一个bean 代表一个对象
    <!--id = 变量名-->
    <!--class = new的对象-->
    <!--property 相当于给对象中的属性设值-->
    <bean id="userdaomysql" class="com.hou.dao.UserDaoMysqlImpl"></bean>
    <bean id="hello" class="com.hou.pojo.Hello">
        <property name="name" value="Spring"/>
        <!--ref引用spring中已经创建很好的对象-->
        <!--value是一个具体的值 一般是基本数据类型-->
        <property name="userDao" ref="userdaomysql"/>
    </bean>
    使用有参构造 ，构造器注入
     <bean id="user" class="com.hou.pojo.User">
         index="0" 参数索引位置 value="hou"对应参数值
        <constructor-arg index="0" value="hou"/>
         
    </bean>
    <bean id="user" class="com.hou.pojo.User">
        name="name"  形参名    value="hou" 形参值
    <constructor-arg name="name" value="hou"></constructor-arg>
	</bean>
    
    起别名  
    <bean id="user" class="com.hou.pojo.User">
    <constructor-arg name="name" value="hou"></constructor-arg>
    </bean>

    <alias name="user" alias="user2aaa  hannian"/>
    name="user" 对应bean的id   
	alias="user2aaa  hannian"  对应的别名 可以取多个  空格隔开
</beans

@test

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());
    }
}

.1，set注入的集中类型

    <bean id="address" class="com.pojo.Address">
        <property name="address" value="xian"></property>
    </bean>
 
	<bean id="student" class="com.pojo.Student">
      	基本类型属性注入
        <property name="name" value="hou"/>
        引用类型 bean 注入
        <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>
        
		 <!--map-->
        <property name="card">
            <map>
                <entry key="1" value="12"/>
                <entry key="2" value="23"/>
            </map>
        </property>
		 <!--set-->
        <property name="game">
            <set>
                <value>wangzhe</value>
                <value>daota</value>
                <value>lol</value>
            </set>
        </property>
		 <!--空值null -->
        <property name="wife">
            <null></null>
        </property>

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

spring 自带 p：和 c：注入

<?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">
	前提 要先引入        
	xmlns:p="http://www.springframework.org/schema/p"
  	xmlns:c="http://www.springframework.org/schema/c"
  	
    <!--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/构造器注入-->
    <bean id="use2" class="com.pojo.User" c:name="kun" c:age="19"></bean>
</beans>

.2 bean 作用域（作用域感觉这个词语在这里有点奇怪，单例模式原型模式和作用域有什么关系）

scope="singleton" 单例模式（默认）

<bean id="use2" class="com.pojo.User" scope="singleton"></bean>

scope="prototype 原型模式: 每次从容器中get的时候，都产生一个新对象！

<bean id="use2" class="com.pojo.User"  scope="prototype"></bean>

其余的request、session、application这些只能在web开放中使用！

.3 bean 的自动装配

bean3种装配方法

在xml中显示配置 set 构造器注入
在java中显示配置直接声明时赋值
隐式的自动装配bean
1. 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
2. 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

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

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

}
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;
    }
}
<?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--> 
        会根据 people类的 属性 private Cat cat; private Dog dog  autowire="byName" 只匹配到dog    id="dog"
    <!--<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-->
    会根据 people类的 属性 private Cat cat; private Dog dog autowire="byType"  类型		一致所以匹配所有 id="cat11" id="dog"
    <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 注解一定是趋势，重点记忆

前提导入context约束

context:annotation-config/

<?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"/>   @Component使用时必写
</beans>

@Autowire ##一定结合自动装配理解

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

public class People {
    @Autowired
    private Cat cat;
    @Autowired
    private Dog dog;
    private String name;
}
@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

```java
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

使用注解开发

@Component
作用域注入
@Scope("singleton")
public class User {
    .1 属性注入
    @Value("dong")
    private String name;

    public String getName() {
        return name;
    }

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

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，只是用到不同层级的实现类中

总结：

xml更加万能
注解，使用有局限性但是节约时间

最好 xml用来管理bean 注解只用来完成属性的注入

使用java方式配置spring JavaConfig

@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();
    }

}
@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 + '\'' +
                '}';
    }
}
springBoot  最多使用  但是我不理解  没关系到springBoot再说

代理

主要目的在不改变原有业务的代码的基础上进行功能扩展，
主要是原有功能类成为代理类的一个属性在使用功能的前后增加新功能

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

aop 实现原理代理模式

1，spring 配置文件 + 继承spring提供接口api实现

<?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>
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");
    }
}
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());
    }
}
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);
    }
}
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】

<?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>
public class DiyPointcut {

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

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

方法三：注解方式

<?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>
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");
    }
}

$$$整合mybatis

1，pom.xml

<?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>

2,mybatis-config.xml

<?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>
        //也可以通过路径方式注册
        <mapper class="com.mapper.UserMapper"/>
    </mappers>
</configuration>

3,userMapper.xml

<?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>

4，接口类

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

整合一

--1实现类 UserMapperImpl

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();
    }
}

--2 spring.xml

<?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-->
    org.springframework.jdbc.datasource.DriverManagerDataSourceb 数据库配置类  对应mybatis sqlSessionFactoryBuilder
    <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-->
    org.mybatis.spring.SqlSessionFactoryBean  数据库池类 对应mybatis sqlSessionFactory
    <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>
org.mybatis.spring.SqlSessionTemplate数据库连接对象  对应mybatis sqlSession
    <bean id="sqlSession" class="org.mybatis.spring.SqlSessionTemplate">
        <constructor-arg index="0" ref="sqlSessionFactory"/>
    </bean>
以上三步都是固定的
    
    
    <bean id="userMapper" class="com.mapper.UserMapperImpl">
        <property name="sqlSessionTemplate" ref="sqlSession"></property>
    </bean>

</beans>

@test

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");
         context对象相当于是spring容器对象用来管理所有bean  实例对象
        
        UserMapper userMapper = context.getBean("userMapper", UserMapper.class);

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

方法二

<?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>
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();
        
        ## 为什么能直接调用getSqlSession();  
        在 Java 中，子类可以直接访问从父类继承的 public 和 protected 方法或属性，就像访问自己的方法一样。所以你无需使用对象或类名调用，只需直接调用 getSqlSession()。为什么能直接调用
        UserMapper mapper = sqlSession.getMapper(UserMapper.class);
        return mapper.selectUser();
    }
}

Spring中的事务管理

事务四个特性

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

<?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>
<?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

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);
}
<?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>
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);
    }
}

posted on 2024-11-29 18:55 韩行一阅读(6) 评论(0) 编辑收藏举报

spring

spring 学习笔记

1，ioc ##控制反转，依赖注入 demo

bean3种装配方法

前提导入context约束

使用注解开发

使用java方式配置spring JavaConfig

代理

aop 实现原理代理模式

$$$整合mybatis

Spring中的事务管理