Spring的简单使用（3）

• 2022 年 8 月 9 日
• 筆記
• Spring的简单使用

一：SM框架的整合：

所需要的依赖：

<dependency>
        <groupId>junit</groupId>
        <artifactId>junit</artifactId>
        <version>4.12</version>
        <scope>test</scope>
    </dependency>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-aspects</artifactId>
        <version>5.2.5.RELEASE</version>
    </dependency>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-context</artifactId>
        <version>5.2.5.RELEASE</version>
    </dependency>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-tx</artifactId>
        <version>5.2.5.RELEASE</version>
    </dependency>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-jdbc</artifactId>
        <version>5.2.5.RELEASE</version>
    </dependency>
    <dependency>
        <groupId>org.mybatis</groupId>
        <artifactId>mybatis</artifactId>
        <version>3.5.1</version>
    </dependency>
    <dependency>
        <groupId>org.mybatis</groupId>
        <artifactId>mybatis-spring</artifactId>
        <version>1.3.1</version>
    </dependency>
    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
        <version>5.1.32</version>
    </dependency>
    <dependency>
        <groupId>com.mchange</groupId>
        <artifactId>c3p0</artifactId>
        <version>0.9.5.4</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>
        </resource>

    </resources>

mybatis核心配置文件：

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

</configuration>

spring—mapper.核心配置文件（接管了mybatis的核心配置文件）：

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="//www.springframework.org/schema/beans"
       xmlns:xsi="//www.w3.org/2001/XMLSchema-instance"
       xmlns:context="//www.springframework.org/schema/context"
       xsi:schemaLocation="//www.springframework.org/schema/beans //www.springframework.org/schema/beans/spring-beans.xsd //www.springframework.org/schema/context //www.springframework.org/schema/context/spring-context.xsd">
<!--读取jdbc配置文件-->
    <context:property-placeholder location="db.properties" system-properties-mode="FALLBACK"></context:property-placeholder>
<!--创建数据源-->
    <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
        <property name="driverClass" value="${jdbc.driver}"/>
        <property name="jdbcUrl" value="${jdbc.url}"/>
        <property name="user" value="${jdbc.username}"/>
        <property name="password" value="${jdbc.password}"/>
    </bean>
<!--配置sqlsessionFactoryBean类-->
    <bean id="sqlSessionFactoryBeanName" class="org.mybatis.spring.SqlSessionFactoryBean">
    <!--    配置数据源-->
     <property name="dataSource" ref="dataSource"></property>
    <!--配置mybatis的核心配置文件-->
        <property name="configLocation" value="mybatis-config.xml"></property>
<!--        注册实体类别名-->
        <property name="typeAliasesPackage" value="com.ztb.pojo"></property>
    </bean>

<!--注册mapper.xml文件-->
    <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
        <property name="basePackage" value="com.ztb.dao"></property>
    </bean>
</beans>

spring-service核心配置文件：

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="//www.springframework.org/schema/beans"
       xmlns:xsi="//www.w3.org/2001/XMLSchema-instance" xmlns:context="//mybatis.org/schema/mybatis-spring"
       xsi:schemaLocation="//www.springframework.org/schema/beans //www.springframework.org/schema/beans/spring-beans.xsd //mybatis.org/schema/mybatis-spring //mybatis.org/schema/mybatis-spring.xsd">
    <import resource="spring-mapper.xml"></import>
    <context:scan base-package="com.ztb.spring"></context:scan>




</beans>

database.properties：

jdbc.driver=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3306/mybatis?useSSL=false&useUnicode=true&characterEncoding=UTF-8
jdbc.username=root
jdbc.password=ztb

dao层：

  dao层接口：

public interface UserMapper {
    int insert(User user);
}

  dao层配置文件：

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
        PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
        "//mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.ztb.dao.UserMapper">
    <insert id="insert" parameterType="com.ztb.pojo.User">
        insert into user values (#{id},#{name},#{pwd})
    </insert>
</mapper>

实体类：

package com.ztb.pojo;

public class User {
    private Integer id;
    private String name;
    private String pwd;

    public User() {
    }

    public User(Integer id, String name, String pwd) {
        this.id = id;
        this.name = name;
        this.pwd = pwd;
    }

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

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

    public String getPwd() {
        return pwd;
    }

    public void setPwd(String pwd) {
        this.pwd = pwd;
    }

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

service层：

   service接口：

public interface UserService {
    int insert(User user);
}

   service实现类：

@Service("user")
public class UserServiceImpl implements UserService{
    @Autowired
    UserMapper userMapper;



    @Override
    public int insert(User user) {
        return userMapper.insert(user);
    }
}

测试：

@Test
public void test1() {
    ApplicationContext context = new ClassPathXmlApplicationContext("spring-service.xml");
    UserService userServiceImpl = (UserService) context.getBean("user");
    int i = userServiceImpl.insert(new User(13, "张三", "2222"));
    System.out.println(i);

二：事务：

分为注解式事务和声明式事务：

1：注解式事务：使用@Transactional注解完成事务控制，此注解可以添加到类上，，则对类中的所有方法都执行事务的处理。也可以添加到方法上，添加到方法上只是对该方法进行事务处理。

由于事务都是在业务逻辑层，所以所有的事务都必须配在service层：

首先需要在spring-service配置文件中添加支持注解式事务：

<!--    1添加事务管理器-->
    <bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
<!--        因为事务必须关联数据库操作，所以要配置数据源-->
        <property name="dataSource" ref="dataSource"></property>
     </bean>
<!--    2添加事务的注解驱动-->
<tx:annotation-driven transaction-manager="transactionManager"></tx:annotation-driven>

注解式事务必须要在实现类上面添加注解：

  2：声明式事务（重要）：在配置文件中添加一次，整个项目都遵循事物的设定。

声明式事务配置如下：

<!--    1添加事务管理器-->
    <bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
<!--        因为事务必须关联数据库操作，所以要配置数据源-->
        <property name="dataSource" ref="dataSource"></property>
     </bean>
<!--    2添加事务的声明驱动-->
    <tx:advice id="myadvice" transaction-manager="transactionManager">
        <tx:attributes>
<!--     *指的是为所有方法添加事务       REQUIRED指的是增删改，-->
            <tx:method name="*" propagation="NOT_SUPPORTED"/>

        </tx:attributes>
    </tx:advice>
<!--    绑定切面和切入点-->
    <aop:config>
        <aop:pointcut id="mycut" expression="execution(* com.ztb.spring.*.*(..))"/>
<!--        把myadvice的事务绑定到mycut的service包（包名写错了sping）下的任意方法中-->
        <aop:advisor advice-ref="myadvice" pointcut-ref="mycut"></aop:advisor>
    </aop:config>

也可以如下写：

事务优先级的处理：

如果有一些方法和声明式事务不匹配，则可以设置优先级：

在配置文件中添加注解式事务，设置优先级比声明式要高，这样在方法上就会选择注解式事务来操作了

<tx:annotation-driven order="100"></tx:annotation-driven>注解式设置为100

<aop:advisor order="1" advice-ref="myadvice" pointcut-ref="mycut"></aop:advisor>声明式设置为1