Mybatis, Spring , SpringMVC框架SSM整合

SSM整合

Maven依赖包

        <!--        测试工具-->
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.13</version>
            <scope>test</scope>
        </dependency>

        <!--        Spring重要核心-->
        <!-- https://mvnrepository.com/artifact/org.springframework/spring-webmvc -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-webmvc</artifactId>
            <version>5.3.16</version>
        </dependency>

        <!--        SpringAOP织入-->
        <!-- https://mvnrepository.com/artifact/org.aspectj/aspectjweaver -->
        <dependency>
            <groupId>org.aspectj</groupId>
            <artifactId>aspectjweaver</artifactId>
            <version>1.9.4</version>
        </dependency>

        <!--        spring中的Mybatis-->
        <!-- https://mvnrepository.com/artifact/org.mybatis/mybatis-spring -->
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis-spring</artifactId>
            <version>2.0.6</version>
        </dependency>

        <!--        mysql驱动-->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>8.0.21</version>
        </dependency>

        <!--        spring的jdbc(使用连接池技术可不用)-->
        <!-- https://mvnrepository.com/artifact/org.springframework/spring-jdbc -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-jdbc</artifactId>
            <version>5.3.16</version>
        </dependency>

        <!-- 数据库连接池 -->
        <dependency>
            <groupId>com.mchange</groupId>
            <artifactId>c3p0</artifactId>
            <version>0.9.5.2</version>
        </dependency>

        <!--        Mybatis-->
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis</artifactId>
            <version>3.5.7</version>
        </dependency>

        <!--Servlet - JSP -->
        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>servlet-api</artifactId>
            <version>2.5</version>
        </dependency>
        <dependency>
            <groupId>javax.servlet.jsp</groupId>
            <artifactId>jsp-api</artifactId>
            <version>2.1</version>
        </dependency>
        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>jstl</artifactId>
            <version>1.2</version>
        </dependency>

Maven资源过滤文件

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

pojo实体类

实体类User

package com.pojo;

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

    public User() {
    }

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

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

 /* getter 和 setter  */
}

dao层

数据库相关配置与Mybatis

数据库配置文件

database.properties

# 注意! 使用了 c3p0 数据库链接池的属性要设置为 jdbc.属性名,不加会报错!
jdbc.driver = com.mysql.cj.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3306/mybatis?useSSL=true&serverTimezone=Asia/Shanghai&useUnicode=true&characterEncoding=UTF-8
jdbc.username=root
jdbc.password=123456

mybati核心配置

mybatis-config.xml , 也可以进行mybatis其他的设置,如起别名等

<?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>
    <mappers>
        <!-- 将包内的映射器接口实现全部注册为映射器,注意配置文件要与接口同名同包 -->
        <package name="com.dao"/>
    </mappers>
</configuration>

Spring中dao层配置文件

spring-dao.xml

<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
       http://www.springframework.org/schema/beans/spring-beans.xsd
       http://www.springframework.org/schema/context
       https://www.springframework.org/schema/context/spring-context.xsd">

    <!-- 配置整合mybatis -->
    <!-- 关联数据库配置文件 -->
    <context:property-placeholder location="classpath:database.properties"/>

    <!-- 2.设置mybatis数据源 -->
    <!--数据库连接池
        dbcp 半自动化操作 不能自动连接
        c3p0 自动化操作（自动的加载配置文件 并且设置到对象里面）     -->
    <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
        <!-- 配置连接池属性 -->
        <property name="driverClass" value="${jdbc.driver}"/>
        <property name="jdbcUrl" value="${jdbc.url}"/>
        <property name="user" value="${jdbc.username}"/>
        <property name="password" value="${jdbc.password}"/>
        <!--        c3p0连接池的私有属性-->
        <!--        <property name="maxPoolSize" value="30"/>-->
        <!--        <property name="minPoolSize" value="10"/>-->
        <!--        关闭连接后不自动commit-->
        <!--        <property name="autoCommitOnClose" value="false"/>-->
        <!--        获取连接超时时间-->
        <!--        <property name="checkoutTimeout" value="10000"/>-->
        <!--        当获取连接失败重试次数-->
        <!--        <property name="acquireRetryAttempts" value="2"/>-->
    </bean>

    <!-- 3.配置SqlSessionFactory对象 -->
    <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
        <!-- 注入数据库连接池 -->
        <property name="dataSource" ref="dataSource"/>
        <!-- 关联MyBaties核心配置文件 -->
        <property name="configLocation" value="classpath:mybatis-config.xml"/>
    </bean>

    <!-- 4.配置扫描Dao接口包，动态实现Dao接口注入到spring容器中 -->
    <!--解释 ：https://www.cnblogs.com/jpfss/p/7799806.html
Mybatis在与Spring集成的时候可以配置MapperFactoryBean来生成Mapper接口的代理.
MapperFactoryBean 创建的代理类实现了 UserMapper 接口,并且注入到应用程序中。 因为代理创建在运行时环境中(Runtime,译者注) ,那么指定的映射器必须是一个接口,而 不是一个具体的实现类。
没有必要在Spring的XML配置文件中注册所有的映射器。相反,你可以使用一个MapperScannerConfigurer, 它将会查找类路 径 下 的 映射器并自动将它们创建成MapperFactoryBean。
<注意!!!>, 没有必要去指定SqlSessionFactory 或 SqlSessionTemplate , 因为MapperScannerConfigurer 将会创建 MapperFactoryBean,之后自动装配。但是,如果你使 用了一个以上的 DataSource ,那么自动装配可能会失效 。这种 情况下,你可以使用 sqlSessionFactoryBeanName 或 sqlSessionTemplateBeanName 属性来设置正确的 bean 名 称来使用。这就是它如何来配置的,<注意!!!>bean的名称是必须的,而不是 bean 的引用,因 此,value 属性在这里替代通常的 ref:

即: 这个扫描类帮我们做了这些事: 扫描指定包下的接口,获得Mapper对象,随后业务层将会用到此Mapper来进行操作
ApplicationContext context = new ClassPathXmlApplicationContext("appconfig.xml");
UserDao userDaoMapper = context.getBean("daoMapper", DaoMapper.class).getMapper(UserDao.class);
-->
    <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
        <!-- 注入sqlSessionFactory -->
        <property name="sqlSessionFactoryBeanName" value="sqlSessionFactory"/>
        <!-- 给出需要扫描Dao接口包 -->
        <property name="basePackage" value="com.dao"/>
    </bean>
</beans>

dao接口 UserMapper

package com.dao;
import com.pojo.User;
import org.apache.ibatis.annotations.Param;
import java.util.List;

public interface UserMapper {
    List getAllUser();

    int addUser(User user);

    int deleteUser(@Param("id") int id);

    int updateUser(User user);

    User getUser(@Param("id") int id);
}

接口映射器(sql配置)

如果是配置文件,最好和接口同包同名 , 也可以在接口上使用注解

<?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.dao.UserMapper">
    <insert id="addUser" parameterType="com.pojo.User">
        insert into `user`
        values (#{id}, #{name}, #{pwd});
    </insert>
    
    <delete id="deleteUser" parameterType="int">
        delete from `user` where id=#{id}
    </delete>

    <update id="updateUser" parameterType="com.pojo.User">
        update `user`
        set id = #{id},name = #{name},pwd = #{pwd}
        where id = #{id}
    </update>

    <select id="getUser" resultType="int">
        select * from `user`
        where id = #{id};
    </select>

    <select id="getAllUser" resultType="com.pojo.User">
        SELECT * from `user`
    </select>
</mapper>

service层(业务层)

Service接口 ,非必需,根据项目情况而定

package com.service;

import com.pojo.User;
import org.apache.ibatis.annotations.Param;

import java.util.List;

interface UserService {
    List getAllUser();

    int addUser(User user);

    int deleteUser(@Param("id") int id);

    int updateUser(User user);

    User getUser(@Param("id") int id);
}

Service实现类

ServiceImp

package com.service;

import com.dao.UserMapper;
import com.pojo.User;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.stereotype.Service;

import java.util.List;

@Service
public class UserServiceImp implements UserService {

    /*
    业务层调用dao层(Mapper对象)来执行对应的数据库操作; 对应接口的MapperBean由Spring的MapperScannerConfigurer生成
    由于UserMapper的映射器对象已经在spring-dao.xml配置中用扫描器注册了,所以可以使用自动装配
    此外: // 官方不建议字段自动装配,而是推荐setter注入更灵活
     */
    @Autowired
    @Qualifier("userMapper")
    private UserMapper userMapper;
    
    @Override
    public List getAllUser() {
        return userMapper.getAllUser();
    }
    @Override
    public int addUser(User user) {
        return userMapper.addUser(user);
    }
    @Override
    public int deleteUser(int id) {
        return userMapper.deleteUser(id);
    }
    @Override
    public int updateUser(User user) {
        return userMapper.updateUser(user);
    }
    @Override
    public User getUser(int id) {
        return userMapper.getUser(id);
    }
}

Spring中Service层配置文件

<?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
   http://www.springframework.org/schema/beans/spring-beans.xsd
   http://www.springframework.org/schema/context
   http://www.springframework.org/schema/context/spring-context.xsd">

    <!-- 扫描service相关的bean -->
    <context:component-scan base-package="com.service" />
    
<!--    
             UserServiceImpl注入到IOC容器中,用 注解@Service来注册bean了就不在需要 
    <bean id="UserServiceImpl" class="com.service.UserServiceImp">

             这里引用的userMapper,在spring-dao.xml中注入了,使用到了Spring自带的扫描器 MapperScannerConfigurer 
        <property name="userMapper" ref="userMapper"/>
    </bean>
-->
    
    <!-- 配置事务管理器,为啥要在这里配置事务管理呢,因为业务层嘛,可能会有一些会回滚的操作,所以业务层才需要事务管理 -->
    <bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
        <!-- 注入数据库连接池,在spring-dao.xml里配置啦 -->
        <property name="dataSource" ref="dataSource" />
    </bean>
</beans>

controller层

控制器

UserController.java

package com.controller;

import com.pojo.User;
import com.service.UserServiceImp;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;

import java.util.List;

@Controller
@RequestMapping("/user")
public class UserController {

    /* controller层调用业务层,
     业务层通过 @Service 注解在Spring中注入了
     这里自动装配 业务层实现类(bean对象)
     控制层通过调用业务层实现类来进行对应的业务操作
     */
    @Autowired  // 官方不建议字段注入 自动装配,而是推荐setter注入更灵活更安全
    @Qualifier("userServiceImp")
    private UserServiceImp mapperImp;

    //由于类也有url,所以请求的url为:user/getAllUser
    @RequestMapping(value = "/getAllUser",produces = "text/html;charset=utf-8")
    @ResponseBody
    public String getAllUser(){

        String date ="";
        List<User> users = mapperImp.getAllUser();
        for (User user:users){
            date+=user+"<br>" ;
            System.out.println(user);
        }
//返回数据
        return date;
    }
}

Spring中的控制层配置文件

spring-controller.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:context="http://www.springframework.org/schema/context"
       xmlns:mvc="http://www.springframework.org/schema/mvc"
       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/mvc
   https://www.springframework.org/schema/mvc/spring-mvc.xsd">

    <!-- 4.扫描web相关的bean -->
    <context:component-scan base-package="com.controller" />

    <!-- 配置SpringMVC -->
    <!-- 1.开启SpringMVC注解驱动 -->
    <mvc:annotation-driven />
    <!-- 2.静态资源默认servlet配置-->
    <mvc:default-servlet-handler/>

    <!-- 3.配置jsp 设置ViewResolver视图解析器相关属性 -->
    <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <property name="viewClass" value="org.springframework.web.servlet.view.JstlView" />
        <property name="prefix" value="/WEB-INF/jsp/" />
        <property name="suffix" value=".jsp" />
    </bean>
</beans>

Spring整合所有应用上下文配置

applicationContext.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"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd">
    
    <import resource="spring-dao.xml"/>   <!--引入dao层配置-->
    <import resource="spring-service.xml"/>     <!--引入业务层配置-->
    <import resource="spring-controller.xml"/>    <!--引入控制层层配置-->
</beans>

web配置

配置整个web应用程序的配置文件``web.xml`

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd"
         version="4.0">

    <!--DispatcherServlet-->
    <servlet>
        <servlet-name>DispatcherServlet</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
        <init-param>
            <param-name>contextConfigLocation</param-name>
            <!--一定要注意:我们这里加载的是总的配置文件，之前被这里坑了
            tomcat是根据总配置文件来启动的-->
            <param-value>classpath:applicationContext.xml</param-value>
        </init-param>
        <load-on-startup>1</load-on-startup>
    </servlet>
    <servlet-mapping>
        <servlet-name>DispatcherServlet</servlet-name>
        <url-pattern>/</url-pattern>
    </servlet-mapping>

    <!--encodingFilter-->
    <filter>
        <filter-name>encodingFilter</filter-name>
        <filter-class>
            org.springframework.web.filter.CharacterEncodingFilter
        </filter-class>
        <init-param>
            <param-name>encoding</param-name>
            <param-value>utf-8</param-value>
        </init-param>
    </filter>
    <filter-mapping>
        <filter-name>encodingFilter</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>

    <!--Session过期时间(根据需要设置)-->
    <session-config>
        <session-timeout>15</session-timeout>
    </session-config>
</web-app>

至此,所有的配置都做完了,完结撒花 🌸🌸🌸