一起学Java——SSM整合及MyBatis-Plus的使用

前言

前面的文章我们已经学习了Spring、Spring MVC和Mybatis，本节我们就来使用他们整合我们的SSM框架的整合运用。

学习内容

什么是SSM？

SSM（Spring+SpringMVC+MyBatis） 框架集由Spring、MyBatis两个开源框架整合而成（SpringMVC是Spring中的部分内容），常作为数据源较简单的web项目的框架。百度百科

SSM整合三阶段

• Spring与Spring MVC环境配置
• Spring与MyBatis的整合配置
• 整合其他组件：声明式事务/日志/任务调度/…

Spring与Spring MVC环境配置

1. pom.xml依赖spring-webmvc

<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">
    <modelVersion>4.0.0modelVersion>

    <groupId>com.fivegroupId>
    <artifactId>five-readerartifactId>
    <version>1.0-SNAPSHOTversion>

    <properties>
        <maven.compiler.source>8maven.compiler.source>
        <maven.compiler.target>8maven.compiler.target>
    properties>


    <repositories>
        <repository>
            <id>aliyunid>
            <name>aliyunname>
            <url>https://maven.aliyun.com/repository/publicurl>
        repository>
    repositories>
    <dependencies>
        <dependency>
            <groupId>org.springframeworkgroupId>
            <artifactId>spring-webmvcartifactId>
            <version>5.2.6.RELEASEversion>
        dependency>

        <dependency>
            <groupId>org.freemarkergroupId>
            <artifactId>freemarkerartifactId>
            <version>2.3.30version>
        dependency>
        <dependency>
            <groupId>org.springframeworkgroupId>
            <artifactId>spring-context-supportartifactId>
            <version>5.2.6.RELEASEversion>
        dependency>


        <dependency>
            <groupId>com.fasterxml.jackson.coregroupId>
            <artifactId>jackson-coreartifactId>
            <version>2.11.0version>
        dependency>

        <dependency>
            <groupId>com.fasterxml.jackson.coregroupId>
            <artifactId>jackson-databindartifactId>
            <version>2.11.0version>
        dependency>

        <dependency>
            <groupId>com.fasterxml.jackson.coregroupId>
            <artifactId>jackson-annotationsartifactId>
            <version>2.11.0version>
        dependency>
    dependencies>

project>

2. web.xml配置DispatcherServlet

<servlet>
    <servlet-name>springmvcservlet-name>
    <servlet-class>org.springframework.web.servlet.DispatcherServletservlet-class>
    <init-param>
        <param-name>contextConfigLocationparam-name>
        <param-value>classpath:applicationContext*.xmlparam-value>
    init-param>
    
    <load-on-startup>0load-on-startup>
servlet>
<servlet-mapping>
    <servlet-name>springmvcservlet-name>
    <url-pattern>/url-pattern>
servlet-mapping>

3. 启用Spring MVC注解模式

<context:component-scan base-package="com.five"/>
<mvc:annotation-driven/>

<mvc:default-servlet-handler/>

4. web.xml配置请求与响应字符集

<filter>
    <filter-name>characterFilterfilter-name>
    <filter-class>org.springframework.web.filter.CharacterEncodingFilterfilter-class>
    <init-param>
        <param-name>encodingparam-name>
        <param-value>UTF-8param-value>
    init-param>
filter>
<filter-mapping>
    <filter-name>characterFilterfilter-name>
    <url-pattern>/*url-pattern>
filter-mapping>

5. 配置FreeMarker模板引擎(applicationContext.xml)

<bean id="freemarkerConfig" class="org.springframework.web.servlet.view.freemarker.FreeMarkerConfigurer">
    <property name="templateLoaderPath" value="/WEB-INF/ftl"/>
    <property name="freemarkerSettings">
        <props>
            
            <prop key="defaultEncoding">UTF-8prop>
        props>
    property>
bean>

<bean id="ViewResolver" class="org.springframework.web.servlet.view.freemarker.FreeMarkerViewResolver">
    <property name="contentType" value="text/html;charset=utf-8"/>
    <property name="suffix" value=".ftl"/>
bean>

6. 配置JSON序列化组件(applicationContext.xml)

测试整合结果：

• 编写测试Controller

/**
 1. Description:
 2.  3. @Author: kk(专业bug开发)
 4. DateTime: 2022-02-11 14:17
 */
@Controller
public class TestController {

    @GetMapping("/test/t1")
    public ModelAndView test1(){
        return new ModelAndView("/test");
    }

    @GetMapping("/test/t2")
    @ResponseBody
    public Map test2(){
        Map result = new HashMap();
        result.put("test", "测试文本");
        return result;
    }
}

• 测试截图

Spring与MyBatis的整合配置

1. 依赖mybatis-spring以及驱动

<dependency>
    <groupId>org.springframeworkgroupId>
    <artifactId>spring-jdbcartifactId>
    <version>5.2.6.RELEASEversion>
dependency>
<dependency>
    <groupId>org.mybatisgroupId>
    <artifactId>mybatisartifactId>
    <version>3.5.4version>
dependency>

<dependency>
    <groupId>org.mybatisgroupId>
    <artifactId>mybatis-springartifactId>
    <version>2.0.3version>
dependency>
<dependency>
    <groupId>mysqlgroupId>
    <artifactId>mysql-connector-javaartifactId>
    <version>8.0.16version>
dependency>
<dependency>
    <groupId>com.alibabagroupId>
    <artifactId>druidartifactId>
    <version>1.1.14version>
dependency>

2. 配置数据源与连接池（applicationContext.xml）

<bean id="dataSource" class="com.alibaba.druid.pool.DruidDataSource">
    <property name="driverClassName" value="com.mysql.cj.jdbc.Driver"/>
    <property name="url" value="jdbc:mysql://localhost:3306/imooc_reader?useSSL=false&useUnicode=true&characterEncoding=UTF-8&serverTimezone=Asia/Shanghai&allowPublicKeyRetrieval=true"/>
    <property name="username" value="root"/>
    <property name="password" value="root"/>
    <property name="initialSize" value="5"/>
    <property name="maxActive" value="20"/>
bean>

3. 配置SqlSessionFactory（applicationContext.xml）

<bean id="sessionFactory" class="com.baomidou.mybatisplus.extension.spring.MybatisSqlSessionFactoryBean">
    <property name="dataSource" ref="dataSource"/>
    <property name="mapperLocations" value="classpath:mappers/*.xml"/>
    
    <property name="configLocation" value="classpath:mybatis-config.xml"/>
bean>

4. 配置Mapper扫描器（applicationContext.xml）

<bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
    <property name="basePackage" value="com.five.reader.mapper"/>
bean>

5. 创建mybatis-config.xml

DOCTYPE configuration
        PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>

    <settings>
        <setting name="mapUnderscoreToCamelCase" value="true"/>
    settings>

configuration>

整合其他组件

• 整合JUnit单元测试

1. pom.xml引入依赖

<dependency>
    <groupId>org.springframeworkgroupId>
    <artifactId>spring-testartifactId>
    <version>5.2.6.RELEASEversion>
dependency>

<dependency>
    <groupId>junitgroupId>
    <artifactId>junitartifactId>
    <version>4.12version>
dependency>

<dependency>
    <groupId>javax.servletgroupId>
    <artifactId>javax.servlet-apiartifactId>
    <version>3.1.0version>
    <scope>providedscope>
dependency>

2. 新建一个测试mapper

3. 新建test.xml的mappers

DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.five.reader.mapper.TestMapper">
    <insert id="insert">
        insert into test(content) values('测试内容')
    insert>
mapper>

4. 新建service

@Service
public class TestService {
    @Resource
    private TestMapper testMapper;

    public void batchImport(){
        for (int i = 0; i < 5; i++) {
            testMapper.insert();
        }
    }
}

5. 新建单元测试用例

测试结果：

• 配置logback日志输出

1. pom.xml添加依赖（Spring会自动检测依赖并使用）

<dependency>
    <groupId>ch.qos.logbackgroupId>
    <artifactId>logback-classicartifactId>
    <version>1.2.3version>
dependency>

自定义日志格式的时候可以参考前面的MyBatis部分的日志管理，新建logback.xml即可！！！

<configuration>
    <appender name="console" class="ch.qos.logback.core.ConsoleAppender">
        <encoder class="ch.qos.logback.classic.encoder.PatternLayoutEncoder">
            <pattern>%d{HH:mm:ss} %-5level [%thread] %logger{30} - %msg%npattern>
            <charset>UTF-8charset>
        encoder>
    appender>
    <root level="debug">
        <appender-ref ref="console"/>
    root>
configuration>

• 声明式事务配置

<bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
    <property name="dataSource" ref="dataSource"/>
bean>
<tx:annotation-driven transaction-manager="transactionManager"/>

Tip：SSM整合完毕！！！！

---

什么是MyBatis-Plus

• MyBatis-Plus是一个MyBatis的增强工具
• 自动实现Mapper CRUD操作，极致提高数据库开发效率
• MyBatis-Plus在MyBatis的基础上只做增强不做改变

官网地址

MyBatis-Plus整合

• pom.xml引入MyBatis-Plus

<dependency>
    <groupId>com.baomidougroupId>
    <artifactId>mybatis-plusartifactId>
    <version>3.3.2version>
dependency>

• applicationContext.xml更改配置SqlSessionFactory实现类

    
    
    <bean id="sessionFactory" class="com.baomidou.mybatisplus.extension.spring.MybatisSqlSessionFactoryBean">
        <property name="dataSource" ref="dataSource"/>
        <property name="mapperLocations" value="classpath:mappers/*.xml"/>
        
        <property name="configLocation" value="classpath:mybatis-config.xml"/>
    bean>

• mybatis-config.xml增加MP分页插件

    <plugins>
        
        <plugin interceptor="com.baomidou.mybatisplus.extension.plugins.PaginationInterceptor">plugin>
    plugins>

MyBatis-Plus使用

1. 创建实体类，@TableName/@TableId/@TableFieId实现映射

注解	说明
@TableName	将实体类与表名映射
@TableId	说明对应属性是表的主键
@TableFieId	设置属性与列名的对应关系

@TableName("test") //用于说明实体对应哪一张表
public class Test {
    @TableId(type = IdType.AUTO)   //用于说明谁是主键
    @TableField("id") //用于说明属性对应哪个字段
    private Integer id;

    @TableField("content") //如果字段名与属性名相同或者符合驼峰命名转换规则,则TableField可省略
    private String content;

    public Integer getId() {
        return id;
    }

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

    public String getContent() {
        return content;
    }

    public void setContent(String content) {
        this.content = content;
    }
}

2. 创建Mapper接口继承BaseMapper，创建Mapper XML

public interface TestMapper extends BaseMapper<Test> {
    public void insertSample();
}

3. 开发时注入Mapper对象，通过内置API实现CRUD操作
   
   
   测试结果：
   
   CRUD测试代码：

package com.five.reader;

import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.five.reader.entity.Test;
import com.five.reader.mapper.TestMapper;
import org.junit.runner.RunWith;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;

import javax.annotation.Resource;
import java.util.List;

/**
 * Description:
 *
 * @Author: kk(专业bug开发)
 * DateTime: 2022-02-11 17:38
 */

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(locations = {"classpath:applicationContext.xml"})
public class MyBatisPlusTest {
    @Resource
    private TestMapper testMapper;

    //测试MP添加数据
    @org.junit.Test
    public void testInsert(){
        Test test = new Test();   //实体类Test
        test.setContent("MyBatis Plus测试");    //设置实体类的内容
        testMapper.insert(test);
    }

    //测试MP更新数据
    @org.junit.Test
    public void testUpdate(){
        Test test = testMapper.selectById(16);   //MP内置的selectById方法
        test.setContent("MyBatis Plus测试1");
        testMapper.updateById(test);
    }

    //测试MP删除数据
    @org.junit.Test
    public void testDelete(){
        testMapper.deleteById(16);
    }

    //测试MP查询方法
    @org.junit.Test
    public void testSelect(){
        QueryWrapper<Test> queryWrapper = new QueryWrapper<Test>();
        queryWrapper.eq("id", 7);
        queryWrapper.gt("id", 5);
        List<Test> list = testMapper.selectList(queryWrapper);   //传入一个包装对象
        System.out.println(list.get(0));
    }
}

查询的时候queryWrapper参见下面的文档说明！！！！
queryWrapper文档地址

总结

这节课应该是个转折点了，前面我们都是单独的开发学习，现在我们对SSM进行了整合，更引入了高效开发的MyBatis-Plus，这样我们结合前面的知识就可以开始我们的SSM开发了~
如果你发现文章中存在问题，欢迎评论区交流指正~