spring boot2 整合（一）Mybatis （特别完整！）
整合Mybatis分为两种模式，一种是xml配置，一种是注解。（类似JPA） 我在这里重点放在xml配置上，因为如果想用注解的话，建议直接用jpa代替，因为Jpa有更成熟的CRUD接口更方便开发。我在后文中也会把注解方式说清楚。 大概介绍下流程： 借助idea实现mybatis逆向工程 用xml配置实现整合 用cmd命令行实现mybatis逆向工程 用mapping.xml配置实现数据交互 用注解的方式实现数据交互 首先我的开发环境： jdk1.8+maven3+IDEA 1. mybatis逆向攻城 逆向工程方式很多，我目前接触到的就两种，一种是借助于ide开发工具，一种是在cmd中执行命令。（其实二者原理都一样，都是执行maven的generator命令，具体请看下文）。 1. 完善pom文件 <?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"> <modelVersion>4.0.0</modelVersion> <groupId>springboot-mybatis</groupId> <artifactId>springboot-mybatis</artifactId> <version>0.0.1-SNAPSHOT</version> <packaging>jar</packaging> <name>springboot-mybatis</name> <description>Demo project for Spring Boot</description> <parent> <groupId>springboot-integration</groupId> <artifactId>springboot-integration</artifactId> <version>1.0-SNAPSHOT</version> </parent> <!-- Add typical dependencies for a web application --> <dependencies> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-jdbc</artifactId> </dependency> <dependency> <groupId>org.mybatis.spring.boot</groupId> <artifactId>mybatis-spring-boot-starter</artifactId> <version>1.3.0</version> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-thymeleaf</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-test</artifactId> <scope>test</scope> </dependency> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <version>5.1.35</version> </dependency> <!-- alibaba的druid数据库连接池 --> <dependency> <groupId>com.alibaba</groupId> <artifactId>druid</artifactId> <version>1.0.11</version> </dependency> <!-- alibaba的druid数据库连接池 --> <dependency> <groupId>com.alibaba</groupId> <artifactId>druid-spring-boot-starter</artifactId> <version>1.1.0</version> </dependency> <dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> <scope>test</scope> </dependency> <!-- 分页插件 --> <dependency> <groupId>com.github.pagehelper</groupId> <artifactId>pagehelper</artifactId> <version>5.0.4</version> </dependency> </dependencies> <!-- Package as an executable jar --> <build> <finalName>springboot-mybatis</finalName> <plugins> <plugin> <groupId>org.apache.maven.plugins</groupId> <artifactId>maven-surefire-plugin</artifactId> <configuration> <testFailureIgnore>true</testFailureIgnore> </configuration> </plugin> <plugin> <groupId>org.mybatis.generator</groupId> <artifactId>mybatis-generator-maven-plugin</artifactId> <version>1.3.2</version> <configuration> <verbose>true</verbose> <overwrite>true</overwrite> </configuration> </plugin> </plugins> </build> </project> 2. 逆向所需配置文件generatorConfig.xml <?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE generatorConfiguration PUBLIC "-//mybatis.org//DTD MyBatis Generator Configuration 1.0//EN" "http://mybatis.org/dtd/mybatis-generator-config_1_0.dtd"> <generatorConfiguration> <!-- 数据库驱动:选择你的本地硬盘上面的数据库驱动包--> <classPathEntry location="E:\lib\mysql_driver\mysql-connector-java-5.1.26-bin.jar"/> <context id="DB2Tables" targetRuntime="MyBatis3"> <commentGenerator> <property name="suppressDate" value="true"/> <!-- 是否去除自动生成的注释 true：是 ： false:否 --> <property name="suppressAllComments" value="true"/> </commentGenerator> <!--数据库链接URL，用户名、密码 --> <jdbcConnection driverClass="com.mysql.jdbc.Driver" connectionURL="jdbc:mysql://127.0.0.1/user" userId="root" password="root"> </jdbcConnection> <javaTypeResolver> <property name="forceBigDecimals" value="false"/> </javaTypeResolver> <!-- 生成模型的包名和位置--> <javaModelGenerator targetPackage="com.fantj.sbmybatis.model" targetProject="src/main/java"> <property name="enableSubPackages" value="true"/> <property name="trimStrings" value="true"/> </javaModelGenerator> <!-- 生成映射文件的包名和位置--> <sqlMapGenerator targetPackage="mapping" targetProject="src/main/resources"> <property name="enableSubPackages" value="true"/> </sqlMapGenerator> <!-- 生成DAO的包名和位置--> <javaClientGenerator type="XMLMAPPER" targetPackage="com.fantj.sbmybatis.mapper" targetProject="src/main/java"> <property name="enableSubPackages" value="true"/> </javaClientGenerator> <!-- 要生成的表 tableName是数据库中的表名或视图名 domainObjectName是实体类名--> <table tableName="user" domainObjectName="User" enableCountByExample="false" enableUpdateByExample="false" enableDeleteByExample="false" enableSelectByExample="false" selectByExampleQueryId="false"></table> </context> </generatorConfiguration> 3. 利用IDE创建逆向工程启动类 4. add一个Maven configuration 5. 我的数据库和表结构 6. application配置文件 server: port: 8080 spring: datasource: name: test url: jdbc:mysql://127.0.0.1:3306/user username: root password: root # druid 连接池 type: com.alibaba.druid.pool.DruidDataSource driver-class-name: com.mysql.jdbc.Driver filters: stat maxActive: 20 initialSize: 1 maxWait: 60000 minIdle: 1 timeBetweenEvictionRunsMillis: 60000 minEvictableIdleTimeMillis: 300000 validationQuery: select 'x' testWhileIdle: true testOnBorrow: false testOnReturn: false poolPreparedStatements: true maxOpenPreparedStatements: 20 mybatis: mapper-locations: classpath:mapping/*.xml type-aliases-package: com.fant.model #pagehelper分页插件 pagehelper: helperDialect: mysql reasonable: true supportMethodsArguments: true params: count=countSql 运行generator工程 自动生成代码 生成的文件 User.java package com.fantj.model; import java.util.Date; public class User { private Integer id; private String username; private Date birthday; private String sex; private String address; public Integer getId() { return id; } public void setId(Integer id) { this.id = id; } public String getUsername() { return username; } public void setUsername(String username) { this.username = username == null ? null : username.trim(); } public Date getBirthday() { return birthday; } public void setBirthday(Date birthday) { this.birthday = birthday; } public String getSex() { return sex; } public void setSex(String sex) { this.sex = sex == null ? null : sex.trim(); } public String getAddress() { return address; } public void setAddress(String address) { this.address = address == null ? null : address.trim(); } } UserMapper .java package com.fantj.mapper; import com.fantj.model.User; import java.util.List; public interface UserMapper { int deleteByPrimaryKey(Integer id); int insert(User record); int insertSelective(User record); User selectByPrimaryKey(Integer id); int updateByPrimaryKeySelective(User record); int updateByPrimaryKey(User record); List<User> selectAll(); } UserMapper.xml <?xml version="1.0" encoding="UTF-8" ?> <!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd" > <mapper namespace="com.fantj.mapper.UserMapper" > <resultMap id="BaseResultMap" type="com.fantj.model.User" > <id column="id" property="id" jdbcType="INTEGER" /> <result column="username" property="username" jdbcType="VARCHAR" /> <result column="birthday" property="birthday" jdbcType="DATE" /> <result column="sex" property="sex" jdbcType="CHAR" /> <result column="address" property="address" jdbcType="VARCHAR" /> </resultMap> <sql id="Base_Column_List" > id, username, birthday, sex, address </sql> <select id="selectAll" resultMap="BaseResultMap" > select <include refid="Base_Column_List" /> from user </select> <select id="selectByPrimaryKey" resultMap="BaseResultMap" parameterType="java.lang.Integer" > select <include refid="Base_Column_List" /> from user where id = #{id,jdbcType=INTEGER} </select> <delete id="deleteByPrimaryKey" parameterType="java.lang.Integer" > delete from user where id = #{id,jdbcType=INTEGER} </delete> <insert id="insert" parameterType="com.fantj.model.User" > insert into user (id, username, birthday, sex, address) values (#{id,jdbcType=INTEGER}, #{username,jdbcType=VARCHAR}, #{birthday,jdbcType=DATE}, #{sex,jdbcType=CHAR}, #{address,jdbcType=VARCHAR}) </insert> <insert id="insertSelective" parameterType="com.fantj.model.User" > insert into user <trim prefix="(" suffix=")" suffixOverrides="," > <if test="id != null" > id, </if> <if test="username != null" > username, </if> <if test="birthday != null" > birthday, </if> <if test="sex != null" > sex, </if> <if test="address != null" > address, </if> </trim> <trim prefix="values (" suffix=")" suffixOverrides="," > <if test="id != null" > #{id,jdbcType=INTEGER}, </if> <if test="username != null" > #{username,jdbcType=VARCHAR}, </if> <if test="birthday != null" > #{birthday,jdbcType=DATE}, </if> <if test="sex != null" > #{sex,jdbcType=CHAR}, </if> <if test="address != null" > #{address,jdbcType=VARCHAR}, </if> </trim> </insert> <update id="updateByPrimaryKeySelective" parameterType="com.fantj.model.User" > update user <set > <if test="username != null" > username = #{username,jdbcType=VARCHAR}, </if> <if test="birthday != null" > birthday = #{birthday,jdbcType=DATE}, </if> <if test="sex != null" > sex = #{sex,jdbcType=CHAR}, </if> <if test="address != null" > address = #{address,jdbcType=VARCHAR}, </if> </set> where id = #{id,jdbcType=INTEGER} </update> <update id="updateByPrimaryKey" parameterType="com.fantj.model.User" > update user set username = #{username,jdbcType=VARCHAR}, birthday = #{birthday,jdbcType=DATE}, sex = #{sex,jdbcType=CHAR}, address = #{address,jdbcType=VARCHAR} where id = #{id,jdbcType=INTEGER} </update> </mapper> 修改启动类 逆向生成代码后，我们还需要在启动类上添加一个@MapperScan("com.fantj.mapper")注解，告诉我们的Mapper需要扫描的包，这样就不用每个Mapper上都添加@Mapper注解了。 @SpringBootApplication @MapperScan("com.fantj.mapper") public class MybatisApplication { public static void main(String[] args) { SpringApplication.run(MybatisApplication.class, args); } } 完善controller和service UserController.java @RestController @RequestMapping("/user") public class UserController { @Autowired private UserService userService; @RequestMapping(method = RequestMethod.GET,value = "/delete/{id}") public void delete(@PathVariable("id")int id){ userService.delete(id); } @RequestMapping(method = RequestMethod.POST,value = "/insert") public void insert(User user){ userService.insert(user); } @RequestMapping(method = RequestMethod.POST,value = "/update/{id}") public void update(@RequestParam User user){ userService.update(user); } @RequestMapping(method = RequestMethod.GET,value = "/{id}/select") public User select(@PathVariable("id")int id){ return userService.selectById(id); } @RequestMapping(method = RequestMethod.GET,value = "/selectAll/{pageNum}/{pageSize}") public List<User> selectAll(@PathVariable("pageNum") int pageNum, @PathVariable("pageSize") int pageSize){ return userService.selectAll(pageNum,pageSize); } } UserService.java package com.fantj.service; import com.fantj.model.User; import java.util.List; public interface UserService { /** 删除 */ public void delete(int id); /** 增加*/ public void insert(User user); /** 更新*/ public int update(User user); /** 查询单个*/ public User selectById(int id); /** 查询全部列表*/ public List<User> selectAll(int pageNum, int pageSize); } UserServiceImpl .java @Service public class UserServiceImpl implements UserService { @Autowired private UserMapper userMapper; /** * 删除 * * @param id */ @Override public void delete(int id) { userMapper.deleteByPrimaryKey(id); } /** * 增加 * * @param user */ @Override public void insert(User user) { userMapper.insert(user); } /** * 更新 * * @param user */ @Override public int update(User user) { return userMapper.updateByPrimaryKey(user); } /** * 查询单个 * * @param id */ @Override public User selectById(int id) { return userMapper.selectByPrimaryKey(id); } /** * 查询全部列表,并做分页 * * @param pageNum 开始页数 * @param pageSize 每页显示的数据条数 */ @Override public List<User> selectAll(int pageNum, int pageSize) { //将参数传给这个方法就可以实现物理分页了，非常简单。 PageHelper.startPage(pageNum,pageSize); return userMapper.selectAll(); } } 浏览器访问127.0.0.1/user/selectAll/0/1 说明我们成功了。 一个小甜点 有人问，get方法可以直接从浏览器地址中的url来测试，那post请求怎么测试呢？ 个人建议用postman工具，也可以写测试类用代码来完成测试。也可以使用idea的一个测试工具Test RESTful Web Service 注解方式 好了，配置方式我们介绍完了，我在这里稍微聊一聊注解开发方式，个人建议如果想用注解开发，直接用jpa，可以更方便自己的开发。 mybatis java api ：http://www.mybatis.org/mybatis-3/zh/java-api.html UserMapper.java package com.fantj.mapper; import com.fantj.model.User; import org.apache.ibatis.annotations.*; import java.util.List; public interface UserMapper { /*int deleteByPrimaryKey(Integer id); int insert(User record); int insertSelective(User record); User selectByPrimaryKey(Integer id); int updateByPrimaryKeySelective(User record); int updateByPrimaryKey(User record); List<User> selectAll();*/ //如果实例对象中的属性名和数据表中字段名不一致，用@Result注解进行说明映射关系，我在这里只是告诉你怎么写 @Select("SELECT * FROM user") @Results({ @Result(property = "username", column = "username"), @Result(property = "sex", column = "sex"), @Result(property = "address",column = "address") }) List<User> selectAll(); @Select("SELECT * FROM user WHERE id = #{id}") @Results({ @Result(property = "sex", column = "sex"), @Result(property = "username", column = "username") }) User selectByPrimaryKey(int id); @Insert({"INSERT INTO user(username,birthday,sex,address}) VALUES(#{userName}, #{birthday}, #{sex},#{address})"}) void insert(User user); @Update("UPDATE user SET userName=#{userName} WHERE id =#{id}") int updateByPrimaryKey(User user); @Delete("DELETE FROM user WHERE id =#{id}") int deleteByPrimaryKey(int id); } 注解的一些解释 @Select 是查询类的注解，所有的查询均使用这个 @Result 修饰返回的结果集，关联实体类属性和数据库字段一一对应，如果实体类* 属性和数据库属性名保持一致，就不需要这个属性来修饰。 @Insert 插入数据库使用，直接传入实体类会自动解析属性到对应的值 @Update 负责修改，也可以直接传入对象 @delete 负责删除 注意将application配置文件中的mybatis.mapper-locations:属性注视掉再启动项目。否则它会报错：Mapped Statements collection already contains value for com.fantj.mapper.UserMapper.insert 。意思是mapper中方法重复。 最后一个甜点 还有一个东西忘说了 -.-,就是用cmd来逆向生成代码。 声称语句 java -jar mybatis-generator-core-1.3.2.jar -configfile generator.xml -overwrite src目录请忽略，这是生成的目录。 好了 干货都分享了，谢谢大家。0.0
