spring boot系列（六）spring boot 配置mybatis(xml简化版)
orm框架的本质是简化编程中操作数据库的编码，发展到现在基本上就剩两家了，一个是宣称可以不用写一句SQL的hibernate，一个是可以灵活调试动态sql的mybatis,两者各有特点，在企业级系统开发中可以根据需求灵活使用。发现一个有趣的现象：传统企业大都喜欢使用hibernate,互联网行业通常使用mybatis。
hibernate特点就是所有的sql都用Java代码来生成，不用跳出程序去写（看）sql，有着编程的完整性，发展到最顶端就是spring data jpa这种模式了，基本上根据方法名就可以生成对应的sql了
mybatis初期使用比较麻烦，需要各种配置文件、实体类、dao层映射关联、还有一大推其它配置。当然mybatis也发现了这种弊端，初期开发了generator可以根据表结果自动生产实体类、配置文件和dao层代码，可以减轻一部分开发量；后期也进行了大量的优化可以使用注解了，自动管理dao层和配置文件等
0 pom.xml增加
<dependency> <groupId>org.mybatis.spring.boot</groupId> <artifactId>mybatis-spring-boot-starter</artifactId> <version>1.3.1</version> </dependency>
1 配置
application.properties新增以下配置：
mybatis.config-locations=classpath:mybatis/mybatis-config.xml
mybatis.mapper-locations=classpath:mybatis/mapper/*.xml
mybatis.type-aliases-package=com.cfj.ceshi.entit
指定了mybatis基础配置文件和实体类映射文件的地址
mybatis-config.xml 配置
<?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> <typeAlias alias="Integer" type="java.lang.Integer" /> <typeAlias alias="Long" type="java.lang.Long" /> <typeAlias alias="HashMap" type="java.util.HashMap" /> <typeAlias alias="LinkedHashMap" type="java.util.LinkedHashMap" /> <typeAlias alias="ArrayList" type="java.util.ArrayList" /> <typeAlias alias="LinkedList" type="java.util.LinkedList" /> </typeAliases> </configuration>
2 添加User映射文件
<?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.cfj.ceshi.mapper.UserMapper" > <resultMap id="BaseResultMap" type="com.cfj.ceshi.entity.UserEntity" > <id column="id" property="id" jdbcType="BIGINT" /> <result column="user_name" property="userName" jdbcType="VARCHAR" /> <result column="pass_word" property="passWord" jdbcType="VARCHAR" /> <result column="user_sex" property="userSex" javaType="com.cfj.ceshi.enums.UserSexEnum"/> <result column="nick_name" property="nickName" jdbcType="VARCHAR" /> </resultMap> <sql id="Base_Column_List" > id, user_name, pass_word, user_sex, nick_name </sql> <select id="getAll" resultMap="BaseResultMap" > SELECT <include refid="Base_Column_List" /> FROM users </select> <select id="getOne" parameterType="java.lang.Long" resultMap="BaseResultMap" > SELECT <include refid="Base_Column_List" /> FROM users WHERE id = #{id} </select> <insert id="insert" parameterType="com.cfj.ceshi.entity.UserEntity" > INSERT INTO users (user_name,pass_word,user_sex) VALUES (#{userName}, #{passWord}, #{userSex}) </insert> <update id="update" parameterType="com.cfj.ceshi.entity.UserEntity" > UPDATE users SET <if test="userName != null">user_name = #{userName},</if> <if test="passWord != null">pass_word = #{passWord},</if> nick_name = #{nickName} WHERE id = #{id} </update> <delete id="delete" parameterType="java.lang.Long" > DELETE FROM users WHERE id =#{id} </delete> </mapper>
3 实体层
package com.cfj.ceshi.entity; import com.cfj.ceshi.enums.UserSexEnum; public class UserEntity { private static final long serialVersionUID = 1L; private Long id; private String userName; private String passWord; private UserSexEnum userSex; private String nickName; public UserEntity() { super(); } public UserEntity(String userName, String passWord, UserSexEnum userSex) { super(); this.passWord = passWord; this.userName = userName; this.userSex = userSex; } public Long getId() { return id; } public void setId(Long id) { this.id = id; } public String getUserName() { return userName; } public void setUserName(String userName) { this.userName = userName; } public String getPassWord() { return passWord; } public void setPassWord(String passWord) { this.passWord = passWord; } public UserSexEnum getUserSex() { return userSex; } public void setUserSex(UserSexEnum userSex) { this.userSex = userSex; } public String getNickName() { return nickName; } public void setNickName(String nickName) { this.nickName = nickName; } @Override public String toString() { // TODO Auto-generated method stub return "userName " + this.userName + ", pasword " + this.passWord + "sex " + userSex.name(); } }
4 Dao层（mapper层）
package com.cfj.ceshi.mapper; import java.util.List; import org.apache.ibatis.annotations.Delete; import org.apache.ibatis.annotations.Insert; import org.apache.ibatis.annotations.Result; import org.apache.ibatis.annotations.Results; import org.apache.ibatis.annotations.Select; import org.apache.ibatis.annotations.Update; import com.cfj.ceshi.entity.UserEntity; import com.cfj.ceshi.enums.UserSexEnum; public interface UserMapper { List<UserEntity> getAll(); UserEntity getOne(Long id); void insert(UserEntity user); void update(UserEntity user); void delete(Long id); }
5 control层（web层）暂时简化掉了service层
package com.cfj.ceshi.web; import java.util.List; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.web.bind.annotation.PathVariable; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RestController; import com.cfj.ceshi.entity.UserEntity; import com.cfj.ceshi.mapper.UserMapper; @RestController public class UserController { @Autowired private UserMapper userMapper; @RequestMapping("/getUsers") public List<UserEntity> getUsers() { List<UserEntity> users=userMapper.getAll(); return users; } @RequestMapping("/getUser") public UserEntity getUser(Long id) { UserEntity user=userMapper.getOne(id); return user; } @RequestMapping("/add") public void save(UserEntity user) { userMapper.insert(user); } @RequestMapping(value="update") public void update(UserEntity user) { userMapper.update(user); } @RequestMapping(value="/delete/{id}") public void delete(@PathVariable("id") Long id) { userMapper.delete(id); } }
