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SpringBoot集成Mybatis(0配置注解版)详解编程语言

• 编程笔记

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可以根据表结构自动生成实体类、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，发展到最顶端就是今天要讲的这种模式，mybatis-spring-boot-starter就是springboot+mybatis完全注解不用任何配置文件，就可以简单配置轻松上手。

mybatis-spring-boot-starter主要有两种解决方案，一种是使用注解解决一切问题，一种是简化后的老传统。

以注解版的方式进行讲解。

users表结构

CREATE TABLE `users` ( 
  `id` bigint(20) NOT NULL AUTO_INCREMENT COMMENT '主键id', 
  `username` varchar(32) DEFAULT NULL COMMENT '用户名', 
  `password` varchar(32) DEFAULT NULL COMMENT '密码', 
  `sex` varchar(32) DEFAULT NULL, 
  `nick_name` varchar(32) DEFAULT NULL, 
  PRIMARY KEY (`id`), 
  UNIQUE KEY `username` (`username`) USING HASH 
) ENGINE=InnoDB AUTO_INCREMENT=39 DEFAULT CHARSET=utf8;

 

1、添加pom文件

<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>com.lynch.springboot</groupId> 
    <artifactId>spring-boot-mybatis-annotation</artifactId> 
    <version>0.0.1-SNAPSHOT</version> 
 
    <parent> 
        <groupId>org.springframework.boot</groupId> 
        <artifactId>spring-boot-starter-parent</artifactId> 
        <version>1.5.10.RELEASE</version> 
    </parent> 
 
    <properties> 
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding> 
        <java.version>1.8</java.version> 
    </properties> 
 
    <dependencies> 
        <dependency> 
            <groupId>org.springframework.boot</groupId> 
            <artifactId>spring-boot-starter</artifactId> 
        </dependency> 
        <dependency> 
            <groupId>org.springframework.boot</groupId> 
            <artifactId>spring-boot-starter-test</artifactId> 
            <scope>test</scope> 
        </dependency> 
        <dependency> 
            <groupId>org.springframework.boot</groupId> 
            <artifactId>spring-boot-starter-web</artifactId> 
        </dependency> 
        <dependency> 
            <groupId>org.mybatis.spring.boot</groupId> 
            <artifactId>mybatis-spring-boot-starter</artifactId> 
            <version>1.3.2</version> 
        </dependency> 
        <!-- mybatis分页插件 --> 
        <dependency> 
            <groupId>com.github.pagehelper</groupId> 
            <artifactId>pagehelper-spring-boot-starter</artifactId> 
            <version>1.1.1</version> 
        </dependency> 
        <dependency> 
            <groupId>mysql</groupId> 
            <artifactId>mysql-connector-java</artifactId> 
        </dependency> 
        <dependency> 
            <groupId>org.springframework.boot</groupId> 
            <artifactId>spring-boot-devtools</artifactId> 
            <optional>true</optional> 
        </dependency> 
    </dependencies> 
 
    <build> 
        <plugins> 
            <plugin> 
                <groupId>org.springframework.boot</groupId> 
                <artifactId>spring-boot-maven-plugin</artifactId> 
            </plugin> 
        </plugins> 
    </build> 
</project>

 

2、application.properties 添加相关配置

#mybatis.type-aliases-package=com.lynch.entity 
 
spring.datasource.driverClassName = com.mysql.jdbc.Driver 
spring.datasource.url = jdbc:mysql://192.168.1.149:3306/aa?useUnicode=true&characterEncoding=utf-8&useSSL=false 
spring.datasource.username = root 
spring.datasource.password = attack

springboot会自动加载spring.datasource.*相关配置，数据源就会自动注入到sqlSessionFactory中，sqlSessionFactory会自动注入到Mapper中，对于开发人员不用管，直接拿来使用即可。

[email protected]

package com.lynch; 
 
import org.mybatis.spring.annotation.MapperScan; 
import org.springframework.boot.SpringApplication; 
import org.springframework.boot.autoconfigure.SpringBootApplication; 
 
@SpringBootApplication 
@MapperScan("com.lynch.mapper") 
public class Application { 
 
    public static void main(String[] args) { 
        SpringApplication.run(Application.class, args); 
    } 
}

[email protected]，建议使用上面那种，不然每个mapper加个注解也挺麻烦的。

3、开发Mapper

package com.lynch.mapper; 
 
import java.util.List; 
 
import org.apache.ibatis.annotations.Delete; 
import org.apache.ibatis.annotations.Insert; 
import org.apache.ibatis.annotations.InsertProvider; 
import org.apache.ibatis.annotations.Param; 
import org.apache.ibatis.annotations.Result; 
import org.apache.ibatis.annotations.Results; 
import org.apache.ibatis.annotations.Select; 
import org.apache.ibatis.annotations.SelectProvider; 
import org.apache.ibatis.annotations.Update; 
import org.apache.ibatis.annotations.UpdateProvider; 
 
import com.lynch.entity.UserEntity; 
import com.lynch.enums.SexEnum; 
 
public interface UserMapper { 
 
    @Select("SELECT * FROM users") 
    @Results({ @Result(property = "sex", column = "sex", javaType = SexEnum.class), 
               @Result(property = "nickName", column = "nick_name") }) 
    List<UserEntity> getAll(); 
 
    @Select("SELECT * FROM users WHERE id = #{id}") 
    @Results({ @Result(property = "sex", column = "sex", javaType = SexEnum.class), 
            @Result(property = "nickName", column = "nick_name") }) 
    UserEntity getOne(Long id); 
 
    @Insert("insert into users(username,password,sex) values(#{username}, #{password}, #{sex})") 
    int insert(UserEntity user); 
     
    @Update("UPDATE users SET userName=#{username},nick_name=#{nickName} WHERE id =#{id}") 
    void update(UserEntity user); 
 
    @Delete("DELETE FROM users WHERE id =#{id}") 
    void delete(Long id); 
     
    @InsertProvider(type=UserProvider.class, method = "batchInsert") 
    int batchInsert(@Param("userList")List<UserEntity> userList); 
     
    @SelectProvider(type = UserProvider.class, method = "queryUser") 
    @Results({  
        @Result(property = "sex", column = "sex", javaType = SexEnum.class), 
        @Result(property = "nickName", column = "nick_name")  
    }) 
    public List<UserEntity> queryUser(UserEntity user); 
     
    @UpdateProvider(type = UserProvider.class, method = "updateUser") 
    public int updateUser(@Param("U")UserEntity user); 
}
package com.lynch.mapper; 
 
import java.util.List; 
import java.util.Map; 
 
import org.apache.ibatis.annotations.Param; 
import org.apache.ibatis.jdbc.SQL; 
 
import com.github.pagehelper.util.StringUtil; 
import com.lynch.entity.UserEntity; 
 
/** 
 * [email protected] 
 *  
 * @author Lynch 
 * 
 */ 
public class UserProvider { 
    public String queryUser(UserEntity user) { 
        StringBuffer sql = new StringBuffer("select * from users where 1=1 "); 
        if(StringUtil.isNotEmpty(user.getUsername())) { 
            sql.append(String.format("and username like '%s'", "%"+user.getUsername()+"%")); 
        } 
         
        return sql.toString(); 
    } 
     
    public String batchInsert(Map map) { 
        List<UserEntity> userList = (List<UserEntity>)map.get("userList"); 
        StringBuffer sql = new StringBuffer("insert into users (username,password) values "); 
         
        for(UserEntity user : userList) { 
            sql.append(String.format("('%s', '%s'),", user.getUsername(), user.getPassword())); 
        } 
         
        sql = sql.deleteCharAt(sql.length() -1); 
        System.out.println(sql.toString()); 
        return sql.toString(); 
    } 
     
    public String updateUser(@Param("U")UserEntity user) { 
            SQL sql = new SQL(){{ 
            UPDATE("users"); 
             
            if (StringUtil.isNotEmpty(user.getNickName())){ 
                SET("nick_name = #{U.nickName}"); 
            } 
             
            WHERE("id = #{U.id}"); 
        }}; 
         
        return sql.toString(); 
    } 
     
 
}

 

注意，使用#符号和$符号的不同：

// This example creates a prepared statement, something like select * from teacher where name = ?; 
@Select("Select * from teacher where name = #{name}") 
Teacher selectTeachForGivenName(@Param("name") String name); 
 
// This example creates n inlined statement, something like select * from teacher where name = 'someName'; 
@Select("Select * from teacher where name = '${name}'") 
Teacher selectTeachForGivenName(@Param("name") String name);

4、单元测试

package com.lynch.mapper; 
 
import java.util.ArrayList; 
import java.util.List; 
 
import org.junit.Test; 
import org.junit.runner.RunWith; 
import org.springframework.beans.factory.annotation.Autowired; 
import org.springframework.boot.test.context.SpringBootTest; 
import org.springframework.test.context.junit4.SpringRunner; 
 
import com.lynch.entity.UserEntity; 
import com.lynch.enums.SexEnum; 
 
@RunWith(SpringRunner.class) 
@SpringBootTest 
public class UserMapperTest { 
 
    @Autowired 
    private UserMapper userMapper; 
 
    @Test 
    public void insert() throws Exception { 
        int result = 0; 
        try { 
            result = userMapper.insert(new UserEntity("lisi", "123456", SexEnum.MAN)); 
        } catch (Exception e) { 
            System.out.println(e.getMessage().indexOf("ConstraintViolationException")); 
        } 
        System.out.println("result=" + result); 
    } 
     
    @Test 
    public void batchInsert() throws Exception { 
        List<UserEntity> userList = new ArrayList<UserEntity>(); 
        userList.add(new UserEntity("a","a",SexEnum.MAN)); 
        userList.add(new UserEntity("c","b",SexEnum.MAN)); 
        userList.add(new UserEntity("b","b",SexEnum.WOMAN)); 
         
        System.out.println("result=" + userMapper.batchInsert(userList));  
    } 
 
 
    @Test 
    public void getAll() throws Exception { 
        List<UserEntity> users = userMapper.getAll(); 
        System.out.println(users.toString()); 
    } 
 
    @Test 
    public void testUpdate() throws Exception { 
        UserEntity user = userMapper.getOne(45L); 
        System.out.println(user.toString()); 
        user.setNickName("neo"); 
        user.setSex(SexEnum.WOMAN); 
        userMapper.update(user); 
    } 
     
    @Test 
    public void queryUser() throws Exception { 
        UserEntity user = new UserEntity(); 
        user.setUsername("l"); 
        System.out.println(userMapper.queryUser(user));  
    } 
     
    @Test 
    public void updateUser() throws Exception { 
        UserEntity user = new UserEntity(); 
        user.setId(45L); 
        user.setNickName("aaa"); 
        System.out.println(userMapper.updateUser(user));  
    } 
 
}

 

 

原创文章，作者：奋斗，如若转载，请注明出处：https://blog.ytso.com/16117.html

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