Mybatis环境搭建

1. 配置依赖

将我们第一次创建项目时注释的关于Mybatis与JDBC依赖打开。

    
        
     
      4.0.0
         
     
      online.suiyu
         
     
      springboot-demo
         
     
      0.0.1-SNAPSHOT
         
     
      jar
         
     
      springboot-demo
         
     
      Demo project for Spring Boot
         
             
      
       org.springframework.boot
              
      
       spring-boot-starter-parent
              
      
       2.0.3.RELEASE
              
       
          
         
             
      
       UTF-8
              
      
       UTF-8
              
      
       1.8
          
         
             
              
              
              
              
                  
       
        org.springframework.boot
                   
       
        spring-boot-starter-jdbc
               
              
                  
       
        mysql
                   
       
        mysql-connector-java
                   
       
        runtime
               
              
                  
       
        org.mybatis.spring.boot
                   
       
        mybatis-spring-boot-starter
                   
       
        1.3.2
               
              
                  
       
        org.springframework.boot
                   
       
        spring-boot-starter-web
               
              
                  
       
        org.springframework.boot
                   
       
        spring-boot-starter-test
                   
       
        test
               
              
                  
       
        io.springfox
                   
       
        springfox-swagger2
                   
       
        2.5.0
               
              
                  
       
        io.springfox
                   
       
        springfox-swagger-ui
                   
       
        2.5.0
               
          
         
             
                  
                       
        
         org.springframework.boot
                        
        
         spring-boot-maven-plugin
                    
               
          
     
    复制代码

2. 修改Controller添加访问路径

package online.suiyu.springbootdemo.controller;@Api("测试类")@RestController@RequestMapping("index")public class IndexController {    @Autowired    private UserService userService;    @ApiOperation(value = "index", notes = "测试方法", tags = {
   "hello"})    @RequestMapping(value = "/hello", method = RequestMethod.GET)    public String index() {        return "Hello,World!";    }    @ApiOperation(value = "getAllUser", notes = "获取所有的内容", tags = "user")    @RequestMapping(value = "/getalluser", method = RequestMethod.GET)    public List
    
      getAllUser() {        return userService.getAllUser();    }    @ApiOperation(value = "getUserBySex", notes = "通过性别获取user", tags = "user")    @RequestMapping(value = "/getuserbysex", method = RequestMethod.GET)    public List
     
       getUserBySex(@RequestParam(value = "sex", required = true) String sex) {        return userService.getUserBySex(sex);    }}复制代码
     
    

对于上方代码，IDEA针对@Autowired报了一个警告Spring Team recommends "Always use constructor based dependency injection in your beans. Always use assertions for mandatory dependencies". Spring推荐使用构造器来注入bean 所以，程序中的bean引入应该写成这样：

private final UserDao userDao;@Autowiredpublic UserServiceImpl(UserDao userDao) {    this.userDao = userDao;}复制代码

了解更多，

3. 修改service

package online.suiyu.springbootdemo.service;@Servicepublic class UserService {    @Autowired    private UserMapper userMapper;    public List
    
      getAllUser() {        return userMapper.getAllUser();    }    public List
     
       getUserBySex(String sex) {        return userMapper.getUserBySex(sex);    }}复制代码
     
    

4. 创建mybatis的xml配置文件 namespace名称需要与对应的DAO接口对齐

    
        
             SELECT * from user    
    复制代码

5. 创建与xml配置文件对应的DAO接口 getUserBySex()方法使用了注解形式，简单的增删改查可以使用注解方式。

package online.suiyu.springbootdemo.mapper;@Componentpublic interface UserMapper {    List
    
      getAllUser();    @Select("select * from user where sex = #{sex}")    List
     
       getUserBySex(String sex);}复制代码
     
    

6. 在入口类中添加@MapperScan

@SpringBootApplication@MapperScan("online.suiyu.springbootdemo.mapper")public class SpringbootDemoApplication {    public static void main(String[] args) {        SpringApplication.run(SpringbootDemoApplication.class, args);    }}复制代码

7. 在配置文件application.yml中配置Mybatis

mybatis:  mapper-locations: classpath:mapper/*.xml  type-aliases-package: online.suiyu.springbootdemo.vo复制代码

可以看出配置的主要是resource中的Mapper.xml文件与javabean文件。

至此，SpringBoot整合Mybatis完成，其项目结构为

如果出现异常，一般都是接口与xml文件对不齐。

添加数据库连接池druid

1. 添加druid的maven依赖

    
        
     
      com.alibaba
         
     
      druid
         
     
      1.1.10
     
    复制代码

2. 配置数据库连接池的参数

为程序体添加事务管理

1. 在主程序中添加注解@EnableTransactionManagement开启事务管理
2. 在所需的方法体上加上@Transactional即可

@Override    @Transactional    public boolean addUsers(List
    
      userList) {        logger.info("UserServiceImpl.addUsers开始");        int num = userDao.addUsers(userList);//        int i = 10 / 0;        logger.info("UserServiceImpl.addUsers结束");        return num > 0;    }复制代码