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IntelliJ IDEA Spring Boot学习(4) 集成mybatis

java 来源:梅利奥达斯 23次浏览

     接下来我们学习spring boot 集成一个数据库框架 mybatis。 上一篇 点击打开链接中讲到没有集成其它数据库框架,发现了一个小意外,这里注明一下。

@Override
public String saveUser(SystemUser user) {
    final String sql = "insert into system_user(uuid,username,password,isRoot,registerDate,status) values(?,?,?,?,?,?)";
    user.setUuid(UUID.randomUUID().toString().replace("-",""));
    jdbcTemplate.update(new PreparedStatementCreator() {
        @Override
        public PreparedStatement createPreparedStatement(Connection connection) throws SQLException {
            PreparedStatement ps = connection.prepareStatement(sql);
            ps.setString(1, user.getUuid());
            ps.setString(2, user.getUsername());
            ps.setString(3,user.getPassword());
            ps.setString(4,user.getIsRoot());
            //ps.setDate(5,new java.sql.Date(user.getRegisterDate().getTime()));//丢失时分秒
            ps.setString(5,new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").format(user.getRegisterDate()));
            ps.setInt(6,user.getStatus());
            return ps;
        }
    });
    return user.getUuid();
}

直接插入sql.Date会导致丢失时分秒,所以可以格式化日期成字符串,也可以顺利插入数据库中。依旧是datetime类型。

  不多说了,接下来集成mybatis

<dependency>
   <groupId>mysql</groupId>
   <artifactId>mysql-connector-java</artifactId>
   <version>5.1.44</version>
</dependency>
<dependency>
   <groupId>com.alibaba</groupId>
   <artifactId>druid</artifactId>
   <version>1.0.31</version>
</dependency>

<dependency>
   <groupId>org.mybatis.spring.boot</groupId>
   <artifactId>mybatis-spring-boot-starter</artifactId>
   <version>1.1.1</version>
</dependency>
#mysql
spring.datasource.driver-class-name= com.mysql.jdbc.Driver
spring.datasource.url=jdbc\:mysql\://localhost\:3306/dadmin?useUnicode\=true&amp;characterEncoding\=UTF-8
spring.datasource.username=root
spring.datasource.password=123456

#druid
spring.datasource.type=com.alibaba.druid.pool.DruidDataSource
spring.datasource.filters=stat
spring.datasource.maxActive= 20
spring.datasource.initialSize= 1
spring.datasource.maxWait= 60000
spring.datasource.minIdle =1
spring.datasource.timeBetweenEvictionRunsMillis= 60000
spring.datasource.minEvictableIdleTimeMillis=300000
spring.datasource.validationQuery= select 'x'
spring.datasource.testWhileIdle= true
spring.datasource.testOnBorrow=false
spring.datasource.testOnReturn= false
spring.datasource.poolPreparedStatements=true
spring.datasource.maxOpenPreparedStatements= 20
@SpringBootApplication
@EnableTransactionManagement
@MapperScan("com.dashuai.springboot.mapper")
public class SpringbootApplication {
   public static void main(String[] args) {
      SpringApplication.run(SpringbootApplication.class, args);
   }

}

这里添加了一个注解@MapperScan,用于扫描mapper的。

public interface SystemUserMapper {

    @Select("select * from system_user where username=#{username}")
    //@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。
    SystemUser findUserByUsername(String username);

    @Select("select * from system_user")
    @Results({
            @Result(property = "uuid",  column = "uuid", javaType = String.class),
            @Result(property = "username", column = "username",javaType = String.class),
            @Result(property = "password", column = "password",javaType = String.class),
            @Result(property = "isRoot", column = "isRoot",javaType = String.class),
            @Result(property = "registerDate", column = "registerDate",javaType = java.util.Date.class),
            @Result(property = "status", column = "status",javaType = Integer.class),
    })
    List<SystemUser> findAllUser();

    @Insert("insert into system_user(uuid,username,password,isRoot,registerDate,status) " +
            " values(#{uuid}, #{username}, #{password},#{isRoot},#{registerDate},#{status})")
    void saveUser(SystemUser user);

    @Delete("delete from system_user where uuid =#{uuid}")
    void deleteUserByUUID(String uuid);

    @Update("update system_user set password=#{password},status=#{status} where uuid=#{uuid}")
    void updateUser(SystemUser user);

那么上述SystemUserMapper我们采用注解的方式。做了一个简单的介绍。

 接下来是service层

public interface SystemUserService {

    SystemUser findUserByUsername(String username);
    List<SystemUser> findAllUser();
    String saveUser(SystemUser user);
    void deleteUserByUUID(String uuid);
    void updateUser(SystemUser user);

}

依旧不变

@Service("systemUserServiceMyBatis")
public class SystemMyBatisUserServiceImpl implements SystemUserService {

    @Autowired
    private SystemUserMapper SystemUserMapper;

    @Transactional(readOnly = true)
    @Override
    public SystemUser findUserByUsername(String username) {
        return SystemUserMapper.findUserByUsername(username);
    }

    @Transactional(readOnly = true)
    @Override
    public List<SystemUser> findAllUser() {
        return SystemUserMapper.findAllUser();
    }

    @Transactional
    @Override
    public String saveUser(SystemUser user) {
         SystemUserMapper.saveUser(user);
         return user.getUuid();
    }

    @Transactional
    @Override
    public void deleteUserByUUID(String uuid) {
        SystemUserMapper.deleteUserByUUID(uuid);
    }

    @Transactional
    @Override
    public void updateUser(SystemUser user) {
        SystemUserMapper.updateUser(user);
    }
}

Service层的实现,很简单的完成了。

难怪要用框架,你看看使用mybatis,我就在注解里面写写sql语句,就完成了。


这个小错误请无视,还有就是 变量名与类名是相同的。

编写测试类

@RunWith(SpringJUnit4ClassRunner.class)
@SpringBootTest
public class TestMyBatis {

 Logger logger= LoggerFactory.getLogger(getClass());

    @Resource(name="systemUserServiceMyBatis")
    SystemUserService systemUserService;

    @Test
    public void saveUser1(){
        SystemUser user = new SystemUser();
        user.setStatus(0);
        user.setUuid(UUID.randomUUID().toString().replace("-",""));
        user.setRegisterDate(new Date());
        user.setPassword("123456");
        user.setIsRoot("0");
        user.setUsername("testZhan");
        String uuid= systemUserService.saveUser(user);
        logger.info("增加成功:uuid{}",uuid);
    }

    @Test
    public void findUser1(){
        SystemUser user = systemUserService.findUserByUsername("testZhang");
        logger.info("user:{}",user);
    }

    @Test
    public void findUser2(){
        List<SystemUser> list = systemUserService.findAllUser();
        logger.info("userlist:{}",list);
    }

    @Test
    public void updateUser(){
        SystemUser user = systemUserService.findUserByUsername("testZhang");
        user.setPassword("1234567");
        user.setStatus(1);
        systemUserService.updateUser(user);
    }

    @Test
    public void deleteUser(){
        systemUserService.deleteUserByUUID("cbb0759e58114171bb33437c7db2a276");
    }

我们设置一下日志

logging.file=mylog.log
logging.level.root=info
logging.level.org.springframework=info
logging.level.com.dashuai.springboot.mapper=debug

看看日志输出吧


注解虽然简单,但是有时候业务逻辑复杂,并不是简单的字符串sql就能处理的,所以我研究了一下动态sql,是如何做的呢。

新建一个类

public class DynamicSQLProvider {

    public String getFindUserByUsernameSQL(){
        return "select * from system_user where username=#{username}";
    }

    public String getGoodFindUserByUsernameSQL(){
        return new SQL(){
            {
            SELECT("*");
            FROM("system_user");
            WHERE("username=#{username}");
            }
        }.toString();
    }

}

上面两个方法都行,有时用纯字符串容易出错,所以用下面的。但两种方式都可以

怎么用呢。看下面

public interface SystemUserMapper {

    @SelectProvider(type = DynamicSQLProvider.class,method = "getGoodFindUserByUsernameSQL")
    SystemUser findUserByUsername(String username);

使用注解 @SelectProvider方式简单搞定。


 越来越觉得 spring boot 强大一塌糊涂。以前觉得 mybatis 集成spring什么的,到处拷贝配置,拷贝什么的,哎。 现在看来简单的一塌糊涂嘛。 spring boot 给你100个赞啊。








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