IntelliJ IDEA Spring Boot(3) 数据库JDBC的使用

   学习web技术，任何新的东西我总是想着要去与数据库打交道。这篇我来学习如何用springboot 集成数据库的使用。这里简单的集成mysql和jdbcTemplate。所有的框架集成都是由少到多的嘛。

   首先我们在pom文件中加上依赖

   org.springframework.boot
   spring-boot-starter-jdbc
   
      
         org.apache.tomcat
         tomcat-jdbc
      
   


   mysql
   mysql-connector-java
   5.1.44


   com.alibaba
   druid
   1.0.31

接下来，我们配置mysql的东西，最起码用户名密码什么的吧。在application.properties文件中配置如下代码

#mysql
spring.datasource.driver-class-name= com.mysql.jdbc.Driver
spring.datasource.url=jdbc\:mysql\://localhost\:3306/dadmin?useUnicode\=true&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

开启事务驱动

@SpringBootApplication
@EnableTransactionManagement
public class SpringbootApplication {
   public static void main(String[] args) {
      SpringApplication.run(SpringbootApplication.class, args);
   }

}

接下来，跑起来。一切正常。

接下来。创建一个实体类和对应的表，进行简单的增删改查。

public class SystemUser implements Serializable {

    private String uuid;     // 表主键
    private String username; // 登录用户名
    private String password; // 登录密码
    private String isRoot; // 最高权限管理员; "1":root "0": notRoot
    @JsonFormat(pattern = "yyyy-MM-dd HH:mm:ss")
    private Date registerDate;
    private Integer status; // 账号状态： 0：正常；1：禁用

public interface SystemUserDao {

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

}

public interface SystemUserService {

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

}

@Repository("systemUserDao")
public class SystemUserDaoImpl implements SystemUserDao{

    @Autowired
    JdbcTemplate jdbcTemplate;

    static class UserRowMapper implements RowMapper{
        @Override
        public SystemUser mapRow(ResultSet rs, int rowNum) throws SQLException {
            SystemUser systemUser = new SystemUser();
            systemUser.setUuid(rs.getString("uuid"));
            systemUser.setUsername(rs.getString("username"));
            systemUser.setPassword(rs.getString("password"));
            systemUser.setIsRoot(rs.getString("isRoot"));
            systemUser.setRegisterDate(new java.util.Date(rs.getDate("registerDate").getTime()));
            systemUser.setStatus(rs.getInt("status"));
            // if the value is SQL NULL, the value returned is 0
            // 如果希望得到null，可以getObject()判断是否为null
            return systemUser;
        }
    }

    @Override
    public SystemUser findUserByUsername(String username) {
        List list = jdbcTemplate.query(
                "select * from system_user where username=?",
                new Object[]{username},
                new int[]{Types.VARCHAR},
                new UserRowMapper()
                );
        if(null!=list&&!list.isEmpty()){
            return list.get(0);
        }
        return null;
    }

    @Override
    public List findAllUser() {
        return jdbcTemplate.query("select * from system_user",new UserRowMapper());
    }

    @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()));
                ps.setInt(6,user.getStatus());
                return ps;
            }
        });
        return user.getUuid();
    }

    @Override
    public void deleteUserByUUID(String uuid) {
        jdbcTemplate.update("delete from system_user where uuid=?",
                new Object[]{uuid},
                new int[]{Types.VARCHAR});
    }

    @Override
    public void updateUser(SystemUser user) {
        jdbcTemplate.update(
                "update system_user set password=?,status=? where uuid=?",
                new Object[]{user.getPassword(), user.getStatus(), user.getUuid()});
    }
}

@Service("systemUserService")
public class SystemUserServiceImpl implements SystemUserService{

    @Autowired
    SystemUserDao systemUserDao;

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

    @Transactional(readOnly = true)
    @Override
    public List findAllUser() {
        return systemUserDao.findAllUser();
    }

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

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

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

解析来，我们来做单元测试，暂时不做业务逻辑处理。

日志级别调整成debug

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

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

    @Autowired
    SystemUserService systemUserService;

    @Test
    public void saveUser(){
        SystemUser user = new SystemUser();
        user.setStatus(0);
        user.setRegisterDate(new Date());
        user.setPassword("123456");
        user.setIsRoot("0");
        user.setUsername("testZhang1");
       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 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");
    }

我们举其中一个例子，来看看log 日志

看到log日志中关键信息，表示 我们这次写的完全正确。

  由此，我来写一个简单的登录案例

class="form-bottom">
    
role="form" action="index.html" th:action="@{/admin/login.do}" method="post" class="login-form">
        
class="form-group">
            class="sr-only" for="form-username">Username                 type="text" name="username" placeholder="请输入用户名"
                class="form-username form-control" id="form-username" />
        
        
class="form-group">
            class="sr-only" for="form-password">Password                 type="password" name="password" placeholder="请输入密码"
                class="form-password form-control" id="form-password" />
        
        type="submit" class="btn">登 陆
    

看到 action和 th:action了吗？ 静态的action，（写静态action，只是为了在使用本地html展示的时候，便于看到效果）th:action就是web应用发挥作用的url。

日志级别还是调回 info； debug级别运行application太慢了。Controller中补充登录逻辑代码。随后我们修改一下表单

@Autowired
SystemUserService systemUserService;

@RequestMapping("/admin/login.do")
public String adminLoginDo(String username, String password, Map,Object> map){
   SystemUser systemUser= systemUserService.findUserByUsername(username);
    if(null==systemUser){
        map.put("loginResult","用户名不存在");
        return  "admin/login";
    }else if(!password.equals(systemUser.getPassword())){
        map.put("loginResult","密码错误");
        return  "admin/login";
    }else{
        // 登录成功！
        return "admin/index";
    }
}

role="form" action="index.html" th:action="@{/admin/login.do}" method="post" class="login-form">
    
class="form-group">
        th:text="${loginResult}" style="color: red">
    
    
class="form-group">
        class="sr-only" for="form-username">Username             type="text" name="username" placeholder="请输入用户名"
            class="form-username form-control" id="form-username" />
    
    
class="form-group">
        class="sr-only" for="form-password">Password             type="password" name="password" placeholder="请输入密码"
            class="form-password form-control" id="form-password" />
    
    type="submit" class="btn">登 陆

这样，一个简单的登录逻辑功能，就使用 spring boot 完成了。本篇博客到此结束。