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

<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-jdbc</artifactId>
<exclusions>
<exclusion><!--排除默认的数据源 -->
<groupId>org.apache.tomcat</groupId>
<artifactId>tomcat-jdbc</artifactId>
</exclusion>
</exclusions>
</dependency>
<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>

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

}

public interface SystemUserService {

SystemUser findUserByUsername(String username);
List<SystemUser> 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<SystemUser>{
@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<SystemUser> 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<SystemUser> 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<SystemUser> 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<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

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

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<String,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";
}
}

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

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。