springboot （四）spring data jpa
添加pom依赖
<!-- mysql驱动:com.mysql.jdbc.Driver -->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
</dependency>
<!-- SpringData-Jpa依赖-->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-jpa</artifactId>
</dependency>建表，编写实体 User.java
@Entity(name = "user")
public class User implements Serializable {
@Id
@GeneratedValue(strategy = GenerationType.AUTO)
Long id;
@Column(name = "name")
String name;
@Column(name = "age")
Integer age;
public Long getId() {
return id;
}
public void setId(Long id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public Integer getAge() {
return age;
}
public void setAge(Integer age) {
this.age = age;
}
}编写dao和service
@Repository
public interface UserRepository extends JpaRepository<User, Long> {
@Query("select p from user p where p.name=:name ")
List<User> findByName(@Param(value = "name") String name);
}UserService 接口
public interface UserService {
List<User> findListByName(String name);
}UserServiceImpl 实现类
@Service
@Transactional(rollbackFor = Exception.class)
public class UserServiceImpl implements UserService {
@Autowired
private UserRepository userRepository;
@Override
public List<User> findListByName(String name) {
if (name == null || name.trim().isEmpty()) {
return null;
}
return userRepository.findByName(name);
}
}编写controller和页面
@Controller
@RequestMapping("/user")
public class UserController {
@Autowired
UserService userService;
@RequestMapping(value = "/")
public String user() {
return "/user";
}
@ResponseBody
@RequestMapping(value = "/findListByUserName")
public Map<String, Object> findListByUserName(@RequestParam(name = "uname") String name) {
Map<String, Object> map = new HashMap<>();
List<User> userList = userService.findListByName(name);
map.put("msg", "处理成功");
map.put("data", userList);
return map;
}
}user.html 页面代码
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>用户界面</title>
</head>
<body>
<h2>添加用户</h2>
<form method="post" action="./addUser">
<label>用户名:</label><input type="text" name="uname">
<label>年龄:</label><input type="number" name="age">
<input type="submit" value="添加"/>
</form>
<form method="post" action="./findListByUserName">
<label>用户名:</label><input type="text" name="uname">
<input type="submit" value="查找用户"/>
</form>
</body>
</html>基于上篇文章，先添加几个用户实体，再查找。效果如下图：
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