1.pom添加依赖
org.springframework.bootspring-boot-starter-data-jpamysqlmysql-connector-java5.1.42
2.添加数据源配置（DataSource啥的，一系列对象spring boot 都会给你注入的，配置配置即可！）
spring.datasource.url=jdbc:mysql:spring.datasource.username==123456--name=-wait=10000-active=300-on-borrow=-size=20
#=====================jpa config================================ #实体类维护数据库表结构的具体行为：update/create/create-drop/validate/none spring.jpa.hibernate.ddl-auto=none #打印sql语句 spring.jpa.show-sql=true #格式化输出的json字符串 spring.jackson.serialization.indent_output=true
3.新建实体
@Entity
@Table(name="user")public class User {
@Id
@Column(name="id")
@GeneratedValue(strategy = GenerationType.IDENTITY)private Integer id;
@Column(name="number")private String number;
@Column(name="name")private String name;public Integer getId() {return id;
}public void setId(Integer id) {this.id = id;
}public String getNumber() {return number;
}public void setNumber(String number) {this.number = number;
}public String getName() {return name;
}public void setName(String name) {this.name = name;
}
}
4.dao层
public interface UserDao{
User getById(int id);
User getByNumber(String number);int addUser(User user);void deleteUserById(int id);
User updateUser(User user);
}
@Repositorypublic class UserDaoImpl implements UserDao {
@PersistenceContextprivate EntityManager entityManager;
@Overridepublic User getById(int id) {//find by primary keyreturn this.entityManager.find(User.class,id);
}
@Overridepublic User getByNumber(String number) {
Query query = this.entityManager.createQuery("from User u where u.number=:number",User.class);
query.setParameter("number",number);
User user = (User)query.getSingleResult();return user;
}
@Overridepublic int addUser(User user) {this.entityManager.persist(user);//print the id System.out.println(user.getId());return user.getId();
}
@Overridepublic void deleteUserById(int id) {
User user = this.entityManager.find(User.class,id); //关联到记录，方可删除this.entityManager.remove(user);
}
@Overridepublic User updateUser(User user) {
User userNew = this.entityManager.merge(user);return userNew;
}
}
5.service层
public interface UserService {
User getById(int id);
User getByNumber(String number);int addUser(User user,boolean throwEx);void deleteUserById(int id);
User updateUser(User user);
}
@Service
@Transactionalpublic class UserServiceImpl implements UserService {
@Autowiredprivate UserDao userDao;
@Override
@Transactional(readOnly = true)public User getById(int id) {return userDao.getById(id);
}
@Override
@Transactional(readOnly = true)public User getByNumber(String number) {return userDao.getByNumber(number);
}
@Overridepublic int addUser(User user,boolean throwEx) {int id= this.userDao.addUser(user);if(throwEx){throw new RuntimeException("throw a ex");
}return id;
}
@Overridepublic void deleteUserById(int id) {this.userDao.deleteUserById(id);
}
@Overridepublic User updateUser(User user) {return this.userDao.updateUser(user);
}
}
6.controller层
@Controller("user1")
@RequestMapping("/jpa/user")public class UserController {/** * 日志（slf4j->logback） */private static final Logger logger = LoggerFactory.getLogger(UserController.class);
@Autowiredprivate UserService userService;/** * 返回text格式数据
* @param id 主键id
* @return 用户json字符串 */@RequestMapping("/get/id/{id}")
@ResponseBodypublic String getUserById(@PathVariable("id")String id){
logger.info("request /user/get/id/{id}, parameter is "+id);
User user = userService.getById(Integer.parseInt(id));return JSONObject.toJSONString(user);
}/** * 返回json格式数据
* @param number 编号
* @return 用户 */@RequestMapping("/get/number/{number}")
@ResponseBodypublic User getUserByNumber(@PathVariable("number")String number){
User user = userService.getByNumber(number);return user;
}
@RequestMapping("/add/{number}/{name}")
@ResponseBodypublic String addUser(@PathVariable("number")String number,@PathVariable("name")String name,boolean throwEx){
User user = new User();
user.setNumber(number);
user.setName(name);int id = -1;try{
id = userService.addUser(user,throwEx);
}catch (RuntimeException ex){
System.out.println(ex.getMessage());
}return String.valueOf(id);
}
@RequestMapping("/delete/{id}")
@ResponseBodypublic void getUserById(@PathVariable("id")int id){this.userService.deleteUserById(id);
}
@RequestMapping("/update/{id}/{number}/{name}")
@ResponseBodypublic User addUser(@PathVariable("id")int id, @PathVariable("number")String number, @PathVariable("name")String name){
User user = new User();
user.setId(id);
user.setNumber(number);
user.setName(name);return userService.updateUser(user);
}
}
7. spring data jpa新使用方式，更高级