springboot结合jpa的简单使用

1.映入jpa依赖

 <!--JPA-->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
        </dependency>

2.编写数据库对应实体

@Entity
@Table(name = "user")
public class User implements Serializable {
    private static final long serialVersionUID = 1L;

    @Id
    @GeneratedValue
    private Long id;
    @Column(nullable = false,unique = true)
    private String userName;
    @Column(nullable = false)
    private String passWord;
    @Column(nullable = false,unique = true)
    private String email;
    @Column(nullable = false,unique = true)
    private String nickName;
    @Column(nullable = false)
    private String regTime;

    public User(){

    }

    public User(String userName, String passWord, String email, String nickName, String regTime) {
        this.userName = userName;
        this.passWord = passWord;
        this.email = email;
        this.nickName = nickName;
        this.regTime = regTime;
    }

    public Long getId() {
        return id;
    }

    public void setId(Long id) {
        this.id = id;
    }

    public String getUserName() {
        return userName;
    }

    public void setUserName(String userName) {
        this.userName = userName;
    }

    public String getPassWord() {
        return passWord;
    }

    public void setPassWord(String passWord) {
        this.passWord = passWord;
    }

    public String getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }

    public String getNickName() {
        return nickName;
    }

    public void setNickName(String nickName) {
        this.nickName = nickName;
    }

    public String getRegTime() {
        return regTime;
    }

    public void setRegTime(String regTime) {
        this.regTime = regTime;
    }
}

3.编写UserRepository继承于JpaRepository，JpaRepository中默认实现了多个方法，包括增删改查。其中Jpa提供多个数据接口，如：
a.CrudRepository 增删改查接口
b.PagingAndSortingRepository分页或 查询接口，继承与CrudRepository接口。
c.可以再实际需求自定义查询接口

public interface UserRepository extends JpaRepository<User,Long> {
}

4.在Controller中调用，使用 @Autowired引入UserRepository

@Autowired
    private UserRepository userRepository;


    @RequestMapping("/home")
    @ResponseBody
    String getProductData(){
        Date date = new Date();
        DateFormat dateFormat = DateFormat.getDateTimeInstance(DateFormat.LONG, DateFormat.LONG);
        String formattedDate = dateFormat.format(date);
        userRepository.save(new User("aa1", "aa@126.com", "aa@126.com", "aa123456",formattedDate));
        //List<User> mList = userRepository.findAll();
        return "success";//+mList.size()
    }