springboot实战(二)——springdatajpa(持

1.修改User实体类代码

@Entity         //  实体
public class User {

    @Id         //主键
    @GeneratedValue(strategy = GenerationType.IDENTITY) //自增策略
    private Long id;        //实体一个唯一标识
    private String name;
    private String email;

    protected User() {          //无参构造函数;设为protected 防止直接使用
    }

    public User(Long id, String name, String email) {
        this.id = id;
        this.name = name;
        this.email = email;
    }

    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 String getEmail() {
        return email;
    }

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

    @Override
    public String toString() {
        return "User{" +
                "id=" + id +
                ", name='" + name + '\'' +
                ", email='" + email + '\'' +
                '}';
    }
}

2.修改UserRepository接口，并删除UserRepositoryImpl实现类

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

3.在mysql里面创建students数据库(不需要建表)
修改application.properties配置文件里的内容,username和password可根据自行修改

spring.datasource.url=jdbc:mysql://localhost:3306/students?characterEncoding=utf-8&useSSL=true&serverTimezone=GMT
spring.datasource.username=root
spring.datasource.password=123456
spring.jpa.database=mysql
spring.jpa.show-sql=true
spring.jpa.hibernate.ddl-auto=update

spring.mvc.view.prefix=/
spring.mvc.view.suffix=.html

spring.thymeleaf.mode=HTML5
spring.thymeleaf.encoding=UTF-8
spring.thymeleaf.cache=false

4.修改UserController

@RestController
@RequestMapping("/users")
public class UserController {
    @Autowired
    private UserRepository userRepository;

    /**
    *@description: 查询所有的用户
    *@author: 一条懒咸鱼
    *@Date: 22:26 2018/10/2
    **/
    @GetMapping
    public ModelAndView list(Model model){
        System.out.println("=============list==============");
        model.addAttribute("userList", userRepository.findAll());
        model.addAttribute("title", "用户管理");
        return new ModelAndView("list", "userModel",model);
    }

    /**
    *@description: 根据id查询用户
    *@author: 一条懒咸鱼
    *@Date: 22:32 2018/10/2
    **/
    @GetMapping("{id}")
    public ModelAndView view(@PathVariable("id") Long id, Model model){
        User user = userRepository.findById(id).get();
        model.addAttribute("user", user);
        model.addAttribute("title", "查看用户");
        return new ModelAndView("view", "userModel",model);
    }

    /**
    *@description: 获取创建表单页面
    *@author: 一条懒咸鱼
    *@Date: 22:34 2018/10/2
    **/
    @GetMapping("/form")
    public ModelAndView createForm(Model model){
        model.addAttribute("user", new User(null,null, null));
        model.addAttribute("title", "创建用户");
        return new ModelAndView("form", "userModel",model);
    }
    
    /**
    *@description: 保存或者修改用户
    *@author:一条懒咸鱼
    *@Date: 22:38 2018/10/2
    **/
    @PostMapping
    public ModelAndView saveOrUpdateUser(User user){
        userRepository.save(user);
        return new ModelAndView("redirect:/users"); //重定向到list页面
    }
    
    /**
    *@description: 删除用户
    *@author: 一条懒咸鱼
    *@Date: 23:15 2018/10/2
    **/
    @GetMapping("/delete/{id}")
    public ModelAndView delete(@PathVariable("id") Long id){
        userRepository.deleteById(id);
        return new ModelAndView("redirect:/users"); //重定向到list页面
    }
    
    /**
    *@description: 获取修改用户的界面
    *@author: 一条懒咸鱼
    *@Date: 21:39 2018/10/3
    **/
    @GetMapping("/modify/{id}")
    public ModelAndView modify(@PathVariable("id") Long id, Model model){
        User user = userRepository.findById(id).get();
        model.addAttribute("user", user);
        model.addAttribute("title", "修改用户");
        return new ModelAndView("form","userModel", model);
    }
}

5.启动测试,数据便会持久化到mysql数据库里面了。