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后端Spring Boot+前端Android交互+MySQL增删查改（Java+Kotlin实现）

来源：SegmentFault 2023-01-09 20:40:01 0浏览收藏

本篇文章向大家介绍《后端Spring Boot+前端Android交互+MySQL增删查改（Java+Kotlin实现）》，主要包括MySQL、android、kotlin，具有一定的参考价值，需要的朋友可以参考一下。

1 前言&概述

这篇文章是基于这篇文章的更新，主要是更新了一些技术栈以及开发工具的版本，还有修复了一些Bug。

本文是

@Entity
@Getter
@Setter
@NoArgsConstructor
@AllArgsConstructor
public class User {
    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private Integer id;

    private String name;
    private String password;
}

基本的

@Repository
public interface UserRepository extends CrudRepository<user> {
    boolean existsByName(String name);
    User findByNameAndPassword(String name,String password);
}</user>

一个需要注意的点是

@Transactional
@Service
@RequiredArgsConstructor(onConstructor = @__(@Autowired))
public class UserService {
    private final UserRepository repository;

    public boolean exists(User user){
        return repository.existsByName(user.getName());
    }

    public User findByNameAndPassword(User user){
        return repository.findByNameAndPassword(user.getName(),user.getPassword());
    }

    public boolean insert(User user){
        repository.save(user);
        return true;
    }

    public boolean update(User user){
        if(repository.findById(user.getId()).isEmpty()){
            return false;
        }
        repository.save(user);
        return true;
    }

    public boolean deleteById(int id){
        if(!repository.existsById(id)){
            return false;
        }
        repository.deleteById(id);
        return true;
    }
}

注解解释如下：

@RestController
@RequestMapping("/")
@RequiredArgsConstructor(onConstructor = @__(@Autowired))
public class UserController {
    private final UserService service;

    @PostMapping("sign/in/up")
    public ResponseBody signInUp(@RequestBody User user) {
        if (service.exists(user)) {
            User u = service.findByNameAndPassword(user);
            return new ResponseBody(u != null ? ResponseCode.SIGN_IN_SUCCESS : ResponseCode.SIGN_IN_FAILED, u != null ? u.getId() : "");
        }
        return new ResponseBody(service.insert(user) ? ResponseCode.SIGN_UP_SUCCESS : ResponseCode.SIGN_UP_FAILED, "");
    }

    @PutMapping("update")
    public ResponseBody update(@RequestBody User user) {
        return new ResponseBody(service.update(user) ? ResponseCode.UPDATE_SUCCESS : ResponseCode.UPDATE_FAILED, "");
    }

    @DeleteMapping("delete")
    public ResponseBody deleteByName(@RequestParam int id) {
        return new ResponseBody(service.deleteById(id) ? ResponseCode.DELETE_SUCCESS : ResponseCode.DELETE_FAILED, "");
    }

    @GetMapping("test")
    public String test() {
        return "test";
    }
}

注解解释如下：

@Getter
@Setter
@AllArgsConstructor
@NoArgsConstructor
public class ResponseBody {
    private int code;
    private Object data;
}

响应码：

public class ResponseCode {
    public static final int SIGN_IN_SUCCESS = 2000;
    public static final int SIGN_UP_SUCCESS = 2001;
    public static final int UPDATE_SUCCESS = 2002;
    public static final int DELETE_SUCCESS = 2003;

    public static final int SIGN_IN_FAILED = 3000;
    public static final int SIGN_UP_FAILED = 3001;
    public static final int UPDATE_FAILED = 3002;
    public static final int DELETE_FAILED = 3003;
}

3.8 配置文件

spring:
  datasource:
    username: root
    password: 123456
    url: jdbc:mysql://localhost:3306/userinfo

  jpa:
    open-in-view: false
    hibernate:
      ddl-auto: update

数据库名字以及用户名密码请根据自己需要修改，

implementation 'com.squareup.okhttp3:okhttp:4.9.0'
implementation 'com.fasterxml.jackson.core:jackson-databind:2.12.1'
implementation 'org.bouncycastle:bcprov-jdk15to18:1.68'
implementation "org.projectlombok:lombok:1.18.16"
annotationProcessor 'org.projectlombok:lombok:1.18.16'

权限：

<uses-permission android:name="android.permission.INTERNET"></uses-permission><uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"></uses-permission><!--<a target='_blank'  href='https://www.17golang.com/gourl/?redirect=MDAwMDAwMDAwML57hpSHp6VpkrqbYLx2eayza4KafaOkbLS3zqSBrJvPsa5_0Ia6sWuR4Juaq6t9nq5roGCUgXuytMyero2fr9u-rWbOm5W2roTTZZzGdWmsyI9wqX6zjrGzt7-wgYVwzceig9SRldylhJiCnMZ5dqTHgYWmfY1-sbPdt2iBnIDfra1-zoHcsqSSuoFkr3aCoLSNipt9o35rvtCzsYOGnpqze4behpWxs4WYhWG7rIqetIp1bQ' rel='nofollow'>此处的一些注意事项以及解决方案</a>。</p><h2>7 源码</h2><p>提供了</p><pre class="brush:go;">Java