SpringBoot项目基本的模块搭建

创建项目，划分好对应包的模块

• 创建项⽬
• 配置启动类
• 建⽴对应的包，先建⽴这些包，其他⽤到再补充
  • controller
  • service
  • dao(mapper)
  • domain
  • utils
• 初始化数据开发：视频、章、默认⽤户信息

请求接口的实战

GET请求

场景：⼀般的查询接⼝就是get请求 注解：@GetMapping = @RequestMapping(method = RequestMethod.GET)

• 注解的组合

@GetMapping = @RequestMapping(method = RequestMethod.GET)
@PostMapping = @RequestMapping(method = RequestMethod.POST)
@PutMapping = @RequestMapping(method = RequestMethod.PUT)
@DeleteMapping = @RequestMapping(method = RequestMethod.DELETE)

开发查询列表的操作

• domain创建实体类，给予相应的属性和方法

public class Video {
    private int id;
    private String title;
    private String summary;
    private int price;
    private String coverImg;
    private Date createTime;

    public Video() {
    }

    public Video(int id, String title) {
        this.id = id;
        this.title = title;
        this.createTime=new Date();
    }

• 在Mapper中模拟一个数据库，并且执行操作返回数据

@Repository
public class VideoMapper {
    //模拟数据库数据
    private static Map<String, Video> videoMap = new HashMap<>();
    static {
        videoMap.put("1",new Video(1,"吉吉波奇"));
        videoMap.put("2",new Video(2,"菲尔"));
        videoMap.put("3",new Video(3,"jjbq"));
        videoMap.put("4",new Video(4,"junko"));
        videoMap.put("5",new Video(5,"啦啦啦"));
    }
    //请求查询所有数据
    public List<Video> findAllVideo(){
        List<Video> videoList = new ArrayList<>();
        videoList.addAll(videoMap.values());
        return videoList;
    }
}

• service创建接口以及实现类

//接口
public interface VideoService {

    public List<Video> findAll();
}

//实现类
@Service
public class VideoServiceImpl implements VideoService {

    @Autowired
    private VideoMapper videoMapper;

    @Override
    public List<Video> findAll() {
        List<Video> allVideo = videoMapper.findAllVideo();
        return allVideo;
    }
}

• controller调用服务

@RestController
@RequestMapping("api/video")
public class VideoController {

    @Autowired
    private VideoService videoService;

    @RequestMapping("findAll")
    public List<Video> findAllVideo(){
        List<Video> all = videoService.findAll();
        return all;
    }
}

在postman中获取数据，可以成功显示

在请求接口的改进思路

状态码

我们上面能够实现数据的返回，但是在对接前端的时候，是否应该给一个状态码用来标识是否成功返回数据，统一协议

自定义返回对象，统一协议

• 在utils包下创建并使用JSONData工具类

public class JsonData {
    private int code;
    private Object data;
    private String msg;

    public static JsonData buildSuccess(Object data){
        return new JsonData(0,data);
    }

    public static JsonData buildError(String msg){
        return new JsonData(-1,"",msg);
    }

    public static JsonData buildError(String msg,int code){
        return new JsonData(code,"",msg);
    }

• 然后只需要在controller中的方法中调用

@RequestMapping("findAll2")
    public Object findAllVideo2(){
        List<Video> all = videoService.findAll();
        return JsonData.buildSuccess(all);
    }

POST请求校验用户名与密码

http的post请求

• POST请求-form表单
  • 场景：表单提交，如果不⽤细分PUT/DELETE⽅法，则都可以⽤POST
  • 注解：@PostMapping = @RequestMapping(method = RequestMethod.POST)
• 开发功能：账号密码提交登录接⼝，form表单形式

开发登录的操作

• domain

public class User {
    private int id;
    private String username;
    private String password;

• mapper

@Repository
public class UserMapper {
    private static Map<String, User> userMap = new HashMap<>();

    static {
        userMap.put("jjbq",new User(1,"jjbq","123123"));
        userMap.put("junko",new User(2,"junko","111111"));
        userMap.put("hhh",new User(3,"hhh","123"));
    }

    public User login(String username,String password){
        User user = userMap.get(username);
        if (user == null ){
            return null;
        }
        if (user.getPassword().equals(password)){
            return user;
        }
        return null;
    }
}

• service

public interface UserService {
    public String login(String username,String password);
}

@Service
public class UserServiceImpl implements UserService {

    private static Map<String,User> sessionMap = new HashMap<>();

    @Autowired
    private UserMapper userMapper;

    @Override
    public String login(String username,String password ) {
        User user = userMapper.login(username,password);
        if (user==null){
            return null;
        }else {
            String token = UUID.randomUUID().toString();
            sessionMap.put(token,user);
            return user.toString()+":"+token;
        }

    }
}

• controller

@RestController
@RequestMapping("api/user")
public class UserController {
    @Autowired
    private UserService userService;

    @PostMapping("login")
    public JsonData login(@RequestBody  User user){
        String login = userService.login(user.getUsername(), user.getPassword());
        if (StringUtils.isEmpty(login)){
            return JsonData.buildError("用户名密码错误");
        }else {
            return JsonData.buildSuccess(login);
        }
    }
}

文章永久链接：https://tech.souyunku.com/27230