java - 从 spring-boot Rest Controller 返回 JSON 对象

Question

我正在尝试检查用户名在 spring-boot 中是否唯一。我想将结果作为 JSON 对象发送。这是 REST Controller

@RequestMapping(value="/checkEmailUnique",method=RequestMethod.POST)
public String checkEmailUnique(@RequestBody String username){

    AppUser app = userRepo.findByUsername(username);
    if(app!=null){
        // I want to return somthing like emailNotTaken: true
    }
    else{
        // and here : emailNotTaken: false  
    }
}

我想获得角度结果，以便我可以在组件中显示错误消息。我怎样才能做到这一点？

有角的一面

客户端.Service.Ts

checkEmailNotTaken(email:string){
    if(this.authService.getToken()==null) {
      this.authService.loadToken();
    }
    return this.http.post(this.host+
      "/checkEmailUnique/",{email},{headers:new HttpHeaders({'Authorization':this.authService.getToken()})});
  }

在 client.component.ts 中

ngOnInit() {

    this.form = this.formBuilder.group({
      prenom: ['', Validators.required],
      nom: ['', Validators.required],
      tel: ['', Validators.required],
      cin: ['', Validators.required],
      username: ['', Validators.required , Validators.email  , this.validateEmailNotTaken.bind(this)],
      passwordG: this.formBuilder.group({
        password: ['',[Validators.required,Validators.minLength(9)]],
        Confirmationpassword : ['',[Validators.required,Validators.minLength(9)]]

      }, {validator: passwordMatch})

    });
  }

    validateEmailNotTaken(control: AbstractControl) {
        return this.clientService.checkEmailNotTaken(control.value).map(res => {
          return  // what to do here ?
        });

      }

编辑

@RequestMapping(value="/checkEmailUnique",method=RequestMethod.POST)
    public EmailStatusCheckJson checkEmailUnique(@RequestBody final String username){

        final EmailStatusCheckJson returnValue = new EmailStatusCheckJson();


         AppUser app = userRepo.findByUsername(username);


         if(app!=null){
             returnValue.setEmailIsAvailable(false);
         }
         else{
             returnValue.setEmailIsAvailable(true);

         }

         return returnValue;
    }

Answer 1

如果您使用的是 spring-boot-starter-web，您的项目已设置为返回 JSON。而不是 String 作为 checkEmailUnique 的返回值，使用您创建的对象类型。

这是一个例子:

public class EmailStatusCheckJson
{
    private Boolean emailIsAvailable;

    public Boolean getEmailIsAvailable()
    {
        return emailIsAvailable;
    }

    public void setEmailIsAvailable(
        final Boolean newValue)
    {
        emailIsAvailable = newValue
    }
}


@RequestMapping(value="/checkEmailUnique",method=RequestMethod.POST)
public EmailStatusCheckJson checkEmailUnique(@RequestBody final String username)
{
    final EmailStatusCheckJson returnValue = new EmailStatusCheckJson();

    if (...) // email is available.
    {
        returnValue.setEmailIsAvailable(true);
    }
    else
    {
        returnValue.setEmailIsAvailable(false);
    }

    return returnValue;        
}

已编辑添加了更多示例。