如何在spring mvc @Controller中返回错误信息 [英] How return error message in spring mvc @Controller

问题描述

我正在使用这样的方法

@RequestMapping(method = RequestMethod.GET)
public ResponseEntity<UserWithPhoto> getUser(@RequestHeader(value="Access-key") String accessKey,
                                     @RequestHeader(value="Secret-key") String secretKey){
    try{
        return new ResponseEntity<UserWithPhoto>((UserWithPhoto)this.userService.chkCredentials(accessKey, secretKey, timestamp),
                new HttpHeaders(),
                HttpStatus.CREATED);
    }
    catch(ChekingCredentialsFailedException e){
        e.printStackTrace();
        return new ResponseEntity<UserWithPhoto>(null,new HttpHeaders(),HttpStatus.FORBIDDEN);
    }
}

我想在发生异常时返回一些短信但现在我只返回status和null对象。有可能吗？

And I want to return some text message when exception occurs but now I just return status and null object. Is it possible to do?

推荐答案

作为 Sotirios Delimanolis 已在评论中指出，有两种选择：

As Sotirios Delimanolis already pointed out in the comments, there are two options:

更改您的方法如下：

@RequestMapping(method = RequestMethod.GET)
public ResponseEntity getUser(@RequestHeader(value="Access-key") String accessKey,
                              @RequestHeader(value="Secret-key") String secretKey) {
    try {
        // see note 1
        return ResponseEntity
            .status(HttpStatus.CREATED)                 
            .body(this.userService.chkCredentials(accessKey, secretKey, timestamp));
    }
    catch(ChekingCredentialsFailedException e) {
        e.printStackTrace(); // see note 2
        return ResponseEntity
            .status(HttpStatus.FORBIDDEN)
            .body("Error Message");
    }
}

注1 ：你不必使用 ResponseEntity 构建器，但我发现它有助于保持代码可读。它还有助于记住特定HTTP状态代码的响应应包含哪些数据。例如，状态代码为201的响应应包含指向 Location 标头中新创建的资源的链接（请参阅状态码定义）。这就是为什么Spring提供了方便的构建方法 ResponseEntity.created（URI）。

Note 1: You don't have to use the ResponseEntity builder but I find it helps with keeping the code readable. It also helps remembering, which data a response for a specific HTTP status code should include. For example, a response with the status code 201 should contain a link to the newly created resource in the Location header (see Status Code Definitions). This is why Spring offers the convenient build method ResponseEntity.created(URI).

注意2 ：不要使用 printStackTrace（），而是使用记录器代替。

Note 2: Don't use printStackTrace(), use a logger instead.

删除从你的方法try-catch块让它抛出异常。然后在使用 @ControllerAdvice 注释的类中创建另一个方法，如下所示：

Remove the try-catch block from your method and let it throw the exception. Then create another method in a class annotated with @ControllerAdvice like this:

@ControllerAdvice
public class ExceptionHandlerAdvice {

    @ExceptionHandler(ChekingCredentialsFailedException.class)
    public ResponseEntity handleException(ChekingCredentialsFailedException e) {
        // log exception
        return ResponseEntity
                .status(HttpStatus.FORBIDDEN)
                .body("Error Message");
    }        
}

请注意使用<$ c $注释的方法c> @ExceptionHandler 可以拥有非常灵活的签名。请参阅 Javadoc 了解详情。

Note that methods which are annotated with @ExceptionHandler are allowed to have very flexible signatures. See the Javadoc for details.

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