调用springboot服务的error接口http响应码返回500的问题

逆光的July

已于 2023-08-09 19:28:33 修改

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于 2023-08-09 19:13:13 首次发布

本文链接：https://blog.youkuaiyun.com/weixin_32840277/article/details/132194532

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背景：

一天早上睡觉醒来，翻了翻手机，发现7点时一个C端服务出现了短暂的报警，通过日志发现，大量的未知请求，有的返回了404，而/error请求http响应码返回了500，很疑惑，按道理服务里没有这个接口应该返回404啊，这个接口有什么特殊之处？于是就调研了一下。

通过排查：

原来springboot中有个BasicErrorController类，这个类有个默认的/error接口，
在这里插入图片描述
当我们调用没有定义的接口时，springboot会自动调用error接口将一个自定义的页面返回给用户，状态码是404

而我们直接调用这个error接口时，由于我们的服务是有默认的error接口的，所以不是404，而由于我们调用时没有传合适的参数，springboot执行逻辑时报错，返回了500状态码。注意：此时我们自定义的ExceptionHandlerAdvice全局异常捕获处理器是捕获不到异常的，因为springboot没有抛出异常，只是返回了500状态码，于是就出现了上边的问题。如何解决呢？如何在这种情况下不返回5xx呢？

解决方案一：

按照BasicErrorController类写一个类似的ServerErrorController，接口名改为/server/error，覆盖BasicErrorController的/error接口，如下：

import org.springframework.boot.autoconfigure.web.ErrorProperties;
import org.springframework.boot.autoconfigure.web.ServerProperties;
import org.springframework.boot.autoconfigure.web.servlet.error.AbstractErrorController;
import org.springframework.boot.web.error.ErrorAttributeOptions;
import org.springframework.boot.web.servlet.error.ErrorAttributes;
import org.springframework.http.HttpStatus;
import org.springframework.http.MediaType;
import org.springframework.http.ResponseEntity;
import org.springframework.stereotype.Controller;
import org.springframework.web.HttpMediaTypeNotAcceptableException;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.servlet.ModelAndView;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.util.Collections;
import java.util.Map;
/**
 * 自定义的异常处理控制器，用于覆盖默认的BasicErrorController;
 **/
@Controller
@RequestMapping("/server/error")
public class ServerErrorController extends AbstractErrorController {

    private final ErrorProperties errorProperties;

    public ServerErrorController(ErrorAttributes errorAttributes, ServerProperties serverProperties) {
        super(errorAttributes);
        this.errorProperties = serverProperties.getError();
    }

    @RequestMapping(
            produces = {"text/html"}
    )
    public ModelAndView errorHtml(HttpServletRequest request, HttpServletResponse response) {
        HttpStatus status = this.getStatus(request);
        Map<String, Object> model = Collections.unmodifiableMap(this.getErrorAttributes(request, this.getErrorAttributeOptions(request, MediaType.TEXT_HTML)));
        //如果>=500返回400
        if (status.value() >= HttpStatus.INTERNAL_SERVER_ERROR.value()) {
            status = HttpStatus.BAD_REQUEST;
        }
        response.setStatus(status.value());
        ModelAndView modelAndView = this.resolveErrorView(request, response, status, model);
        return modelAndView != null ? modelAndView : new ModelAndView("error", model);
    }

    @RequestMapping
    public ResponseEntity<Map<String, Object>> error(HttpServletRequest request) {
        HttpStatus status = this.getStatus(request);
        //如果>=500返回400
        if (status.value() >= HttpStatus.INTERNAL_SERVER_ERROR.value()) {
            status = HttpStatus.BAD_REQUEST;
        }
        if (status == HttpStatus.NO_CONTENT) {
            return new ResponseEntity(status);
        } else {
            Map<String, Object> body = this.getErrorAttributes(request, this.getErrorAttributeOptions(request, MediaType.ALL));
            return new ResponseEntity(body, status);
        }
    }

    @ExceptionHandler({HttpMediaTypeNotAcceptableException.class})
    public ResponseEntity<String> mediaTypeNotAcceptable(HttpServletRequest request) {
        HttpStatus status = this.getStatus(request);
        return ResponseEntity.status(status).build();
    }

    protected ErrorAttributeOptions getErrorAttributeOptions(HttpServletRequest request, MediaType mediaType) {
        ErrorAttributeOptions options = ErrorAttributeOptions.defaults();
        if (this.errorProperties.isIncludeException()) {
            options = options.including(new ErrorAttributeOptions.Include[]{ErrorAttributeOptions.Include.EXCEPTION});
        }

        if (this.isIncludeStackTrace(request, mediaType)) {
            options = options.including(new ErrorAttributeOptions.Include[]{ErrorAttributeOptions.Include.STACK_TRACE});
        }

        if (this.isIncludeMessage(request, mediaType)) {
            options = options.including(new ErrorAttributeOptions.Include[]{ErrorAttributeOptions.Include.MESSAGE});
        }

        if (this.isIncludeBindingErrors(request, mediaType)) {
            options = options.including(new ErrorAttributeOptions.Include[]{ErrorAttributeOptions.Include.BINDING_ERRORS});
        }

        return options;
    }

    protected boolean isIncludeStackTrace(HttpServletRequest request, MediaType produces) {
        switch(this.getErrorProperties().getIncludeStacktrace()) {
            case ALWAYS:
                return true;
            case ON_PARAM:
                return this.getTraceParameter(request);
            default:
                return false;
        }
    }

    protected boolean isIncludeMessage(HttpServletRequest request, MediaType produces) {
        switch(this.getErrorProperties().getIncludeMessage()) {
            case ALWAYS:
                return true;
            case ON_PARAM:
                return this.getMessageParameter(request);
            default:
                return false;
        }
    }

    protected boolean isIncludeBindingErrors(HttpServletRequest request, MediaType produces) {
        switch(this.getErrorProperties().getIncludeBindingErrors()) {
            case ALWAYS:
                return true;
            case ON_PARAM:
                return this.getErrorsParameter(request);
            default:
                return false;
        }
    }

    protected ErrorProperties getErrorProperties() {
        return this.errorProperties;
    }

然后修改application.yml配置：

server:
  error:
    path: /server/error

这样就覆盖了/error接口，当调用未定义的接口时，springboot会转到我们定义的/server/error接口。并且我们可以自定义接口的逻辑，例如，当状态码是5xx时，返回400.

/@RequestMapping(
            produces = {"text/html"}
    )
    public ModelAndView errorHtml(HttpServletRequest request, HttpServletResponse response) {
        HttpStatus status = this.getStatus(request);
        Map<String, Object> model = Collections.unmodifiableMap(this.getErrorAttributes(request, this.getErrorAttributeOptions(request, MediaType.TEXT_HTML)));
        //如果>=500返回400
        if (status.value() >= HttpStatus.INTERNAL_SERVER_ERROR.value()) {
            status = HttpStatus.BAD_REQUEST;
        }
        response.setStatus(status.value());
        ModelAndView modelAndView = this.resolveErrorView(request, response, status, model);
        return modelAndView != null ? modelAndView : new ModelAndView("error", model);
    }

注意：BasicErrorController中其实是有两个接口，
一个是：(这个接口会返回一个html页面。当我们用浏览器调用时会调用这个，因为Content-Type是text/html)

    @RequestMapping(produces = {"text/html"})
    public ModelAndView errorHtml(HttpServletRequest request, HttpServletResponse response)
    {}

另一个是：(这个接口会返回json数据。当我们用postman调用时会调用这个，因为Content-Type是application/json)

	@RequestMapping
	public ResponseEntity<Map<String, Object>> error(HttpServletRequest request) 
	{}

因此两个接口都要改。
这样就解决了调用/error时返回500的问题

解决方案二：

直接在nginx侧改，当调用error时，返回4xx，简单粗暴。

哪个方案更好：

如果可以在不重启服务、不重启nginx的情况在nginx修改，肯定选择方案二。因为方案一虽然返回了4xx，但是请求仍然进了服务，消耗了服务资源。

举一反三：

因此我们的服务接口是不是应该搞个统一的前缀呢？这样就可以直接在nginx侧统一过滤掉错误请求了，使服务更健康。