Nginx转发请求到后端服务报400 Bad Request

• 问题描述

• 系统部署好后，进行测试时发现有部分接口出错，项目采用Nginx作为后端代理服务器，有Nginx统一将请求转发到后端的网关服务，再由网关服务路由到具体的服务上，发布好后，大部分接口都是正常的，只有部分接口出现400 Bad Request，报错信息如下。

• 后端具体的服务报错信息如下

2023-08-16 20:57:28.753 ERROR [nio-9001-exec-7] c.y.s.f.w.c.ExceptionController          : JSON_FORMAT_ERROR JSON数据格式错误 null org.springframework.http.converter.HttpMessageNotReadableException: JSON parse error: Unexpected character ('-' (code 45)) in numeric value: expected digit (0-9) to follow minus sign, for valid numeric value; nested exception is com.fasterxml.jackson.core.JsonParseException: Unexpected character ('-' (code 45)) in numeric value: expected digit (0-9) to follow minus sign, for valid numeric value
 at [Source: (PushbackInputStream); line: 1, column: 3]
    at org.springframework.http.converter.json.AbstractJackson2HttpMessageConverter.readJavaType(AbstractJackson2HttpMessageConverter.java:283) ~[spring-web-5.1.18.RELEASE.jar:5.1.18.RELEASE]
    at org.springframework.http.converter.json.AbstractJackson2HttpMessageConverter.read(AbstractJackson2HttpMessageConverter.java:241) ~[spring-web-5.1.18.RELEASE.jar:5.1.18.RELEASE]
    at org.springframework.web.servlet.mvc.method.annotation.AbstractMessageConverterMethodArgumentResolver.readWithMessageConverters(AbstractMessageConverterMethodArgumentResolver.java:205) ~[spring-webmvc-5.1.18.RELEASE.jar:5.1.18.RELEASE]
    at org.springframework.web.servlet.mvc.method.annotation.RequestResponseBodyMethodProcessor.readWithMessageConverters(RequestResponseBodyMethodProcessor.java:158) ~[spring-webmvc-5.1.18.RELEASE.jar:5.1.18.RELEASE]
    at org.springframework.web.servlet.mvc.method.annotation.RequestResponseBodyMethodProcessor.resolveArgument(RequestResponseBodyMethodProcessor.java:131) ~[spring-webmvc-5.1.18.RELEASE.jar:5.1.18.RELEASE]
    at org.springframework.web.method.support.HandlerMethodArgumentResolverComposite.resolveArgument(HandlerMethodArgumentResolverComposite.java:127) ~[spring-web-5.1.18.RELEASE.jar:5.1.18.RELEASE]
    at org.springframework.web.method.support.InvocableHandlerMethod.getMethodArgumentValues(InvocableHandlerMethod.java:167) ~[spring-web-5.1.18.RELEASE.jar:5.1.18.RELEASE]
    at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:134) ~[spring-web-5.1.18.RELEASE.jar:5.1.18.RELEASE]
    at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:105) ~[spring-webmvc-5.1.18.RELEASE.jar:5.1.18.RELEASE]
    at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:892) ~[spring-webmvc-5.1.18.RELEASE.jar:5.1.18.RELEASE]
    at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:797) ~[spring-webmvc-5.1.18.RELEASE.jar:5.1.18.RELEASE]
    at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87) ~[spring-webmvc-5.1.18.RELEASE.jar:5.1.18.RELEASE]
    at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1040) [spring-webmvc-5.1.18.RELEASE.jar:5.1.18.RELEASE]
    at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:943) [spring-webmvc-5.1.18.RELEASE.jar:5.1.18.RELEASE]
    at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1006) [spring-webmvc-5.1.18.RELEASE.jar:5.1.18.RELEASE]
    at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:909) [spring-webmvc-5.1.18.RELEASE.jar:5.1.18.RELEASE]
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:652) [tomcat-embed-core-9.0.43.jar:4.0.FR]
    at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:883) [spring-webmvc-5.1.18.RELEASE.jar:5.1.18.RELEASE]
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:733) [tomcat-embed-core-9.0.43.jar:4.0.FR]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:227) [tomcat-embed-core-9.0.43.jar:9.0.43]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162) [tomcat-embed-core-9.0.43.jar:9.0.43]
    at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53) [tomcat-embed-websocket-9.0.43.jar:9.0.43]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189) [tomcat-embed-core-9.0.43.jar:9.0.43]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162) [tomcat-embed-core-9.0.43.jar:9.0.43]
    at org.springframework.boot.actuate.web.trace.servlet.HttpTraceFilter.doFilterInternal(HttpTraceFilter.java:88) [spring-boot-actuator-2.1.17.RELEASE.jar:2.1.17.RELEASE]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) [spring-web-5.1.18.RELEASE.jar:5.1.18.RELEASE]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189) [tomcat-embed-core-9.0.43.jar:9.0.43]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162) [tomcat-embed-core-9.0.43.jar:9.0.43]
    at com.ydtf.soa.framework.web.authority.XssFilter.doFilter(XssFilter.java:36) [soa-framework-web-1.0-SNAPSHOT.jar:1.0-SNAPSHOT]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189) [tomcat-embed-core-9.0.43.jar:9.0.43]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162) [tomcat-embed-core-9.0.43.jar:9.0.43]
    at com.ydtf.soa.framework.web.authority.ViewAuthFilter.doFilter(ViewAuthFilter.java:61) [soa-framework-web-1.0-SNAPSHOT.jar:1.0-SNAPSHOT]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189) [tomcat-embed-core-9.0.43.jar:9.0.43]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162) [tomcat-embed-core-9.0.43.jar:9.0.43]
    at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:100) [spring-web-5.1.18.RELEASE.jar:5.1.18.RELEASE]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) [spring-web-5.1.18.RELEASE.jar:5.1.18.RELEASE]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189) [tomcat-embed-core-9.0.43.jar:9.0.43]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162) [tomcat-embed-core-9.0.43.jar:9.0.43]
    at org.springframework.web.filter.FormContentFilter.doFilterInternal(FormContentFilter.java:93) [spring-web-5.1.18.RELEASE.jar:5.1.18.RELEASE]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) [spring-web-5.1.18.RELEASE.jar:5.1.18.RELEASE]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189) [tomcat-embed-core-9.0.43.jar:9.0.43]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162) [tomcat-embed-core-9.0.43.jar:9.0.43]
    at org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:94) [spring-web-5.1.18.RELEASE.jar:5.1.18.RELEASE]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) [spring-web-5.1.18.RELEASE.jar:5.1.18.RELEASE]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189) [tomcat-embed-core-9.0.43.jar:9.0.43]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162) [tomcat-embed-core-9.0.43.jar:9.0.43]
    at org.springframework.session.web.http.SessionRepositoryFilter.doFilterInternal(SessionRepositoryFilter.java:151) [spring-session-core-2.1.13.RELEASE.jar:2.1.13.RELEASE]
    at org.springframework.session.web.http.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:86) [spring-session-core-2.1.13.RELEASE.jar:2.1.13.RELEASE]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189) [tomcat-embed-core-9.0.43.jar:9.0.43]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162) [tomcat-embed-core-9.0.43.jar:9.0.43]
    at org.springframework.boot.actuate.metrics.web.servlet.WebMvcMetricsFilter.filterAndRecordMetrics(WebMvcMetricsFilter.java:114) [spring-boot-actuator-2.1.17.RELEASE.jar:2.1.17.RELEASE]
    at org.springframework.boot.actuate.metrics.web.servlet.WebMvcMetricsFilter.doFilterInternal(WebMvcMetricsFilter.java:104) [spring-boot-actuator-2.1.17.RELEASE.jar:2.1.17.RELEASE]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) [spring-web-5.1.18.RELEASE.jar:5.1.18.RELEASE]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189) [tomcat-embed-core-9.0.43.jar:9.0.43]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162) [tomcat-embed-core-9.0.43.jar:9.0.43]
    at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:201) [spring-web-5.1.18.RELEASE.jar:5.1.18.RELEASE]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) [spring-web-5.1.18.RELEASE.jar:5.1.18.RELEASE]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189) [tomcat-embed-core-9.0.43.jar:9.0.43]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162) [tomcat-embed-core-9.0.43.jar:9.0.43]
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:202) [tomcat-embed-core-9.0.43.jar:9.0.43]
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:97) [tomcat-embed-core-9.0.43.jar:9.0.43]
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:542) [tomcat-embed-core-9.0.43.jar:9.0.43]
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:143) [tomcat-embed-core-9.0.43.jar:9.0.43]
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92) [tomcat-embed-core-9.0.43.jar:9.0.43]
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:78) [tomcat-embed-core-9.0.43.jar:9.0.43]
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:346) [tomcat-embed-core-9.0.43.jar:9.0.43]
    at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:374) [tomcat-embed-core-9.0.43.jar:9.0.43]
    at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65) [tomcat-embed-core-9.0.43.jar:9.0.43]
    at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:887) [tomcat-embed-core-9.0.43.jar:9.0.43]
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1684) [tomcat-embed-core-9.0.43.jar:9.0.43]
    at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) [tomcat-embed-core-9.0.43.jar:9.0.43]
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) [?:1.8.0_221]
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) [?:1.8.0_221]
    at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) [tomcat-embed-core-9.0.43.jar:9.0.43]
    at java.lang.Thread.run(Thread.java:748) [?:1.8.0_221]
Caused by: com.fasterxml.jackson.core.JsonParseException: Unexpected character ('-' (code 45)) in numeric value: expected digit (0-9) to follow minus sign, for valid numeric value
 at [Source: (PushbackInputStream); line: 1, column: 3]
    at com.fasterxml.jackson.core.JsonParser._constructError(JsonParser.java:1851) ~[jackson-core-2.11.2.jar:2.11.2]
    at com.fasterxml.jackson.core.base.ParserMinimalBase._reportError(ParserMinimalBase.java:707) ~[jackson-core-2.11.2.jar:2.11.2]
    at com.fasterxml.jackson.core.base.ParserMinimalBase.reportUnexpectedNumberChar(ParserMinimalBase.java:536) ~[jackson-core-2.11.2.jar:2.11.2]
    at com.fasterxml.jackson.core.json.UTF8StreamJsonParser._handleInvalidNumberStart(UTF8StreamJsonParser.java:2813) ~[jackson-core-2.11.2.jar:2.11.2]
    at com.fasterxml.jackson.core.json.UTF8StreamJsonParser._parseNegNumber(UTF8StreamJsonParser.java:1450) ~[jackson-core-2.11.2.jar:2.11.2]
    at com.fasterxml.jackson.core.json.UTF8StreamJsonParser._nextTokenNotInObject(UTF8StreamJsonParser.java:847) ~[jackson-core-2.11.2.jar:2.11.2]
    at com.fasterxml.jackson.core.json.UTF8StreamJsonParser.nextToken(UTF8StreamJsonParser.java:757) ~[jackson-core-2.11.2.jar:2.11.2]
    at com.fasterxml.jackson.databind.ObjectMapper._initForReading(ObjectMapper.java:4662) ~[jackson-databind-2.11.2.jar:2.11.2]
    at com.fasterxml.jackson.databind.ObjectMapper._readMapAndClose(ObjectMapper.java:4511) ~[jackson-databind-2.11.2.jar:2.11.2]
    at com.fasterxml.jackson.databind.ObjectMapper.readValue(ObjectMapper.java:3519) ~[jackson-databind-2.11.2.jar:2.11.2]
    at org.springframework.http.converter.json.AbstractJackson2HttpMessageConverter.readJavaType(AbstractJackson2HttpMessageConverter.java:272) ~[spring-web-5.1.18.RELEASE.jar:5.1.18.RELEASE]
    ... 74 more

• 关键信息

org.springframework.http.converter.HttpMessageNotReadableException: JSON parse error: Unexpected character ('-' (code 45)) in numeric value

问题分析：

    请求已经到了服务端，在进行接口参数解析的时候报错，未进入Controller就报错了，排查后发现这个接口是使用formdata上传文件并携带了其他的参数，前端请求接口的时候应该设置请求头的"Content-type": "multipart/form-data"，前端使用

const formData = new FormData();
formData.append('file', param.file);
formData.append('fileModuleType', 1);

对象将文件与对应的数据参数一并的传给后端服务接口，思路上没有问题，但是数据到具体的服务时为什么解析不了了呢？应该是数据经过转发后发生了变化。开始排查nginx配置。

location /cbdacim-auxiliary-library-ms-dev {
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header X-Forwarded-Host $host;
        proxy_set_header X-Forwarded-Server $host;
        proxy_set_header Host $host;
        proxy_set_header accept-encodeing 'gzip, deflate';
        proxy_set_header content-type 'application/json';
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header authorization $http_authorization;
        proxy_set_header accept '*/*';
        proxy_set_header x-bce-date $http_x_bce_date;
        proxy_connect_timeout 300;
        proxy_send_timeout 300;
        proxy_read_timeout 300;
        client_max_body_size    300m;
        proxy_pass http://gatewayservers;        
   }

其中 proxy_set_header content-type 'application/json';配置会将转发的请求重新设置content-type，而在传输文件时需要设置content-type为"multipart/form-data"，从而后端服务无法解析传过来的参数数据。至此问题原因找到。解决如下。

location /cbdacim-auxiliary-library-ms-dev {
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header X-Forwarded-Host $host;
        proxy_set_header X-Forwarded-Server $host;
        proxy_set_header Host $host;
        proxy_set_header accept-encodeing 'gzip, deflate';
        #proxy_set_header content-type 'application/json';
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header authorization $http_authorization;
        proxy_set_header accept '*/*';
        proxy_set_header x-bce-date $http_x_bce_date;
        proxy_connect_timeout 300;
        proxy_send_timeout 300;
        proxy_read_timeout 300;
        client_max_body_size    300m;
        proxy_pass http://gatewayservers;        
   }