java 记录资源下载时报异常

控制台错误信息(部分):

org.springframework.web.HttpMediaTypeNotAcceptableException: Could not find acceptable representation
	at org.springframework.web.servlet.mvc.method.annotation.AbstractMessageConverterMethodProcessor.writeWithMessageConverters(AbstractMessageConverterMethodProcessor.java:307)
	at org.springframework.web.servlet.mvc.method.annotation.RequestResponseBodyMethodProcessor.handleReturnValue(RequestResponseBodyMethodProcessor.java:180)
	at org.springframework.web.method.support.HandlerMethodReturnValueHandlerComposite.handleReturnValue(HandlerMethodReturnValueHandlerComposite.java:82)
	at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:119)
	at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:895)
	at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:800)
	 ...
	at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66)
	at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:834)
	at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1415)
	at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
	at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
	at java.lang.Thread.run(Unknown Source)
java.lang.IllegalStateException: Cannot call sendError() after the response has been committed
	at org.apache.catalina.connector.ResponseFacade.sendError(ResponseFacade.java:472)
	at javax.servlet.http.HttpServletResponseWrapper.sendError(HttpServletResponseWrapper.java:129)
	at com.alibaba.druid.support.http.WebStatFilter$StatHttpServletResponseWrapper.sendError(WebStatFilter.java:343)
	at org.springframework.web.servlet.mvc.support.DefaultHandlerExceptionResolver.handleHttpMediaTypeNotAcceptable(DefaultHandlerExceptionResolver.java:304)
	at org.springframework.web.servlet.mvc.support.DefaultHandlerExceptionResolver.doResolveException(DefaultHandlerExceptionResolver.java:181)
	at org.springframework.web.servlet.handler.AbstractHandlerExceptionResolver.resolveException(AbstractHandlerExceptionResolver.java:139)
	at org.springframework.web.servlet.handler.HandlerExceptionResolverComposite.resolveException(HandlerExceptionResolverComposite.java:80)org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1055)
	at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:942)
...
	at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:834)
	at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1415)
	at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
	at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
	at java.lang.Thread.run(Unknown Source)

前端接收

downFile(that.url.exportGroupAppraise+"/"+param+"/"+flag).then((res)=>{
          if (typeof window.navigator.msSaveBlob !== 'undefined') {
            window.navigator.msSaveBlob(new Blob([res], {
            type: 'application/application/vnd.openxmlformats-officedocument.wordprocessingml.document'
          }), fileName + '.docx')
          } else {
            let url = window.URL.createObjectURL(new Blob([res], {
              type: 'application/application/vnd.openxmlformats-officedocument.wordprocessingml.document'
            }))
            let link = document.createElement('a')
            link.style.display = 'none'
            link.href = url
            //这是下载的文件名
            link.setAttribute('download', fileName + '.docx')
            document.body.appendChild(link)
            link.click()
            document.body.removeChild(link); //下载完成移除元素
            window.URL.revokeObjectURL(url); //释放掉blob对象
          }
        })

从上面代码可以看到 这里是将res直接处理了,而不是当做json处理

但是后端java代码是返回的json

所以会报错

将后端返回的json置空 返回void就可以了

原java代码

 @ApiOperation("***")
 @RequestMapping("exportGroupAppraise/{id}/{flag}")
 public Result<?> exportGroupAppraise(){}

修改后的

 @ApiOperation("***")
 @RequestMapping("exportGroupAppraise/{id}/{flag}")
 public void exportGroupAppraise(){}