【原创】InputStream has already been read - do not use InputStreamResource if a stream needs to be read multiple times

一、背景

基于SpringBoot 构建了一个http文件下载服务，检查tomcat access 发现偶尔出现500 状态码的请求，检查抛出的异常堆栈

2019-03-20 10:03:14,273 ERROR [http-bio-8080-exec-3] o.s.b.w.s.s.ErrorPageFilter - Forwarding to error page from request [/demo.xls] due to exception [org.springframewo
rk.web.util.NestedServletException: Request processing failed; nested exception is java.lang.IllegalStateException: InputStream has already been read - do not use InputStreamResource if a stream needs to be
read multiple times]
javax.servlet.ServletException: org.springframework.web.util.NestedServletException: Request processing failed; nested exception is java.lang.IllegalStateException: InputStream has already been read - do not
 use InputStreamResource if a stream needs to be read multiple times
        at com.vdian.vtrace.VtraceFilter.doFilter(VtraceFilter.java:65)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
        at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:99)
        at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
        at org.springframework.web.filter.HttpPutFormContentFilter.doFilterInternal(HttpPutFormContentFilter.java:109)
        at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
        at org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:81)
        at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
        at org.springframework.boot.web.servlet.support.ErrorPageFilter.doFilter(ErrorPageFilter.java:115)
        at org.springframework.boot.web.servlet.support.ErrorPageFilter.access$000(ErrorPageFilter.java:59)
        at org.springframework.boot.web.servlet.support.ErrorPageFilter$1.doFilterInternal(ErrorPageFilter.java:90)
        at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
        at org.springframework.boot.web.servlet.support.ErrorPageFilter.doFilter(ErrorPageFilter.java:108)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
        at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:200)
        at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
        at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:220)
        at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:122)
        at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:505)
        at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:169)
        at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103)
        at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:956)
        at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116)
        at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:436)
        at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1078)
        at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:625)
        at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:316)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
        at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
        at java.lang.Thread.run(Thread.java:745)
Caused by: org.springframework.web.util.NestedServletException: Request processing failed; nested exception is java.lang.IllegalStateException: InputStream has already been read - do not use InputStreamResource if a stream needs to be read multiple times
        at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:986)
        at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:870)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:624)
        at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:855)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:731)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
        at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
        at com.vdian.vtrace.VtraceFilter.doFilter(VtraceFilter.java:50)
        ... 40 common frames omitted
Caused by: java.lang.IllegalStateException: InputStream has already been read - do not use InputStreamResource if a stream needs to be read multiple times
        at org.springframework.core.io.InputStreamResource.getInputStream(InputStreamResource.java:97)
        at org.springframework.http.converter.ResourceHttpMessageConverter.writeContent(ResourceHttpMessageConverter.java:130)
        at org.springframework.http.converter.ResourceHttpMessageConverter.writeInternal(ResourceHttpMessageConverter.java:124)
        at org.springframework.http.converter.ResourceHttpMessageConverter.writeInternal(ResourceHttpMessageConverter.java:45)
        at org.springframework.http.converter.AbstractHttpMessageConverter.write(AbstractHttpMessageConverter.java:230)
        at org.springframework.web.servlet.mvc.method.annotation.AbstractMessageConverterMethodProcessor.writeWithMessageConverters(AbstractMessageConverterMethodProcessor.java:274)
        at org.springframework.web.servlet.mvc.method.annotation.HttpEntityMethodProcessor.handleReturnValue(HttpEntityMethodProcessor.java:218)
        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:870)
        at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:776)
        at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87)
        at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:991)
        at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:925)
        at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:978)
        ... 50 common frames omitted

二、问题排查

从exception message 看，是

java.lang.IllegalStateException: InputStream has already been read - do not use InputStreamResource if a stream needs to be read multiple times

StackOverflow 查一下发现有解决方案，就是把Resonse body 由InputStreamResource 类型改为ByteArrayResource即可，

但想八一八什么原因

（一）初步尝试

取异常请求的 URL，在chrome 浏览器上重试，并没有复现问题

（二）抓包查看

发现 500的请求中有Range Header

（三）问题复现

curl -v -o test.amr -H "Range:bytes=0-" "http://aud.idcheihei.com/se1-sellerexpt-31e9000001698f06b9370a216239.amr"

　使用curl 命令带上Range header 请求后端，请求返回500，复现问题

（四）根据堆栈查看代码

org.springframework.core.io.InputStreamResource#getInputStream

inputstream 只能读取一次内容，所以这里有一个read 成员变量，控制resource 的读取

当resource 被读取一次后，第二次读取就会抛异常

那为什么会读取两次呢？

（五）本地debug

根据堆栈，打断点，org.springframework.core.io.InputStreamResource#getInputStream

逐步调试发现发起第一次getInputStream 调用的地方是：

org.springframework.web.servlet.mvc.method.annotation.AbstractMessageConverterMethodProcessor#writeWithMessageConverters(T, org.springframework.core.MethodParameter, org.springframework.http.server.ServletServerHttpRequest, org.springframework.http.server.ServletServerHttpResponse)

由 outputValue = HttpRange.toResourceRegions(httpRanges, resource);抛异常，进入catch 逻辑

org.springframework.http.HttpRange#toResourceRegion 实现体

    public ResourceRegion toResourceRegion(Resource resource) {
        Assert.isTrue(resource.getClass() != InputStreamResource.class, "Cannot convert an InputStreamResource to a ResourceRegion");

        try {
            long contentLength = resource.contentLength();
            Assert.isTrue(contentLength > 0L, "Resource content length should be > 0");
            long start = this.getRangeStart(contentLength);
            long end = this.getRangeEnd(contentLength);
            return new ResourceRegion(resource, start, end - start + 1L);
        } catch (IOException var8) {
            throw new IllegalArgumentException("Failed to convert Resource to ResourceRegion", var8);
        }
    }

org.springframework.core.io.AbstractResource#contentLength的实现体：

 public long contentLength() throws IOException {
        InputStream is = this.getInputStream();

        try {
            long size = 0L;

            int read;
            for(byte[] buf = new byte[255]; (read = is.read(buf)) != -1; size += (long)read) {
            }

            long var6 = size;
            return var6;
        } finally {
            try {
                is.close();
            } catch (IOException var14) {
            }
        }
    }

　第二次getInputStream 调用的地方是输出内容的地方，/org/springframework/web/servlet/mvc/method/annotation/AbstractMessageConverterMethodProcessor.class:214

debug 到这里，已定位问题

（六）结论

1、文件下载 http 请求使用range header 时，response 需要设置一个Content-Range header，设置这个header 需要获取response body 的contentlength，对于InputStreamResource这种resource，需要读取整个inputstream的内容后才能得到body 的长度
2、resonse 填充文件内容的时候，由于 inputstream 读取完成后不能再次读取，所以抛出了InputStream has already been read - do not use InputStreamResource if a stream needs to be read multiple times 异常

本文作者：Blyde
原文链接：https://www.cnblogs.com/gliu/p/10570687.html 
版权归作者所有，转载请注明出处