发生io异常后，服务器无法响应任何http请求

Question

@PostMapping("/upload-fetal")
public Boolean uploadFetalFile(@RequestParam("file") MultipartFile multipartFile) {
    try {
        String path = env.getProperty("application.ctg.fetal") + File.separator;
        String fileName = path + multipartFile.getOriginalFilename();
        File file = new File(fileName);
        FileUtils.copyInputStreamToFile(multipartFile.getInputStream(), file);
    } catch (Exception e) {
        log.error(ExceptionUtil.collectExceptionStackMsg(e));
        return false;
    }
    return true;
}

有一些设备通过上面的方法上传文件，有时会导致如下异常：

Caused by: java.io.IOException: UT000128: Remote peer closed connection before all data could be read
at io.undertow.conduits.FixedLengthStreamSourceConduit.exitRead(FixedLengthStreamSourceConduit.java:351)
at io.undertow.conduits.FixedLengthStreamSourceConduit.read(FixedLengthStreamSourceConduit.java:264)
at org.xnio.conduits.ConduitStreamSourceChannel.read(ConduitStreamSourceChannel.java:127)
at io.undertow.channels.DetachableStreamSourceChannel.read(DetachableStreamSourceChannel.java:209)
at io.undertow.server.HttpServerExchange$ReadDispatchChannel.read(HttpServerExchange.java:2430)
at org.xnio.channels.Channels.readBlocking(Channels.java:344)
at io.undertow.servlet.spec.ServletInputStreamImpl.readIntoBuffer(ServletInputStreamImpl.java:192)
at io.undertow.servlet.spec.ServletInputStreamImpl.read(ServletInputStreamImpl.java:168)
at io.undertow.server.handlers.form.MultiPartParserDefinition$MultiPartUploadHandler.parseBlocking(MultiPartParserDefinition.java:226)
at io.undertow.servlet.spec.HttpServletRequestImpl.parseFormData(HttpServletRequestImpl.java:792)
... 45 common frames omitted

极少数情况下服务器将无法处理此后的请求，我收集了服务器的堆栈消息，大部分线程的堆栈是如下所示：

java.lang.Thread.State: RUNNABLE
at sun.nio.ch.WindowsSelectorImpl$SubSelector.poll0(Native Method)
at sun.nio.ch.WindowsSelectorImpl$SubSelector.poll(Unknown Source)
at sun.nio.ch.WindowsSelectorImpl$SubSelector.access$400(Unknown Source)
at sun.nio.ch.WindowsSelectorImpl.doSelect(Unknown Source)
at sun.nio.ch.SelectorImpl.lockAndDoSelect(Unknown Source)
- locked <0x00000006cd569f88> (a sun.nio.ch.Util$3)
- locked <0x00000006cd569f78> (a java.util.Collections$UnmodifiableSet)
- locked <0x00000006cd569d18> (a sun.nio.ch.WindowsSelectorImpl)
at sun.nio.ch.SelectorImpl.select(Unknown Source)
at sun.nio.ch.SelectorImpl.select(Unknown Source)
at org.xnio.nio.SelectorUtils.await(SelectorUtils.java:51)
at org.xnio.nio.NioSocketConduit.awaitReadable(NioSocketConduit.java:358)
at org.xnio.conduits.AbstractSourceConduit.awaitReadable(AbstractSourceConduit.java:66)
at io.undertow.conduits.ReadDataStreamSourceConduit.awaitReadable(ReadDataStreamSourceConduit.java:101)
at io.undertow.conduits.FixedLengthStreamSourceConduit.awaitReadable(FixedLengthStreamSourceConduit.java:294)
at org.xnio.conduits.ConduitStreamSourceChannel.awaitReadable(ConduitStreamSourceChannel.java:151)
at io.undertow.channels.DetachableStreamSourceChannel.awaitReadable(DetachableStreamSourceChannel.java:77)
at io.undertow.server.HttpServerExchange$ReadDispatchChannel.awaitReadable(HttpServerExchange.java:2290)
at org.xnio.channels.Channels.readBlocking(Channels.java:345)
at io.undertow.servlet.spec.ServletInputStreamImpl.readIntoBuffer(ServletInputStreamImpl.java:192)
at io.undertow.servlet.spec.ServletInputStreamImpl.read(ServletInputStreamImpl.java:168)
at io.undertow.server.handlers.form.MultiPartParserDefinition$MultiPartUploadHandler.parseBlocking(MultiPartParserDefinition.java:226)
at io.undertow.servlet.spec.HttpServletRequestImpl.parseFormData(HttpServletRequestImpl.java:792)
at io.undertow.servlet.spec.HttpServletRequestImpl.getParameter(HttpServletRequestImpl.java:665)
at org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:84)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
at io.undertow.servlet.core.ManagedFilter.doFilter(ManagedFilter.java:61)
at io.undertow.servlet.handlers.FilterHandler$FilterChainImpl.doFilter(FilterHandler.java:131)
at org.springframework.boot.actuate.metrics.web.servlet.WebMvcMetricsFilter.filterAndRecordMetrics(WebMvcMetricsFilter.java:117)
at org.springframework.boot.actuate.metrics.web.servlet.WebMvcMetricsFilter.doFilterInternal(WebMvcMetricsFilter.java:106)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
at io.undertow.servlet.core.ManagedFilter.doFilter(ManagedFilter.java:61)
at io.undertow.servlet.handlers.FilterHandler$FilterChainImpl.doFilter(FilterHandler.java:131)
at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:200)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
at io.undertow.servlet.core.ManagedFilter.doFilter(ManagedFilter.java:61)
at io.undertow.servlet.handlers.FilterHandler$FilterChainImpl.doFilter(FilterHandler.java:131)
at io.undertow.servlet.handlers.FilterHandler.handleRequest(FilterHandler.java:84)
at io.undertow.servlet.handlers.security.ServletSecurityRoleHandler.handleRequest(ServletSecurityRoleHandler.java:62)
at io.undertow.servlet.handlers.ServletChain$1.handleRequest(ServletChain.java:65)
at io.undertow.servlet.handlers.ServletDispatchingHandler.handleRequest(ServletDispatchingHandler.java:36)
at io.undertow.servlet.handlers.security.SSLInformationAssociationHandler.handleRequest(SSLInformationAssociationHandler.java:132)
at io.undertow.servlet.handlers.security.ServletAuthenticationCallHandler.handleRequest(ServletAuthenticationCallHandler.java:57)
at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43)

因此，服务器收到的任何请求都被阻塞在那里等待数据，根本原因可能是什么？

Answer 1

Java IOException 是输入/输出异常 (I/O)，每当输入或输出操作失败或解释时就会发生。例如，如果您尝试读取不存在的文件，Java 将抛出 I/O 异常。