处理的异常仍被写入标准输出

Question

我正在使用码头服务器来托管我的 java 应用程序。我最近添加了请求超时来终止需要太长时间的请求。记录我的stdout（通常应该为空）的文件开始填满InterruptedException 堆栈跟踪。比如：

java.lang.InterruptedException
    ...... Some lower level code-lines of my project
    at com.mycompany.webapps.MyController.myMethod(MyController.java:252)
    at sun.reflect.GeneratedMethodAccessor67.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:601)
    at org.springframework.web.method.support.InvocableHandlerMethod.invoke(InvocableHandlerMethod.java:219)
    at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:132)
    at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:104)
    at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandleMethod(RequestMappingHandlerAdapter.java:745)
    at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:686)
    at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:80)
    at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:925)
    at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:856)
    at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:920)
    at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:816)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:687)
    at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:801)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:790)
    at org.eclipse.jetty.servlet.ServletHolder.handle(ServletHolder.java:738)
    at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1651)
    at org.eclipse.jetty.servlets.UserAgentFilter.doFilter(UserAgentFilter.java:83)
    at org.eclipse.jetty.servlets.GzipFilter.doFilter(GzipFilter.java:310)
    at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1622)
    at org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:549)
    at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:143)
    at org.eclipse.jetty.security.SecurityHandler.handle(SecurityHandler.java:568)
    at org.eclipse.jetty.server.session.SessionHandler.doHandle(SessionHandler.java:221)
    at org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1111)
    at org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:478)
    at org.eclipse.jetty.server.session.SessionHandler.doScope(SessionHandler.java:183)
    at org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:1045)
    at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:141)
    at org.eclipse.jetty.server.handler.ContextHandlerCollection.handle(ContextHandlerCollection.java:199)
    at org.eclipse.jetty.server.handler.HandlerCollection.handle(HandlerCollection.java:109)
    at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:97)
    at org.eclipse.jetty.server.handler.StatisticsHandler.handle(StatisticsHandler.java:159)
    at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:97)
    at org.eclipse.jetty.server.Server.handle(Server.java:462)
    at org.eclipse.jetty.server.HttpChannel.handle(HttpChannel.java:279)
    at org.eclipse.jetty.server.HttpConnection.onFillable(HttpConnection.java:232)
    at org.eclipse.jetty.io.AbstractConnection$2.run(AbstractConnection.java:534)
    at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:607)
    at org.eclipse.jetty.util.thread.QueuedThreadPool$3.run(QueuedThreadPool.java:536)

所以，我在myMethod 中添加了try-catch（我可以控制的最高方法）：

@RequestMapping(value = "/myUrl/{id}", method = RequestMethod.GET)
@ResponseBody
public ResponseEntity<byte[]> myMethod(final HttpServletRequest request, @PathVariable final EncodedId id) {
  try {
    return serveImageRequest(request, sourceId.getId(), docId.getId(), dimensions.getWidth(), dimensions.getHeight());
  } catch (Exception ex) {
    log.error(ex.getMessage());
    return null;
  }
}

log 变量是一个记录器实例（使用log4j），它将消息写入专用日志文件（而不是stdout）。尽管如此，消息仍会写入stdout。唯一的区别是现在它们也被写入日志文件。我找不到将其写入stdout 的原因，我必须避免它，因为代表stdout 的文件没有滚动策略。

Answer 1

原来问题的根源在于第 3 方库，该库捕获异常并将其堆栈跟踪打印到标准输出。尽管我捕获并处理了异常，但这是正在打印的。