java servlet調用永遠不會到達servlet

Question

我有一個java web應用程序，我已經部署在wildfly 10 web服務器中。該應用程序在大多數情況下都可以正常工作，但非常意外的是，對java servlet的調用永遠不會到達servlet。

我變得好奇，分析了visualvm中野蠻服務器的線程轉儲。雖然我不是分析線程轉儲的專家，但我期望發生一些線程鎖定，因爲該servlet調用的任務線程從未執行;一直在等待。

現在我不知道這是否是應用程序方面的問題。我懷疑這是我設置爲默認的servlet容器配置的問題，還是這是一些wild bug漏洞？..，我希望不是這樣。請回復。

這是我的登錄servlet代碼：

response.setContentType("application/json"); 
    UserInfo user = null; 
    boolean authenticated = false; 
    String message = ""; 
    String ipAddress = request.getHeader("X-FORWARDED-FOR"); 
    if (ipAddress == null) { 
     ipAddress = request.getRemoteAddr(); 
    } 

    try { 
     ApplicationHelper.clearSession(request); 
     String body = request.getReader().lines().reduce("", (accumulator, actual) -> accumulator + actual); 
     HashMap inputDataMap = new ObjectMapper().readValue(body, HashMap.class); 
     String userName = (String) inputDataMap.get("username"); 
     String password = (String) inputDataMap.get("password"); 
     user = UserDataProvider.verifyEncryptedAccount(userName, password); 

     if (user != null) { 
      UserDataProvider.updateLoginStatus(user.getIdKey(), request.getSession().getId(), ipAddress, true); 
      request.getSession(true).setAttribute("userInfo", user); 
      authenticated = true; 
      message = MPHLTHConstants.Success; 
     } else { 
      throw new InsufficientAccessException("Insufficient access"); 
     } 

    } catch (Exception ex) { 
     authenticated = false; 
     if (ex instanceof ApplicationException) { 
      message = ex.getMessage(); 
     } 
     ExceptionDataProvider.logException(ex, request, user); 
    } finally { 
     try { 
      Response objResponse = new Response(user, message, authenticated, 1); 
      Map<String, String[]> jsonFilters = new HashMap<>(); 
      jsonFilters.put("ResponseFilter", new String[0]); 
      jsonFilters.put("UserInfoFilter", new String[0]); 
      JSONHelper.writeJSONResponse(objResponse, response, jsonFilters); 
     } catch (Exception ex) { 
      ExceptionDataProvider.logException(ex, request, user); 
     } 
    } 

這些都是在那裏我看到了鎖的線程，和我幾個人在不同的時間和這些並沒有隨着時間而改變：

"default task-64" #206 prio=5 os_prio=0 tid=0x000000001c59b800 nid=0x5608 waiting for monitor entry [0x000000001f8bd000] java.lang.Thread.State: BLOCKED (on object monitor) 
    at java.io.PrintStream.println(PrintStream.java:805) 
    - waiting to lock <0x00000000e0058f58> (a java.io.PrintStream) 
    at org.jboss.stdio.StdioContext$DelegatingPrintStream.println(StdioContext.java:474 

這一個：

> "default task-61" #203 prio=5 os_prio=0 tid=0x000000001c599000 nid=0x4934 runnable [0x000000001f5bd000] 
    java.lang.Thread.State: RUNNABLE 
    at java.io.FileOutputStream.writeBytes(Native Method) 
    at java.io.FileOutputStream.write(FileOutputStream.java:326) 
    at java.io.BufferedOutputStream.flushBuffer(BufferedOutputStream.java:82) 
    at java.io.BufferedOutputStream.flush(BufferedOutputStream.java:140) 
    - locked <0x00000000e0aeb790> (a java.io.BufferedOutputStream) 
    at java.io.PrintStream.write(PrintStream.java:482) 
    - locked <0x00000000e0aeb770> (a java.io.PrintStream) 
    at org.jboss.logmanager.handlers.UncloseableOutputStream.write(UncloseableOutputStream.java:44) 
    at org.jboss.logmanager.handlers.UninterruptibleOutputStream.write(UninterruptibleOutputStream.java:84) 
    at sun.nio.cs.StreamEncoder.writeBytes(StreamEncoder.java:221) 
    at sun.nio.cs.StreamEncoder.implFlushBuffer(StreamEncoder.java:291) 
    at sun.nio.cs.StreamEncoder.implFlush(StreamEncoder.java:295) 
    at sun.nio.cs.StreamEncoder.flush(StreamEncoder.java:141) 
    - locked <0x00000000e0aeb738> (a java.io.OutputStreamWriter) 
    at java.io.OutputStreamWriter.flush(OutputStreamWriter.java:229) 
    at java.io.BufferedWriter.flush(BufferedWriter.java:254) 
    - locked <0x00000000e0aeb738> (a java.io.OutputStreamWriter) 
    at org.jboss.logmanager.handlers.WriterHandler.safeFlush(WriterHandler.java:170) 
    at org.jboss.logmanager.handlers.WriterHandler.flush(WriterHandler.java:139) 
    - locked <0x00000000e0aeb700> (a java.lang.Object) 
    at org.jboss.logmanager.ExtHandler.doPublish(ExtHandler.java:104) 
    at org.jboss.logmanager.handlers.WriterHandler.doPublish(WriterHandler.java:67) 
    - locked <0x00000000e0aeb700> (a java.lang.Object) 
    at org.jboss.logmanager.ExtHandler.publish(ExtHandler.java:76) 
    at org.jboss.logmanager.LoggerNode.publish(LoggerNode.java:314) 
    at org.jboss.logmanager.LoggerNode.publish(LoggerNode.java:322) 
    at org.jboss.logmanager.Logger.logRaw(Logger.java:850) 
    at org.jboss.logmanager.Logger.log(Logger.java:596) 
    at org.jboss.stdio.AbstractLoggingWriter.write(AbstractLoggingWriter.java:71) 
    - locked <0x00000000e0058fb8> (a java.lang.StringBuilder) 
    at org.jboss.stdio.WriterOutputStream.finish(WriterOutputStream.java:143) 
    at org.jboss.stdio.WriterOutputStream.flush(WriterOutputStream.java:164) 
    - locked <0x00000000e0059128> (a sun.nio.cs.SingleByte$Decoder) 
    at java.io.PrintStream.write(PrintStream.java:482) 
    - locked <0x00000000e0058f58> (a java.io.PrintStream) 
    at sun.nio.cs.StreamEncoder.writeBytes(StreamEncoder.java:221) 
    at sun.nio.cs.StreamEncoder.implFlushBuffer(StreamEncoder.java:291) 
    at sun.nio.cs.StreamEncoder.flushBuffer(StreamEncoder.java:104) 
    - locked <0x00000000e00579c0> (a java.io.OutputStreamWriter) 
    at java.io.OutputStreamWriter.flushBuffer(OutputStreamWriter.java:185) 
    at java.io.PrintStream.newLine(PrintStream.java:546) 
    - locked <0x00000000e0058f58> (a java.io.PrintStream) 
    at java.io.PrintStream.println(PrintStream.java:807) 
    - locked <0x00000000e0058f58> (a java.io.PrintStream) 
    at org.jboss.stdio.StdioContext$DelegatingPrintStream.println(StdioContext.java:474) 

Answer 1

這個問題最終被解決。發現由於println（）語句存在於應用程序中的幾個地方，導致線程鎖定。 WildFly 10中的日誌子系統和println（）語句正在爲打印輸出流創建鎖，並最終陷入死鎖。