Question

我有一个已经工作了几个月的代码库，今天我部署了一个客户站点的更新，我开始得到以下例外：

线程“Thread-75”中的异常线程“Thread-66”中的异常 java.lang.NullPointerException at org.apache.log4j.spi.LocationInfo。（LocationInfo.java:112）在 org.apache.log4j.spi.LoggingEvent.getLocationInformation（LoggingEvent.java:247）在 org.apache.log4j.helpers.PatternParser $ LocationPatternConverter.convert（PatternParser.java:483）在 org.apache.log4j.helpers.PatternConverter.format（PatternConverter.java:65）在 org.apache.log4j.PatternLayout.format（PatternLayout.java:502）在 org.apache.log4j.WriterAppender.subAppend（WriterAppender.java:302）在 org.apache.log4j.RollingFileAppender.subAppend（RollingFileAppender.java:263）在 org.apache.log4j.WriterAppender.append（WriterAppender.java:160）在 org.apache.log4j.AppenderSkeleton.doAppend（AppenderSkeleton.java:251）在 org.apache.log4j.helpers.AppenderAttachableImpl.appendLoopOnAppenders（AppenderAttachableImpl.java:66）在 org.apache.log4j.Category.callAppenders（Category.java:206）在 org.apache.log4j.Category.forcedLog（Category.java:391）在 org.apache.log4j.Category.debug（Category.java:260）

启动它的代码是一个log.debug（）语句，我不知道为什么会发生这种情况。它也适用于我的机器，但在客户现场失败。

以下是日志配置的匿名版本：

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE log4j:configuration SYSTEM "log4j.dtd">
<log4j:configuration xmlns:log4j="http://jakarta.apache.org/log4j/">
  <appender name="stdout" class="org.apache.log4j.ConsoleAppender"> 
    <param name="Threshold" value="ERROR"/>
    <layout class="org.apache.log4j.PatternLayout"> 
      <!-- Print the date in ISO 8601 format -->
      <param name="ConversionPattern" value="[%d{dd-MM-yyyy HH:mm:ss.SS}][line:%3L] [%5p] [%F %M()] - %m%n"/> 
    </layout> 
  </appender> 
  <appender name="x_trace" class="org.apache.log4j.RollingFileAppender"> 
    <param name="File" value="C:/apache-tomcat-5.5.17/logs/x_trace.log"/>
    <param name="MaxFileSize" value="100MB" />
    <param name="MaxBackupIndex" value="10" />
    <param name="Append" value="true"/>
    <param name="Threshold" value="ALL"/>
    <layout class="org.apache.log4j.PatternLayout"> 
      <param name="ConversionPattern" value="[%d{dd-MM-yyyy HH:mm:ss.SS}][line:%3L]%5p [%t] ( %F %M()) - %m%n"/> 
    </layout> 
  </appender>  
  <appender name="y_trace" class="org.apache.log4j.RollingFileAppender"> 
    <param name="File" value="C:/apache-tomcat-5.5.17/logs/y_trace.log"/>
    <param name="MaxFileSize" value="100MB" />
    <param name="MaxBackupIndex" value="10" />
    <param name="Append" value="true"/>
    <param name="Threshold" value="ALL"/>
    <layout class="org.apache.log4j.PatternLayout"> 
      <param name="ConversionPattern" value="[%d{dd-MM-yyyy HH:mm:ss.SS}][line:%3L]%5p [%t] ( %F %M()) - %m%n"/> 
    </layout> 
  </appender>  
  <appender name="application" class="org.apache.log4j.RollingFileAppender"> 
    <param name="File" value="C:/apache-tomcat-5.5.17/logs/application.log"/>
    <param name="MaxFileSize" value="100MB" />
    <param name="MaxBackupIndex" value="20" />
    <param name="Append" value="true"/>
    <param name="Threshold" value="ALL"/>
    <layout class="org.apache.log4j.PatternLayout"> 
      <param name="ConversionPattern" value="[%d{dd-MM-yyyy HH:mm:ss.SS}][line:%3L]%5p [%t] ( %F %M()) - %m%n"/> 
    </layout> 
  </appender> 
  <!-- failureLogger Logs SQL queries that were not written to the database so they can be rolled in -->
  <appender name="failureLogger" class="org.apache.log4j.DailyRollingFileAppender"> 
    <param name="File" value="C:/apache-tomcat-5.5.17/logs/failures.log"/>
    <param name="Append" value="true"/>
    <param name="Threshold" value="ALL"/>
    <param name="DatePattern" value="'.'yyyy-MM-dd"/>
    <layout class="org.apache.log4j.PatternLayout"> 
      <param name="ConversionPattern" value="%m%n"/> 
    </layout> 
  </appender> 
  <logger name="nanoxml" additivity="false">
    <level value="debug"/>  
    <appender-ref ref="application"/>   
  </logger>   
  <logger name="uk.co.companyName.application" additivity="false">
    <level value="debug"/>  
    <appender-ref ref="application"/>   
  </logger>   
  <logger name="uk.co.companyName.application.applicationContainer" additivity="false">
    <level value="debug"/>  
    <appender-ref ref="application"/>   
  </logger> 
  <logger name="uk.co.companyName.application.addressbook.AddressBook" additivity="false">
    <level value="debug"/>  
    <appender-ref ref="application"/>
  </logger>   
   <logger name="uk.co.companyName.application.component1.Component1" additivity="false">
    <level value="debug"/>  
    <appender-ref ref="application"/>
  </logger>   
  <logger name="uk.co.companyName.application.component2.Component2" additivity="false">
    <level value="debug"/>  
    <appender-ref ref="application"/>
  </logger>  
  <logger name="uk.co.companyName.application.web.filters" additivity="false">
    <level value="error"/>  
    <appender-ref ref="application"/>
  </logger>  
  <logger name="uk.co.companyName.application.web" additivity="false">
    <level value="debug"/>  
    <appender-ref ref="application"/>
  </logger>  
  <logger name="uk.co.companyName.application.util.SettingsHandler" additivity="false">
    <level value="debug"/>  
    <appender-ref ref="application"/>
  </logger> 
  <logger name="uk.co.companyName.application.util" additivity="false">
    <level value="debug"/>  
    <appender-ref ref="application"/>
  </logger> 
  <logger name="org.apache.axis.enterprise" additivity="false">
    <level value="FATAL"/>  
    <appender-ref ref="application"/>
  </logger>  
  <logger name="com.vendor.api1" additivity="false">
    <level value="debug"/>  
    <appender-ref ref="x_trace"/>
  </logger>
  <logger name="com.vendor.api2" additivity="false">
    <level value="debug"/>  
    <appender-ref ref="y_trace"/>
  </logger>
  <logger name="com.vendor.lib1" additivity="false">
    <level value="debug"/>  
    <appender-ref ref="y_trace"/>
  </logger>
  <logger name="ch.ecma" additivity="false">
    <level value="debug"/>  
    <appender-ref ref="y_trace"/>
  </logger>
  <logger name="uk.co.companyName.vendor.middlewareAPI" additivity="false">
    <level value="debug"/>  
    <appender-ref ref="application"/>   
  </logger>
  <logger name="uk.co.companyName.vendor2.workStationAPI" additivity="false">
    <level value="debug"/>  
    <appender-ref ref="application"/>   
  </logger>   
  <logger name="uk.co.companyName.CustomerLib1" additivity="false">
    <level value="debug"/>  
    <appender-ref ref="application"/>   
  </logger>   
  <logger name="FaileStatementLogger" additivity="false">
    <level value="debug"/>
    <appender-ref ref="failureLogger"/>
  </logger>
  <root>  
    <priority value="DEBUG" />
    <!-- <appender-ref ref="stdout" /> -->
  </root>
</log4j:configuration>

Answer 1

根据code for 1.2.15，private static StringWriter似乎是null，这可能表示缺少可用内存。不是100％确定哪些场景会允许一个类在这种情况下结束。

特别是，代码看起来像这样

56    private static StringWriter sw = new StringWriter();
57    private static PrintWriter pw = new PrintWriter(sw);

112    synchronized(sw) {
113        t.printStackTrace(pw);
114        s = sw.toString();
115        sw.getBuffer().setLength(0);
116    }

您正在获取同步呼叫的NPE，该呼叫位于静态成员上。

Answer 2

你能检查你的消费者盒类路径你有什么log4j版本以及你的lib中有什么？尝试不在lib文件夹中提供log4j jar。

为什么我得到这个奇怪的log4j异常？

2 个答案: