unix重定向之前，在log4j中捕获java stderr和stdout

Question

我在应用程序中使用log4j以不同的日志级别记录某些包

然而，stderr和stdout似乎并没有被捕获在此日志文件中，而是在应用程序启动时打印在一个文件中

java AppName >> out.log

是否可以在log4j中捕获stdout和stderr（例如，stdout作为info，stderr作为WARN/ERROR）以及out中。日志文件

log4j的设置如下所示：

<log4j:configuration xmlns:log4j="http://jakarta.apache.org/log4j/">
    <appender name="FileAppender" class="org.apache.log4j.DailyRollingFileAppender">
        <param name="File" value="${MDCapture.logfile.dir}/${APP_NAME}.log"/>
        <param name="BufferedIO" value="false"/>
        <param name="DatePattern" value="'.'yyyy-MMM-dd"/>
        <layout class="org.apache.log4j.TTCCLayout">
            <param name="DateFormat" value="ISO8601"/>
        </layout>
    </appender>

    <appender name="AsyncAppenders" class="org.apache.log4j.AsyncAppender">
        <appender-ref ref="FileAppender"/>
    </appender>

<!-- LOGGER PACKAGES -->

<root>
    <priority value="info"/>
    <appender-ref ref="AsyncAppenders"/>
</root>
</log4j:configuration>

更新：

stackoverflow错误的Stacktrace：

WARN root buffer size limit:65log4j:WARN root buffer size limit:65Exception in thread "Thread-12"
2013-03-22 09:14:24,451 [Thread-12] ERROR root - java.lang.StackOverflowError
2013-03-22 09:14:24,452 [Thread-12] ERROR root -        at java.io.BufferedWriter.write(BufferedWriter.java:202)
2013-03-22 09:14:24,452 [Thread-12] ERROR root -        at java.io.Writer.write(Writer.java:140)
2013-03-22 09:14:24,452 [Thread-12] ERROR root -        at java.io.PrintStream.write(PrintStream.java:475)
2013-03-22 09:14:24,452 [Thread-12] ERROR root -        at java.io.PrintStream.print(PrintStream.java:619)
2013-03-22 09:14:24,452 [Thread-12] ERROR root -        at java.io.PrintStream.println(PrintStream.java:756)
2013-03-22 09:14:24,452 [Thread-12] ERROR root -        at org.apache.log4j.helpers.LogLog.warn(LogLog.java:171)
2013-03-22 09:14:24,452 [Thread-12] ERROR root -        at org.apache.log4j.AsyncAppender.append(AsyncAppender.java:175)
2013-03-22 09:14:24,452 [Thread-12] ERROR root -        at org.apache.log4j.AppenderSkeleton.doAppend(AppenderSkeleton.java:251)
2013-03-22 09:14:24,452 [Thread-12] ERROR root -        at org.apache.log4j.helpers.AppenderAttachableImpl.appendLoopOnAppenders(AppenderAttachableImpl.java:66)


2013-03-22 09:14:24,452 [Thread-12] ERROR root -        at org.apache.log4j.Category.callAppenders(Category.java:206)
2013-03-22 09:14:24,452 [Thread-12] ERROR root -        at org.apache.log4j.Category.forcedLog(Category.java:391)
2013-03-22 09:14:24,452 [Thread-12] ERROR root -        at org.apache.log4j.Category.log(Category.java:838)
2013-03-22 09:14:24,453 [Thread-12] ERROR root -        at com.company.something.AClass.LoggingOutputStream.flush(LoggingOutputStream.java:198)
2013-03-22 09:14:24,453 [Thread-12] ERROR root -        at java.io.PrintStream.write(PrintStream.java:432)
2013-03-22 09:14:24,453 [Thread-12] ERROR root -        at sun.nio.cs.StreamEncoder.writeBytes(StreamEncoder.java:202)
2013-03-22 09:14:24,453 [Thread-12] ERROR root -        at sun.nio.cs.StreamEncoder.implFlushBuffer(StreamEncoder.java:272)
2013-03-22 09:14:24,453 [Thread-12] ERROR root -        at sun.nio.cs.StreamEncoder.flushBuffer(StreamEncoder.java:85)
2013-03-22 09:14:24,453 [Thread-12] ERROR root -        at java.io.OutputStreamWriter.flushBuffer(OutputStreamWriter.java:168)
2013-03-22 09:14:24,453 [Thread-12] ERROR root -        at java.io.PrintStream.write(PrintStream.java:477)
2013-03-22 09:14:24,453 [Thread-12] ERROR root -        at java.io.PrintStream.print(PrintStream.java:619)
2013-03-22 09:14:24,453 [Thread-12] ERROR root -        at java.io.PrintStream.println(PrintStream.java:756)
2013-03-22 09:14:24,453 [Thread-12] ERROR root -        at org.apache.log4j.helpers.LogLog.warn(LogLog.java:171)
2013-03-22 09:14:24,453 [Thread-12] ERROR root -        at org.apache.log4j.AsyncAppender.append(AsyncAppender.java:175)
2013-03-22 09:14:24,453 [Thread-12] ERROR root -        at org.apache.log4j.AppenderSkeleton.doAppend(AppenderSkeleton.java:251)
2013-03-22 09:14:24,453 [Thread-12] ERROR root -        at org.apache.log4j.helpers.AppenderAttachableImpl.appendLoopOnAppenders(AppenderAttachableImpl.java:

Answer 1

对于log4j 2。x:

System.setErr(IoBuilder.forLogger(LogManager.getRootLogger()).setLevel(Level.ERROR).buildPrintStream());
System.setOut(IoBuilder.forLogger(LogManager.getRootLogger()).setLevel(Level.INFO).buildPrintStream());

依赖项信息：

• 组：org。阿帕奇。登录中。log4j
• 工件：log4j iostreams

Answer 2

要将stdout和stderr重定向到log4j，请尝试以下操作：

System.setErr( new PrintStream( new LoggingOutputStream( Logger.getRootLogger(  ), Level.ERROR ), true);

System.setOut( new PrintStream( new LoggingOutputStream( Logger.getRootLogger(  ), Level.INFO ), true);

对于LoggingOutputStream你可以从this example开始

要让log4j将您想要的内容打印到控制台（如果需要，并将其捕获回文件/节点），请将ConsoleAppender启用到适当的级别