Java 为什么Log4J2在文件名中查找带有类加载器字符串的配置文件？
我正在尝试设置Log4J2，并将其Java 为什么Log4J2在文件名中查找带有类加载器字符串的配置文件？,java,classloader,embedded-resource,log4j2,Java,Classloader,Embedded Resource,Log4j2,我正在尝试设置Log4J2，并将其StatusLogger打印到控制台，以便理解为什么它没有看到我的配置文件（出于好奇，我认为问题在于Log4J2使用的JSON库不在我的类路径中，所以它以静默方式失败，但不幸的是，我不确定） 然而，一旦我将StatusLogger设置为打印TRACE语句，我注意到一些奇怪的事情-它似乎在寻找文件名中调用sun.misc.Launcher$AppClassLoader.toString（）的资源，例如（为了可读性增加了新行）： 它要查找的文件本质上是“log4j2
StatusLoggerStatusLoggerTRACEsun.misc.Launcher$AppClassLoader.toString（）“log4j2”+classLoader+“.json”ClassLoaderContextSelector.locateContext（）private LoggerContext locateContext(final ClassLoader loader,
final URI configLocation {
final String name = loader.toString();
...
LoggerContext ctx = new LoggerContext(name, null, configLocation);
...
}
ctx.start（）Loader.getResource（）Loader.toString（）的值作为resource
字符串的一部分传入。从这个角度看，这种行为似乎相当有意图，但我无法想象为什么寻找这样一个资源名称会有好处。这给我们带来了什么？这是虫子吗
SSCCE：
import org.apache.logging.log4j.Level;
import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.status.StatusConsoleListener;
import org.apache.logging.log4j.status.StatusLogger;
public class L4JTrace {
public static void main(String[] args) {
StatusConsoleListener listener = new StatusConsoleListener(Level.ALL);
StatusLogger.getLogger().registerListener(listener);
LogManager.getLogger(MyApp.class.getName());
}
}
这应该输出如下内容：
2013-12-09 01:22:27,132 WARN Multiple logging implementations found:
Factory: org.apache.logging.log4j.core.impl.Log4jContextFactory, Weighting: 10
Using factory: org.apache.logging.log4j.core.impl.Log4jContextFactory
2013-12-09 01:22:27,148 DEBUG ServletContext not present - WebLookup not added
2013-12-09 01:22:27,160 DEBUG Found Plugin Map at jar:file:LOCALPATH
2013-12-09 01:22:27,162 DEBUG ServletContext not present - WebLookup not added
2013-12-09 01:22:27,202 WARN JmDNS or serviceInfo class not found java.lang.ClassNotFoundException: javax.jmdns.JmDNS # Exception truncated
2013-12-09 01:22:27,221 DEBUG Generated plugins in 0.062408180 seconds
2013-12-09 01:22:27,240 DEBUG Jansi is not installed, cannot find org.fusesource.jansi.WindowsAnsiOutputStream
2013-12-09 01:22:27,241 DEBUG Starting OutputStreamManager SYSTEM_OUT
2013-12-09 01:22:27,242 DEBUG Reconfiguration started for context sun.misc.Launcher$AppClassLoader@765291
2013-12-09 01:22:27,242 DEBUG Generated plugins in 0.000013583 seconds
2013-12-09 01:22:27,245 DEBUG ServletContext not present - WebLookup not added
2013-12-09 01:22:27,245 DEBUG Missing dependencies for Json support
2013-12-09 01:22:27,245 DEBUG ServletContext not present - WebLookup not added
2013-12-09 01:22:27,245 TRACE Trying to find [log4j2-testsun.misc.Launcher$AppClassLoader@765291.json] using context classloader sun.misc.Launcher$AppClassLoader@765291.
2013-12-09 01:22:27,246 TRACE Trying to find [log4j2-testsun.misc.Launcher$AppClassLoader@765291.json] using sun.misc.Launcher$AppClassLoader@765291 class loader.
2013-12-09 01:22:27,246 TRACE Trying to find [log4j2-testsun.misc.Launcher$AppClassLoader@765291.json] using sun.misc.Launcher$AppClassLoader@765291 class loader.
2013-12-09 01:22:27,246 TRACE Trying to find [log4j2-testsun.misc.Launcher$AppClassLoader@765291.json] using ClassLoader.getSystemResource().
2013-12-09 01:22:27,246 TRACE Trying to find [log4j2-testsun.misc.Launcher$AppClassLoader@765291.jsn] using context classloader sun.misc.Launcher$AppClassLoader@765291.
2013-12-09 01:22:27,246 TRACE Trying to find [log4j2-testsun.misc.Launcher$AppClassLoader@765291.jsn] using sun.misc.Launcher$AppClassLoader@765291 class loader.
2013-12-09 01:22:27,247 TRACE Trying to find [log4j2-testsun.misc.Launcher$AppClassLoader@765291.jsn] using sun.misc.Launcher$AppClassLoader@765291 class loader.
2013-12-09 01:22:27,247 TRACE Trying to find [log4j2-testsun.misc.Launcher$AppClassLoader@765291.jsn] using ClassLoader.getSystemResource().
2013-12-09 01:22:27,247 TRACE Trying to find [log4j2-testsun.misc.Launcher$AppClassLoader@765291.xml] using context classloader sun.misc.Launcher$AppClassLoader@765291.
2013-12-09 01:22:27,247 TRACE Trying to find [log4j2-testsun.misc.Launcher$AppClassLoader@765291.xml] using sun.misc.Launcher$AppClassLoader@765291 class loader.
2013-12-09 01:22:27,247 TRACE Trying to find [log4j2-testsun.misc.Launcher$AppClassLoader@765291.xml] using sun.misc.Launcher$AppClassLoader@765291 class loader.
2013-12-09 01:22:27,247 TRACE Trying to find [log4j2-testsun.misc.Launcher$AppClassLoader@765291.xml] using ClassLoader.getSystemResource().
2013-12-09 01:22:27,248 TRACE Trying to find [log4j2-test.json] using context classloader sun.misc.Launcher$AppClassLoader@765291.
2013-12-09 01:22:27,248 TRACE Trying to find [log4j2-test.json] using sun.misc.Launcher$AppClassLoader@765291 class loader.
2013-12-09 01:22:27,248 TRACE Trying to find [log4j2-test.json] using sun.misc.Launcher$AppClassLoader@765291 class loader.
2013-12-09 01:22:27,248 TRACE Trying to find [log4j2-test.json] using ClassLoader.getSystemResource().
2013-12-09 01:22:27,248 TRACE Trying to find [log4j2-test.jsn] using context classloader sun.misc.Launcher$AppClassLoader@765291.
2013-12-09 01:22:27,248 TRACE Trying to find [log4j2-test.jsn] using sun.misc.Launcher$AppClassLoader@765291 class loader.
2013-12-09 01:22:27,248 TRACE Trying to find [log4j2-test.jsn] using sun.misc.Launcher$AppClassLoader@765291 class loader.
2013-12-09 01:22:27,249 TRACE Trying to find [log4j2-test.jsn] using ClassLoader.getSystemResource().
2013-12-09 01:22:27,249 TRACE Trying to find [log4j2-test.xml] using context classloader sun.misc.Launcher$AppClassLoader@765291.
2013-12-09 01:22:27,249 TRACE Trying to find [log4j2-test.xml] using sun.misc.Launcher$AppClassLoader@765291 class loader.
2013-12-09 01:22:27,249 TRACE Trying to find [log4j2-test.xml] using sun.misc.Launcher$AppClassLoader@765291 class loader.
2013-12-09 01:22:27,249 TRACE Trying to find [log4j2-test.xml] using ClassLoader.getSystemResource().
2013-12-09 01:22:27,250 TRACE Trying to find [log4j2sun.misc.Launcher$AppClassLoader@765291.json] using context classloader sun.misc.Launcher$AppClassLoader@765291.
2013-12-09 01:22:27,250 TRACE Trying to find [log4j2sun.misc.Launcher$AppClassLoader@765291.json] using sun.misc.Launcher$AppClassLoader@765291 class loader.
2013-12-09 01:22:27,250 TRACE Trying to find [log4j2sun.misc.Launcher$AppClassLoader@765291.json] using sun.misc.Launcher$AppClassLoader@765291 class loader.
2013-12-09 01:22:27,250 TRACE Trying to find [log4j2sun.misc.Launcher$AppClassLoader@765291.json] using ClassLoader.getSystemResource().
2013-12-09 01:22:27,250 TRACE Trying to find [log4j2sun.misc.Launcher$AppClassLoader@765291.jsn] using context classloader sun.misc.Launcher$AppClassLoader@765291.
2013-12-09 01:22:27,251 TRACE Trying to find [log4j2sun.misc.Launcher$AppClassLoader@765291.jsn] using sun.misc.Launcher$AppClassLoader@765291 class loader.
2013-12-09 01:22:27,251 TRACE Trying to find [log4j2sun.misc.Launcher$AppClassLoader@765291.jsn] using sun.misc.Launcher$AppClassLoader@765291 class loader.
2013-12-09 01:22:27,251 TRACE Trying to find [log4j2sun.misc.Launcher$AppClassLoader@765291.jsn] using ClassLoader.getSystemResource().
2013-12-09 01:22:27,251 TRACE Trying to find [log4j2sun.misc.Launcher$AppClassLoader@765291.xml] using context classloader sun.misc.Launcher$AppClassLoader@765291.
2013-12-09 01:22:27,251 TRACE Trying to find [log4j2sun.misc.Launcher$AppClassLoader@765291.xml] using sun.misc.Launcher$AppClassLoader@765291 class loader.
2013-12-09 01:22:27,251 TRACE Trying to find [log4j2sun.misc.Launcher$AppClassLoader@765291.xml] using sun.misc.Launcher$AppClassLoader@765291 class loader.
2013-12-09 01:22:27,252 TRACE Trying to find [log4j2sun.misc.Launcher$AppClassLoader@765291.xml] using ClassLoader.getSystemResource().
2013-12-09 01:22:27,252 TRACE Trying to find [log4j2.json] using context classloader sun.misc.Launcher$AppClassLoader@765291.
2013-12-09 01:22:27,252 TRACE Trying to find [log4j2.json] using sun.misc.Launcher$AppClassLoader@765291 class loader.
2013-12-09 01:22:27,252 TRACE Trying to find [log4j2.json] using sun.misc.Launcher$AppClassLoader@765291 class loader.
2013-12-09 01:22:27,252 TRACE Trying to find [log4j2.json] using ClassLoader.getSystemResource().
2013-12-09 01:22:27,252 TRACE Trying to find [log4j2.jsn] using context classloader sun.misc.Launcher$AppClassLoader@765291.
2013-12-09 01:22:27,252 TRACE Trying to find [log4j2.jsn] using sun.misc.Launcher$AppClassLoader@765291 class loader.
2013-12-09 01:22:27,253 TRACE Trying to find [log4j2.jsn] using sun.misc.Launcher$AppClassLoader@765291 class loader.
2013-12-09 01:22:27,253 TRACE Trying to find [log4j2.jsn] using ClassLoader.getSystemResource().
2013-12-09 01:22:27,253 TRACE Trying to find [log4j2.xml] using context classloader sun.misc.Launcher$AppClassLoader@765291.
2013-12-09 01:22:27,253 TRACE Trying to find [log4j2.xml] using sun.misc.Launcher$AppClassLoader@765291 class loader.
2013-12-09 01:22:27,253 TRACE Trying to find [log4j2.xml] using sun.misc.Launcher$AppClassLoader@765291 class loader.
2013-12-09 01:22:27,253 TRACE Trying to find [log4j2.xml] using ClassLoader.getSystemResource().
2013-12-09 01:22:27,254 DEBUG ServletContext not present - WebLookup not added
2013-12-09 01:22:27,254 DEBUG Generated plugins in 0.000012075 seconds
2013-12-09 01:22:27,254 DEBUG Jansi is not installed, cannot find org.fusesource.jansi.WindowsAnsiOutputStream
2013-12-09 01:22:27,261 DEBUG Generated plugins in 0.000015998 seconds
2013-12-09 01:22:27,261 DEBUG Reconfiguration completed
2013-12-09 01:22:27,263 DEBUG ServletContext not present - WebLookup not added
2013-12-09 01:22:27,264 DEBUG Shutting down OutputStreamManager SYSTEM_OUT
我认为这可能与web应用程序有关；多个web应用程序可以同时共存，并且需要有一个单独的LoggerContext。ClassLoader对象toString保证LoggerContext的名称是唯一的
如果您在log4j开发人员邮件列表中询问，log4j团队成员可能会对此有更多的了解
2013-12-09 01:22:27,132 WARN Multiple logging implementations found:
Factory: org.apache.logging.log4j.core.impl.Log4jContextFactory, Weighting: 10
Using factory: org.apache.logging.log4j.core.impl.Log4jContextFactory
2013-12-09 01:22:27,148 DEBUG ServletContext not present - WebLookup not added
2013-12-09 01:22:27,160 DEBUG Found Plugin Map at jar:file:LOCALPATH
2013-12-09 01:22:27,162 DEBUG ServletContext not present - WebLookup not added
2013-12-09 01:22:27,202 WARN JmDNS or serviceInfo class not found java.lang.ClassNotFoundException: javax.jmdns.JmDNS # Exception truncated
2013-12-09 01:22:27,221 DEBUG Generated plugins in 0.062408180 seconds
2013-12-09 01:22:27,240 DEBUG Jansi is not installed, cannot find org.fusesource.jansi.WindowsAnsiOutputStream
2013-12-09 01:22:27,241 DEBUG Starting OutputStreamManager SYSTEM_OUT
2013-12-09 01:22:27,242 DEBUG Reconfiguration started for context sun.misc.Launcher$AppClassLoader@765291
2013-12-09 01:22:27,242 DEBUG Generated plugins in 0.000013583 seconds
2013-12-09 01:22:27,245 DEBUG ServletContext not present - WebLookup not added
2013-12-09 01:22:27,245 DEBUG Missing dependencies for Json support
2013-12-09 01:22:27,245 DEBUG ServletContext not present - WebLookup not added
2013-12-09 01:22:27,245 TRACE Trying to find [log4j2-testsun.misc.Launcher$AppClassLoader@765291.json] using context classloader sun.misc.Launcher$AppClassLoader@765291.
2013-12-09 01:22:27,246 TRACE Trying to find [log4j2-testsun.misc.Launcher$AppClassLoader@765291.json] using sun.misc.Launcher$AppClassLoader@765291 class loader.
2013-12-09 01:22:27,246 TRACE Trying to find [log4j2-testsun.misc.Launcher$AppClassLoader@765291.json] using sun.misc.Launcher$AppClassLoader@765291 class loader.
2013-12-09 01:22:27,246 TRACE Trying to find [log4j2-testsun.misc.Launcher$AppClassLoader@765291.json] using ClassLoader.getSystemResource().
2013-12-09 01:22:27,246 TRACE Trying to find [log4j2-testsun.misc.Launcher$AppClassLoader@765291.jsn] using context classloader sun.misc.Launcher$AppClassLoader@765291.
2013-12-09 01:22:27,246 TRACE Trying to find [log4j2-testsun.misc.Launcher$AppClassLoader@765291.jsn] using sun.misc.Launcher$AppClassLoader@765291 class loader.
2013-12-09 01:22:27,247 TRACE Trying to find [log4j2-testsun.misc.Launcher$AppClassLoader@765291.jsn] using sun.misc.Launcher$AppClassLoader@765291 class loader.
2013-12-09 01:22:27,247 TRACE Trying to find [log4j2-testsun.misc.Launcher$AppClassLoader@765291.jsn] using ClassLoader.getSystemResource().
2013-12-09 01:22:27,247 TRACE Trying to find [log4j2-testsun.misc.Launcher$AppClassLoader@765291.xml] using context classloader sun.misc.Launcher$AppClassLoader@765291.
2013-12-09 01:22:27,247 TRACE Trying to find [log4j2-testsun.misc.Launcher$AppClassLoader@765291.xml] using sun.misc.Launcher$AppClassLoader@765291 class loader.
2013-12-09 01:22:27,247 TRACE Trying to find [log4j2-testsun.misc.Launcher$AppClassLoader@765291.xml] using sun.misc.Launcher$AppClassLoader@765291 class loader.
2013-12-09 01:22:27,247 TRACE Trying to find [log4j2-testsun.misc.Launcher$AppClassLoader@765291.xml] using ClassLoader.getSystemResource().
2013-12-09 01:22:27,248 TRACE Trying to find [log4j2-test.json] using context classloader sun.misc.Launcher$AppClassLoader@765291.
2013-12-09 01:22:27,248 TRACE Trying to find [log4j2-test.json] using sun.misc.Launcher$AppClassLoader@765291 class loader.
2013-12-09 01:22:27,248 TRACE Trying to find [log4j2-test.json] using sun.misc.Launcher$AppClassLoader@765291 class loader.
2013-12-09 01:22:27,248 TRACE Trying to find [log4j2-test.json] using ClassLoader.getSystemResource().
2013-12-09 01:22:27,248 TRACE Trying to find [log4j2-test.jsn] using context classloader sun.misc.Launcher$AppClassLoader@765291.
2013-12-09 01:22:27,248 TRACE Trying to find [log4j2-test.jsn] using sun.misc.Launcher$AppClassLoader@765291 class loader.
2013-12-09 01:22:27,248 TRACE Trying to find [log4j2-test.jsn] using sun.misc.Launcher$AppClassLoader@765291 class loader.
2013-12-09 01:22:27,249 TRACE Trying to find [log4j2-test.jsn] using ClassLoader.getSystemResource().
2013-12-09 01:22:27,249 TRACE Trying to find [log4j2-test.xml] using context classloader sun.misc.Launcher$AppClassLoader@765291.
2013-12-09 01:22:27,249 TRACE Trying to find [log4j2-test.xml] using sun.misc.Launcher$AppClassLoader@765291 class loader.
2013-12-09 01:22:27,249 TRACE Trying to find [log4j2-test.xml] using sun.misc.Launcher$AppClassLoader@765291 class loader.
2013-12-09 01:22:27,249 TRACE Trying to find [log4j2-test.xml] using ClassLoader.getSystemResource().
2013-12-09 01:22:27,250 TRACE Trying to find [log4j2sun.misc.Launcher$AppClassLoader@765291.json] using context classloader sun.misc.Launcher$AppClassLoader@765291.
2013-12-09 01:22:27,250 TRACE Trying to find [log4j2sun.misc.Launcher$AppClassLoader@765291.json] using sun.misc.Launcher$AppClassLoader@765291 class loader.
2013-12-09 01:22:27,250 TRACE Trying to find [log4j2sun.misc.Launcher$AppClassLoader@765291.json] using sun.misc.Launcher$AppClassLoader@765291 class loader.
2013-12-09 01:22:27,250 TRACE Trying to find [log4j2sun.misc.Launcher$AppClassLoader@765291.json] using ClassLoader.getSystemResource().
2013-12-09 01:22:27,250 TRACE Trying to find [log4j2sun.misc.Launcher$AppClassLoader@765291.jsn] using context classloader sun.misc.Launcher$AppClassLoader@765291.
2013-12-09 01:22:27,251 TRACE Trying to find [log4j2sun.misc.Launcher$AppClassLoader@765291.jsn] using sun.misc.Launcher$AppClassLoader@765291 class loader.
2013-12-09 01:22:27,251 TRACE Trying to find [log4j2sun.misc.Launcher$AppClassLoader@765291.jsn] using sun.misc.Launcher$AppClassLoader@765291 class loader.
2013-12-09 01:22:27,251 TRACE Trying to find [log4j2sun.misc.Launcher$AppClassLoader@765291.jsn] using ClassLoader.getSystemResource().
2013-12-09 01:22:27,251 TRACE Trying to find [log4j2sun.misc.Launcher$AppClassLoader@765291.xml] using context classloader sun.misc.Launcher$AppClassLoader@765291.
2013-12-09 01:22:27,251 TRACE Trying to find [log4j2sun.misc.Launcher$AppClassLoader@765291.xml] using sun.misc.Launcher$AppClassLoader@765291 class loader.
2013-12-09 01:22:27,251 TRACE Trying to find [log4j2sun.misc.Launcher$AppClassLoader@765291.xml] using sun.misc.Launcher$AppClassLoader@765291 class loader.
2013-12-09 01:22:27,252 TRACE Trying to find [log4j2sun.misc.Launcher$AppClassLoader@765291.xml] using ClassLoader.getSystemResource().
2013-12-09 01:22:27,252 TRACE Trying to find [log4j2.json] using context classloader sun.misc.Launcher$AppClassLoader@765291.
2013-12-09 01:22:27,252 TRACE Trying to find [log4j2.json] using sun.misc.Launcher$AppClassLoader@765291 class loader.
2013-12-09 01:22:27,252 TRACE Trying to find [log4j2.json] using sun.misc.Launcher$AppClassLoader@765291 class loader.
2013-12-09 01:22:27,252 TRACE Trying to find [log4j2.json] using ClassLoader.getSystemResource().
2013-12-09 01:22:27,252 TRACE Trying to find [log4j2.jsn] using context classloader sun.misc.Launcher$AppClassLoader@765291.
2013-12-09 01:22:27,252 TRACE Trying to find [log4j2.jsn] using sun.misc.Launcher$AppClassLoader@765291 class loader.
2013-12-09 01:22:27,253 TRACE Trying to find [log4j2.jsn] using sun.misc.Launcher$AppClassLoader@765291 class loader.
2013-12-09 01:22:27,253 TRACE Trying to find [log4j2.jsn] using ClassLoader.getSystemResource().
2013-12-09 01:22:27,253 TRACE Trying to find [log4j2.xml] using context classloader sun.misc.Launcher$AppClassLoader@765291.
2013-12-09 01:22:27,253 TRACE Trying to find [log4j2.xml] using sun.misc.Launcher$AppClassLoader@765291 class loader.
2013-12-09 01:22:27,253 TRACE Trying to find [log4j2.xml] using sun.misc.Launcher$AppClassLoader@765291 class loader.
2013-12-09 01:22:27,253 TRACE Trying to find [log4j2.xml] using ClassLoader.getSystemResource().
2013-12-09 01:22:27,254 DEBUG ServletContext not present - WebLookup not added
2013-12-09 01:22:27,254 DEBUG Generated plugins in 0.000012075 seconds
2013-12-09 01:22:27,254 DEBUG Jansi is not installed, cannot find org.fusesource.jansi.WindowsAnsiOutputStream
2013-12-09 01:22:27,261 DEBUG Generated plugins in 0.000015998 seconds
2013-12-09 01:22:27,261 DEBUG Reconfiguration completed
2013-12-09 01:22:27,263 DEBUG ServletContext not present - WebLookup not added
2013-12-09 01:22:27,264 DEBUG Shutting down OutputStreamManager SYSTEM_OUT