如何在 eclipse-rcp 应用程序中使用 org.apache.logging.log4j.jul.LogManager？

Question

我正在尝试在 Eclipse rcp 应用程序中使用 log4j2 LogManager。 我有

-Djava.util.logging.manager=org.apache.logging.log4j.jul.LogManager

设置为启动参数。从我的 Eclipse IDE 中启动 rcp 应用程序，一切都按预期工作。但是一旦我将它作为独立应用程序启动，日志记录将不起作用。

可能的提示可能是来自客户端控制台的以下堆栈跟踪：

Could not load Logmanager "org.apache.logging.log4j.jul.LogManager"
java.lang.ClassNotFoundException: org.apache.logging.log4j.jul.LogManager
        at java.net.URLClassLoader.findClass(Unknown Source)
        at java.lang.ClassLoader.loadClass(Unknown Source)
        at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
        at java.lang.ClassLoader.loadClass(Unknown Source)
        at org.eclipse.core.runtime.internal.adaptor.ContextFinder.loadClass(ContextFinder.java:131)
        at java.lang.ClassLoader.loadClass(Unknown Source)
        at java.util.logging.LogManager$1.run(Unknown Source)
        at java.util.logging.LogManager$1.run(Unknown Source)
        at java.security.AccessController.doPrivileged(Native Method)
        at java.util.logging.LogManager.<clinit>(Unknown Source)
        at java.util.logging.Logger.demandLogger(Unknown Source)
        at java.util.logging.Logger.getLogger(Unknown Source)
        at org.apache.felix.gogo.runtime.threadio.ThreadIOImpl.<clinit>(ThreadIOImpl.java:30)
        at org.apache.felix.gogo.runtime.activator.Activator.start(Activator.java:75)
        at org.eclipse.osgi.framework.internal.core.BundleContextImpl$1.run(BundleContextImpl.java:711)
        at java.security.AccessController.doPrivileged(Native Method)
        at org.eclipse.osgi.framework.internal.core.BundleContextImpl.startActivator(BundleContextImpl.java:702)
        at org.eclipse.osgi.framework.internal.core.BundleContextImpl.start(BundleContextImpl.java:683)
        at org.eclipse.osgi.framework.internal.core.BundleHost.startWorker(BundleHost.java:381)
        at org.eclipse.osgi.framework.internal.core.AbstractBundle.start(AbstractBundle.java:300)
        at org.eclipse.equinox.console.command.adapter.Activator.startBundle(Activator.java:248)
        at org.eclipse.equinox.console.command.adapter.Activator.start(Activator.java:237)
        at org.eclipse.osgi.framework.internal.core.BundleContextImpl$1.run(BundleContextImpl.java:711)
        at java.security.AccessController.doPrivileged(Native Method)
        at org.eclipse.osgi.framework.internal.core.BundleContextImpl.startActivator(BundleContextImpl.java:702)
        at org.eclipse.osgi.framework.internal.core.BundleContextImpl.start(BundleContextImpl.java:683)
        at org.eclipse.osgi.framework.internal.core.BundleHost.startWorker(BundleHost.java:381)
        at org.eclipse.osgi.framework.internal.core.AbstractBundle.start(AbstractBundle.java:300)
        at org.eclipse.osgi.framework.internal.core.ConsoleManager.checkForConsoleBundle(ConsoleManager.java:215)
        at org.eclipse.core.runtime.adaptor.EclipseStarter.startup(EclipseStarter.java:297)
        at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:176)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
        at java.lang.reflect.Method.invoke(Unknown Source)
        at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java:629)
        at org.eclipse.equinox.launcher.Main.basicRun(Main.java:584)
        at org.eclipse.equinox.launcher.Main.run(Main.java:1438)

如果不从我的 IDE 中启动 RCP 应用程序，我需要做什么才能在 RCP 应用程序中运行日志记录？

Answer 1

听起来 eclipse 知道你对这个类的依赖，并且能够为你将它添加到类路径中。当您在 Eclipse 之外运行它时，您需要一种将依赖项添加到类路径的方法。要解决此问题，请确保类 org.apache.logging.log4j.jul.LogManager 在类路径上。这可以通过 -cp 和 jar 文件的路径来完成。例如，如果您尝试运行一个类 com.org.Main。

java -cp your.jar:log4j-jul-2.3.jar com.org.Main

your.jar 是包含您的应用程序的 jar，而 log4j-jul-2.3.jar 是包含缺少的类的 jar。