如何从JNDI加载log4j2配置文件

Question

我正在将一些web应用程序从log4j1.12迁移到Log4j2。由于公司政策，我们的log4j。xml文件位置在应用服务器中配置为URL，应用程序必须使用JNDI获取它们。我们实现了一个ServletContextListener，它允许我们以这种方式初始化log4j基础结构：

public void contextInitialized(ServletContextEvent servletContextEvent) {
    ...
    urlLogConfig = (URL) context.lookup("java:comp/env/"+logLocation);
    ...
    //urlLogConfig -> file:///somepath/log4j.xml
    DOMConfigurator.configureAndWatch(urlLogConfig.getPath());
}
public void contextDestroyed(ServletContextEvent servletContextEvent) {
    ServletContext servletContext = servletContextEvent.getServletContext();
    servletContext.log("Log4jConfigurationListener - Shutting down log4j");
    LogManager.shutdown();
}

但是，随着log4j2api的更改，这将无法再使用。Log4j2提供了lo4j2web。jar模块，它使用Log4jServletContainerInitializer初始化库。这将调用Log4jWebInitializerImpl。getConfigURI（），负责获取配置文件的URI。

有什么方法可以自定义Log4jWebIdazerImpl的行为，使其从JNDI名称解析xml文件？

Answer 1

像这样的东西怎么样：

...
import org.apache.logging.log4j.core.config.Configurator;
...

    private LoggerContext loggerContext;

    public void contextInitialized(ServletContextEvent servletContextEvent) {
       ...
       urlLogConfig = (URL) context.lookup("java:comp/env/"+logLocation);
       ...
       //urlLogConfig -> file:///somepath/log4j.xml
       ServletContext servletContext = servletContextEvent.getServletContext();
       String contextName = servletContext.getServletContextName();
       Classloader classloader = this.getClass().getClassloader();
       loggerContext = Configurator.initialize(contextName, classloader, urlLogConfig.toURI());
    }

    public void contextDestroyed(ServletContextEvent servletContextEvent) {
        ServletContext servletContext = servletContextEvent.getServletContext();
        servletContext.log("Log4jConfigurationListener - Shutting down log4j");
        if (loggerContext != null) 
             Configurator.shutdown(loggerContext);
    }