为Log4j 1.2注册自定义LoggerFactory的正确方法？

Question

我正在使用Log4j(1.2.16)登录的Web应用程序.为了避免编辑大量文件,我试图挂钩一个自定义的LoggerFactory实现,以防止日志伪造.

看来可以设置log4j.loggerFactory配置设置(项目使用属性文件方法)来指定要使用的记录器工厂.但是,这似乎不起作用.在检查了Log4j的源代码之后,看起来该属性从未真正使用过,即使它是由PropertyConfigurator类读取的.

检查更多的Log4j源代码,它似乎是实现我想要的唯一方法,我必须创建Log4j类的自定义子类.这是唯一的方法吗？

以下代表我在Web应用程序上下文监听器中必须要做的事情,以初始化Log4j,以便使用我的自定义记录器工厂:

package com.example.myapp.log4j;

import javax.servlet.ServletContextListener;
import javax.servlet.ServletContextEvent;
import javax.servlet.*;

public class MyLog4jInitContextListener implements ServletContextListener
{
  public void contextInitialized(
      ServletContextEvent event
  ) {
    this.context = event.getServletContext();

    String file = context.getInitParameter("log4jConfiguration");
    if (file != null) {
      String prefix = context.getRealPath("/");
      String pathname = prefix+file;
      event.getServletContext().log("Initializing log4j with "+pathname);
      org.apache.log4j.LogManager.setRepositorySelector(
          new org.apache.log4j.spi.DefaultRepositorySelector(
            new MyHierarchy(
              new org.apache.log4j.spi.RootLogger(
                (org.apache.log4j.Level)org.apache.log4j.Level.INFO))), this);
      new MyPropertyConfigurator().doConfigure(
          pathname, org.apache.log4j.LogManager.getLoggerRepository());
    } else {
      event.getServletContext().log(
          "No log4jConfiguration parameter specified");
    }
  }

  public void contextDestroyed(
      ServletContextEvent event
  ) {
    this.context = null;
  }

  private ServletContext context = null;
}

我不得不创建一个自定义,Hierarchy因为它看起来硬编码默认的日志工厂.这个版本确保在调用单个参数getLogger()方法时使用我的工厂(这似乎通过Logger.getLogger() - > LogManager.getLogger() - > Hierarchy.getLogger()):

MyHierarchy.java

package com.example.myapp.log4j;
import org.apache.log4j.Hierarchy;
import org.apache.log4j.Logger;
import org.apache.log4j.spi.LoggerFactory;

public class MyHierarchy extends Hierarchy
{
  public MyHierarchy(Logger root) { super(root); }
  @Override
  public Logger getLogger(String name) {
    return getLogger(name, defaultFactory);
  }
  private LoggerFactory defaultFactory = new MyLoggerFactory();
}

我不确定我是否需要自定义PropertyConfigurator,但我确实存在一些实际使用记录器工厂实例的执行路径,它保留了对它的引用.

MyPropertyConfigurator.java

package com.example.myapp.log4j;
import org.apache.log4j.PropertyConfigurator;

public class MyPropertyConfigurator extends PropertyConfigurator
{
  public MyPropertyConfigurator() {
    loggerFactory = new MyLoggerFactory();
  }
  @Override
  protected void configureLoggerFactory(java.util.Properties props) {
  }
}

以下是我的记录器工厂实现.MyEscapedLogger实现是Log4j的Logger类的子类,但它会覆盖forcedLog()protected方法,以在调用方法的超级版本之前转义消息中的字符.

MyLoggerFactory.java

package com.example.myapp.log4j;
import org.apache.log4j.spi.LoggerFactory;

public class MyLoggerFactory implements LoggerFactory
{
  public Logger makeNewLoggerInstance(String name) {
    return new MyEscapedLogger(name);
  }
}

Answer 1

经过一段时间的搜索后，我发现了这个非常好的解决方案：

        final LoggerFactory loggerFactory = new LoggerFactory()
        {

            @Override
            public Logger makeNewLoggerInstance(String name)
            {
                return new MyCustomLogger(name);
                // or (if you don't need a custom Logger implementation):
                // Logger logger = new Logger(name);
                // logger.setSTUFF(...);
                // return logger;
            }

        };

        LoggerRepository rep = new Hierarchy(new RootLogger(Level.DEBUG))
        {

            @Override
            public Logger getLogger(String name)
            {
                return super.getLogger(name, loggerFactory);
            }

        };

        LogManager.setRepositorySelector(new DefaultRepositorySelector(rep), null);

我正在使用：log4j 1.2.17