Spring容器启动后，加载log4j配置文件log4j.properties或log4j.xml：

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.util.InvalidPropertiesFormatException;
import java.util.Map;
import java.util.Properties;

import javax.servlet.ServletContext;

import org.apache.log4j.PropertyConfigurator;
import org.apache.log4j.xml.DOMConfigurator;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.InitializingBean;
import org.springframework.web.context.ServletContextAware;

public class Log4jConfigBean implements InitializingBean, ServletContextAware {
	
	private static Logger LOGGER = LoggerFactory.getLogger( Log4jConfigBean.class );
	
	@Override
	public void setServletContext( ServletContext servletContext ) {
		
		
		String filePath=servletContext.getRealPath( "/" );
		
		//properties配置方式
		PropertyConfigurator.configure(filePath + "/WEB-INF/classes/log4j.properties" );
		//xml配置方式
		DOMConfigurator.configure( filePath + "/WEB-INF/classes/log4j.xml" );
	}

	@Override
	public void afterPropertiesSet() throws Exception {
		
	}

}