java 日志 基础理解

package com.log;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.log4j.Logger;
import org.apache.log4j.BasicConfigurator;
import org.apache.log4j.Level;

public class Log4jTest {
public static void main(String argv[]) {
// Create a logger by the name of class Log4jTest.
Logger logger = Logger.getLogger(Log4jTest.class.getName());
/*
* 这个Log必须和上面的那个Logger一起用,下面那个才能用,不如舍弃Log
* 因为这个Log是common的一个包,它是以来log4j的，舍弃
*/
Log myLog = LogFactory.getLog(Log4jTest.class);
// Use the default configuration.
/**
* 当在src下放入了log4j.properties后,那么 BasicConfigurator.configure()就不需要了;
*/
BasicConfigurator.configure();
// PropertyConfigurator.configure ("c:/log4j.properties");引用文件目录
// Set the logger level to Level.INFO
logger.setLevel(Level.INFO);

// This request will be disabled since Level.DEBUG < Level.INFO.
logger.debug("This is debug.");

// These requests will be enabled.
logger.info("This is an info.");
logger.warn("This is a warning.");
logger.error("This is an error.");
logger.fatal("This is a fatal error.");
myLog.warn("this is my_Log waring");
myLog.debug("this is my_debug...");
myLog.info("This is my_info.");
return;
}
}