java.util.log学习

今天学习java.util.logging类包方便以后查看。
这里以一个例子说明：

import java.util.logging.ConsoleHandler;
import java.util.logging.FileHandler;
import java.util.logging.Formatter;
import java.util.logging.Handler;
import java.util.logging.Level;
import java.util.logging.LogManager;
import java.util.logging.Logger;
import java.util.logging.LoggingMXBean;
import java.util.logging.MemoryHandler;
import java.util.logging.SimpleFormatter;
import java.util.logging.SocketHandler;

public class LoggingProgramSetPubSubpro {
	public static void main(String[] args) throws Exception
	{ 
		LogManager lm = LogManager.getLogManager();
		Logger logger = Logger.getLogger("loggingTest");
		Logger logger1 = Logger.getLogger("loggingTest.b");
		lm.addLogger(logger);
		lm.addLogger(logger1);


		logger.setLevel(Level.INFO);//这个设定最重要


		Handler consoleHandler = new ConsoleHandler();//控制台handler
		consoleHandler.setLevel(Level.ALL);
		Formatter ft1 = new YAYFormatter();//定义自己的formatter
		consoleHandler.setFormatter(ft1);
		logger.addHandler(consoleHandler);


		Handler fh = new FileHandler("c:\\java%g.log");//文件handler
		logger.addHandler(fh);//一个logger可以有多个handler
		Formatter ft = new SimpleFormatter();//FileHandler默认的Formatter是XMLFormatter 
		fh.setFormatter(ft);
		fh.setLevel(Level.OFF);

		Handler handler = new SocketHandler("localhost", 8099); //网络handler
		handler.setFormatter(new SimpleFormatter());
		logger.addHandler(handler);     

		Handler meh = new MemoryHandler(fh,1,Level.WARNING);//内存handler,当目标target的level等级超过Level.WARNING时向target push记录
		logger.addHandler(meh);

		logger.severe("嚴重訊息");
		logger.warning("警示訊息");
		logger.info("一般訊息");
		logger.config("設定方面的訊息");
		logger.fine("細微的訊息");
		logger.finer("更細微的訊息");
		logger.finest("最細微的訊息");
		
		
		LoggingMXBean mx = LogManager.getLoggingMXBean();
		logger.info("loggingTest的level是："+mx.getLoggerLevel("loggingTest"));
		logger.info("loggingTest的父 logger 名称是："+mx.getParentLoggerName("loggingTest.b"));
		logger.info(mx.getLoggerNames().size()+"" );
		consoleHandler.close();
		fh.close();
		meh.close();
		handler.close();
	}

}

定义自己的formmater

import java.util.logging.Formatter;
import java.util.logging.LogRecord;

public class YAYFormatter extends Formatter {

	@Override
	public String format(LogRecord logRecord) {

		return   "LogRecord info: " + logRecord.getSourceClassName() +//就是哪个类里面用的了你
		"\n" +"Level\t|\tLoggerName\t|\tMessage\t|\n" +
		logRecord.getLevel() + //是SEVERE还是WARNING还是别的
		"\t|\t" + 
		logRecord.getLoggerName() +//这个logger发布者
		"\t|\t" + 
		logRecord.getMessage() + //消息内容
		"\t|\n\n";  
	}

}

读取sockethandler的服务端

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.ServerSocket;
import java.net.Socket;

import javax.net.ServerSocketFactory;

public class LogServer {
	private static final int PORT_NUM = 8099;   
	public static void main(String args[]) {   
		ServerSocketFactory serverSocketFactory =   
			ServerSocketFactory.getDefault();   
		ServerSocket serverSocket = null;   
		try {   
			serverSocket =   
				serverSocketFactory.createServerSocket(PORT_NUM);   
		} catch (IOException ignored) {   
			System.err.println("无法创建服务");   
			System.exit(-1);   
		}   
		System.out.printf("LogServer 运行端口: %s%n", PORT_NUM);   
		while (true)   

		{   
			Socket socket = null;   
			try {   
				socket = serverSocket.accept();   
				InputStream is = socket.getInputStream();   
				BufferedReader br = new BufferedReader(   
						new InputStreamReader(is, "GBK"));   
				String line = null;   
				while ((line = br.readLine()) != null    
				) {   
					System.out.println(line);   
				}   
			} catch (IOException exception) {   
				// 处理下在个请求.   
			} finally {   
				if (socket != null) {   
					try {   
						socket.close();   
					} catch (IOException ignored) {   
					}   
				}   
			}   
		}   
	} 
}

Handler 对象从 Logger 中获取日志信息，并将这些信息导出。例如，它可将这些信息写入控制台或文件中，也可以将这些信息发送到网络日志服务中，或将其转发到操作系统日志中。


java类库提供了以上几种handler实现



上图是java.util.logging的uml