Java 中log4j 的使用

package org.logtest; import java.io.BufferedReader; import java.io.IOException; import java.io.InputStream; import java.io.InputStreamReader; import java.io.OutputStream; import java.io.OutputStreamWriter; import java.io.PrintWriter; import java.net.ServerSocket; import java.net.Socket; import java.util.Date; import org.apache.log4j.Logger; import org.apache.log4j.PropertyConfigurator; public class ServerWithLog4j { private final static int SERVER_PORT = 8001; // this server's port private static Logger logger = Logger.getLogger(ServerWithLog4j.class); public static void main(String args[]) { String clientRequest = null; BufferedReader reader = null; PrintWriter writer = null; ServerSocket server = null; Socket socket = null; InputStream in = null; OutputStream out = null; PropertyConfigurator.configure("ServerWithLog4j.properties"); try { server = new ServerSocket(SERVER_PORT); logger.info("ServerSocket before accept: " + server); logger.info("Java server with log4j, on-line!"); socket = server.accept(); logger.info("ServerSocket after accept: " + server); in = socket.getInputStream(); out = socket.getOutputStream(); } catch (IOException e) { logger.error("Server constructor IOException: " + e); System.exit(0); } reader = new BufferedReader(new InputStreamReader(in)); writer = new PrintWriter(new OutputStreamWriter(out), true); writer.println("Java server with log4j, " + new Date()); while (true) { try { clientRequest = reader.readLine(); logger.debug("Client says: " + clientRequest); if (clientRequest.startsWith("HELP")) { logger.debug("OK!"); writer.println("Vocabulary: HELP QUIT"); } else { if (clientRequest.startsWith("QUIT")) { logger.debug("OK!"); System.exit(0); } else { logger.warn("Command '" + clientRequest + "' not understood."); writer.println("Command '" + clientRequest + "' not understood."); } } } catch (IOException e) { logger.error("IOException in Server " + e); System.exit(0); } } } }