/* * Copyright 1999-2005 The Apache Software Foundation. *  * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at *  *      http://www.apache.org/licenses/LICENSE-2.0 *  * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */package org.apache.log4j.varia;import org.apache.log4j.Logger;import org.apache.log4j.BasicConfigurator;import java.io.IOException;import java.io.DataInputStream;import java.io.DataOutputStream;import java.net.Socket;/**   A simple application to send roll over messages to a potentially   remote {@link ExternallyRolledFileAppender}.    <p>It takes two arguments, the <code>host_name</code> and   <code>port_number</code> where the   <code>ExternallyRolledFileAppender</code> is listening.      @author Ceki G&uuml;lc&uuml;   @since version 0.9.0 */public class Roller {  static Logger cat = Logger.getLogger(Roller.class);    static String host;  static int port;  // Static class.  Roller() {  }  /**     Send a "RollOver" message to     <code>ExternallyRolledFileAppender</code> on <code>host</code>     and <code>port</code>.   */  public   static   void main(String argv[]) {    BasicConfigurator.configure();    if(argv.length == 2)       init(argv[0], argv[1]);    else       usage("Wrong number of arguments.");        roll();  }  static  void usage(String msg) {    System.err.println(msg);    System.err.println( "Usage: java " + Roller.class.getName() +			"host_name port_number");    System.exit(1);  }  static   void init(String hostArg, String portArg) {    host = hostArg;    try {      port =  Integer.parseInt(portArg);    }    catch(java.lang.NumberFormatException e) {      usage("Second argument "+portArg+" is not a valid integer.");    }  }  static  void roll() {    try {      Socket socket = new Socket(host, port);      DataOutputStream dos = new DataOutputStream(socket.getOutputStream());      DataInputStream dis = new DataInputStream(socket.getInputStream());      dos.writeUTF(ExternallyRolledFileAppender.ROLL_OVER);      String rc = dis.readUTF();      if(ExternallyRolledFileAppender.OK.equals(rc)) {	cat.info("Roll over signal acknowledged by remote appender.");      } else {	cat.warn("Unexpected return code "+rc+" from remote entity.");	System.exit(2);      }    } catch(IOException e) {      cat.error("Could not send roll signal on host "+host+" port "+port+" .",		e);      System.exit(2);    }    System.exit(0);  }}