gistfile1.java

package socket;

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.net.ConnectException;
import java.net.Socket;
import java.net.UnknownHostException;
import java.text.SimpleDateFormat;
import java.util.Date;

public class AliveMonitor {

	private static final int PORT = 5550;
	private static final String HOST = "localhost";
	public static final int INTERVAL = 1000;
	public static final int INTERVAL_LONG = 1000 * 10;
	public static final long NOT_RECEIVE_TIME = 1000 * 10;
	public static final int DISCONNECT_COUNT = 3;

	public AliveMonitor(){

		Process process = null;
		while(true){
			boolean isAlive = true;
			OutputStreamWriter osw = null;
			BufferedWriter bw = null;
			InputStream is = null;
			BufferedReader br = null;
			Socket socket = null;
			try {
				socket = new Socket(HOST, PORT);
				System.out.println("monitor: " + socket.getInetAddress() + ", connect.");

				osw = new OutputStreamWriter(socket.getOutputStream());
				bw = new BufferedWriter(osw);

				is = socket.getInputStream();
				br = new BufferedReader(new InputStreamReader(is));

				boolean connect = true;
				int sendCount = 0;
				while(connect){
					bw.write("hello.");
					bw.flush();
					sendCount++;

					long waitingTime = System.currentTimeMillis();
					while (is.available() >= 0) {
						if(is.available() == 0){
							System.out.println("monitor: waiting.");
							sleep(INTERVAL);

							if(System.currentTimeMillis() - waitingTime > NOT_RECEIVE_TIME){
								break;
							}
							continue;
						}

						System.out.println("monitor: something received.");
						char[] data = new char[is.available()];
						br.read(data, 0, is.available());
						String data_str = String.valueOf(data);
						System.out.println("monitor: " + data_str + ", received.");
						sendCount = 0;

						break;
					}

					if(sendCount > DISCONNECT_COUNT){
						isAlive = false;
						connect = false;
					}
					else{
						sleep(INTERVAL_LONG);
					}
				}

			} catch (ConnectException e) {
				e.printStackTrace();
				isAlive = false;

			} catch (UnknownHostException e) {
				e.printStackTrace();
			} catch (IOException e) {
				e.printStackTrace();
			} finally {
				try {
					if(osw != null)
						osw.close();
					if(bw != null)
						bw.close();
					if(is != null)
						is.close();
					if(br != null)
						br.close();
					if(socket != null)
						socket.close();
				} catch (IOException e) {
					e.printStackTrace();
				}
			}

			SimpleDateFormat sdf = new SimpleDateFormat("yyyy/MM/dd HH:mm:ss");
			String date = sdf.format(new Date());
			if(!isAlive){
				System.out.println("monitor: " + date + ", app is NOT alive.");
				Runtime rt = Runtime.getRuntime();
				try {
					if(process != null){
						process.destroy();
						System.out.println("monitor: kill process.");
					}
					String cmd = "java -jar c:/Users/cs/Desktop/test.jar";
					process = rt.exec(cmd);
					System.out.println("monitor: " + cmd + " process is restarted.");
				} catch (IOException e) {
					e.printStackTrace();
				}
			}
			else{
				System.out.println("monitor: " + date + ", app is alive.");
			}

			sleep(INTERVAL);
		}
	}

	public static void sleep(long millis){
		try {
			Thread.sleep(millis);
		} catch (InterruptedException e) {
			e.printStackTrace();
		}
	}

	public static void main(String[] args) {
		try {
			new AliveMonitor();
		} catch (Exception e) {
			e.printStackTrace();
		}
	}
}

gistfile2.java

package socket;

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

public class ServerSocketThread extends Thread {

	private static final int PORT = 5550;
	public static final int INTERVAL = 100;
	public static final long DISCONNECT_TIME = 1000 * 30;

	public ServerSocketThread(){
	}

	public void run(){

		while(true){

			ServerSocket serverSocket = null;
			Socket socket = null;
			OutputStreamWriter osw = null;
			BufferedWriter bw = null;
			InputStream is = null;
			BufferedReader br = null;

			try{
				serverSocket = new ServerSocket(PORT);

				boolean disconnected = false;
				while(!disconnected){
					System.out.println("client: waiting.");
					socket = serverSocket.accept();
					System.out.println("client: " + socket.getInetAddress() + ": connected.");

					osw = new OutputStreamWriter(socket.getOutputStream());
					bw = new BufferedWriter(osw);

					is = socket.getInputStream();
					br = new BufferedReader(new InputStreamReader(is));

					boolean isClosed = false;
					long waitingStart = System.currentTimeMillis();
					while (is.available() >= 0) {
						if(socket.isClosed() || !socket.isConnected()){
							System.out.println("client: closed.");
							isClosed = true;
							break;
						}
						if(socket.isInputShutdown() || socket.isOutputShutdown()){
							System.out.println("client: stream closed.");
							isClosed = true;
							break;
						}
						if(System.currentTimeMillis() - waitingStart > DISCONNECT_TIME){
							System.out.println("client: timeout.");
							isClosed = true;
							break;
						}

						if (is.available() == 0) {
							sleep(INTERVAL);
							System.out.print(".");
							continue;
						}
						System.out.println("");

						char[] data = new char[is.available()];
						br.read(data, 0, is.available());

						String data_str = String.valueOf(data);
						if(data_str.startsWith("exit")){
							bw.write("close");
							bw.flush();
							System.out.println("client: " + data_str);
							isClosed = true;
							break;
						}
						else {
							bw.write(data);
							bw.flush();
							System.out.println("client: " + data_str);
						}
						sleep(INTERVAL);
						waitingStart = System.currentTimeMillis();
					}

					if(isClosed){
						disconnected = true;
					}
					else{
						sleep(INTERVAL);
					}
				}
				System.out.println("client: " + socket.getInetAddress() + ": disconnected.");

			} catch (IOException e) {
				e.printStackTrace();
			} finally {
				try {
					if(osw != null)
						osw.close();
					if(bw != null)
						bw.close();
					if(is != null)
						is.close();
					if(bw != null)
						bw.close();
					if(socket != null)
						socket.close();
					if(serverSocket != null)
						serverSocket.close();
				} catch (IOException e) {
					e.printStackTrace();
				}
			}
		}
	}

	public static void sleep(long millis){
		try {
			Thread.sleep(millis);
		} catch (InterruptedException e) {
			e.printStackTrace();
		}
	}

	public static void main(String[] args) {
		// このプログラムはjarにしておいて、AliveMonitorから起動する
		ServerSocketThread st = new ServerSocketThread();
		st.start();
	}

}