Java program to ping an IP address

PingIP.java

/*
 * execution example: pinger.jar "8.8.8.8" "C:\\tmp\\out.txt"
 * 
 * Motivation: Guys in UnityMedia.de are not masters of stable internet connection. Before complaining to their help desk
 * I needed some hard evidence of the connection's disruptions.
 * 
 * Description: Invokes system's command line and executes endless ping command. Reads command line's output, parses it
 * and outputs it into a pipe-delimited text file for analysis in tools such as Tableau.
 */
package pinger;

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;

public class Pinger {
	public static final boolean DEBUG = true;
	public static final int BUFFERSIZE = 60;
	public static String filePath;

	public static void main(String[] args) {
		System.out.println("Pinger for Windows by Jiri Hubacek, forked from https://gist.github.com/madan712/4509039");
		if (args.length != 2) {
			System.out.println("Argument error. Expected arguments: <ipaddress> <filepath>");
			System.exit(-1);
		}
		String ip = args[0];
		filePath = args[1];
		System.out.println("Entering endless ping loop");
		while (1 == 1) {
			runSystemCommand("ping " + ip + " -t");
		}
	}

	public static void runSystemCommand(String command) {
		List<String> buffer = new ArrayList<String>(BUFFERSIZE);
		try {
			Process p = Runtime.getRuntime().exec(command);
			BufferedReader inputStream = new BufferedReader(new InputStreamReader(p.getInputStream()));

			String s = "";
			int timeoutCounter = 0;
			SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss.SSS");
			
			// reading the command's output stream
			while ((s = inputStream.readLine()) != null) {
				if (s.contains("Reply")) {
					timeoutCounter=0;
					if (DEBUG) System.out.println(sdf.format(new Date()) + "|" + s.substring(s.indexOf("time=") + 4 + 1, s.indexOf("ms")) + "|0" );
					buffer.add(sdf.format(new Date()) + "|" + s.substring(s.indexOf("time=") + 4 + 1, s.indexOf("ms")) + "|0" );

				} else if (s.contains("Request timed")) {
					timeoutCounter++;
					if (timeoutCounter >= 5) {
						// set flag to 1 as there's longer than 5 second timeout
						if (DEBUG) System.out.println( sdf.format(new Date()) + "|1000|1");
						buffer.add(sdf.format(new Date()) + "|1000|1");
					} else {
						if (DEBUG) System.out.println( sdf.format(new Date()) + "|1000|0");
						buffer.add(sdf.format(new Date()) + "|1000|0");
					}
					
				} else if (s.contains("General failure.")) {
					// general failure is triggered in situations such as when the network cable is unplugged or the NIC restarts
					// therefore lag flag is not being set
					if (DEBUG) System.out.println( sdf.format(new Date()) + "|1100|0");
					buffer.add(sdf.format(new Date()) + "|1100|0");
				}
					
				if (buffer.size() == BUFFERSIZE) {
					try {
						System.out.println("Buffer limit of " + BUFFERSIZE + " hit, flushing buffer to file");
						writeFile(buffer);
						buffer.clear();
					} catch (IOException e) {
						e.printStackTrace();
					}
				}
			}
		} catch (Exception e) {
			e.printStackTrace();
		}
	}


	public static void writeFile(List<String> in) throws IOException {
		File fout = new File(filePath);
		FileOutputStream fos;
		BufferedWriter bw;
		
		if (fout.exists()) {
			fos = new FileOutputStream(fout, true);
			bw = new BufferedWriter(new OutputStreamWriter(fos));
		}	
		else {
			fos = new FileOutputStream(fout, false);
			bw = new BufferedWriter(new OutputStreamWriter(fos));
			bw.write("ts|latency|lag_flag");
			bw.newLine();
		}
			
		// flushing buffer
		for (String item : in) {
			bw.write(item);
			bw.newLine();	
		}
		bw.close();
	}

}