Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Java External Program Control

  1. Jul 5, 2007 #1
    Hi, i would like to make a program which can detect my latency, if it's low then it would open a program and if it's high it'd do nothing, i'd also like to loop it so it tries every half an hour or so. Would this be possible? If so any advice on how to start i'm a bit rusty and have only tried simple programs before (although i suppose this probably is simple :tongue2: ).

    Could it use "ping www.google.co.uk" in cmd to get my latency?

  2. jcsd
  3. Jul 5, 2007 #2


    User Avatar
    Science Advisor

    You can't do a ping with Java directly because it can't send ICMP packets, but you can have Java call ping.exe and read the standard output, for example. I've done something similar with c++.
  4. Jul 5, 2007 #3
    Thanks -Job- i managed to make it, my code is a bit messy but here it is if anyone is interested =)

    import java.io.IOException;
    import java.io.InputStream;

    public class PingDownload {

    public PingDownload() {}

    public static void main(String[] args) {

    int ReadCounter = 0;
    int NumTotal = 0;
    int LoopParameter = 0;

    try {

    String command = "ping www.google.co.uk";
    String command2 = "cmd /c start C:\\ProgramShortcut";

    while(LoopParameter != 1) {

    Process child = Runtime.getRuntime().exec(command);
    //Executes the command string
    InputStream in = child.getInputStream();

    while (ReadCounter != 169) {

    int CharA = in.read();
    //Reads the first character and stores its ASCII value
    int CharB = in.read();
    //Reads the second character and stores its ASCII value
    int CharC = in.read();
    //Reads the third character and stores its ASCII value

    if(47<CharA && CharA<58 && ReadCounter>150) NumTotal = NumTotal + CharA;
    if(47<CharB && CharB<58 && ReadCounter>150) NumTotal = NumTotal + CharB;
    if(47<CharC && CharC<58 && ReadCounter>150) NumTotal = NumTotal + CharC;

    //If any of the characters are numbers and the counter is near the end
    //(above 150)
    //add them to NumTotal this ensures only the last 3 numbers from the ping
    //command are taken which are the maximum minimum and average pings

    ReadCounter++; //Increment the counter


    //When my ping is high all three numbers consist of three digits and the
    //value these can take is 0 so i know if the total is below 48x9 = 432 my ping
    //is low

    if(NumTotal < 432) {

    child = Runtime.getRuntime().exec(command2);
    LoopParameter = 1; //If the program is opened end the loop


    catch (IOException e) {}

    *cough* There might be bits wrong with it other than the way i've went about it but it worked in Netbeans and compiled ok.
    Last edited: Jul 5, 2007
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?

Similar Discussions: Java External Program Control
  1. Java programs (Replies: 9)

  2. Java Programming (Replies: 12)