How to Ping External IP from Java Android

Question

I am developing a Ping application for Android 2.2.

I try my code and it works, but only in local IPs, that's my problem I want to do ping to external servers too.

Here is my code:

  private OnClickListener milistener = new OnClickListener() {
    public void onClick(View v) {
        TextView info = (TextView) findViewById(R.id.info);
        EditText edit = (EditText) findViewById(R.id.edit);
        Editable host = edit.getText();
        InetAddress in;
        in = null;
        // Definimos la ip de la cual haremos el ping
        try {
            in = InetAddress.getByName(host.toString());
        } catch (UnknownHostException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        // Definimos un tiempo en el cual ha de responder
        try {
            if (in.isReachable(5000)) {
                info.setText("Responde OK");
            } else {
                info.setText("No responde: Time out");
            }
        } catch (IOException e) {
            // TODO Auto-generated catch block
            info.setText(e.toString());
        }
    }
};

Ping 127.0.0.1 -> OK
Ping 8.8.8.8 (Google DNS) -> Time Out

I put the following line at Manifest XML too:

<uses-permission android:name="android.permission.INTERNET"></uses-permission>

Can anyone suggest me where I'm doing wrong?

Answer 1

Run the ping utility in Android's command and parse output (assuming you have root permissions)

See the following Java code snippet:

executeCmd("ping -c 1 -w 1 google.com", false);

public static String executeCmd(String cmd, boolean sudo){
    try {

        Process p;
        if(!sudo)
            p= Runtime.getRuntime().exec(cmd);
        else{
            p= Runtime.getRuntime().exec(new String[]{"su", "-c", cmd});
        }
        BufferedReader stdInput = new BufferedReader(new InputStreamReader(p.getInputStream()));

        String s;
        String res = "";
        while ((s = stdInput.readLine()) != null) {
            res += s + "\n";
        }
        p.destroy();
        return res;
    } catch (Exception e) {
        e.printStackTrace();
    }
    return "";

}

Answer 2

This is what I implemented myself, which returns the average latency:

/*
Returns the latency to a given server in mili-seconds by issuing a ping command.
system will issue NUMBER_OF_PACKTETS ICMP Echo Request packet each having size of 56 bytes
every second, and returns the avg latency of them.
Returns 0 when there is no connection
 */
public double getLatency(String ipAddress){
    String pingCommand = "/system/bin/ping -c " + NUMBER_OF_PACKTETS + " " + ipAddress;
    String inputLine = "";
    double avgRtt = 0;

    try {
        // execute the command on the environment interface
        Process process = Runtime.getRuntime().exec(pingCommand);
        // gets the input stream to get the output of the executed command
        BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(process.getInputStream()));

        inputLine = bufferedReader.readLine();
        while ((inputLine != null)) {
            if (inputLine.length() > 0 && inputLine.contains("avg")) {  // when we get to the last line of executed ping command
                break;
            }
            inputLine = bufferedReader.readLine();
        }
    }
    catch (IOException e){
        Log.v(DEBUG_TAG, "getLatency: EXCEPTION");
        e.printStackTrace();
    }

    // Extracting the average round trip time from the inputLine string
    String afterEqual = inputLine.substring(inputLine.indexOf("="), inputLine.length()).trim();
    String afterFirstSlash = afterEqual.substring(afterEqual.indexOf('/') + 1, afterEqual.length()).trim();
    String strAvgRtt = afterFirstSlash.substring(0, afterFirstSlash.indexOf('/'));
    avgRtt = Double.valueOf(strAvgRtt);

    return avgRtt;
}

Answer 3

Ping for the google server or any other server

public boolean isConecctedToInternet() {

    Runtime runtime = Runtime.getRuntime();
    try {
        Process ipProcess = runtime.exec("/system/bin/ping -c 1 8.8.8.8");
        int     exitValue = ipProcess.waitFor();
        return (exitValue == 0);
    } catch (IOException e)          { e.printStackTrace(); }
    catch (InterruptedException e) { e.printStackTrace(); }
    return false;
}