how to icmp ping on android

问题

I need to do a icmp ping to a host from my android device. I need to measure the round trip time. I am proficient with android and java, just dont know what library to use. How do I do it? Is it possible via 3G, Edge?

回答1:

Yes you can ping with 3G, edge, wireless whatever, as long as you have connectivity. The only limitation is in the emulator, see here: http://groups.google.com/group/android-developers/browse_thread/thread/8657506be6819297

Here is my ping function:

package com.namespace.router.api;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

import android.util.Log;

public class Network {

    private static final String TAG = "Network.java";   

    public static String pingError = null;

    /**
     * Ping a host and return an int value of 0 or 1 or 2 0=success, 1=fail, 2=error
     * 
     * Does not work in Android emulator and also delay by '1' second if host not pingable
     * In the Android emulator only ping to 127.0.0.1 works
     * 
     * @param String host in dotted IP address format
     * @return
     * @throws IOException
     * @throws InterruptedException
     */
    public static int pingHost(String host) throws IOException, InterruptedException {
        Runtime runtime = Runtime.getRuntime();
        Process proc = runtime.exec("ping -c 1 " + host);
        proc.waitFor();     
        int exit = proc.exitValue();
        return exit;
    }

    public static String ping(String host) throws IOException, InterruptedException {
        StringBuffer echo = new StringBuffer();
        Runtime runtime = Runtime.getRuntime();
        Log.v(TAG, "About to ping using runtime.exec");
        Process proc = runtime.exec("ping -c 1 " + host);
        proc.waitFor();
        int exit = proc.exitValue();
        if (exit == 0) {
            InputStreamReader reader = new InputStreamReader(proc.getInputStream());
            BufferedReader buffer = new BufferedReader(reader);
            String line = "";
            while ((line = buffer.readLine()) != null) {
                echo.append(line + "\n");
            }           
            return getPingStats(echo.toString());   
        } else if (exit == 1) {
            pingError = "failed, exit = 1";
            return null;            
        } else {
            pingError = "error, exit = 2";
            return null;    
        }       
    }

    /**
     * getPingStats interprets the text result of a Linux ping command
     * 
     * Set pingError on error and return null
     * 
     * http://en.wikipedia.org/wiki/Ping
     * 
     * PING 127.0.0.1 (127.0.0.1) 56(84) bytes of data.
     * 64 bytes from 127.0.0.1: icmp_seq=1 ttl=64 time=0.251 ms
     * 64 bytes from 127.0.0.1: icmp_seq=2 ttl=64 time=0.294 ms
     * 64 bytes from 127.0.0.1: icmp_seq=3 ttl=64 time=0.295 ms
     * 64 bytes from 127.0.0.1: icmp_seq=4 ttl=64 time=0.300 ms
     *
     * --- 127.0.0.1 ping statistics ---
     * 4 packets transmitted, 4 received, 0% packet loss, time 0ms
     * rtt min/avg/max/mdev = 0.251/0.285/0.300/0.019 ms
     * 
     * PING 192.168.0.2 (192.168.0.2) 56(84) bytes of data.
     * 
     * --- 192.168.0.2 ping statistics ---
     * 1 packets transmitted, 0 received, 100% packet loss, time 0ms
     *
     * # ping 321321.
     * ping: unknown host 321321.
     * 
     * 1. Check if output contains 0% packet loss : Branch to success -> Get stats
     * 2. Check if output contains 100% packet loss : Branch to fail -> No stats
     * 3. Check if output contains 25% packet loss : Branch to partial success -> Get stats
     * 4. Check if output contains "unknown host"
     * 
     * @param s
     */
    public static String getPingStats(String s) {
        if (s.contains("0% packet loss")) {
            int start = s.indexOf("/mdev = ");
            int end = s.indexOf(" ms\n", start);
            s = s.substring(start + 8, end);            
            String stats[] = s.split("/");
            return stats[2];
        } else if (s.contains("100% packet loss")) {
            pingError = "100% packet loss";
            return null;            
        } else if (s.contains("% packet loss")) {
            pingError = "partial packet loss";
            return null;
        } else if (s.contains("unknown host")) {
            pingError = "unknown host";
            return null;
        } else {
            pingError = "unknown error in getPingStats";
            return null;
        }       
    }
}

回答2:

You will probably want to use the isReachable - see more details in the Android doc. However, apparently some networks block ICMP. There is a post where you can read more about this issue here.

回答3:

you can use the open source code of terminal emulator available here

build the library(using cygwin and android-ndk) file and then use

回答4:

From the socket(2) man page ping access in the device is restricted by the content of the /proc/sys/net/ipv4/ping_group_range file

$ cat /proc/sys/net/ipv4/ping_group_range

It is "1 0" by default, meaning that nobody (not even root) may create ping sockets. Setting it to "100 100" would grant permissions to the single group (to either make /sbin/ping g+s and owned by this group or to grant permissions to the "netadmins" group), "0 4294967295" would enable it for the world, "100 4294967295" would enable it for the users, but not daemons.

so any devices with other than "0 4294967295" cant access from an android java application

In emulator you can test this be resetting

sysctl -w net.ipv4.ping_group_range="0 0" // to some range

来源：https://stackoverflow.com/questions/7451200/how-to-icmp-ping-on-android