我需要从我的 Android 设备对主机执行 icmp ping。我需要测量往返时间。我精通android和java，只是不知道该使用什么库。 我该怎么做？ 可以通过 3G、Edge 吗？
是的，只要有连接，您就可以通过 3G、边缘、无线等方式进行 ping 操作。唯一的限制是模拟器，请参见此处： http://groups.google.com/group/android-developers/browse_thread/thread/8657506be6819297
这是我的 ping 函数：
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;
}
}
}
您可以使用终端模拟器的开源代码这里
构建库（使用cygwin和android-ndk）文件，然后使用
icmp4a 库（我的库）使测量 ICMP 往返时间变得容易。此外，它不涉及通过
pingRuntime.exec()示例：
implementation "com.marsounjan:icmp4a:1.0.0"
val icmp = Icmp4a()
val host = "google.com"
try {
val status = icmp.ping( host = "8.8.8.8")
val result = status.result
when (result) {
is Icmp.PingResult.Success -> Log.d("ICMP", "$host(${status.ip.hostAddress}) ${result.packetSize} bytes - ${result.ms} ms")
is Icmp.PingResult.Failed -> Log.d("ICMP", "$host(${status.ip.hostAddress}) Failed: ${result.message}")
}
} catch (error: Icmp.Error.UnknownHost) {
Log.d("ICMP", "Unknown host $host")
}
Logcat 输出
2024-01-26 16:22:48.515 ICMP D google.com(8.8.8.8) 64 bytes - 12 ms
val icmp = Icmp4a()
val host = "google.com"
try {
icmp.pingInterval(
"8.8.8.8",
count = 5,
intervalMillis = 1000
)
.onEach { status ->
val result = status.result
when (result) {
is Icmp.PingResult.Success -> Log.d("ICMP", "$host(${status.ip.hostAddress}) ${result.packetSize} bytes - ${result.ms} ms")
is Icmp.PingResult.Failed -> Log.d("ICMP", "$host(${status.ip.hostAddress}) Failed: ${result.message}")
}
}
.launchIn(viewModelScope)
} catch (error: Icmp.Error.UnknownHost) {
Log.d("ICMP", "Unknown host $host")
}
Logcat 输出
2024-01-26 16:29:16.633 ICMP D google.com(8.8.8.8) 64 bytes - 15 ms
2024-01-26 16:29:17.577 ICMP D google.com(8.8.8.8) 64 bytes - 17 ms
2024-01-26 16:29:18.598 ICMP D google.com(8.8.8.8) 64 bytes - 17 ms
2024-01-26 16:29:19.614 ICMP D google.com(8.8.8.8) 64 bytes - 15 ms
2024-01-26 16:29:20.630 ICMP D google.com(8.8.8.8) 64 bytes - 13 ms
从 socket(2) 手册页来看，设备中的 ping 访问受到 /proc/sys/net/ipv4/ping_group_range 文件内容的限制
$ cat /proc/sys/net/ipv4/ping_group_range
默认为“1 0”，意思是 没有人（甚至 root 也不能）可以创建 ping 套接字。将其设置为“100 100" 将向单个组授予权限（使 /sbin/ping g+s 并归该组所有或授予权限 “netadmins”组），“0 4294967295”将为全世界启用它，“100 4294967295”将为用户启用它，但不会为守护进程启用它。
因此除“0 4294967295”之外的任何设备都无法从 Android java 应用程序访问
在模拟器中您可以测试是否重置
sysctl -w net.ipv4.ping_group_range="0 0" // 到某个范围