Tôi biết đây là một câu hỏi rất cũ nhưng có một phương pháp nữa để làm điều này. Dưới đây biên dịch mã nhưng tôi chưa thử. Bạn có thể viết một số mã C và sử dụng JNI (Java Native Interface) để lấy địa chỉ MAC. Đây là ví dụ về mã hoạt động chính:
package com.example.getmymac;
import android.os.Bundle;
import android.util.Log;
import android.widget.TextView;
import androidx.appcompat.app.AppCompatActivity;
public class GetMyMacActivity extends AppCompatActivity {
static { // here we are importing native library.
// name of the library is libnet-utils.so, in cmake and java code
// we just use name "net-utils".
System.loadLibrary("net-utils");
}
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main_screen);
// some debug text and a TextView.
Log.d(NetUtilsActivity.class.getSimpleName(), "Starting app...");
TextView text = findViewById(R.id.sample_text);
// the get_mac_addr native function, implemented in C code.
byte[] macArr = get_mac_addr(null);
// since it is a byte array, we format it and convert to string.
String val = String.format("%02x:%02x:%02x:%02x:%02x:%02x",
macArr[0], macArr[1], macArr[2],
macArr[3], macArr[4], macArr[5]);
// print it to log and TextView.
Log.d(NetUtilsActivity.class.getSimpleName(), val);
text.setText(val);
}
// here is the prototype of the native function.
// use native keyword to indicate it is a native function,
// implemented in C code.
private native byte[] get_mac_addr(String interface_name);
}
Và tệp bố cục, main_screen.xml:
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent">
<TextView
android:id="@+id/sample_text"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/app_name"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintTop_toTopOf="parent"/>
</androidx.constraintlayout.widget.ConstraintLayout>
Tệp kê khai, tôi không biết phải thêm quyền gì nên tôi đã thêm một số.
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.getmymac">
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>
<uses-permission android:name="android.permission.INTERNET"/>
<application
android:allowBackup="true"
android:icon="@mipmap/ic_launcher"
android:label="@string/app_name"
android:roundIcon="@mipmap/ic_launcher_round"
android:supportsRtl="true"
android:theme="@style/AppTheme">
<activity android:name=".GetMyMacActivity">
<intent-filter>
<action android:name="android.intent.action.MAIN"/>
<category android:name="android.intent.category.LAUNCHER"/>
</intent-filter>
</activity>
</application>
</manifest>
C thực hiện hàm get_mac_addr.
/* length of array that MAC address is stored. */
#define MAC_ARR_LEN 6
#define BUF_SIZE 256
#include <jni.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <net/if.h>
#include <sys/ioctl.h>
#include <unistd.h>
#define ERROR_IOCTL 1
#define ERROR_SOCKT 2
static jboolean
cstr_eq_jstr(JNIEnv *env, const char *cstr, jstring jstr) {
/* see [this](https://stackoverflow.com/a/38204842) */
jstring cstr_as_jstr = (*env)->NewStringUTF(env, cstr);
jclass cls = (*env)->GetObjectClass(env, jstr);
jmethodID method_id = (*env)->GetMethodID(env, cls, "equals", "(Ljava/lang/Object;)Z");
jboolean equal = (*env)->CallBooleanMethod(env, jstr, method_id, cstr_as_jstr);
return equal;
}
static void
get_mac_by_ifname(jchar *ifname, JNIEnv *env, jbyteArray arr, int *error) {
/* see [this](https://stackoverflow.com/a/1779758) */
struct ifreq ir;
struct ifconf ic;
char buf[BUF_SIZE];
int ret = 0, sock = socket(AF_INET, SOCK_DGRAM, IPPROTO_IP);
if (sock == -1) {
*error = ERROR_SOCKT;
return;
}
ic.ifc_len = BUF_SIZE;
ic.ifc_buf = buf;
ret = ioctl(sock, SIOCGIFCONF, &ic);
if (ret) {
*error = ERROR_IOCTL;
goto err_cleanup;
}
struct ifreq *it = ic.ifc_req; /* iterator */
struct ifreq *end = it + (ic.ifc_len / sizeof(struct ifreq));
int found = 0; /* found interface named `ifname' */
/* while we find an interface named `ifname' or arrive end */
while (it < end && found == 0) {
strcpy(ir.ifr_name, it->ifr_name);
ret = ioctl(sock, SIOCGIFFLAGS, &ir);
if (ret == 0) {
if (!(ir.ifr_flags & IFF_LOOPBACK)) {
ret = ioctl(sock, SIOCGIFHWADDR, &ir);
if (ret) {
*error = ERROR_IOCTL;
goto err_cleanup;
}
if (ifname != NULL) {
if (cstr_eq_jstr(env, ir.ifr_name, ifname)) {
found = 1;
}
}
}
} else {
*error = ERROR_IOCTL;
goto err_cleanup;
}
++it;
}
/* copy the MAC address to byte array */
(*env)->SetByteArrayRegion(env, arr, 0, 6, ir.ifr_hwaddr.sa_data);
/* cleanup, close the socket connection */
err_cleanup: close(sock);
}
JNIEXPORT jbyteArray JNICALL
Java_com_example_getmymac_GetMyMacActivity_get_1mac_1addr(JNIEnv *env, jobject thiz,
jstring interface_name) {
/* first, allocate space for the MAC address. */
jbyteArray mac_addr = (*env)->NewByteArray(env, MAC_ARR_LEN);
int error = 0;
/* then just call `get_mac_by_ifname' function */
get_mac_by_ifname(interface_name, env, mac_addr, &error);
return mac_addr;
}
Và cuối cùng, tệp CMakeLists.txt
cmake_minimum_required(VERSION 3.4.1)
add_library(net-utils SHARED src/main/cpp/net-utils.c)
target_link_libraries(net-utils android log)