2.5 mac地址存储文件（mac获取失败就随机一个）；监听返回按键，提示是否退出程序的提示窗口

app/src/main/java/chaoran/business/activity/MainActivity.java

@@ -2,7 +2,9 @@ package chaoran.business.activity;
 
 import android.annotation.SuppressLint;
 import android.app.Activity;
+import android.app.AlertDialog;
 import android.content.Context;
+import android.content.DialogInterface;
 import android.content.Intent;
 import android.content.SharedPreferences;
 import android.content.pm.ActivityInfo;
@@ -493,5 +495,22 @@ public class MainActivity extends AppCompatActivity implements ResultListener{
         super.onConfigurationChanged(newConfig);
     }
 
-
+    @Override
+    public void onBackPressed() {
+        // 创建退出确认对话框
+        new AlertDialog.Builder(this)
+                .setTitle("提示")
+                .setMessage("是否退出程序？")
+                .setPositiveButton("确定", new DialogInterface.OnClickListener() {
+                    @Override
+                    public void onClick(DialogInterface dialog, int which) {
+                        finish(); // 关闭当前 Activity
+                        // 如果需要彻底退出应用（适用于多任务场景），可以添加：
+                        // System.exit(0);
+                    }
+                })
+                .setNegativeButton("取消", null)
+                .show();
+        // 不调用 super.onBackPressed()，避免直接退出
+    }
 }

app/src/main/java/chaoran/business/utils/LocalAddressUtil.java

@@ -22,6 +22,7 @@ import java.net.InetAddress;
 import java.net.NetworkInterface;
 import java.net.SocketException;
 import java.util.Enumeration;
+import java.util.Random;
 
 import chaoran.business.BuildConfig;
 
@@ -67,12 +68,29 @@ public class LocalAddressUtil {
     @SuppressLint("JavascriptInterface")
     @JavascriptInterface
     public String getMacAddress(){//可以兼容安卓7以下
+        SharedPreferences spf = context.getSharedPreferences("chaoran_mac", Context.MODE_PRIVATE);
+        String saveMac  = spf.getString("chaoran_mac", "");
+        if (!"".equalsIgnoreCase(saveMac)) {
+            return saveMac;
+        }
+        SharedPreferences.Editor editor = spf.edit();
+        String androidMac = getAndroidMac();
+        editor.putString("chaoran_mac", androidMac);
+        editor.apply();
+        return androidMac;
+    }
+
+    /**
+     * 获取安卓的mac
+     * @return
+     */
+    private String getAndroidMac() {
         if (Build.VERSION.SDK_INT >= 34) { // Android 14 is code-named Tiramisu
             try {
                 return Settings.Secure.getString(context.getContentResolver(), Settings.Secure.ANDROID_ID);
             }catch (Exception e) {
                 e.printStackTrace();
-                return "02:00:00:00:00:02";
+                return generateRandomMacAddress();
             }
         }
         String macAddress = null;
@@ -84,7 +102,7 @@ public class LocalAddressUtil {
                 networkInterface = NetworkInterface.getByName("wlan0");
             }
             if (networkInterface == null) {
-                return "02:00:00:00:00:02";
+                return generateRandomMacAddress();
             }
             byte[] addr = networkInterface.getHardwareAddress();
             for (byte b : addr) {
@@ -94,12 +112,28 @@ public class LocalAddressUtil {
                 buf.deleteCharAt(buf.length() - 1);
             }
             macAddress = buf.toString();
-        } catch (SocketException e) {
+        } catch (Exception e) {
             e.printStackTrace();
-            return "02:00:00:00:00:02";
+            macAddress = generateRandomMacAddress();
+        }
+        if (macAddress.length() < 4) {
+            macAddress = generateRandomMacAddress();
         }
         return macAddress;
     }
+
+    private static String generateRandomMacAddress() {
+        Random rand = new Random();
+        byte[] macBytes = new byte[6];
+        rand.nextBytes(macBytes);
+        macBytes[0] = (byte) (macBytes[0] & 0xfe | 0x02);
+        StringBuilder macAddress = new StringBuilder();
+        for (int i = 0; i < macBytes.length; i++) {
+            macAddress.append(String.format("%02X%s", macBytes[i], (i < macBytes.length - 1) ? ":" : ""));
+        }
+        return macAddress.toString();
+    }
+
     @SuppressLint("JavascriptInterface")
     @JavascriptInterface
     public String getInfo(int type){