android 获取当前进程的名称

原文地址：https://juejin.im/post/6877127949452050446
1 通过ActivityManager 获取进程名

public static String getCurrentProcessNameByActivityManager(@NonNull Context context) {
  int pid = Process.myPid();
  ActivityManager am = (ActivityManager) context.getSystemService(Context.ACTIVITY_SERVICE);
  if (am != null) {
    List<ActivityManager.RunningAppProcessInfo> runningAppList = am.getRunningAppProcesses();
    if (runningAppList != null) {
      for (ActivityManager.RunningAppProcessInfo processInfo : runningAppList) {
        if (processInfo.pid == pid) {
          return processInfo.processName;
        }
      }
    }
  }
  return null;
}

缺点：
1 am.getRunningAppProcesses()需要跨进程通信，效率不高
2 ActivityManager.getRunningAppProcesses() 有可能调用失败，虽然概率不高但是当用户数量达到一定级别还是有概率失败的。
2 Application.getProcessName()
只能Api28 以上的系统调用

最优解：

public class ProcessUtil {
  private static String currentProcessName;

  /**
  * @return 当前进程名
  */
  @Nullable
  public static String getCurrentProcessName(@NonNull Context context) {
    if (!TextUtils.isEmpty(currentProcessName)) {
      return currentProcessName;
    }

    //1)通过Application的API获取当前进程名
    currentProcessName = getCurrentProcessNameByApplication();
    if (!TextUtils.isEmpty(currentProcessName)) {
      return currentProcessName;
    }

    //2)通过反射ActivityThread获取当前进程名
    currentProcessName = getCurrentProcessNameByActivityThread();
    if (!TextUtils.isEmpty(currentProcessName)) {
      return currentProcessName;
    }

    //3)通过ActivityManager获取当前进程名
    currentProcessName = getCurrentProcessNameByActivityManager(context);

    return currentProcessName;
  }


  /**
  * 通过Application新的API获取进程名，无需反射，无需IPC，效率最高。
  */
  public static String getCurrentProcessNameByApplication() {
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.P) {
      return Application.getProcessName();
    }
    return null;
  }

  /**
  * 通过反射ActivityThread获取进程名，避免了ipc
  */
  public static String getCurrentProcessNameByActivityThread() {
    String processName = null;
    try {
      final Method declaredMethod = Class.forName("android.app.ActivityThread", false, Application.class.getClassLoader())
        .getDeclaredMethod("currentProcessName", (Class<?>[]) new Class[0]);
      declaredMethod.setAccessible(true);
      final Object invoke = declaredMethod.invoke(null, new Object[0]);
      if (invoke instanceof String) {
        processName = (String) invoke;
      }
    } catch (Throwable e) {
      e.printStackTrace();
    }
    return processName;
  }

  /**
  * 通过ActivityManager 获取进程名，需要IPC通信
  */
  public static String getCurrentProcessNameByActivityManager(@NonNull Context context) {
    if (context == null) {
      return null;
    }
    int pid = Process.myPid();
    ActivityManager am = (ActivityManager) context.getSystemService(Context.ACTIVITY_SERVICE);
    if (am != null) {
      List<ActivityManager.RunningAppProcessInfo> runningAppList = am.getRunningAppProcesses();
      if (runningAppList != null) {
        for (ActivityManager.RunningAppProcessInfo processInfo : runningAppList) {
          if (processInfo.pid == pid) {
            return processInfo.processName;
          }
        }
      }
    }
    return null;
  }
}