这里列出的许多答案都有内在的问题:

Checking for test-keys is correlated with root access but doesn't necessarily guarantee it "PATH" directories should be derived from the actual "PATH" environment variable instead of being hard coded The existence of the "su" executable doesn't necessarily mean the device has been rooted The "which" executable may or may not be installed, and you should let the system resolve its path if possible Just because the SuperUser app is installed on the device does not mean the device has root access yet

Stericson的RootTools库似乎可以更合理地检查root。它还有很多额外的工具和实用程序，所以我强烈推荐它。然而，并没有解释它是如何专门检查根目录的，而且它可能比大多数应用程序真正需要的要重一些。

我已经创建了几个基于RootTools库的实用程序方法。如果你只是想检查“su”可执行文件是否在设备上，你可以使用以下方法:

public static boolean isRootAvailable(){
    for(String pathDir : System.getenv("PATH").split(":")){
        if(new File(pathDir, "su").exists()) {
            return true;
        }
    }
    return false;
}

这个方法简单地遍历“PATH”环境变量中列出的目录，并检查其中是否存在“su”文件。

为了真正检查root访问权限，必须实际运行“su”命令。如果安装了一个像SuperUser这样的应用程序，那么在这一点上它可能会要求root访问，或者如果它已经被授予/拒绝，吐司可能会显示是否授予/拒绝访问。一个很好的命令是“id”，这样您可以验证用户id实际上是0(根)。

下面是一个示例方法来确定是否授予了根访问权:

public static boolean isRootGiven(){
    if (isRootAvailable()) {
        Process process = null;
        try {
            process = Runtime.getRuntime().exec(new String[]{"su", "-c", "id"});
            BufferedReader in = new BufferedReader(new InputStreamReader(process.getInputStream()));
            String output = in.readLine();
            if (output != null && output.toLowerCase().contains("uid=0"))
                return true;
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            if (process != null)
                process.destroy();
        }
    }

    return false;
}

实际测试运行"su"命令是很重要的，因为一些模拟器已经预安装了"su"可执行文件，但只允许某些用户像adb shell一样访问它。

在尝试运行“su”可执行文件之前检查它的存在也是很重要的，因为android已经知道不会正确地处理试图运行缺失命令的进程。随着时间的推移，这些幽灵进程会消耗大量内存。

除了@Kevins的回答之外，我最近在使用他的系统时发现，Nexus 7.1对所有三个方法都返回false——没有哪个命令，没有测试键，SuperSU没有安装在/system/app中。

我补充说:

public static boolean checkRootMethod4(Context context) {
    return isPackageInstalled("eu.chainfire.supersu", context);     
}

private static boolean isPackageInstalled(String packagename, Context context) {
    PackageManager pm = context.getPackageManager();
    try {
        pm.getPackageInfo(packagename, PackageManager.GET_ACTIVITIES);
        return true;
    } catch (NameNotFoundException e) {
        return false;
    }
}

这在某些情况下有点不太有用(如果你需要保证root访问)，因为SuperSU完全有可能安装在没有SU访问的设备上。

然而，由于SuperSU可以安装并工作，但不在/system/app目录下，这个额外的情况将会根除(哈哈)这样的情况。

使用c++和ndk是最好的方法来检测根，即使用户使用的应用程序隐藏了他的根，如RootCloak。我用RootCloak测试了这段代码，即使用户试图隐藏它，我也能够检测到根。 所以你的cpp文件是这样的:

#include <jni.h>
#include <string>


/**
 *
 * function that checks for the su binary files and operates even if 
 * root cloak is installed
 * @return integer 1: device is rooted, 0: device is not 
 *rooted
*/
extern "C"
JNIEXPORT int JNICALL


Java_com_example_user_root_1native_rootFunction(JNIEnv *env,jobject thiz){
const char *paths[] ={"/system/app/Superuser.apk", "/sbin/su", "/system/bin/su",
                      "/system/xbin/su", "/data/local/xbin/su", "/data/local/bin/su", "/system/sd/xbin/su",
                      "/system/bin/failsafe/su", "/data/local/su", "/su/bin/su"};

int counter =0;
while (counter<9){
    if(FILE *file = fopen(paths[counter],"r")){
        fclose(file);
        return 1;
    }
    counter++;
}
return 0;
}

您将从java代码中调用该函数，如下所示

public class Root_detect {



   /**
    *
    * function that calls a native function to check if the device is 
    *rooted or not
    * @return boolean: true if the device is rooted, false if the 
    *device is not rooted
   */
   public boolean check_rooted(){

        int checker = rootFunction();

        if(checker==1){
           return true;
        }else {
           return false;
        }
   }
   static {
    System.loadLibrary("cpp-root-lib");//name of your cpp file
   }

   public native int rootFunction();
}

如果你已经在使用Fabric/Firebase Crashlytics，你可以打电话

CommonUtils.isRooted(context)

这是该方法的当前实现:

public static boolean isRooted(Context context) {
    boolean isEmulator = isEmulator(context);
    String buildTags = Build.TAGS;
    if (!isEmulator && buildTags != null && buildTags.contains("test-keys")) {
        return true;
    } else {
        File file = new File("/system/app/Superuser.apk");
        if (file.exists()) {
            return true;
        } else {
            file = new File("/system/xbin/su");
            return !isEmulator && file.exists();
        }
    }
}

public static boolean isEmulator(Context context) {
    String androidId = Secure.getString(context.getContentResolver(), "android_id");
    return "sdk".equals(Build.PRODUCT) || "google_sdk".equals(Build.PRODUCT) || androidId == null;
}

使用谷歌SafetyNet认证API，您可以轻松检查您的设备是否已根:

Add dependency in build.gradle(:app) implementation 'com.google.android.gms:play-services-safetynet:17.0.0' Get Api key and enable Android Device Verification API using link public static void sendSafetyNetRequest(Activity context) { if(GoogleApiAvailability.getInstance().isGooglePlayServicesAvailable(context, 13000000) == ConnectionResult.SUCCESS) { Log.e(TAG, "The SafetyNet Attestation API is available"); // TODO(developer): Change the nonce generation to include your own, used once value, // ideally from your remote server. String nonceData = "Safety Net Sample: " + System.currentTimeMillis(); ByteArrayOutputStream byteStream = new ByteArrayOutputStream(); Random mRandom = new SecureRandom(); byte[] bytes = new byte[24]; mRandom.nextBytes(bytes); try { byteStream.write(bytes); byteStream.write(nonceData.getBytes()); } catch (IOException e) { e.printStackTrace(); } byte[] nonce = byteStream.toByteArray(); SafetyNetClient client = SafetyNet.getClient(context); Task<SafetyNetApi.AttestationResponse> task = client.attest(nonce, API_KEY_FROM_STEP_2_LINK); task.addOnSuccessListener(context, attestationResponse -> { /* TODO(developer): Forward this result to your server together with the nonce for verification. You can also parse the JwsResult locally to confirm that the API returned a response by checking for an 'error' field first and before retrying the request with an exponential backoff. NOTE: Do NOT rely on a local, client-side only check for security, you must verify the response on a remote server! */ String jwsResult = attestationResponse.getJwsResult(); Log.e(TAG, "Success! SafetyNet result:\n" + jwsResult + "\n"); if (jwsResult == null) { Log.e(TAG, "jwsResult Null"); } final String[] jwtParts = jwsResult.split("\\."); if (jwtParts.length == 3) { String decodedPayload = new String(Base64.decode(jwtParts[1], Base64.DEFAULT)); Log.e(TAG, "decodedPayload : " + decodedPayload); } }); task.addOnFailureListener(context, e -> { // An error occurred while communicating with the service. String mResult = null; if (e instanceof ApiException) { // An error with the Google Play Services API contains some additional details. ApiException apiException = (ApiException) e; Util.showLog(TAG, "Error: " + CommonStatusCodes.getStatusCodeString(apiException.getStatusCode()) + ": " + apiException.getStatusMessage()); } else { // A different, unknown type of error occurred. Log.e(TAG, "ERROR! " + e.getMessage()); } }); } else { Log.e(TAG, "Prompt user to update Google Play services."; } } ` Check your logs for decodedPayload if ctsProfileMatch and basicIntegrity both are false it means your device is rooted . The Attestation API returns a JWS response which looks like:

{"nonce": "6pLrr9zWyl6TNzj+kpbR4LZcfPY3U2FmZXR5IE5ldCBTYW1wbGU6IDE2MTQ2NzkwMTIzNjc="， " timestamms ": 9860437986543， "apkPackageName": "你的包名将显示在这里"，"ctsProfileMatch": true， "apkDigestSha256": ["base64编码，用于签名请求应用程序的证书的SHA-256哈希值"]，"basicIntegrity": true， "evaluationType": "BASIC"}

欲了解更多信息，请查看此链接。

这确实是一个有趣的问题，到目前为止还没有人获奖。我使用以下代码:

  boolean isRooted() {
      try {
                ServerSocket ss = new ServerSocket(81);
                ss.close();
                                    return true;
            } catch (Exception e) {
                // not sure
            }
    return false;
  }

代码当然不是无懈可击的，因为网络可能不可用，所以会出现异常。如果该方法返回true，则99%可以确定，否则只有50%不确定。网络权限也可能破坏解决方案。