checkRootMethods.java

private static boolean checkRootMethod1() {
  String buildTags = android.os.Build.TAGS;
  return buildTags != null && buildTags.contains("test-keys");
}

private static boolean checkRootMethod2() {
  String[] 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"};
  for (String path : paths) {
    if (new File(path).exists()) return true;
  }
  return false;
}

private static boolean checkRootMethod3() {
  Process process = null;
  try {
    process = Runtime.getRuntime().exec(new String[] { "/system/xbin/which", "su" });
    BufferedReader in = new BufferedReader(new InputStreamReader(process.getInputStream()));
    if (in.readLine() != null) return true;
    return false;
  } catch (Throwable t) {
    return false;
  } finally {
    if (process != null) process.destroy();
  }
}