title: No implementation found for boolean
body: <p>I'm trying to call the function but I get the following error</p>
  
  <blockquote>
    <p>Caused by: java.lang.UnsatisfiedLinkError: No implementation found for
    boolean com.example.rosaa.ftp.FTPClient.ftpIsConnected() (tried
    Java_com_example_rosaa_ftp_FTPClient_ftpIsConnected and
    Java_com_example_rosaa_ftp_FTPClient_ftpIsConnected__)
            at com.example.rosaa.ftp.FTPClient.ftpIsConnected(Native Method)
            at com.example.rosaa.ftp.FTPClient.isConnected(FTPClient.java:227)
            at com.example.rosaa.myapplication.tasks.CheckDroneNetworkAvailabilityTask.doInBackground(CheckDroneNetworkAvailabilityTask.java:86) </p>
  </blockquote>
  
  <p>here is the function</p>
  
  <pre><code>private native boolean ftpIsConnected();
  </code></pre>
  
  <p>function in jni</p>
  
  <pre><code>JNIEXPORT jboolean JNICALL
  Java_com_example_rosaa_ftp_FTPClient_ftpIsConnected(JNIEnv *env, jobject obj)
  {
      _ftp_t* ftp = get_ftp_handle(env, obj);
  
      if (ftp != NULL) {
          return (ftp-&gt;connected&gt;0?TRUE:FALSE);
      }
  
      return FALSE;
  }
  </code></pre>