title: Parameters send from Java to JNI are not being sent
body: <p>I have read about on how parameters are being send from Java to a JNI function. I first tried to send an ArrayList because im trying to get Android phonebooks.</p>
  
  <p>After a lot of problems I made it simple to be completely sure that a simple parameter (a String) is being send.</p>
  
  <p>This is my Java declaration of the function:</p>
  
  <pre><code>public static native void nativeCallback(String params);
  </code></pre>
  
  <p>and this is the JNI function:</p>
  
  <pre><code>JNIEXPORT void JNICALL
  Java_example_nativeCallback(JNIEnv*  env,jstring params)
  </code></pre>
  
  <p>I check and the function is being called. I used this to see if there is actually a String being send:</p>
  
  <pre><code>int sizeOfChain = env-&gt;GetStringLenght(params);
  std::ostringstream convert;
  convert&lt;&lt;sizeOfChain;
  convert.flush();
  std::string finalString = convert.str();
  </code></pre>
  
  <p>When printing <strong>finalString</strong> it is 0.</p>
  
  <p>This is how the function is being called from Java:</p>
  
  <pre><code>nativeCallback("TEST_STRING");
  </code></pre>
  
  <p>Also, sending an ArrayList is valid as jobjectArray?</p>