Web3j Contract Invocation – Smart Contract Function Returning 0

please help me in this problem.
I am successful to compile and deploy my smart contract using web3j on testrpc. But When I call the function that returns uint in this contract from web3j, I always receive 0. I present below my contract and my Java program.
1. My Smart Contracts:

pragma solidity ^0.4.6;
contract grandParentContract{

  address public myAddr = 0x1005...;

  modifier onlyFromMe() {
    if ((myAddr != address(0)) && (tx.origin != myAddr)) {
        Msg("Permission Error: this function is limited to the my address origin.");
        return;
    }
    _;
  }
}

pragma solidity ^0.4.6;
contract parentContract is grandParentContract {

/**************BEGIN: attributes or properties or dataobjectType**********/ 


 uint public maxIdValue=0;
 uint public minIdValue=0;

 event ElementAddition(uint _id);

 function parentContract() grandParentContract() {
   maxIdValue = 0;
   minIdValue = 0;
 }

}

contract MyContract is parentContract {
  struct MyElement {

    uint id; 
    string name;
    string description;
    uint[] currentForeignKeys;
  }
  mapping(uint => MyElement) public myElementMap; 


  function MyContract() parentContract() {

  }

  function addNewElement(string _name, string _description) public onlyFromMe() returns (uint) {
    uint _id = maxIdValue+1;


    myElementMap[_id].name = _name;
    myElementMap[_id].description = _description;

    maxIdValue = _id;
    ElementAddition(_id);
    return _id;
  }

}

2. Compile and Deploy successfully
   I use testrpc

   Web3j web3 = Web3j.build(new HttpService("testrpcIp:testrpcPort"));

When I compile smart contracts, I obtains 3 *.bin files and 3 *.abi files
MyContract.bin(abi), parentContract.bin(abi), grandParentContract.bin(abi)
I deploy successfully the smart contract using the file MyContract.bin and web3j
(Note that, when I deploy this smart contract, I only load the content of this MyContract.bin file, not add 0x before this content)

3. Call addNewElement function from Java and receive always 0 (zero)

   List<String> results= callMyFunction(web3,aCredential,contractAddress, "addNewElement", Arrays.<Type>asList(new Utf8String("name1"),new Utf8String("description of name1")), Arrays.asList(new TypeReference<Uint>() {}));
   System.out.println("results = " + results);
   
   
   public static synchronized List<String> callMyFunction(Web3j web3, Credentials creds, String contractAddress, String functionName, List inputArgs, List outputs) throws Exception {
   
       List<String> results = new ArrayList();
       Function function = new Function(functionName, inputArgs, outputs);
       String encodedFunction = FunctionEncoder.encode(function);
       EthCall response = web3.ethCall(Transaction.createEthCallTransaction(creds.getEcKeyPair().getPrivateKey().toString(16), contractAddress, encodedFunction), DefaultBlockParameterName.LATEST).sendAsync().get();
       if(response.hasError()){
           System.out.println("functionCall: " + response.getError().getMessage());
       }
       convertMyResult((response != null) && (response.getValue() != null) ? FunctionReturnDecoder.decode(response.getValue(), function.getOutputParameters()) : new ArrayList(), results);
       return results;
   }
   
   public static void convertMyResult(List<Type> returns, List<String> results) throws Exception {
       if (returns.size() > 0) {
   
           for(int i=0; i<returns.size(); i++){
   
                   results.add(returns.get(i).getValue().toString());
   
           }
       }
   }
   

I always receive the results : [0].
I tried to put maxIdValue in the MyContract instead of in ParentContract, but the result is the same