addTextChangedListener显示来自多个Web服务的响应

Question

当我在EditText中输入＆gt; = 3个字符时，请求将发送到我的webservice并返回匹配的内容。但是，当我输入超过3个字符时，列表会更新，但元素会显示2次，3次等。我每次清除arraylist但结果仍然错误。你能告诉我有什么问题吗？这是addTextChangedListener。

etRec.addTextChangedListener(new TextWatcher()
        {

            @Override
            public void afterTextChanged(Editable s) {
                // TODO Auto-generated method stub

            }

            @Override
            public void beforeTextChanged(CharSequence s, int start, int count,
                    int after) {
                // TODO Auto-generated method stub

            }

            @Override
            public void onTextChanged(CharSequence s, int start, int before,
                    int count) {
                // TODO Auto-generated method stub

                text_for_search = etRec.getText().toString();
                if (etRec.getText().length()>=3){

                    if (destinataire!=null)
                        destinataire.clear();

                    if (infodata!=null)
                        infodata.clear();

                    //check internet connection
                    if (Util.haveNetworkConnection(m)==true){

                        new loadingTask().execute();

                    }else {

                        InternetConnectionDialog.button_text=m.getResources().getString(R.string.recommencer_en);
                        m.startActivity(new Intent(m, InternetConnectionDialog.class));
                    }

                }}});