SdkConnection browse(BrowseConfig config) API is not working properly.

I am trying to create a java application using Bot Libre library. Facing problem on browsing bot/avatar API. My code is given below:

import java.util.List;

import org.botlibre.sdk.config.BrowseConfig;
import org.botlibre.sdk.config.WebMediumConfig;

public class BrowseAvater {

  public static void main(String[] args) {
    BrowseAvater test = new BrowseAvater();
    test.getAvatarList();
  }

  public void getAvatarList() {
    // Get bot list
    BrowseConfig browse = new BrowseConfig();
    browse.type = "Bot";
    browse.category = "Entertainment";
    browse.typeFilter = "Public";
    browse.tag = "cool";
    browse.sort = "name";
    System.out.println("Started to load avatar list");
    List<WebMediumConfig> bots = BotLibreSdk.getConnection().browse(browse);
    System.out.println("Bot list found : " + bots);
  }
}

Sometimes it working nice but average time found no response from POST (String url, String xml) API. This post API is called from browse(BrowseConfig config) API.

No error throws in this scenario. Additionally in android I found it's working nice.

Thanks in advance for your support.