Java implementation of small I robot API interface call example

package com.weixin.util;
import java.io.IOException;
import java.util.Random;
import org.apache.commons.codec.binary.Hex;
import org.apache.commons.codec.digest.DigestUtils;
import org.apache.commons.httpclient.HttpClient;
import org.apache.commons.httpclient.HttpException;
import org.apache.commons.httpclient.methods.PostMethod;
import org.apache.commons.httpclient.params.HttpMethodParams;
import org.apache.commons.lang.StringUtils;
public class XiaoI {
 private final static String APP_KEY = "*****";
 private final static String APP_SECRET = "****";
 public String Tess(String key, String names) {
  String realm = "xiaoi.com";
  String method = "POST";
  String uri = "/robot/ask.do";
  byte[] b = new byte[20];
  new Random().nextBytes(b);
  String nonce = new String(Hex.encodeHex(b));
  String HA1 = DigestUtils.shaHex(StringUtils.join(new String[] {
    APP_KEY, realm, APP_SECRET }, ":"));
  String HA2 = DigestUtils.shaHex(StringUtils.join(new String[] { method,
    uri }, ":"));
  String sign = DigestUtils.shaHex(StringUtils.join(new String[] { HA1,
    nonce, HA2 }, ":"));
  String str = null;
  HttpClient hc = new HttpClient();
  PostMethod pm = new PostMethod("http://nlp.xiaoi.com/robot/ask.do");
  pm.getParams().setParameter(HttpMethodParams.HTTP_CONTENT_CHARSET,
    "utf-8");
  pm.addRequestHeader("X-Auth", "app_key="7HHk65oE2Ngy", nonce=""
    + nonce + "", signature="" + sign + """);
  pm.setParameter("platform", "weixin");
  pm.setParameter("type", "0");
  pm.setParameter("userId", names);
  pm.setParameter("question", key);
  int re_code;
  try {
   re_code = hc.executeMethod(pm);
   if (re_code == 200) {
    str = pm.getResponseBodyAsString();
   }
  } catch (HttpException e) {
   // TODO Auto-generated catch block
   e.printStackTrace();
  } catch (IOException e) {
   // TODO Auto-generated catch block
   e.printStackTrace();
  }
  return str;
 }
}