java的get请求

/** * @author xiongyw */public class Test {    public static void getState() throws Exception {        String url = "xxx";        Test.doGet(url);    }    public static String getSha1(String str) {        if (str == null || str.length() == 0) {            return null;        }        char hexDigits[] = {'0', '1', '2', '3', '4', '5', '6', '7', '8', '9',                'a', 'b', 'c', 'd', 'e', 'f'};        try {            MessageDigest mdTemp = MessageDigest.getInstance("SHA1");            mdTemp.update(str.getBytes("UTF-8"));            byte[] md = mdTemp.digest();            int j = md.length;            char buf[] = new char[j * 2];            int k = 0;            for (int i = 0; i < j; i++) {                byte byte0 = md[i];                buf[k++] = hexDigits[byte0 >>> 4 & 0xf];                buf[k++] = hexDigits[byte0 & 0xf];            }            return new String(buf);        } catch (Exception e) {            // TODO: handle exception            return null;        }    }       public static String doGet(String urlWithParams){        System.out.println(urlWithParams);        CloseableHttpClient httpClient = HttpClientUtil.createSSLClientDefault();        HttpGet httpget = new HttpGet(urlWithParams);        CloseableHttpResponse response = null;        String jsonStr=null;        try {            response = httpClient.execute(httpget);            System.out.println("StatusCode -> " + response.getStatusLine().getStatusCode());            HttpEntity entity = response.getEntity();             jsonStr = EntityUtils.toString(entity);//, "utf-8");            System.out.println(jsonStr);            httpget.releaseConnection();        } catch (IOException e) {            e.printStackTrace();        }        return jsonStr;    }}