客户端发一个post请求

public static String doPostStr(String httpUrl, String str) {
        HttpPost httpPost = null;
        try {
            HttpClient client = getHttpClient();
            httpPost = new HttpPost(httpUrl);
            StringEntity entity = new StringEntity(str);
            entity.setContentType("application/x-www-form-urlencoded");
            entity.setContentEncoding("utf-8");

            httpPost.setEntity(entity);

            HttpResponse response = client.execute(httpPost);
            String result = EntityUtils.toString(response.getEntity(), DEFAULT_CHARSET);
            return result;
        } catch (Exception e) {
            logger.error("http post is error," + e.getMessage(), e.fillInStackTrace());
        } finally {
            httpPost.releaseConnection();
        }
        return null;
    }