public static String getPageSourceByHTTPClientPost(String pageUrl, String host, String referer, String userAgent, Map paras) throws IOException {
        HttpClient client = new HttpClient();
        if (host != null) {
            client.getHostConfiguration().setHost(host, 80, "http");
        }
        PostMethod postMethod = new PostMethod(pageUrl);
        if (paras != null) {
            Set keySet = paras.keySet();
            for (Iterator it = keySet.iterator(); it.hasNext();) {
                String s = (String) it.next();
                postMethod.addParameter(s, (String) paras.get(s));
            }
        }
        if (referer != null) {
            postMethod.setRequestHeader("Referer", referer);
        }
        if (userAgent != null) {
            postMethod.setRequestHeader("User-Agent", userAgent);
        }
        postMethod.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");
        postMethod.setRequestHeader("X-Requested-With", "XMLHttpRequest");
        client.executeMethod(postMethod);
        BufferedReader reader = new BufferedReader(new InputStreamReader(postMethod.getResponseBodyAsStream(), "UTF-8"));
        String s; // 依次循环，至到读的值为空
        StringBuilder sb = new StringBuilder();
        while ((s = reader.readLine()) != null) {
            sb.append(s);
        }
        reader.close();
        postMethod.releaseConnection();
        return s;
    }