public static String sendPost(String url, Map<String, ?> paramMap) {
    PrintWriter out = null;
    BufferedReader in = null;
    String result = "";
    String param = "";
    Iterator<String> it = paramMap.keySet().iterator();
    while (it.hasNext()) {
        String key = it.next();
        param += key + "=" + paramMap.get(key) + "&";
    }
    param = param.substring(0, param.length() - 1);
    try {
        URL realUrl = new URL(url);
        // 打开和URL之间的连接
        URLConnection conn = realUrl.openConnection();
        // 设置通用的请求属性
        conn.setRequestProperty("accept", "*/*");
        conn.setRequestProperty("connection", "Keep-Alive");
        conn.setRequestProperty("Accept-Charset", "utf-8");
        conn.setRequestProperty("user-agent", "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1;SV1)");
        // 发送POST请求必须设置如下两行
        conn.setDoOutput(true);
        conn.setDoInput(true);
        // 获取URLConnection对象对应的输出流
        out = new PrintWriter(conn.getOutputStream());
        // 发送请求参数
        out.print(param);
        // flush输出流的缓冲
        out.flush();
        // 定义BufferedReader输入流来读取URL的响应
        in = new BufferedReader(new InputStreamReader(conn.getInputStream(), "UTF-8"));
        String line;
        while ((line = in.readLine()) != null) {
            result += line;
        }
    } catch (Exception e) {
        System.out.println(e.getMessage());
        //log.info(e.getMessage(), e);
    }
    // 使用finally块来关闭输出流、输入流
    finally {
        try {
            if (out != null) {
                out.close();
            }
            if (in != null) {
                in.close();
            }
        } catch (IOException ex) {
            System.out.println(ex.getMessage());
           // ex.printStackTrace();
        }
    }
    log.info("wechat          "+result);
    return result;
}