post推送消息乱码解决

今天在post推送消息的时候老师乱码。导致推送消息不成功。放在本地的时候是可以的，单一放到服务器就报错。搞死了，查了资料，然后才发现是这个小问题

// 获取URLConnection对象对应的输出流
OutputStreamWriter outWriter = new OutputStreamWriter(conn.getOutputStream(), "utf-8");
out = new PrintWriter(outWriter);

乱码时候的写法是：

in = new BufferedReader(new InputStreamReader(conn.getInputStream()));

下面是代码：

 public static String sendPost(String url, JSONObject params) {
        PrintWriter out = null;
        BufferedReader in = null;
        String result = "";
        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
            //设置通用的请求属性
            conn.setRequestProperty("user-agent","Mozilla/5.0 (Windows NT 6.1; WOW64; rv:21.0) Gecko/20100101 Firefox/21.0)");
            conn.setRequestProperty("Content-Type", "application/json;charset=utf-8");
            // 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
            OutputStreamWriter outWriter = new OutputStreamWriter(conn.getOutputStream(), "utf-8");
            out = new PrintWriter(outWriter);
            // 发送请求参数
            out.print(params);
            // 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()));
            String line;
            while ((line = in.readLine()) != null) {
                result += line;
            }
        } catch (Exception e) {
            System.out.println("发送 POST 请求出现异常！"+e);
            e.printStackTrace();
        }
        //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){
                ex.printStackTrace();
            }
        }
        return result;
    }