post推送消息时的乱码

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;
}

// 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()));