HTTPURLConnection 发送Post数据

byte[] body = new byte[512]; // 需要发送的body数据
URL url = new URL(buildSpiderURL(host));
HttpURLConnection conn = null;
try {
conn = (HttpURLConnection) url.openConnection();
conn.setRequestMethod("POST");
conn.setRequestProperty(key, value); // 设置消息头
conn.setDoOutput(true); // post发送数据时必须设置为true，否则对方无法接收到数据
conn.connect();
conn.getOutputStream().write(body);
conn.getOutputStream().flush();
conn.getOutputStream().close();
}catch(Exception ex) {
//todo something
}finally {
conn.disconnect();
}