请求（需要发送数据给别人）：
URL url = new URL("需要请求的URL连接");
HttpURLConnection httpConnection = (HttpURLConnection) url.openConnection();
// 以POST或GET方式通信
conn.setRequestMethod("POST");
// 设置连接超时时间
httpConnection.setConnectTimeout(this.timeOut * 1000);
// User-Agent
httpConnection.setRequestProperty("User-Agent",
"Mozilla/4.0 (compatible; MSIE 6.0; Windows XP)");
// 不使用缓存
httpConnection.setUseCaches(false);
// 允许输入输出
httpConnection.setDoInput(true);
httpConnection.setDoOutput(true);
// Content-Type
httpConnection.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
// 取得输出流
BufferedOutputStream out = new BufferedOutputStream(conn.getOutputStream());
// 长度以1KB为单位进行写
final
int len = 1024;
// 将要输出的字符通过流做输出
String postData = "需要POST出去的数据";
byte[] outData = postData.getBytes(this.charset);
int dataLen = outData.length;
int off = 0;
// 以1KB为单位写
while (off < dataLen) {
if (len >= dataLen) {
out.write(outData, off, dataLen);
} else {
out.write(outData, off, len);
}
// 刷新缓冲区
out.flush();
off += len;
dataLen -= len;
}
// 关闭流
out.close();
// 取得应答码
int
respCode = conn.getResponseCode();
// 取得返回的输入流
InputStream inputStream = conn.getInputStream();
接收（接收请求数据并应答）:
// 取得输入流
InputStream in = request.getInputStream();
// 使用Reader取得输入流数据
BufferedReader br = new BufferedReader(new InputStreamReader(in, "UTF-8"));
// 将Reader转成字符串
String temp;
StringBuffer sb = new StringBuffer();
while (null != (temp = br.readLine())) {
sb.append(temp);
}
// 取得最终收到的字符串
String originalReturnData = sb.toString();
???? // 应答给请求方的数据
String responseString = "收到请求之后应答的数据";
// 取得输出器
PrintWriter out = response.getWriter();
// 直接输出
out.println(responseString);
// 刷新输出
out.flush();
// 关闭输出
out.close();