http请求中传输的流要什么格式才能收到？该如何处理

http请求中传输的流要什么格式才能收到？
初学者，请多见谅。

我要用Post方式提交一些数据，这些数据要封装到流中，请问这个流要满足什么样的格式才能在servlet中的doPost方法中读取到。以下是java代码

InputStream is=request.getInputStream();
InputStreamReader isr = new InputStreamReader(is, "utf-8");
BufferedReader bf = new BufferedReader(isr);
// 可变字符串
StringBuffer sb = new StringBuffer();
// 存储一行数据（br.readLine每次读写一行)
String readLine=null;  
while((readLine=bf.readLine())!=null){  
sb.append(readLine).append("\n");  
} 
System.out.println(sb.toString());

[解决办法]
不用表单就用HttpURLConnection

Java code

//这里面两个参数//url 服务器端servlet的访问地址//aOutputData 字节数组 内容为key1＝value1&key2=value2&key3=value3的形式 ，然后getBytes();HttpURLConnection http=url.openConnection();http.setConnectTimeout(5000);        http.setReadTimeout(5000);        http.setDoOutput(true);        http.setDoInput(true);        http.setAllowUserInteraction(false);        http.setUseCaches(false);        http.setRequestMethod("POST");        http.setRequestProperty("Content-Type",                "application/x-www-form-urlencoded");        http.setRequestProperty("Content-Length", String                .valueOf(aOutputData.length));        http.setRequestProperty("Connection", "close");        http                .setRequestProperty(                        "User-Agent",                        "*** client");        http.setRequestProperty("Accept", "text/xml");                http.connect();        OutputStream out = http.getOutputStream();        out.write(aOutputData);        out.flush();