如何清空HttpURLConnection的inputStream

[staticabc]

下面是一段HTTP请求的代码，在标红的地方抛出了异常，如果把Eclipse重启，第一次debug没问题，第二次以后就一直过不去，抛：
ProtocolException:Cannot write output after reading input.
请各位看看为什么？

	public static String queryInfo(String request, String serviceurl, int timeout){
		HttpURLConnection conn = null;
		try {
			URL url = new URL(serviceurl);
			conn = (HttpURLConnection) url.openConnection();
			conn.setRequestProperty("User-Agent",
			        "Mozilla/5.0 (iPhone; CPU iPhone OS 5_1_1 like Mac OS X) AppleWebKit/534.46 (KHTML, like Gecko) Mobile/9B206 Mojo/IOS");
			conn.setRequestProperty("Accept", "application/xml;charset=UTF-8, text/javascript, */*; q=0.01");
			conn.setRequestProperty("Content-Type", "application/xml;charset=UTF-8");
			// conn.setRequestProperty("Referer", "http://wsa.sg.redatoms.com");
			conn.setRequestProperty("gamelanguage", "zh_cn");
			conn.setRequestProperty("X-Requested-With", "XMLHttpRequest");
			conn.setRequestProperty("Connection", "keep-alive");
			conn.setRequestProperty("Host", "wsa.sg.redatoms.com");
			// conn.setRequestProperty("Cookie", cookie);
			conn.setDoInput(true);
			conn.setDoOutput(true);
			conn.setRequestMethod("POST");
			conn.setConnectTimeout(timeout);
			conn.setInstanceFollowRedirects(false);
			conn.connect();
			OutputStreamWriter out = new OutputStreamWriter(conn.getOutputStream(), "UTF-8");

			out.write(request);
			out.flush();
			out.close();
			String strLine = "";
			String strResponse = "";
			InputStream in = conn.getInputStream();
			
			BufferedReader reader = new BufferedReader(new InputStreamReader(in,"UTF-8"));
			while ((strLine = reader.readLine()) != null)
			{
				strResponse += strLine;
			}
			
			conn.getInputStream().close();
			return strResponse;
		
		} catch (MalformedURLException e) {
			e.printStackTrace();
		} catch (ProtocolException e) {
			e.printStackTrace();
		} catch (UnsupportedEncodingException e) {
			e.printStackTrace();
		} catch (IOException e) {
			e.printStackTrace();
		} catch (Exception e) {
			e.printStackTrace();
		} finally {
			conn.disconnect();
			System.out.print("");
		}
		
		return null;
	}

[staticabc]

红色没显示出来，就是这句： OutputStreamWriter out = new OutputStreamWriter(conn.getOutputStream(), "UTF-8"); 我debug的时候发现，第一次走到这句之前conn的inputstream=null，第二次debug在这句conn = (HttpURLConnection) url.openConnection();之后，inputstream就有值了，我想问下，为什么会有值？怎么置成null？

[weinianjie1]

无论什么情况，finally里请务必要关闭IO，就是in和out

[王司徒]

第29行的那个InputStream没有关闭吧， 楼上说的很对 in和out都要关闭，而且在finally里面