获取HttpURLConnection 响应体内容

java 中，有时需要使用HttpURLConnection 模拟浏览器发送http请求，那么如何获取HttpURLConnection 中的响应体呢？

private static byte[] connection(HttpURLConnection huc, byte[] sendBytes,
			String mode) throws Exception {
		if (mode.equalsIgnoreCase("POST") && sendBytes != null) {
			huc.getOutputStream().write(sendBytes);
			huc.getOutputStream().flush();
			huc.getOutputStream().close();
		}

		int resCode = huc.getResponseCode();

		if (resCode == HttpURLConnection.HTTP_OK) {
			int contentLength = huc.getContentLength();
			if (contentLength > 0) {
//				
				System.out.println("httputil,contentLength:"+contentLength);
//				return readData(huc);
				return readDataFromLength(huc, contentLength);
			} else {
				return readData(huc);
			}
		}
		return null;
	}

private static byte[] readData(HttpURLConnection huc) throws Exception {
		InputStream in = huc.getInputStream();
		return FileUtils.readBytes(in);

	}

	private static byte[] readDataFromLength(HttpURLConnection huc,
			int contentLength) throws Exception {

		InputStream in = huc.getInputStream();
		BufferedInputStream bis = new BufferedInputStream(in);

		// 数据字节数组
		byte[] receData = new byte[contentLength];
		int readLength = 0;
		// 数据数组偏移量
		int offset = 0;

		readLength = bis.read(receData, offset, contentLength);
		// 已读取的长度
		int readAlreadyLength = readLength;
		while (readAlreadyLength < contentLength) {
			readLength = bis.read(receData, readAlreadyLength, contentLength-readAlreadyLength);
			readAlreadyLength = readAlreadyLength + readLength;
		}

		return receData;
	}