InputString String之间转化

封装

	/**
	 * 
	 * @param inputStream
	 * @param bufferSize
	 * @return
	 * @throws Exception
	 */
	private String inputStream2String(InputStream inputStream, int bufferSize)
			throws Exception {

		if (inputStream == null || bufferSize < 1) {
			return null;
		}
		int i = -1;
		byte[] b = new byte[bufferSize];
		StringBuffer sb = new StringBuffer();
		while ((i = inputStream.read(b)) != -1) {
			sb.append(new String(b, 0, i));
		}
		return sb.toString();

	}

	/**
	 * 
	 * @param inputStream
	 * @return
	 * @throws Exception
	 */
	private String inputStream2String(InputStream inputStream) throws Exception {

		if (inputStream == null) {
			return null;
		}
		int i = -1;
		ByteArrayOutputStream baos = new ByteArrayOutputStream();
		while ((i = inputStream.read()) != -1) {
			baos.write(i);
		}
		return baos.toString();

	}

	/**
	 * 
	 * @param string
	 * @return
	 */
	private InputStream string2InputStream(String string) {
		if (string == null) {
			return null;
		}
		return new ByteArrayInputStream(string.getBytes());
	}