从服务器路径中读出图片流

 response.setContentType("image/gif"); 
	
	OutputStream outputStream = response.getOutputStream();
	InputStream inputStream = new FileInputStream(imageFilePath);
	try {
	    byte[] buffer = new byte[1024];
	    int i = -1;
	    while ((i = inputStream.read(buffer)) != -1) {
		outputStream.write(buffer, 0, i);
	    }

	    outputStream.flush();
	} finally {
	    if (outputStream != null) {
		outputStream.close();
	    }
	    if (inputStream != null) {
		inputStream.close();
	    }
	}
	return null;