如何在servlet中提供存储在硬盘上的图片?
例如:
我有一张存储在路径'Images/button.png'
中的图片,并且我想在servlet中使用URL file/button.png
来提供这张图片。
这是可用的代码:
public void doGet(HttpServletRequest req, HttpServletResponse resp) throws IOException {
ServletContext cntx= req.getServletContext();
// Get the absolute path of the image
String filename = cntx.getRealPath("Images/button.png");
// retrieve mimeType dynamically
String mime = cntx.getMimeType(filename);
if (mime == null) {
resp.setStatus(HttpServletResponse.SC_INTERNAL_SERVER_ERROR);
return;
}
resp.setContentType(mime);
File file = new File(filename);
resp.setContentLength((int)file.length());
FileInputStream in = new FileInputStream(file);
OutputStream out = resp.getOutputStream();
// Copy the contents of the file to the output stream
byte[] buf = new byte[1024];
int count = 0;
while ((count = in.read(buf)) >= 0) {
out.write(buf, 0, count);
}
out.close();
in.close();
}
/file
的url-patternresponse.getOutputStream()
Content-Type
头为image/png
File file = new File("imageman.png");
BufferedImage image = ImageIO.read(file);
ImageIO.write(image, "PNG", resp.getOutputStream());
Content-Type
的重要性吗?在下面的答案中提到,它应该设置为image/png
或任何你需要的类型。 - Lion