java servlet：从url获取图像并显示它

Question

我将如何去从URL中抓取图像，然后显示它...很像代理服务器？

我想我需要先将图像传输到文件流然后输出文件。这里的代码：

protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { 

     // temporarily hard-code the image 
     String imageUrlString = "http://i.imgur.com/3lQAD2E.jpg"; 

     // Read the image ... 
     URL urlConn = new URL(imageUrlString); 
     InputStream inputStream  = urlConn.openStream(); 
     ByteArrayOutputStream output = new ByteArrayOutputStream(); 
     byte [] buffer    = new byte[ 1024 ]; 

     int n = 0; 
     while (-1 != (n = inputStream.read(buffer))) { 
      output.write(buffer, 0, n); 
     } 
     inputStream.close(); 

     // Here's the content of the image... 
     byte [] data = output.toByteArray(); 

     PrintWriter out = response.getWriter(); 
     out.print(data);  
    } 

但是，返回只是一个破碎的图像文件。

Answer 1

您应该使用OutputStream from the response而不是Writer。作家处理角色数据。您也可以拨打set the MIME type correctly作为回应。