根据Url抓取图片在浏览器显示

阳光穿透心脏的1/2处 2021-06-11 15:12 416阅读 0赞

抓取了不同网站的图片，其中一个可以显示，另一个提示格式不对，在浏览器里对比了两个图片的响应头，不同之处是一个经过了压缩

![70][]

在Response里对其进行设置

response.setHeader("Content-Encoding","gzip");

完整代码

protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    	        String USER_AGENT = "Mozilla/5.0 (compatible; MSIE 9.0; Windows NT 6.1; WOW64; Trident/5.0)";
                //图片的url
    	        String strUrl = request.getParameter("url");
    	  
    	        ServletOutputStream out = null;
    	        try {    
    	            URL url = new URL(strUrl);
    	            HttpURLConnection conn = (HttpURLConnection)url.openConnection();
    	            conn.setRequestProperty("User-Agent", USER_AGENT);
    	            conn.setRequestMethod("GET");
    	            conn.setConnectTimeout(5 * 1000);
    	           
    	            InputStream inStream = conn.getInputStream();
    	            String contentType = conn.getHeaderField("Content-Type");
                        //设置返回的图片格式
    	            if(null != contentType){
    	                response.setContentType(contentType);
    	                System.out.println("Content-Type:  "+contentType);
    	            }
                        //设置返回的编码格式
    	            String contentEncoding = conn.getHeaderField("Content-Encoding");
    	            if(null != contentEncoding){
    	                response.setHeader("Content-Encoding",contentEncoding);
    	                System.out.println("Content-Encoding:  "+contentEncoding);
    	            }
    	            out = response.getOutputStream();
    	            int len = 0;
    	            byte[] byteImg = new byte[2048];
    	            while((len = inStream.read(byteImg)) != -1){
    	                out.write(byteImg,0, len);
    	            }
    	            
    	            out.flush();
    	        } catch (Exception e) {
    	        }finally{
    	            try {
    	                if(null != out)
    	                out.close();
    	            } catch (IOException e) {
    	            }
    	        }
    		
    		
    }

[70]: /images/20210606/437322e93852418fb2db56ce83edf7ca.png