图片显示

来源：互联网发布：淘宝买家信用怎么提高编辑：程序博客网时间：2024/04/29 15:01

将图片上传到阿里云服务器时，通过外网无法直接访问图片路径，这时就必须要通过IO流在界面上显示。

在web.xml配置文件中加上：

<servlet>
       <servlet-name>OSSReader</servlet-name>
       <servlet-class>action.OSSReader</servlet-class>
   </servlet>
   <servlet-mapping>
       <servlet-name>OSSReader</servlet-name>
       <url-pattern>/img</url-pattern>
   </servlet-mapping>

界面中显示图片已

<img src="<%=basePath %>/img?fileName=${fileName }" onload="javascript:if (this.width>121) this.width=121;if(this.height>121) this.height=121"/>

OSSReader：

   public class OSSReader extends HttpServlet {

   private Logger log = LoggerFactory.getLogger(OSSReader.class);

   private static final long serialVersionUID = 4029716041969911408L;

   protected void service(HttpServletRequest request,
           HttpServletResponse response) throws ServletException,
           java.io.IOException {
       InputStream is = null;
       OutputStream os = null;
       try {
           String fileName = request.getParameter("fileName");
           log.debug("fileName=" + fileName);
           if (StringUtils.isBlank(fileName)) {
               fileName = "user_logo/default_logo.png";
           }
           is = downLoadFile(fileName);//从阿里云服务器获取IO流
           if (null != is) {
               response.setContentType("image/jpeg");
               os = response.getOutputStream(); // 创建输出流
               int c = 0;
               while ((c = is.read()) != -1) {
                   os.write(c);
               }
           }
       } catch (Exception e) {
           log.error(e.getMessage(), e);
       }
   }

   /**
   * 这个方法可以写在阿里云公共方法中
   */

   public static InputStream downLoadFile(String fileName) throws Exception {
       log.info("downLoadFile start");
       InputStream fileStream = null;
       OSSClient client = null;
       try {
           // 创建上传客户端
           client = new OSSClient(endpoint, accessKeyId, accessKeySecret);
           OSSObject data = client.getObject(bucketName, fileName);
           fileStream = data.getObjectContent();
           log.info("get file " + fileName + "   success!");
           log.info("downLoadFile end");
       } catch (Exception e) {
           log.error(e.getMessage(),e);
       } finally {
//           client.shutdown();
       }
       return fileStream;
   }

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

   protected void doPost(HttpServletRequest request,
           HttpServletResponse response) throws ServletException, IOException {
       service(request, response);
   }
}

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