Spring File Upload + image zoom + image Capture (Avatar function)

Implement image upload
Users must be able to upload images, so the ability to upload files is required. The more common file Upload component has Commons FileUpload, here we choose commons FileUpload.

The first is the form of the page form settings, remember to match the method and Enctype properties Oh!!

<form action= "upload.do" method= "post" enctype= "Multipart/form-data" > <input name= "File" type= "File" > <input type= "Submit" value= "Submit" ></form>

Because post a form that contains file uploads is sent to the server as a multipart/form-data request, you must explicitly tell Dispatcherservlet how to handle the multipartrequest. First declare a multipartresolver in Dispatcher-servlet.xml:

<bean id= "Multipartresolver" class= "Org.springframework.web.multipart.commons.CommonsMultipartResolver" > <!--set the maximum size of the uploaded file to 1MB-<property name= "Maxuploadsize" > <value>1048576 </value> </property> </bean>

So once a request is a multipartrequest, it is first processed by Multipartresolver and then forwarded to the appropriate controller.
In Fileaction, HttpServletRequest is transformed into Multiparthttpservletrequest, which makes it very easy to get the file name and the content of the files.

     @RequestMapping (value =  "/upload", method =  Requestmethod.post)     public string upload (Httpservletrequest request, Httpservletresponse response)  throws IOException, IllegalStateException {         //  Transformation to multiparthttprequest:         MultipartHttpServletRequest multipartRequest =  (multiparthttpservletrequest)  request ;        //  Get File:         Multipartfile multipartfile = multipartrequest.getfile ("file");         //  get filename:          string filename  =multipartfile.getoriginalfilename ();         string tmps[]  = filename.split ("\ \"); /  "." have special meanings in regular expressions    so to escape         /**          * {1}  get input stream   write file    (   here   implement zoom function of picture   and   interception capabilities   )          **/         inputstream input = multipartfile.getinputstream ();//         createpreviewimage (Input, "small-" +tmps[0]+ ". jpg");         createpreviewimageofcut (Input, "smallcut-" +tmps[0]+ ". jpg");         /**         * {2} or:          **/        file source  = new file ("f://" + "normal-" +tmps[0]+ ". jpg");   //normal size picture          multipaRtfile.transferto (source);        return  "FileUpload";     }

The remaining picture scaling and image interception are all in the following code, which is relatively simple and does not explain too much

    //Create thumbnail     public void createpreviewimage (InputStream  input,string filename)  throws IOException {          file fo = new file ("f://" +filename); //  target picture              bufferedimage bis = imageio.read (input);   //original picture         int w = bis.getwidth ();      //Picture Original Size         int h =  Bis.getheight ();            int nw ;                          //the size of the picture after zooming         int nh  ;     The standard   for    //thumbnails is   120*120 (equal scale)         if   (w / h < 1    Double) {             nh = 120;             nw = nh*w/h;        }else {             nw = 120;             nh = nw*h/w;        }         bufferedimage _image = new bufferedimage ( NW,&NBSP;NH,BUFFEREDIMAGE.TYPE_INT_RGB);         _image.getgraphics (). DrawImage (bis, 0, 0, nw, nh, null);  //drawing a reduced figure          fileoutputStream newimageout = new fileoutputstream (FO);  //output to file stream          /*         * JPEGImageEncoder  Encode the image buffer data as a  JPEG  data stream. Users of this interface should be in the  Raster         *  or  BufferedImage  Provide image data in the  JPEGEncodeParams  object to set the necessary parameters,         *  and successfully opened the  outputstream (encoding  JPEG  flow intent stream). jpegimageencoder  interface          *  encode image data as an interchangeable thumbnail  jpeg   The data stream that will be written to the  OutputStream  provided to the encoder.           Note that the classes in the:com.sun.image.codec.jpeg  package do not belong to the core  java  api. They are part of the  Sun  release          JDK  and  JRE  products. While other licensees may choose to publish these classes, developers cannot send           expect software to be implemented from non- Sun To get them in. We expect that the same functionality will ultimately be available in the core  API  or standard expansion           show.         */         Jpegimageencoder encoder = jpegcodec.createjpegencoder (newimageout);         encoder.encode (_image);  //near JPEG encoding          Newimageout.close ();     }        //Create intercept map      public void createpreviewimageofcut (Inputstream input,string filename)  throws ioexception {         file fo =  new file ("f://" +filename); //  target picture              bufferedimage bis = imageio.read (input);   //Original Image          int w&nbsP;= bis.getwidth ();      //Picture Original Size          Int h = bis.getheight ();                   //Four parameters are image start coordinates and width height, i.e. cropimagefilter (int x,int y,int  Width,int height), please refer to Api        imagefilter cropfilter for more information.  =new cropimagefilter (0,0,200,200);         //Get pictures          image croppedimage = toolkit.getdefaulttoolkit (). CreateImage (New filteredimagesource (Bis.getsource (), cropfilter));         //Image  Switch to   BufferedImage         Bufferedimage bufimg = new bufferedimage (Croppedimage.getwidth (NULL),  Croppedimage.getheight (NULL), BUFFEREDIMAGE.TYPE_INT_RGB);            bufimg .creategraphics (). DrawImage ( croppedimage, 0, 0, null);           //Output as Picture file         imageio.write (bufimg,  "JPEG", &NBSP;FO);             }}

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Spring File Upload + image zoom + image Capture (Avatar function)