Java supports image cropping and preview.

Java supports image cropping and preview.

 

 

In the project, we need to do something similar to the Avatar upload and image cropping functions. OK, read the following article!

 

Plug-ins required:JQuery Jcrop

Backend code:

 

 

Package org. csg. upload; import java. awt. rectangle; import java. awt. image. bufferedImage; import java. io. file; import java. io. fileInputStream; import java. io. IOException; import java. util. iterator; import javax. imageio. imageIO; import javax. imageio. imageReadParam; import javax. imageio. imageReader; import javax. imageio. stream. imageInputStream; public class Upload {/*** @ author the legend of the night * @ param path1 original path * @ param path2 the path stored after cropping * @ param x axis * @ param y axis * @ param w * @ param h */public static void CutImage (String path1, string path2, int x, int y, int w, int h) {FileInputStream fileInputStream = null; ImageInputStream iis = null; try {// read image files, create a file input stream fileInputStream = new FileInputStream (path1); // create an image file stream Iterator
 
  
It = ImageIO. getImageReadersByFormatName (jpg); ImageReader reader = it. next (); // obtain the image stream to create the image file stream iis = ImageIO. createImageInputStream (fileInputStream); // gets the default image parameter reader. setInput (iis, true); ImageReadParam param = reader. getDefaultReadParam (); // defines the cropping area Rectangle rect = new Rectangle (x, y, w, h); param. setSourceRegion (rect); BufferedImage bi = reader. read (0, param); ImageIO. write (bi, jpg, new File (path2);} catch (Exception E) {e. printStackTrace (); System. out. println (cropping failed);} finally {try {if (fileInputStream! = Null) {fileInputStream. close ();} if (iis! = Null) {iis. close () ;}} catch (IOException e) {e. printStackTrace ();}}}}
 

Access code:

 

 

<% @ Page language = java import = java. util. *, org. csg. upload. * pageEncoding = UTF-8 %> <% // relative path of the image String imagPath = request. getParameter (imgPath); String relPath = request. getRealPath (/); // obtain the absolute address of the image Server String newFileName = new date().gettime()).jpg; // The actual image path String path1 = relPath + imagPath; // specifies the image path String path2 = relPath +/images/+ newFileName; int x = Integer. parseInt (request. getParameter (x); int y = Integer. parseInt (request. getParameter (y); int w = Integer. parseInt (request. getParameter (w); int h = Integer. parseInt (request. getParameter (h); try {Upload. cutImage (path1, path2, x, y, w, h); out. print (

);} Catch (Exception e) {e. printStackTrace (); out. print (image cropping failed);} %>

 

 

Jsp code:

 

<%@ page language=java import=java.util.* pageEncoding=utf-8%>

<Script type = text/javascript src = js/jquery. min. js> </script> <script type = text/javascript src = js/jquery. jcrop. min. js> </script> <Script type = text/javascript> $ (function () {var jcrop_api, boundx =, boundy =, $ preview = $ ('# preview-pane '), $ pcnt = $ ('# preview-pane. preview-iner '), $ pimg = $ (' # preview-pane. preview-container img '), xsize = $ pcnt. width (), ysize = $ pcnt. height (); $ ('# cutimage '). jcrop ({onChange: showCoords, // obtain the selected value onSelect: showCoords, // obtain the drag value aspectRatio: xsize/ysize}, function () {var bounds = this. getBounds (); boundx = bounds [0]; boundy = bounds [1]; jcrop_api = this; $ preview. appendTo (jcrop_api.ui.holder) ;}); function showCoords (c) {var x = c. x; var y = c. y; var w = c. w; var h = c. h; $ (# x1 ). val (parseInt (x); $ (# y1 ). val (parseInt (y); $ (# w ). val (parseInt (w); $ (# h ). val (parseInt (h); if (parseInt (c. w)> 0) {var rx = xsize/c. w; var ry = ysize/c. h; Define pimg.css ({width: Math. round (rx * boundx) + 'px ', height: Math. round (ry * boundy) + 'px ', marginLeft:'-'+ Math. round (rx * c. x) + 'px ', marginTop:'-'+ Math. round (ry * c. y) + 'px '}) ;}}}); </script> Java development QQ Avatar Cropping System

 

 

 

Well, let's look at the source code below?