Java實現圖片裁剪預覽功能
在項目中，我們需要做些類似頭像上傳，圖片裁剪的功能，ok看下面文章！
需要插件：jQuery Jcrop
后端代碼：
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 小夜的傳說 * @param path1 圖片原路徑 * @param path2 裁剪后存儲的路徑 * @param x x軸 * @param y y軸 * @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 { //讀取圖片文件，建立文件輸入流 fileInputStream=new FileInputStream(path1); //創建圖片的文件流 迭代器 Iterator<ImageReader> it = ImageIO.getImageReadersByFormatName("jpg"); ImageReader reader=it.next(); //獲取圖片流 建立文圖 文件流 iis=ImageIO.createImageInputStream(fileInputStream); //獲取圖片默認參數 reader.setInput(iis, true); ImageReadParam param=reader.getDefaultReadParam(); //定義裁剪區域 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("裁剪失敗"); }finally{ try { if(fileInputStream!=null){ fileInputStream.close(); } if(iis!=null){ iis.close(); } } catch (IOException e) { e.printStackTrace(); } } } } </pre>
訪問代碼：<%@ page language="java" import="java.util.,org.csg.upload." pageEncoding="utf-8"%>
<%
//圖片的相對路徑
String imagPath=request.getParameter("imgPath");
String relPath=request.getRealPath("/");//獲取圖片服務器絕對地址
String newFileName=new Date().getTime()+".jpg";
//實際圖片路徑
String path1=relPath+imagPath;
//裁剪后存儲到服務器的圖片路徑
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("<img src='images/"+newFileName+"'/>"); }catch(Exception e){ e.printStackTrace(); out.print("圖片裁剪失敗"); } %> </pre>
jsp代碼：<%@ page language="java" import="java.util." pageEncoding="utf-8"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>Jsp開發頭像裁剪</title>
<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
<link rel="stylesheet" href="css/jquery.Jcrop.css" type="text/css" />
<script type="text/javascript" src="js/jquery.min.js"></script>
<script type="text/javascript" src="js/jquery.Jcrop.min.js"></script>
<style type="text/css"> {margin: 0;padding: 0;}
.cut{
margin-top: 20px;
}#preview-pane { display: block; position: absolute; z-index: 2000; top: 10px; right: -280px; padding: 6px; border: 1px rgba(0,0,0,.4) solid; background-color: white; -webkit-border-radius: 6px; -moz-border-radius: 6px; border-radius: 6px; -webkit-box-shadow: 1px 1px 5px 2px rgba(0, 0, 0, 0.2); -moz-box-shadow: 1px 1px 5px 2px rgba(0, 0, 0, 0.2); box-shadow: 1px 1px 5px 2px rgba(0, 0, 0, 0.2); } #preview-pane .preview-container { width: 250px; height: 170px; overflow: hidden; } </style> <script type="text/javascript"> $(function(){ var jcrop_api, boundx="", boundy="", $preview = $('#preview-pane'), $pcnt = $('#preview-pane .preview-container'), $pimg = $('#preview-pane .preview-container img'), xsize = $pcnt.width(), ysize = $pcnt.height(); $('#cutImage').Jcrop({ onChange:showCoords,//獲取選中的值 onSelect:showCoords,//獲取拖拽的值 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; $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> </head> <body> <h1>Java開發QQ頭像裁剪系統</h1> <div class="cut"> <img id="cutImage" alt="" src="images/1.jpg" > <div id="preview-pane"> <div class="preview-container"> <img src="images/1.jpg" class="jcrop-preview" alt="Preview" /> </div> </div> </div> <form action="success.jsp" method="post" > <input type="text" value="images/1.jpg" name="imgPath"> x軸:<input type="text" size="4" id="x1" name="x" /> y軸:<input type="text" size="4" id="y1" name="y"/> 寬度:<input type="text" size="4" id="w" name="w"/> 高度:<input type="text" size="4" id="h" name="h"/> <input type="submit" value="裁剪"/> </form> </body> </html> </pre>
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