jcrop实现图片剪裁
现在一些图片上传都需要处理一下大小，特别是头像的上传，具体怎么裁剪呢？这里介绍一款好用的插件 jcrop
下载地址 里面有简单的 页面demo jcrop下载
官网API ：http://code.ciaoca.com/jquery/jcrop/ 官网的demo是php 的
下面我介绍一下java的裁剪
图片剪裁需要的步骤
1、先上传需要裁剪的图片
html代码如下：
<!DOCTYPE HTML><html><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8" /><title>图片上传</title><base target="_self"><link href="${base}/cms/css/file.css" rel="stylesheet" type="text/css" /><script type="text/javascript" charset="utf-8" src="${base}/js/frame/jquery-1.9.1.js"></script><script src="${base}/js/frameNew/jquery.form.min.js" type="text/javascript"></script><script type="text/javascript" src="${base}/artdialog/artDialog.js?skin=blue"></script><script type="text/javascript" src="${base}/artdialog/plugins/iframeTools.js"></script><script type="text/JavaScript">function imageChange(){$("#fm").submit();}function subForm(){var path = '${returnPath?if_exists}';if($("#file").val()==''&& path == ""){$("#ff").html("请您选择要上传的图片!");return;}art.dialog.data("imagepath",$("#returnPath").val());art.dialog.close();}</script></head><body><div class="pop-up_box" id="div0"><div class="pop-up_bottom"><div class="mainright" style="width:570px; height:450px"><div class="pop_upload"><div class="upload_bar"><div><a href="#" class="active"><img src="${base}/cms/images/file/pop-up_20.gif" />上传图片</a></div></div><div class="upload_main2"><table width="100%" border="0" align="center" cellpadding="0" cellspacing="0" class="upload_table"><tr><th width="11%">说明：</th><td width="89%">每个图片允许大小2M,支持格式jpg/jpeg/png文件</td></tr></table><div class="upload_imgtable"><form id="fm" action="${base}/uploadSerevice.action" method="post" enctype="multipart/form-data"><input type="hidden" id="entId" name="entId" value="${newsId?if_exists}"><input type = "hidden" id="returnPath" value="${returnPath?if_exists}"/><div style="margin:12px 0 0 12px"><input id="file" type="file" name="file" class="upload_text" style="width:270px;height:20px;"onchange="imageChange()"/></div><div style="margin:12px 0 0 12px"><font id ="ff"color="red">${msg?if_exists} </font></div></form></div><div style="margin:12px 0 0 12px" ><#if returnPath?exists><#if '${returnPath?if_exists}'!=""><img id="imgLogo" src="${base}/${returnPath?if_exists}" style="border:none;" width="254" height="142"/><#else></#if><#else></#if></div><div class="tijiao"style="margin:20px 0 0 12px"><a href="#" onclick="subForm();" ><img src="${base}/images/tijiao.gif" width="82" height="35" /></a><a href="#" onclick="art.dialog.close();" ><img src="${base}/images/quxiao.gif" width="82" height="35" /></a></div></div></div></div></div></div></div></body></html>
选择图片后自动提交到action，action代码下面会讲到，这里使用的方法是：
uploadSerevice（）
2、展示上传的图片，然后进行需要裁剪的区域选择（提交图片后，跳转的页面，显示上一步上传的图片）
首先页面需要引用jcrop的js和css 以及初始化的一些function
引用：
<link rel="stylesheet" href="${base}/jcrop/css/jquery.Jcrop.css" type="text/css" /><script src="${base}/js/frame/jquery-17.1.min.js" type="text/javascript"></script><script src="${base}/jcrop/js/jquery.Jcrop.js" type="text/javascript"></script>
比较常用的几个参数这里介绍一下：
| aspectRatio | 1 | 选框宽高比。说明：width/height； |
| boxWidth | 508 | 画布宽度 |
| boxHeight | 284 | 画布高度 |
下面是我自己的一段js，和html，适用于自己的场景，需要的可以参考：
<script type="text/javascript">jQuery(function($){var jcrop_api, boundx, boundy;$('#target').Jcrop({onChange: updatePreview,//调用的function 选框改变时的事件onSelect: updatePreview,//调用的function 选框选定时的事件aspectRatio: 254/142, //裁剪框的比例大小boxWidth:300, //画布的宽boxHeight:284,//画布的高},function(){// Use the API to get the real image sizevar bounds = this.getBounds(); //获取图片实际尺寸，格式为：[w, h]boundx = bounds[0];boundy = bounds[1];// Store the API in the jcrop_api variablejcrop_api = this;jcrop_api.animateTo([0,0,142,142]);//初始化裁剪框位置});function updatePreview(c){if (parseInt(c.w) > 0){var rx = 127/ c.w; //widthvar ry = 71/ c.h;$('#preview').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'});}$("#width").attr("value",c.w);//c.w 裁剪区域的宽$("#height").attr("value",c.h);//c.h 裁剪区域的高$("#x").attr("value",c.x);//c.x 裁剪区域左上角顶点相对于图片左上角顶点的x坐标$("#y").attr("value",c.y); //c.y 裁剪区域顶点的y坐标};});function subForm(){$("#fm").submit();}</script>
下面这段js 是我初始化页面从后台获取的原始图片，个人根据自己的需要进行设置
<script type="text/JavaScript">$(document).ready(function(){var img = (document.getElementById("image1").value).replace(/\\/g,'/');document.getElementById("preview").src = img;document.getElementById("target").src = img;});</script>
页面html
<body><!--right开始--><form action="${base}/cutservicePic.action" method="post"id="fm"><input type="hidden" name="entId" id="entId" value="${entId?if_exists}"/><input type="hidden" name="image.x" id="x" value=""/><input type="hidden" name="image.y" id="y" value=""/><input type="hidden" name="image.width" id="width" value=""/><input type="hidden" name="image.height" id="height" value=""/><input type="hidden" name="pathPic" value="${pathPic?if_exists}"/><input type="hidden" id="image1" value="${pathPic?if_exists}"/> <!--后台传过来的需要裁剪的页面地址--><table width="532" height="354" border="0" style="border:1px solid #ddd;"><tr><td height="292" colspan="2"><a href="#"><div class="tutu1" ><img src="" id="target" alt="" /> <!--后台传过来的需要裁剪的页面地址，当然自己测试时候可以直接使用本地文件--></div></td><td width="204"><div class="you1"><strong>效果预览</strong> </div><div class="you2">请注意预览效果是否清晰 </div><div class="tutu2" style="width:127px;height:71px;overflow:hidden; solid gray;"><img src="" id="preview" /> <!--后台传过来的需要裁剪的页面地址，当然自己测试时候可以直接使用本地文件--></div></td></tr></table><div class="zuo"><div class="tijiao"><a href="#" onclick="subForm();" ><img src="${base}/images/tijiao.gif" width="82" height="35" /></a><a href="#" onclick="art.dialog.close();" ><img src="${base}/images/quxiao.gif" width="82" height="35" /></a></div></div></body>
效果图如下图：
左边的是 id为target 的图片 右边的是id为preview 的 图片地址都是一样的 ，左上角的是剪裁框；
需要预览不同大小的话继续添加preview1 等；就会出来两个预览框，当然还需要添加相应的js，这时候效果如下（下面是我做头像 高宽1:1时候的样子）
3、根据选择区域剪切成自己想要的图片，以java为例，php的看官网，官网有现成的demo；
在上面的js里面你会发现 你可以获取到你裁剪的图片的四个坐标；把这些坐标提交到后台：
我用的post提交，把这些从js 赋值给input隐藏域：也就是最上面html代码中的隐藏域 image.x image.y这些值
提交到后台获取到坐标：
下面贴上整个action类
package cn.fulong.omp.web.action.person;import java.awt.Color;import java.awt.Graphics;import java.awt.Image;import java.awt.image.BufferedImage;import java.awt.image.ConvolveOp;import java.awt.image.Kernel;import java.io.File;import java.io.FileOutputStream;import java.io.IOException;import java.sql.Timestamp;import javax.swing.ImageIcon;import org.apache.commons.io.FileUtils;import org.apache.commons.lang.StringUtils;import org.apache.struts2.ServletActionContext;import cn.fulong.frame.config.Platform;import cn.fulong.frame.transaction.BaseTransaction;import cn.fulong.frame.web.action.BaseAction;import cn.fulong.omp.dm.CommonOrganization;import com.sun.image.codec.jpeg.JPEGCodec;import com.sun.image.codec.jpeg.JPEGEncodeParam;import com.sun.image.codec.jpeg.JPEGImageEncoder;public class ImageCutAction extends BaseAction{/*** 上传的文件*/private File file;private String entId;private String pathPic;private String fileFileName;private String msg;private String url;private OperateImage image;/*** 剪裁后的图片地址*/private String returnPath;public String getReturnPath() {return returnPath;}public void setReturnPath(String returnPath) {this.returnPath = returnPath;}public OperateImage getImage() {return image;}public void setImage(OperateImage image) {this.image = image;}public String getUrl() {return url;}public void setUrl(String url) {this.url = url;}Timestamp currentTime = new Timestamp(System.currentTimeMillis());public String getEntId() {return entId;}public void setEntId(String entId) {this.entId = entId;}public String getPathPic() {return pathPic;}public void setPathPic(String pathPic) {this.pathPic = pathPic;}public String getFileFileName() {return fileFileName;}public void setFileFileName(String fileFileName) {this.fileFileName = fileFileName;}public String getMsg() {return msg;}public void setMsg(String msg) {this.msg = msg;}public File getFile() {return file;}public void setFile(File file) {this.file = file;}/*** 这里是一个图片的压缩方法，可以用可以不用，需要压缩的可以使用* @param originalFile 原始图片* @param resizedFile 压缩图片* @param newWidth 新的高度* @param quality 像素* @throws IOException*/private void resize(File originalFile, File resizedFile,int newWidth, float quality) throws IOException {if (quality > 1) {throw new IllegalArgumentException("Quality has to be between 0 and 1");}ImageIcon ii = new ImageIcon(originalFile.getCanonicalPath());Image i = ii.getImage();Image resizedImage = null;int iWidth = i.getWidth(null);int iHeight = i.getHeight(null);if (iWidth > iHeight) {resizedImage = i.getScaledInstance(newWidth, (newWidth * iHeight)/ iWidth, Image.SCALE_SMOOTH);} else {resizedImage = i.getScaledInstance((newWidth * iWidth) / iHeight,newWidth, Image.SCALE_SMOOTH);}// This code ensures that all the pixels in the image are loaded.Image temp = new ImageIcon(resizedImage).getImage();// Create the buffered image.BufferedImage bufferedImage = new BufferedImage(temp.getWidth(null),temp.getHeight(null), BufferedImage.TYPE_INT_RGB);// Copy image to buffered image.Graphics g = bufferedImage.createGraphics();// Clear background and paint the image.g.setColor(Color.white);g.fillRect(0, 0, temp.getWidth(null), temp.getHeight(null));g.drawImage(temp, 0, 0, null);g.dispose();// Soften.float softenFactor = 0.05f;float[] softenArray = { 0, softenFactor, 0, softenFactor,1 - (softenFactor * 4), softenFactor, 0, softenFactor, 0 };Kernel kernel = new Kernel(3, 3, softenArray);ConvolveOp cOp = new ConvolveOp(kernel, ConvolveOp.EDGE_NO_OP, null);bufferedImage = cOp.filter(bufferedImage, null);// Write the jpeg to a file.FileOutputStream out = new FileOutputStream(resizedFile);// Encodes image as a JPEG data streamJPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(out);JPEGEncodeParam param = encoder.getDefaultJPEGEncodeParam(bufferedImage);param.setQuality(quality, true);encoder.setJPEGEncodeParam(param);encoder.encode(bufferedImage);} // Example usage/*** 上传服务图片 这个类是上传原是图片的方法* @return*/public String uploadSerevice() {url="/ueditor/executeSerevice.action?newsId="+entId;String extFileName = "";if ((file != null) && (file.length() > 0L)) {int index = StringUtils.lastIndexOf(fileFileName, '.');if (index == -1){msg = "附件名称错误！";return "success";}extFileName = StringUtils.substring(fileFileName, index + 1);if ((!"jpg".equalsIgnoreCase(extFileName)) && (!"jpeg".equalsIgnoreCase(extFileName))&&(!"png".equalsIgnoreCase(extFileName))&&(!"gif".equalsIgnoreCase(extFileName))){msg = "文件类型不正确，必须为jpg/jpeg/png/gif文件！";return "success";}if (this.file.length() > 1048576L*2){msg = "文件太大，不能超过2M！";return "success";}String separator = File.separator;String rootpath = Platform.getInstance().getRealPath() ;//项目所在位置String mypath = "file" + separator+"logo" + separator;//定义文件夹//original// 存入磁盘String filename = "original_"+entId+"_"+currentTime.getTime()+ "." + extFileName.toLowerCase();//定义文件名称 //原图String path= rootpath +separator+ mypath+filename;String cutfilename = "original_cut_"+entId+"_"+currentTime.getTime()+ "." + extFileName.toLowerCase();//定义文件名称 //经过压缩的图片String cutPath = rootpath +separator+ mypath+cutfilename;System.out.println("---文件上传位置---"+path);File destFile = new File(path);File cutFile = new File(cutPath);pathPic = mypath+filename;//pathPic=mypath+cutfilename;try {FileUtils.copyFile(file, destFile);// ImageHepler help = new ImageHepler();//help.saveImageAsJpg(path, cutPath, 500, 500, true);//resize(destFile, cutFile, 254, 1f); //需要压缩的 ，调用压缩方}catch (Exception e) {e.printStackTrace();msg = "上传图片失败";return "success";}}return "uploadSerevice";}/*** 剪切服务产品图片* @return*/public String cutservicePic() {String name = ServletActionContext.getServletContext().getRealPath(pathPic);image.setSrcpath(name);//原始文件int index = StringUtils.lastIndexOf(pathPic, '.');String extFileName = StringUtils.substring(pathPic, index + 1);String separator = File.separator;String rootpath = Platform.getInstance().getRealPath() ;//项目所在位置String mypath = "file" + separator+"logo" + separator;//定义文件夹String filename = entId+"_"+currentTime.getTime()+"_1." + extFileName.toLowerCase();//定义文件名称 裁剪后的String newPic = rootpath+separator+mypath+filename;String resizeFilename = entId+"_"+currentTime.getTime()+"." + extFileName.toLowerCase();//定义文件名称 裁剪后的 再次进行压缩的String newResizePic = rootpath+separator+mypath+resizeFilename;// returnPath = mypath+resizeFilename; 返回压缩过的图片returnPath = mypath+filename;System.out.println("-----剪裁图片地址-----"+newPic);image.setSubpath(newPic);//裁剪后的文件地址try {image.cut(); //执行裁剪操作 执行完后即可生成目标图在对应文件夹内。</span>File newFile = new File(newPic);File newResizeFile = new File(newResizePic);//resize(newFile, newResizeFile, 254, 1f); //生成第二个压缩图片，需要压缩的使用} catch (IOException e) {e.printStackTrace();}url="/ueditor/executeSerevice.action?newsId="+entId;return "success";}}
OperateImage类
package cn.fulong.omp.web.action.person;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 OperateImage {// ===源图片路径名称如:c:\1.jpgprivate String srcpath;// ===剪切图片存放路径名称.如:c:\2.jpgprivate String subpath;// ===剪切点x坐标private int x;private int y;// ===剪切点宽度private int width;private int height;public String getSrcpath() {return srcpath;}public void setSrcpath(String srcpath) {this.srcpath = srcpath;}public String getSubpath() {return subpath;}public void setSubpath(String subpath) {this.subpath = subpath;}public int getX() {return x;}public void setX(int x) {this.x = x;}public int getY() {return y;}public void setY(int y) {this.y = y;}public int getWidth() {return width;}public void setWidth(int width) {this.width = width;}public int getHeight() {return height;}public void setHeight(int height) {this.height = height;}public OperateImage() {}/** 对图片裁剪，并把裁剪完的新图片保存 */public void cut() throws IOException {FileInputStream is = null;ImageInputStream iis = null;try {// 读取图片文件is = new FileInputStream(srcpath);/** 返回包含所有当前已注册 ImageReader 的 Iterator，这些 ImageReader 声称能够解码指定格式。* 参数：formatName - 包含非正式格式名称 . （例如 "jpeg" 或 "tiff"）等 。*/Iterator<ImageReader> it = ImageIO.getImageReadersByFormatName("jpg");ImageReader reader = it.next();// 获取图片流iis = ImageIO.createImageInputStream(is);/** <p>iis:读取源.true:只向前搜索 </p>.将它标记为 ‘只向前搜索’。* 此设置意味着包含在输入源中的图像将只按顺序读取，可能允许 reader 避免缓存包含与以前已经读取的图像关联的数据的那些输入部分。*/reader.setInput(iis, true);/** <p>描述如何对流进行解码的类<p>.用于指定如何在输入时从 Java Image I/O* 框架的上下文中的流转换一幅图像或一组图像。用于特定图像格式的插件 将从其 ImageReader 实现的* getDefaultReadParam 方法中返回 ImageReadParam 的实例。*/ImageReadParam param = reader.getDefaultReadParam();/** 图片裁剪区域。Rectangle 指定了坐标空间中的一个区域，通过 Rectangle 对象* 的左上顶点的坐标（x，y）、宽度和高度可以定义这个区域。*/Rectangle rect = new Rectangle(x, y, width, height);// 提供一个 BufferedImage，将其用作解码像素数据的目标。param.setSourceRegion(rect);/** 使用所提供的 ImageReadParam 读取通过索引 imageIndex 指定的对象，并将 它作为一个完整的* BufferedImage 返回。*/BufferedImage bi = reader.read(0, param);// 保存新图片ImageIO.write(bi, "jpg", new File(subpath));} finally {if (is != null)is.close();if (iis != null)iis.close();}}}
到这里就全部完成了。
可以自己到剪裁后文件夹内看到剪裁的图片；
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