因为项目当中用到图片裁剪，本来可以不用到后台进行裁剪的，但是要兼容万恶的IE浏览器，所以不得不使用后台进行裁剪。
这次使用到imgareaselect 插件获取需要裁剪区域的坐标，再由后台进行裁剪操作。先上个效果图再说
但是这里有一个坑就是上传的图片过大，可能会造成裁剪的区域跟插件中显示的不一样，所以得现在后台对云图片进行压缩在裁剪。
/**
* 等比例压缩算法：
* 算法思想：根据压缩基数和压缩比来压缩原图，生产一张图片效果最接近原图的缩略图
* @param srcURL 原图地址
* @param deskURL 缩略图地址
* @param comBase 压缩基数
* @param scale 压缩限制(宽/高)比例 一般用1：
* 当scale>=1,缩略图height=comBase,width按原图宽高比例;若scale<1,缩略图width=comBase,height按原图宽高比例
* @throws Exception
*/
public static void saveMinPhoto(String srcURL, String deskURL, double comBase,
double scale) throws Exception {
File srcFile = new java.io.File(srcURL);
String ext = srcURL.substring(srcURL.lastIndexOf(".") + 1);
Image src = ImageIO.read(srcFile);
int srcHeight = src.getHeight(null);
int srcWidth = src.getWidth(null);
int deskHeight = 0;// 缩略图高
int deskWidth = 0;// 缩略图宽
double srcScale = (double) srcHeight / srcWidth;
/**缩略图宽高算法*/
if ((double) srcHeight > comBase || (double) srcWidth > comBase) {
if (srcScale >= scale || 1 / srcScale > scale) {
if (srcScale >= scale) {
deskHeight = (int) comBase;
deskWidth = srcWidth * deskHeight / srcHeight;
} else {
deskWidth = (int) comBase;
deskHeight = srcHeight * deskWidth / srcWidth;
}
} else {
if ((double) srcHeight > comBase) {
deskHeight = (int) comBase;
deskWidth = srcWidth * deskHeight / srcHeight;
} else {
deskWidth = (int) comBase;
deskHeight = srcHeight * deskWidth / srcWidth;
}
}
} else {
deskHeight = srcHeight;
deskWidth = srcWidth;
}
BufferedImage tag = new BufferedImage(deskWidth, deskHeight, BufferedImage.TYPE_3BYTE_BGR);
tag.getGraphics().drawImage(src, 0, 0, deskWidth, deskHeight, null); //绘制缩小后的图
FileOutputStream deskImage = new FileOutputStream(deskURL); //输出到文件流
ImageIO.write(tag, ext, new File(deskURL));
deskImage.close();
}
这就是压缩之后在进行裁剪了，好了上完整代码先
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <title>上传头像</title> <link rel="stylesheet" href="../../statics/css/ewt/style_1.css" rel="external nofollow" type="text/css"> <link rel="stylesheet" href="../../statics/css/ewt/style_shangchuangtouxiang.css" rel="external nofollow" > <link rel="stylesheet" type="text/css" href="../../statics/css/ewt/imgareaselect-default.css" rel="external nofollow" > <link rel="stylesheet" href="../../statics/css/ewt/style.css" rel="external nofollow" type="text/css" /> <link rel="stylesheet" href="../../statics/scripts/layer/skin/default/layer.css" rel="external nofollow" > <script src="/UploadFiles/2021-04-02/jquery.min.js">js 代码
function preview(img, selection) { if (!selection.width || !selection.height) return; var scaleX = 100 / selection.width; var scaleY = 100 / selection.height; $('#preview img').css({ width: Math.round(scaleX * 300), height: Math.round(scaleY * 300), marginLeft: -Math.round(scaleX * selection.x1), marginTop: -Math.round(scaleY * selection.y1) }); $('#x1').val(selection.x1); $('#y1').val(selection.y1); $('#x2').val(selection.x2); $('#y2').val(selection.y2); $('#w').val(selection.width); $('#h').val(selection.height); } $(function () { }); //上传原始图片 function uplodImage(target) { if(checkImage(target)){ var url = httpUtils.rootPath+'/component/upload.do'; $.ajaxFileUpload({ url: url, //用于文件上传的服务器端请求地址 secureuri: false, //是否需要安全协议，一般设置为false fileElementId: 'uplodimage', //文件上传域的ID dataType: 'json', //返回值类型 一般设置为json success: function (data) //服务器成功响应处理函数 { var filePath = data.filePath; $('#photo').attr('src',httpUtils.rootPath+'/component/upload.do"50"); $('#y1').val("50"); $('#x2').val("241"); $('#y2').val("241"); $('#w').val("191"); $('#h').val("191"); } }); } } //上传裁剪后的图片 function upold() { if($('#imgUrl').val()==''){ layer.alert("请先选择图片在上传"); return false; } $.ajax({ type: "post", url:httpUtils.rootPath+'/user/setHeadPicture', beforeSend: function(request) { request.setRequestHeader("jmtcp", header); }, async:false, data: { x:$('#x1').val(), y:$('#y1').val(), width: $('#w').val(), imgUrl : $('#imgUrl').val(), heigth: $('#h').val() }, dataType: "json", success: function(data){ if(data.code==1){ layer.alert(data.message,function(){ window.location.href = '../user/grzy.html'; }); }else{ layer.alert(data.message); } } }); } function checkImage(target) { var isIE = /msie/i.test(navigator.userAgent) && !window.opera; var fileSize = 0; var filepath = target.value; // 为了避免转义反斜杠出问题，这里将对其进行转换 var re = /(\+)/g; var filename = filepath.replace(re, "#"); // 对路径字符串进行剪切截取 var one = filename.split("#"); // 获取数组中最后一个，即文件名 var two = one[one.length - 1]; // 再对文件名进行截取，以取得后缀名 var three = two.split("."); // 获取截取的最后一个字符串，即为后缀名 var last = three[three.length - 1]; // 添加需要判断的后缀名类型 var tp = "jpg,gif,bmp,JPG,GIF,BMP,png"; // 返回符合条件的后缀名在字符串中的位置 var rs = tp.indexOf(last); // 如果返回的结果大于或等于0，说明包含允许上传的文件类型 if(rs < 0){ layer.alert('您选择的上传文件不是有效的图片文件'); return false; } // if (isIE && !target.files) { // IE浏览器 // var filePath = target.value; // 获得上传文件的绝对路径 // var fileSystem = new ActiveXObject("Scripting.FileSystemObject"); // // GetFile(path) 方法从磁盘获取一个文件并返回。 // var file = fileSystem.GetFile(filePath); // fileSize = file.Size; // 文件大小，单位：b // } // else { // 非IE浏览器 // fileSize = target.files[0].size; // } var img1 = document.getElementById('photo'); //img1.dynsrc=target.value; //img1.fileSize：IE ， fileObj.files[0].fileSize：chrome， fileObj.files[0].size：FF var fileSize = img1.fileSize || target.files[0].fileSize || target.files[0].size; var size = fileSize / 1024 / 1024; if (size > 5) { layer.alert("图片不能大于5M"); return false; } return true; }后台代码
public class CutImageUtils { public static SecureRandom rnd = new SecureRandom(); public static String cutImage(int x, int y, int width, int height,String srcPath) throws Exception{ String root = ApplicationContext.getProperty("upload_folder"); String imagePath = root+srcPath; FileInputStream is = null; ImageInputStream iis = null; String uploadFolder = null ; String filepath = null ; String serverName = null ; uploadFolder = ApplicationContext.getProperties().getProperty("upload_folder").toString() ; filepath = generateServerFolder() ; serverName = generateServerName(srcPath) ; File file = new File(uploadFolder + filepath); if (!file.exists()) { file.mkdirs(); } try { // 读取图片文件 saveMinPhoto(imagePath, imagePath, 300, 0.9d); //resetsize(imagePath, imagePath); is = new FileInputStream(imagePath); String ext = srcPath.substring(srcPath.lastIndexOf(".") + 1); Iterator<ImageReader> it = ImageIO.getImageReadersByFormatName(ext); ImageReader reader = it.next(); // 获取图片流 iis = ImageIO.createImageInputStream(is); reader.setInput(iis, true); 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); BufferedImage bi = reader.read(0, param); // 保存新图片 ImageIO.write(bi, ext, new File(uploadFolder + filepath + serverName)); } catch (FileNotFoundException e) { // TODO Auto-generated catch block if (is != null) is.close(); if (iis != null) iis.close(); e.printStackTrace(); } return filepath + serverName ; } /** * * @param config * @param file * @param request * @return */ public static String generateServerName(String clientPath) { //按当前时间的分钟毫秒+3位随机数 Calendar c = Calendar.getInstance(); String min = get(c,Calendar.MINUTE); String sec = get(c,Calendar.SECOND); String mis = get(c,Calendar.MILLISECOND); String rnd = random(); String ext = getFileExt(getClientName(clientPath)); return min + sec + mis + rnd + ext ; } /** 客户端文件名 */ public static String getClientName(String clientPath) { if(null != clientPath){ int index1 = clientPath.lastIndexOf("/"); int index2 = clientPath.lastIndexOf("\\"); if(index2 > index1){ index1 = index2; } return clientPath.substring(index1+1,clientPath.length()); } return null; } public static String getFileExt(String fileName){ if(null != fileName){ int dot = fileName.lastIndexOf("."); if(dot >= 0){ return fileName.substring(dot); } } return ""; } public static String random(){ String value = String.valueOf(rnd.nextInt(1000)); if(value.length() < 3){ for(int i=value.length();i<3;i++){ value = "0" + value; } } return value; } public static String generateServerFolder() { //按当前年月日和小时生成文件路径 Calendar c = Calendar.getInstance(); String year = get(c,Calendar.YEAR); String mon = get(c,Calendar.MONTH); String day = get(c,Calendar.DAY_OF_MONTH); String hour = get(c,Calendar.HOUR_OF_DAY); return year + "/" + mon + "/" + day + "/" + hour + "/"; } public static String get(Calendar c,int field){ int v = c.get(field); if(field == Calendar.MONTH){ v += 1; } String value = String.valueOf(v); if(value.length() == 1){ value = "0" + value; } return value; } /** * 缩小图片到固定长高 * @param srcImagePath 读取图片路径 * @param toImagePath 写入图片路径 * @param width 缩小后图片宽度 * @param height 缩小后图片长度 * @throws IOException */ public static void reduceImageByWidthHeight(String srcImagePath, String toImagePath, int width, int height) throws IOException{ FileOutputStream out = null; try{ //读入文件 File file = new File(srcImagePath); String ext = srcImagePath.substring(srcImagePath.lastIndexOf(".") + 1); // 构造Image对象 BufferedImage src = javax.imageio.ImageIO.read(file); // 缩小边长 BufferedImage tag = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB); // 绘制缩小后的图片 tag.getGraphics().drawImage(src, 0, 0, width, height, null); out = new FileOutputStream(toImagePath); ImageIO.write(tag, ext, new File(toImagePath)); }catch(Exception e){ e.printStackTrace(); }finally{ if(out != null){ out.close(); } out = null; System.gc(); } } /** * 等比例压缩算法： * 算法思想：根据压缩基数和压缩比来压缩原图，生产一张图片效果最接近原图的缩略图 * @param srcURL 原图地址 * @param deskURL 缩略图地址 * @param comBase 压缩基数 * @param scale 压缩限制(宽/高)比例 一般用1： * 当scale>=1,缩略图height=comBase,width按原图宽高比例;若scale<1,缩略图width=comBase,height按原图宽高比例 * @throws Exception */ public static void saveMinPhoto(String srcURL, String deskURL, double comBase, double scale) throws Exception { File srcFile = new java.io.File(srcURL); String ext = srcURL.substring(srcURL.lastIndexOf(".") + 1); Image src = ImageIO.read(srcFile); int srcHeight = src.getHeight(null); int srcWidth = src.getWidth(null); int deskHeight = 0;// 缩略图高 int deskWidth = 0;// 缩略图宽 double srcScale = (double) srcHeight / srcWidth; /**缩略图宽高算法*/ if ((double) srcHeight > comBase || (double) srcWidth > comBase) { if (srcScale >= scale || 1 / srcScale > scale) { if (srcScale >= scale) { deskHeight = (int) comBase; deskWidth = srcWidth * deskHeight / srcHeight; } else { deskWidth = (int) comBase; deskHeight = srcHeight * deskWidth / srcWidth; } } else { if ((double) srcHeight > comBase) { deskHeight = (int) comBase; deskWidth = srcWidth * deskHeight / srcHeight; } else { deskWidth = (int) comBase; deskHeight = srcHeight * deskWidth / srcWidth; } } } else { deskHeight = srcHeight; deskWidth = srcWidth; } BufferedImage tag = new BufferedImage(deskWidth, deskHeight, BufferedImage.TYPE_3BYTE_BGR); tag.getGraphics().drawImage(src, 0, 0, deskWidth, deskHeight, null); //绘制缩小后的图 FileOutputStream deskImage = new FileOutputStream(deskURL); //输出到文件流 ImageIO.write(tag, ext, new File(deskURL)); deskImage.close(); } public static void main(String[] args) { try { String src = CutImageUtils.cutImage(11, 12, 100, 100, "2017/01/04/17/6348162d-5b50-4e7d-b414-93140498f8de.jpg"); System.out.println(src); } catch (Exception e) { // TODO Auto-generated catch block e.printStackTrace(); } } }以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持。