前言：在做网站的时候经常用的功能就是，用户上传图片对自己上传的图片进行截图，DIV自己的头像。或者上传幻灯片大图进行DIV设置小图。
解决方案：目前我知道的解决方案有两个如下：
一、flash用户上传头像组件 ，地址： http://www.hdfu.net/index.html （但收费）
二、jq插件imgAreaSelect， 地址：http://odyniec.net/projects/imgareaselect/
注：官网文档为英文的，如果想看中文的这里也有，http://www.jb51.net/article/28485.htm（不一定定保证是最新的）
说了这么多先看看效果吧
直接上代码:
<%@ page contentType="text/html;charset=UTF-8" language="java" %> <html> <head> <title>imgAreaSelect图片截图</title> <script type="text/javascript" src="imgareaselect/scripts/jquery.min.js"></script> <script type="text/javascript" src="swfupload/swfupload.js"></script> <script type="text/javascript" src="imgareaselect/scripts/jquery.imgareaselect.pack.js"></script> <link href="css/style.css" rel="stylesheet" type="text/css"/> <link href="css/default.css" rel="stylesheet" type="text/css"/> <link href="imgareaselect/css/imgareaselect-default.css" rel="stylesheet" type="text/css"/> <script type="text/javascript"> $(function () { //回调方法 function preview(img, selection) { if (!selection.width || !selection.height) return; var scaleX = 100 / selection.width; var scaleY = 100 / selection.height; $('#preview img').css({ Math.round(scaleX * 300), height: Math.round(scaleY * 300), marginLeft: -Math.round(scaleX * selection.x1), marginTop: -Math.round(scaleY * selection.y1) }); //完成后对表单进行赋值 $('input[name="x1"]').val(selection.x1); $('input[name="y1"]').val(selection.y1); $('input[name="x2"]').val(selection.x2); $('input[name="y2"]').val(selection.y2); $('input[name="path"]').val($('img#photo').attr("src")); $('#x1').val(selection.x1); $('#y1').val(selection.y1); $('#x2').val(selection.x2); $('#y2').val(selection.y2); $('#w').val(selection.width); $('#h').val(selection.height); $('#btn').show(); } $('#photo').imgAreaSelect({ aspectRatio: '1:1', //设置区域的比例 handles: true, //设置区域的四角显示 fadeSpeed: 200, //动画效果时间 onSelectChange: preview //选择完成后调用的方法 }); //表单提交事件 $('#btn').click(function () { if ($('#x1').val() == '') { alert('还没有进行截图'); return; } $.ajax({ type: 'POST', url: '/uploadarea?operate=2', data: $('#dataForm').serialize(), dataType: 'json', cache: false, success: function (data) { if (data.success) { var imgLi = $("<li></li>"); var newImg = $('<div" class="img_box ' + '">' + '<img src="' + data.imgs + '" />').appendTo(imgLi); $("#show_list ul").append(imgLi); } } }); }); }); </script> </head> <body> <h2 style="text-align: center">截图演示</h2> <div class="container demo"> <div style="float: left; 50%;"> <p class="instructions"> 点击这里，选择截图区域，<font color="red">必须为等比例图片</font> </p> <div class="frame" style="margin: 0 0.3em; 300px; height: 300px;"> <img id="photo" src="img/605.jpg"> </div> </div> <div style="float: left; 50%;"> <p style="font-size: 110%; font-weight: bold; padding-left: 0.1em;"> 选择区域预览 </p> <div class="frame" style="margin: 0 1em; 100px; height: 100px;"> <div id="preview" style=" 100px; height: 100px; overflow: hidden;"> <img src="img/605.jpg" style=" 100px; height: 100px;"> </div> </div> <%--表单数据--%> <form id="dataForm" style="position: absolute;top:25%;left:60%;"> <input type="hidden" name="x1" value=""/> <input type="hidden" name="y1" value=""/> <input type="hidden" name="x2" value=""/> <input type="hidden" name="y2" value=""/> <input type="hidden" name="path"/> <input type="button" id="btn" style="display: none;" value="进行截图"/> </form> <table style="margin-top: 1em;"> <thead> <tr> <th colspan="2" style="font-size: 110%; font-weight: bold; text-align: left; padding-left: 0.1em;"> 坐标 </th> <th colspan="2" style="font-size: 110%; font-weight: bold; text-align: left; padding-left: 0.1em;"> 尺寸 </th> </tr> </thead> <tbody> <tr> <td style=" 10%;"><b>X<sub>1</sub>:</b></td> <td style=" 30%;"><input type="text" id="x1" value="-"></td> <td style=" 20%;"><b>Width:</b></td> <td><input type="text" value="-" id="w"></td> </tr> <tr> <td><b>Y<sub>1</sub>:</b></td> <td><input type="text" id="y1" value="-"></td> <td><b>Height:</b></td> <td><input type="text" id="h" value="-"></td> </tr> <tr> <td><b>X<sub>2</sub>:</b></td> <td><input type="text" id="x2" value="-"></td> <td></td> <td></td> </tr> <tr> <td><b>Y<sub>2</sub>:</b></td> <td><input type="text" id="y2" value="-"></td> <td></td> <td></td> </tr> </tbody> </table> </div> </div> <div style="margin: 0 auto;960px;"> <h3>所得截图</h3> <div id="show_list"> <ul> </ul> </div> </div> </body> </html>
上传的Servlet代码：
package com.zxd.tool; import org.apache.commons.fileupload.FileItem; import org.apache.commons.fileupload.FileUploadException; import org.apache.commons.fileupload.disk.DiskFileItemFactory; import org.apache.commons.fileupload.servlet.ServletFileUpload; import javax.jws.WebService; import javax.servlet.ServletConfig; import javax.servlet.ServletException; import javax.servlet.annotation.WebServlet; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import java.io.File; import java.io.IOException; import java.io.PrintWriter; import java.util.List; import java.util.UUID; /** * 图片上传后进行，处理的裁剪类 * * @author 张晓东 */ @WebServlet("/uploadarea") public class UploadArea extends HttpServlet { private File tempDir; //临时路径 private File saveDir; //保存路径 private File cutDir; //裁剪图片保存的路径 /** * servlet初始化事件 * * @param config * @throws ServletException */ public void init(ServletConfig config) throws ServletException { String uploadPath = config.getServletContext().getRealPath("/"); StringBuffer sb = new StringBuffer(uploadPath); saveDir = new File(sb.append("\upload").toString()); tempDir = new File(sb.append("\temp").toString()); cutDir = new File(uploadPath + "\upload\cut"); if (!saveDir.exists()) { saveDir.mkdir(); } if (!tempDir.exists()) { tempDir.mkdir(); } if (!cutDir.exists()) { cutDir.mkdir(); } } protected void doGet(HttpServletRequest request, HttpServletResponse response) throws IOException, ServletException { this.doPost(request, response); } public void doPost(HttpServletRequest request, HttpServletResponse response) throws IOException, ServletException { int operate = request.getParameter("operate").isEmpty() ? 0 : Integer.valueOf(request.getParameter("operate")); //方法操作 switch (operate) { case 1: //上传操作 uploadImg(request, response); break; case 2: //截图操作 cutImg(request, response); break; } } //上传图片 private void uploadImg(HttpServletRequest request, HttpServletResponse response) throws IOException { DiskFileItemFactory factory = new DiskFileItemFactory(); factory.setSizeThreshold(1 * 1024 * 1024); //设置缓冲区大小 factory.setRepository(tempDir); //设置临时保存目录 ServletFileUpload sfu = new ServletFileUpload(factory); //Servelt文件上传对象 sfu.setFileSizeMax(200 * 1024 * 1024); //200M 文件上传大小 sfu.setHeaderEncoding("utf-8"); List<FileItem> list = null; try { list = sfu.parseRequest(request); //得到文件 } catch (FileUploadException e) { e.printStackTrace(); } int size = list.size(); StringBuffer json = new StringBuffer("{"success":true,"imgs":["); //输出到页面的json PrintWriter out = response.getWriter(); for (int i = 0; i < size; i++) { //循环保存文件 FileItem file = list.get(i); if (file.isFormField()) { //如果是表单字段 String name = file.getFieldName(); // 获得该字段名称 String value = file.getString("utf-8"); //获得该字段值 } else { String extName = file.getName().substring( //得到扩展名 file.getName().lastIndexOf(".")); String fname = UUID.randomUUID() + extName; try { file.write(new File(saveDir, fname)); // 写入文件 String path = request.getSession().getServletContext().getRealPath("/"); if (i == size) { json.append(saveDir.toString() + "\" + fname + "]}"); //回传上传图片路径 } } catch (Exception e) { e.printStackTrace(); } } } out.flush(); out.print(json); out.close(); } //裁剪图片 private void cutImg(HttpServletRequest request, HttpServletResponse response) throws IOException { StringBuffer json = new StringBuffer("{"success":true,"imgs":"); //输出到页面的json response.setContentType("text/plain;charset=utf-8"); response.setCharacterEncoding("utf-8"); //得到坐标 Integer x1 = Integer.parseInt(request.getParameter("x1")); Integer y1 = Integer.parseInt(request.getParameter("y1")); Integer x2 = Integer.parseInt(request.getParameter("x2")); Integer y2 = Integer.parseInt(request.getParameter("y2")); String basePath = request.getSession().getServletContext().getRealPath("/"); //项目物理路径 String path = request.getParameter("path"); //原图片路径 String extName = path.substring(path.lastIndexOf(".")); //文件扩展名 int width = x2 - x1; //图像的宽度 int height = y2 - y1;//图像的高度 String cutFileName ="\cut_" + UUID.randomUUID() + extName; ImageUtils.cut(basePath + "\" + path, cutDir.toString() + cutFileName, x1, y1, width, height); json.append(""upload\\cut\"+cutFileName+""}"); PrintWriter out = response.getWriter(); out.flush(); out.print(json); out.close(); } }
ImagesUtils.java
package com.zxd.tool; /** * Created by zhang on 14-3-1. * 图片的常用操作类 */ import java.awt.AlphaComposite; import java.awt.Color; import java.awt.Font; import java.awt.Graphics; import java.awt.Graphics2D; import java.awt.Image; import java.awt.Toolkit; import java.awt.color.ColorSpace; import java.awt.geom.AffineTransform; import java.awt.image.AffineTransformOp; import java.awt.image.BufferedImage; import java.awt.image.ColorConvertOp; import java.awt.image.CropImageFilter; import java.awt.image.FilteredImageSource; import java.awt.image.ImageFilter; import java.io.File; import java.io.IOException; import javax.imageio.ImageIO; /** * 图片处理工具类：<br> * 功能：缩放图像、切割图像、图像类型转换、彩色转黑白、文字水印、图片水印等 * * @author Administrator */ public class ImageUtils { /** * 几种常见的图片格式 */ public static String IMAGE_TYPE_GIF = "gif";// 图形交换格式 public static String IMAGE_TYPE_JPG = "jpg";// 联合照片专家组 public static String IMAGE_TYPE_JPEG = "jpeg";// 联合照片专家组 public static String IMAGE_TYPE_BMP = "bmp";// 英文Bitmap（位图）的简写，它是Windows操作系统中的标准图像文件格式 public static String IMAGE_TYPE_PNG = "png";// 可移植网络图形 public static String IMAGE_TYPE_PSD = "psd";// Photoshop的专用格式Photoshop /** * 缩放图像（按比例缩放） * * @param srcImageFile 源图像文件地址(绝对路径) * @param result 缩放后的图像地址(绝对路径) * @param scale 缩放比例 * @param flag 缩放选择:true 放大; false 缩小; */ public final static void scale(String srcImageFile, String result, int scale, boolean flag) { try { BufferedImage src = ImageIO.read(new File(srcImageFile)); // 读入文件 int width = src.getWidth(); // 得到源图宽 int height = src.getHeight(); // 得到源图长 if (flag) {// 放大 width = width * scale; height = height * scale; } else {// 缩小 width = width / scale; height = height / scale; } Image image = src.getScaledInstance(width, height, Image.SCALE_DEFAULT); BufferedImage tag = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB); Graphics g = tag.getGraphics(); g.drawImage(image, 0, 0, null); // 绘制缩小后的图 g.dispose(); ImageIO.write(tag, "JPEG", new File(result));// 输出到文件流 } catch (IOException e) { e.printStackTrace(); } } /** * 缩放图像（按高度和宽度缩放） * * @param srcImageFile 源图像文件地址(绝对路径) * @param result 缩放后的图像地址(绝对路径) * @param height 缩放后的高度 * @param width 缩放后的宽度 * @param bb 比例不对时是否需要补白：true为补白; false为不补白; */ public final static void scale2(String srcImageFile, String result, int height, int width, boolean bb) { try { double ratio = 0.0; // 缩放比例 File f = new File(srcImageFile); BufferedImage bi = ImageIO.read(f); Image itemp = bi.getScaledInstance(width, height, bi.SCALE_SMOOTH); // 计算比例 if ((bi.getHeight() > height) || (bi.getWidth() > width)) { if (bi.getHeight() > bi.getWidth()) { ratio = (new Integer(height)).doubleValue() / bi.getHeight(); } else { ratio = (new Integer(width)).doubleValue() / bi.getWidth(); } AffineTransformOp op = new AffineTransformOp(AffineTransform .getScaleInstance(ratio, ratio), null); itemp = op.filter(bi, null); } if (bb) {//补白 BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB); Graphics2D g = image.createGraphics(); g.setColor(Color.white); g.fillRect(0, 0, width, height); if (width == itemp.getWidth(null)) g.drawImage(itemp, 0, (height - itemp.getHeight(null)) / 2, itemp.getWidth(null), itemp.getHeight(null), Color.white, null); else g.drawImage(itemp, (width - itemp.getWidth(null)) / 2, 0, itemp.getWidth(null), itemp.getHeight(null), Color.white, null); g.dispose(); itemp = image; } ImageIO.write((BufferedImage) itemp, "JPEG", new File(result)); } catch (IOException e) { e.printStackTrace(); } } /** * 图像切割(按指定起点坐标和宽高切割) * * @param srcImageFile 源图像地址 (绝对路径) * @param result 切片后的图像地址 (绝对路径) * @param x 目标切片起点坐标X * @param y 目标切片起点坐标Y * @param width 目标切片宽度 * @param height 目标切片高度 */ public final static void cut(String srcImageFile, String result, int x, int y, int width, int height) { try { // 读取源图像 BufferedImage bi = ImageIO.read(new File(srcImageFile)); int srcWidth = bi.getHeight(); // 源图宽度 int srcHeight = bi.getWidth(); // 源图高度 if (srcWidth > 0 && srcHeight > 0) { Image image = bi.getScaledInstance(srcWidth, srcHeight, Image.SCALE_DEFAULT); // 四个参数分别为图像起点坐标和宽高 // 即: CropImageFilter(int x,int y,int width,int height) ImageFilter cropFilter = new CropImageFilter(x, y, width, height); Image img = Toolkit.getDefaultToolkit().createImage( new FilteredImageSource(image.getSource(), cropFilter)); BufferedImage tag = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB); Graphics g = tag.getGraphics(); g.drawImage(img, 0, 0, width, height, null); // 绘制切割后的图 g.dispose(); // 输出为文件 ImageIO.write(tag, "JPEG", new File(result)); } } catch (Exception e) { e.printStackTrace(); } } /** * 图像切割（指定切片的行数和列数） * * @param srcImageFile 源图像地址 (绝对路径) * @param descDir 切片目标文件夹 * @param rows 目标切片行数。默认2，必须是范围 [1, 20] 之内 * @param cols 目标切片列数。默认2，必须是范围 [1, 20] 之内 */ public final static void cut2(String srcImageFile, String descDir, int rows, int cols) { try { if (rows <= 0 || rows > 20) rows = 2; // 切片行数 if (cols <= 0 || cols > 20) cols = 2; // 切片列数 // 读取源图像 BufferedImage bi = ImageIO.read(new File(srcImageFile)); int srcWidth = bi.getHeight(); // 源图宽度 int srcHeight = bi.getWidth(); // 源图高度 if (srcWidth > 0 && srcHeight > 0) { Image img; ImageFilter cropFilter; Image image = bi.getScaledInstance(srcWidth, srcHeight, Image.SCALE_DEFAULT); int destWidth = srcWidth; // 每张切片的宽度 int destHeight = srcHeight; // 每张切片的高度 // 计算切片的宽度和高度 if (srcWidth % cols == 0) { destWidth = srcWidth / cols; } else { destWidth = (int) Math.floor(srcWidth / cols) + 1; } if (srcHeight % rows == 0) { destHeight = srcHeight / rows; } else { destHeight = (int) Math.floor(srcWidth / rows) + 1; } // 循环建立切片 // 改进的想法:是否可用多线程加快切割速度 for (int i = 0; i < rows; i++) { for (int j = 0; j < cols; j++) { // 四个参数分别为图像起点坐标和宽高 // 即: CropImageFilter(int x,int y,int width,int height) cropFilter = new CropImageFilter(j * destWidth, i * destHeight, destWidth, destHeight); img = Toolkit.getDefaultToolkit().createImage( new FilteredImageSource(image.getSource(), cropFilter)); BufferedImage tag = new BufferedImage(destWidth, destHeight, BufferedImage.TYPE_INT_RGB); Graphics g = tag.getGraphics(); g.drawImage(img, 0, 0, null); // 绘制缩小后的图 g.dispose(); // 输出为文件 ImageIO.write(tag, "JPEG", new File(descDir + "_r" + i + "_c" + j + ".jpg")); } } } } catch (Exception e) { e.printStackTrace(); } } /** * 图像切割（指定切片的宽度和高度） * * @param srcImageFile 源图像地址 (绝对路径) * @param descDir 切片目标文件夹 * @param destWidth 目标切片宽度。默认200 * @param destHeight 目标切片高度。默认150 */ public final static void cut3(String srcImageFile, String descDir, int destWidth, int destHeight) { try { if (destWidth <= 0) destWidth = 200; // 切片宽度 if (destHeight <= 0) destHeight = 150; // 切片高度 // 读取源图像 BufferedImage bi = ImageIO.read(new File(srcImageFile)); int srcWidth = bi.getHeight(); // 源图宽度 int srcHeight = bi.getWidth(); // 源图高度 if (srcWidth > destWidth && srcHeight > destHeight) { Image img; ImageFilter cropFilter; Image image = bi.getScaledInstance(srcWidth, srcHeight, Image.SCALE_DEFAULT); int cols = 0; // 切片横向数量 int rows = 0; // 切片纵向数量 // 计算切片的横向和纵向数量 if (srcWidth % destWidth == 0) { cols = srcWidth / destWidth; } else { cols = (int) Math.floor(srcWidth / destWidth) + 1; } if (srcHeight % destHeight == 0) { rows = srcHeight / destHeight; } else { rows = (int) Math.floor(srcHeight / destHeight) + 1; } // 循环建立切片 // 改进的想法:是否可用多线程加快切割速度 for (int i = 0; i < rows; i++) { for (int j = 0; j < cols; j++) { // 四个参数分别为图像起点坐标和宽高 // 即: CropImageFilter(int x,int y,int width,int height) cropFilter = new CropImageFilter(j * destWidth, i * destHeight, destWidth, destHeight); img = Toolkit.getDefaultToolkit().createImage( new FilteredImageSource(image.getSource(), cropFilter)); BufferedImage tag = new BufferedImage(destWidth, destHeight, BufferedImage.TYPE_INT_RGB); Graphics g = tag.getGraphics(); g.drawImage(img, 0, 0, null); // 绘制缩小后的图 g.dispose(); // 输出为文件 ImageIO.write(tag, "JPEG", new File(descDir + "_r" + i + "_c" + j + ".jpg")); } } } } catch (Exception e) { e.printStackTrace(); } } /** * 图像类型转换：GIF->JPG、GIF->PNG、PNG->JPG、PNG->GIF(X)、BMP->PNG * * @param srcImageFile 源图像地址 (绝对路径) * @param formatName 包含格式非正式名称的 String：如JPG、JPEG、GIF等 * @param destImageFile 目标图像地址 (绝对路径) */ public final static void convert(String srcImageFile, String formatName, String destImageFile) { try { File f = new File(srcImageFile); f.canRead(); f.canWrite(); BufferedImage src = ImageIO.read(f); ImageIO.write(src, formatName, new File(destImageFile)); } catch (Exception e) { e.printStackTrace(); } } /** * 彩色转为黑白 * * @param srcImageFile 源图像地址 (绝对路径) * @param destImageFile 目标图像地址 (绝对路径) */ public final static void gray(String srcImageFile, String destImageFile) { try { BufferedImage src = ImageIO.read(new File(srcImageFile)); ColorSpace cs = ColorSpace.getInstance(ColorSpace.CS_GRAY); ColorConvertOp op = new ColorConvertOp(cs, null); src = op.filter(src, null); ImageIO.write(src, "JPEG", new File(destImageFile)); } catch (IOException e) { e.printStackTrace(); } } /** * 给图片添加文字水印 * * @param pressText 水印文字 * @param srcImageFile 源图像地址 (绝对路径) * @param destImageFile 目标图像地址 (绝对路径) * @param fontName 水印的字体名称 * @param fontStyle 水印的字体样式 * @param color 水印的字体颜色 * @param fontSize 水印的字体大小 * @param x 修正值 * @param y 修正值 * @param alpha 透明度：alpha 必须是范围 [0.0, 1.0] 之内（包含边界值）的一个浮点数字 */ public final static void pressText(String pressText, String srcImageFile, String destImageFile, String fontName, int fontStyle, Color color, int fontSize, int x, int y, float alpha) { try { File img = new File(srcImageFile); Image src = ImageIO.read(img); int width = src.getWidth(null); int height = src.getHeight(null); BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB); Graphics2D g = image.createGraphics(); g.drawImage(src, 0, 0, width, height, null); g.setColor(color); g.setFont(new Font(fontName, fontStyle, fontSize)); g.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_ATOP, alpha)); // 在指定坐标绘制水印文字 g.drawString(pressText, (width - (getLength(pressText) * fontSize)) / 2 + x, (height - fontSize) / 2 + y); g.dispose(); ImageIO.write((BufferedImage) image, "JPEG", new File(destImageFile));// 输出到文件流 } catch (Exception e) { e.printStackTrace(); } } /** * 给图片添加文字水印 * * @param pressText 水印文字 * @param srcImageFile 源图像地址 (绝对路径) * @param destImageFile 目标图像地址 (绝对路径) * @param fontName 字体名称 * @param fontStyle 字体样式 * @param color 字体颜色 * @param fontSize 字体大小 * @param x 修正值 * @param y 修正值 * @param alpha 透明度：alpha 必须是范围 [0.0, 1.0] 之内（包含边界值）的一个浮点数字 */ public final static void pressText2(String pressText, String srcImageFile, String destImageFile, String fontName, int fontStyle, Color color, int fontSize, int x, int y, float alpha) { try { File img = new File(srcImageFile); Image src = ImageIO.read(img); int width = src.getWidth(null); int height = src.getHeight(null); BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB); Graphics2D g = image.createGraphics(); g.drawImage(src, 0, 0, width, height, null); g.setColor(color); g.setFont(new Font(fontName, fontStyle, fontSize)); g.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_ATOP, alpha)); // 在指定坐标绘制水印文字 g.drawString(pressText, (width - (getLength(pressText) * fontSize)) / 2 + x, (height - fontSize) / 2 + y); g.dispose(); ImageIO.write((BufferedImage) image, "JPEG", new File(destImageFile)); } catch (Exception e) { e.printStackTrace(); } } /** * 给图片添加图片水印 * * @param pressImg 水印图片 (绝对路径) * @param srcImageFile 源图像地址 (绝对路径) * @param destImageFile 目标图像地址 (绝对路径) * @param x 修正值。 默认在中间 * @param y 修正值。 默认在中间 * @param alpha 透明度：alpha 必须是范围 [0.0, 1.0] 之内（包含边界值）的一个浮点数字 */ public final static void pressImage(String pressImg, String srcImageFile, String destImageFile, int x, int y, float alpha) { try { File img = new File(srcImageFile); Image src = ImageIO.read(img); int wideth = src.getWidth(null); int height = src.getHeight(null); BufferedImage image = new BufferedImage(wideth, height, BufferedImage.TYPE_INT_RGB); Graphics2D g = image.createGraphics(); g.drawImage(src, 0, 0, wideth, height, null); // 水印文件 Image src_biao = ImageIO.read(new File(pressImg)); int wideth_biao = src_biao.getWidth(null); int height_biao = src_biao.getHeight(null); g.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_ATOP, alpha)); g.drawImage(src_biao, (wideth - wideth_biao) / 2, (height - height_biao) / 2, wideth_biao, height_biao, null); // 水印文件结束 g.dispose(); ImageIO.write((BufferedImage) image, "JPEG", new File(destImageFile)); } catch (Exception e) { e.printStackTrace(); } } /** * 计算text的长度（一个中文算两个字符） * * @param text * @return */ public final static int getLength(String text) { int length = 0; for (int i = 0; i < text.length(); i++) { if (new String(text.charAt(i) + "").getBytes().length > 1) { length += 2; } else { length += 1; } } return length / 2; } }
注：如果在JQ中ajax方法没有执行，请检查Json返回的数据格式是否正确！