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JQ插件之imgAreaSelect实现对图片的在线截图功能(java版)

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

image

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({                    width: 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=http://www.mamicode.com/" + 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; width: 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; width: 300px; height: 300px;">            <img id="photo" src="img/605.jpg">        </div>    </div>    <div style="float: left; width: 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; width: 100px; height: 100px;">            <div id="preview" style="width: 100px; height: 100px; overflow: hidden;">                <img src="img/605.jpg" style="width: 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="width: 10%;"><b>X<sub>1</sub>:</b></td>                <td style="width: 30%;"><input type="text" id="x1" value="-"></td>                <td style="width: 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;width: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 = http://www.mamicode.com/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!

JQ插件之imgAreaSelect实现对图片的在线截图功能(java版)