功能描述:點擊用戶頭像,彈出一個圖片裁剪的modal,提交後,java後端保存裁剪後的圖片,然後返回該圖片url給前端顯示。Cropper官網及下載
Cropper依賴於jquery、bootstrap。
1.Java核心圖片裁剪工具類 ImageCut.java
package com.jykj.demo.util;
import java.io.*;
import java.awt.*;
import java.awt.image.*;
import java.awt.Graphics;
import java.awt.color.ColorSpace;
import javax.imageio.ImageIO;
public class ImageCut {
/**
* 圖像切割(改) *
* @param srcImageFile 源圖像地址
* @param dirImageFile 新圖像地址
* @param x 目標切片起點x座標
* @param y 目標切片起點y座標
* @param destWidth 目標切片寬度
* @param destHeight 目標切片高度
*/
public static void abscut(String srcImageFile,String dirImageFile, int x, int y, int destWidth,
int destHeight) {
try {
Image img;
ImageFilter cropFilter;
// 讀取源圖像
BufferedImage bi = ImageIO.read(new File(srcImageFile));
int srcWidth = bi.getWidth(); // 源圖寬度
int srcHeight = bi.getHeight(); // 源圖高度
if (srcWidth >= destWidth && srcHeight >= destHeight) {
Image image = bi.getScaledInstance(srcWidth, srcHeight,
Image.SCALE_DEFAULT);
// 改進的想法:是否可用多線程加快切割速度
// 四個參數分別爲圖像起點座標和寬高
// 即: CropImageFilter(int x,int y,int width,int height)
cropFilter = new CropImageFilter(x, y, 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); // 繪製縮小後的圖
g.dispose();
// 輸出爲文件
ImageIO.write(tag, "JPEG", new File(dirImageFile));
}
} catch (Exception e) {
e.printStackTrace();
}
}
public static void cut(InputStream is,File dirImageFile, int x, int y, int destWidth,
int destHeight) throws IOException {
cut(ImageIO.read(is),dirImageFile,x,y,destWidth,destHeight);
}
public static void cut(BufferedImage bi,File dirImageFile, int x, int y, int destWidth,
int destHeight) {
try {
Image img;
ImageFilter cropFilter;
// 讀取源圖像
int srcWidth = bi.getWidth(); // 源圖寬度
int srcHeight = bi.getHeight(); // 源圖高度
if (srcWidth >= destWidth && srcHeight >= destHeight) {
Image image = bi.getScaledInstance(srcWidth, srcHeight,
Image.SCALE_DEFAULT);
// 改進的想法:是否可用多線程加快切割速度
// 四個參數分別爲圖像起點座標和寬高
// 即: CropImageFilter(int x,int y,int width,int height)
cropFilter = new CropImageFilter(x, y, 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); // 繪製縮小後的圖
g.dispose();
// 輸出爲文件
ImageIO.write(tag, "JPEG", dirImageFile);
}
} catch (Exception e) {
e.printStackTrace();
}
}
/**
* 縮放圖像
*
* @param srcImageFile 源圖像文件地址
* @param result 縮放後的圖像地址
* @param scale 縮放比例
* @param flag 縮放選擇:true 放大; false 縮小;
*/
public static void scale(String srcImageFile, String result, int scale,
boolean flag) {
try {
BufferedImage src = ImageIO.read(new File(srcImageFile)); // 讀入文件
int width = src.getWidth(); // 得到源圖寬
int height = src.getHeight(); // 得到源圖長
if (flag) {
// 放大
width = width * scale;
height = height * scale;
} else {
// 縮小
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); // 繪製縮小後的圖
g.dispose();
ImageIO.write(tag, "JPEG", new File(result));// 輸出到文件流
} catch (IOException e) {
e.printStackTrace();
}
}
/**
* 重新生成按指定寬度和高度的圖像
* @param srcImageFile 源圖像文件地址
* @param result 新的圖像地址
* @param _width 設置新的圖像寬度
* @param _height 設置新的圖像高度
*/
public static void scale(String srcImageFile, String result, int _width,int _height) {
scale(srcImageFile,result,_width,_height,0,0);
}
public static void scale(String srcImageFile, String result, int _width,int _height,int x,int y) {
try {
BufferedImage src = ImageIO.read(new File(srcImageFile)); // 讀入文件
int width = src.getWidth(); // 得到源圖寬
int height = src.getHeight(); // 得到源圖長
if (width > _width) {
width = _width;
}
if (height > _height) {
height = _height;
}
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, x, y, null); // 繪製縮小後的圖
g.dispose();
ImageIO.write(tag, "JPEG", new File(result));// 輸出到文件流
} catch (IOException e) {
e.printStackTrace();
}
}
/**
* 圖像類型轉換 GIF->JPG GIF->PNG PNG->JPG PNG->GIF(X)
*/
public static void convert(String source, String result) {
try {
File f = new File(source);
f.canRead();
f.canWrite();
BufferedImage src = ImageIO.read(f);
ImageIO.write(src, "JPG", new File(result));
} catch (Exception e) {
e.printStackTrace();
}
}
/**
* 彩色轉爲黑白
*
* @param source
* @param result
*/
public static void gray(String source, String result) {
try {
BufferedImage src = ImageIO.read(new File(source));
ColorSpace cs = ColorSpace.getInstance(ColorSpace.CS_GRAY);
ColorConvertOp op = new ColorConvertOp(cs, null);
src = op.filter(src, null);
ImageIO.write(src, "JPEG", new File(result));
} catch (IOException e) {
e.printStackTrace();
}
}
}
2. Java後端圖片裁剪處理(Controller)
//圖片裁剪功能
@RequestMapping(value = "/imgCut.do",method = RequestMethod.POST, produces="text/html;charset=utf-8")
@ResponseBody
public String profile_imgCut(MultipartFile avatar_file,String avatar_src,String avatar_data, HttpServletRequest request, Model model) {
String dir = ConfigInfo.resources_upload_path;
String path = request.getSession().getServletContext().getRealPath(dir);
String name = avatar_file.getOriginalFilename();
//判斷文件的MIMEtype
String type = avatar_file.getContentType();
if(type==null || !type.toLowerCase().startsWith("image/")) return JSON.toJSONString(new Result(false,"不支持的文件類型,僅支持圖片!"));
System.out.println("file type:"+type);
String fileName = new Date().getTime()+""+new Random().nextInt(10000)+"_"+name.substring(name.lastIndexOf('.'));
System.out.println("文件路徑:"+path+":"+fileName);
JSONObject joData = (JSONObject) JSONObject.parse(avatar_data);
// 用戶經過剪輯後的圖片的大小
float x = joData.getFloatValue("x");
float y = joData.getFloatValue("y");
float w = joData.getFloatValue("width");
float h = joData.getFloatValue("height");
//開始上傳
File targetFile = new File(path, fileName);
//保存
try {
if(!targetFile.exists()){
targetFile.mkdirs();
InputStream is = avatar_file.getInputStream();
ImageCut.cut(is, targetFile, (int)x,(int)y,(int)w,(int)h);
is.close();
}
} catch (Exception e) {
e.printStackTrace();
return JSON.toJSONString(new Result(false,"上傳失敗,出現異常:"+e.getMessage()));
}
return JSON.toJSONString(new Result(true,"上傳成功!",request.getSession().getServletContext().getContextPath()+dir+fileName));
}
3. 前端form提交(test.html)
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<title>TEST</title>
<!-- Tell the browser to be responsive to screen width -->
<meta content="width=device-width, initial-scale=1, maximum-scale=1, user-scalable=no" name="viewport">
<link rel="stylesheet" href="${request.contextPath}/resources/bootstrap/css/bootstrap.min.css">
<link rel="stylesheet" href="${request.contextPath}/resources/cropper/cropper.min.css"/>
<link rel="stylesheet" href="${request.contextPath}/resources/cropper/crop-avatar/css/main.css"/>
</head>
<body>
<div class="container" id="crop-avatar">
<!-- Current avatar -->
<div class="avatar-view" title="Change the avatar">
<img src="${request.contextPath}/resources/cropper/crop-avatar/img/picture.jpg" alt="Avatar">
</div>
<!-- Cropping modal -->
<div class="modal fade" id="avatar-modal" aria-hidden="true" aria-labelledby="avatar-modal-label" role="dialog" tabindex="-1">
<div class="modal-dialog modal-lg">
<div class="modal-content">
<form class="avatar-form" action="imgCut.do" enctype="multipart/form-data" method="post" accept="image/*">
<div class="modal-header">
<button type="button" class="close" data-dismiss="modal">×</button>
<h4 class="modal-title" id="avatar-modal-label">Change Avatar</h4>
</div>
<div class="modal-body">
<div class="avatar-body">
<!-- Upload image and data -->
<div class="avatar-upload">
<input type="hidden" class="avatar-src" name="avatar_src">
<input type="hidden" class="avatar-data" name="avatar_data">
<label for="avatarInput" class="btn btn-primary">選擇圖片</label>
<input type="file" class="avatar-input" id="avatarInput" name="avatar_file" style="display: none;" accept="image/*">
</div>
<!-- Crop and preview -->
<div class="row">
<div class="col-md-9">
<div class="avatar-wrapper"></div>
</div>
<div class="col-md-3">
<div class="avatar-preview preview-lg"></div>
<div class="avatar-preview preview-md"></div>
<div class="avatar-preview preview-sm"></div>
</div>
</div>
<div class="row avatar-btns">
<div class="col-md-9">
<div class="btn-group">
<button type="button" class="btn btn-primary" data-method="rotate" data-option="-90" title="Rotate -90 degrees">Rotate Left</button>
<button type="button" class="btn btn-primary" data-method="rotate" data-option="-15">-15deg</button>
<button type="button" class="btn btn-primary" data-method="rotate" data-option="-30">-30deg</button>
<button type="button" class="btn btn-primary" data-method="rotate" data-option="-45">-45deg</button>
</div>
<div class="btn-group">
<button type="button" class="btn btn-primary" data-method="rotate" data-option="90" title="Rotate 90 degrees">Rotate Right</button>
<button type="button" class="btn btn-primary" data-method="rotate" data-option="15">15deg</button>
<button type="button" class="btn btn-primary" data-method="rotate" data-option="30">30deg</button>
<button type="button" class="btn btn-primary" data-method="rotate" data-option="45">45deg</button>
</div>
</div>
<div class="col-md-3">
<button type="submit" class="btn btn-primary btn-block avatar-save">Done</button>
</div>
</div>
</div>
</div>
<!-- <div class="modal-footer">
<button type="button" class="btn btn-default" data-dismiss="modal">Close</button>
</div> -->
</form>
</div>
</div>
</div><!-- /.modal -->
<!-- Loading state -->
<div class="loading" aria-label="Loading" role="img" tabindex="-1"></div>
</div>
<!-- jQuery -->
<script src="${request.contextPath}/resources/plugins/jQuery/jquery-2.2.4.min.js"></script>
<script src="${request.contextPath}/resources/bootstrap/js/bootstrap.min.js"></script>
<script src="${request.contextPath}/resources/cropper/cropper.min.js"></script>
<script src="${request.contextPath}/resources/cropper/crop-avatar/js/main.js"></script>
</body>
</html>
注意:從Cropper官網上下載下來後,在examples目錄下有一個示例crop-avatar,將其中的main.css以及main.js複製到你的項目中,Cropper是依賴於jquery以及bootstrap的,所以也要把相應的css和js引進來。
4. 頁面展示效果
點擊頭像,彈出modal。點擊Done提交form後生成目標裁剪圖片保存到服務器,並返回給頁面顯示。
5.配置文件上傳
由於上面圖片裁剪涉及到圖片上傳,所以需要配置Spring支持文件上傳功能。
5.1 依賴的jar
<!-- https://mvnrepository.com/artifact/commons-fileupload/commons-fileupload -->
<dependency>
<groupId>commons-fileupload</groupId>
<artifactId>commons-fileupload</artifactId>
<version>1.3.1</version>
</dependency>
5.2 在Spring配置文件中添加文件上傳支持
<!-- 支持上傳文件 -->
<bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver"/>
6. 說明
Cropper 使用的是html5的一個新特性(FormData)來提交表單,在其main.js文件中有這樣一行代碼:
var data = new FormData(this.$avatarForm[0]);
這本質上也就是對錶單進行了序列化。Cropper同時也支持旋轉,只是在後臺處理旋轉會比較麻煩點。
前端form提交的數據有 :avatar_file(源文件),avatar_data(裁剪參數JSON),如下通過FormData序列化後所提交的form的數據,後臺控制器參數名只要對上就可以了:
------WebKitFormBoundaryx52DDecBJ0KiNHRY
Content-Disposition: form-data; name="avatar_src"
------WebKitFormBoundaryx52DDecBJ0KiNHRY
Content-Disposition: form-data; name="avatar_data"
{"x":76.49999999999999,"y":22.000000000000007,"height":176.00000000000003,"width":176.00000000000003,"rotate":0}
------WebKitFormBoundaryx52DDecBJ0KiNHRY
Content-Disposition: form-data; name="avatar_file"; filename="3.jpg"
Content-Type: image/jpeg
------WebKitFormBoundaryx52DDecBJ0KiNHRY--
另外Result是自定義的類,很簡單:
public class Result {
private boolean success;
private String info;
private Object data;//也可用來標識錯誤代碼
... 此處省略get和set方法
}
用到的JSON,當然可以用其他的JSON的jar包:
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>fastjson</artifactId>
<version>1.2.12</version>
</dependency>