头像上传裁剪预览功能-java

1.实现说明

原文是开源中国上的一个demo,文章最后给出原文链接,上面有源码。实现框架是:maven+springmvc+jcrop。需要的主要js和css文件为jquery.Jcrop.css,jquery.min.js,jquery.Jcrop.js。

2.一言不合上代码

2.1 controller层

import java.io.File;

import javax.servlet.http.HttpServletRequest;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.multipart.MultipartFile;

@Controller 
@RequestMapping("/UploadDemo")
public class UploadImgController {

    @RequestMapping(value = "/uploadHeadImage",method = RequestMethod.POST)
    public String uploadHeadImage(
            HttpServletRequest request,
            @RequestParam(value = "x") String x,
            @RequestParam(value = "y") String y,
            @RequestParam(value = "h") String h,
            @RequestParam(value = "w") String w,
            @RequestParam(value = "imgFile") MultipartFile imageFile
    ) throws Exception{
        System.out.println("==========Start=============");
        String realPath = request.getSession().getServletContext().getRealPath("/");
        String resourcePath = "resources/uploadImages/";
        if(imageFile!=null){
            if(FileUploadUtil.allowUpload(imageFile.getContentType())){
                String fileName = FileUploadUtil.rename(imageFile.getOriginalFilename());
                int end = fileName.lastIndexOf(".");
                String saveName = fileName.substring(0,end);
                File dir = new File(realPath + resourcePath);
                if(!dir.exists()){
                    dir.mkdirs();
                }
                File file = new File(dir,saveName+"_src.jpg");
                imageFile.transferTo(file);
                String srcImagePath = realPath + resourcePath + saveName;
                int imageX = Integer.parseInt(x);
                int imageY = Integer.parseInt(y);
                int imageH = Integer.parseInt(h);
                int imageW = Integer.parseInt(w);
                //这里开始截取操作
                System.out.println("==========imageCutStart=============");
                ImgCut.imgCut(srcImagePath,imageX,imageY,imageW,imageH);
                System.out.println("==========imageCutEnd=============");
                request.getSession().setAttribute("imgSrc",resourcePath + saveName+"_src.jpg");//成功之后显示用
                request.getSession().setAttribute("imgCut",resourcePath + saveName+"_cut.jpg");//成功之后显示用
            }
        }
        return "success";
    }

}


2.2 两个工具类

文件上传工具类:

import java.util.Arrays;
import java.util.Date;
import java.util.List;
import java.util.Random;

public class FileUploadUtil {
     public static final List ALLOW_TYPES = Arrays.asList(
                "image/jpg","image/jpeg","image/png","image/gif"
        );
    //文件重命名
        public static String rename(String fileName){
            int i = fileName.lastIndexOf(".");
            String str = fileName.substring(i);
            return new Date().getTime()+""+ new Random().nextInt(99999999) +str;
        }
    //校验文件类型是否是被允许的
        public static boolean allowUpload(String postfix){
            return ALLOW_TYPES.contains(postfix);
        }
}

图片裁剪工具类:
import java.awt.Graphics;
import java.awt.Image;
import java.awt.Toolkit;
import java.awt.image.BufferedImage;
import java.awt.image.CropImageFilter;
import java.awt.image.FilteredImageSource;
import java.awt.image.ImageFilter;
import java.io.File;

import javax.imageio.ImageIO;

public class ImgCut {
/**
* 截取图片
* @param srcImageFile 原图片地址
* @param x 截取时的x坐标
* @param y 截取时的y坐标
* @param desWidth 截取的宽度
* @param desHeight 截取的高度
*/
public static void imgCut(String srcImageFile, int x, int y, int desWidth,
int desHeight) {
try {
Image img;
ImageFilter cropFilter;
BufferedImage bi = ImageIO.read(new File(srcImageFile+”_src.jpg”));
int srcWidth = bi.getWidth();
int srcHeight = bi.getHeight();
if (srcWidth >= desWidth && srcHeight >= desHeight) {
Image image = bi.getScaledInstance(srcWidth, srcHeight,Image.SCALE_DEFAULT);
cropFilter = new CropImageFilter(x, y, desWidth, desHeight);
img = Toolkit.getDefaultToolkit().createImage(
new FilteredImageSource(image.getSource(), cropFilter));
BufferedImage tag = new BufferedImage(desWidth, desHeight,
BufferedImage.TYPE_INT_RGB);
Graphics g = tag.getGraphics();
g.drawImage(img, 0, 0, null);
g.dispose();
//输出文件
ImageIO.write(tag, “JPEG”, new File(srcImageFile+”_cut.jpg”));
}
} catch (Exception e) {
e.printStackTrace();
}
}
}

2.3 Jsp页面

index.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%>

<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>demotitle>
<link rel="stylesheet" href="resources/jcrop/css/jquery.Jcrop.css"/>" type="text/css">link>
<script type="text/javascript" src="resources/jcrop/js/jquery.min.js"/>">script>
<script type="text/javascript" src="resources/jcrop/js/jquery.Jcrop.js"/>">script>
head>
<body>
    <form name="form" action="<%=request.getContextPath()%>/UploadDemo/uploadHeadImage" class="form-horizontal" method="post" enctype="multipart/form-data">
        <div class="modal-body text-center">
            <div class="zxx_main_con">
                <div class="zxx_test_list">
                    <input class="photo-file" type="file" name="imgFile" id="fcupload" onchange="readURL(this);" />
                    <img alt="" src="" id="cutimg" /> 
                    <input type="hidden" id="x" name="x" /> 
                    <input type="hidden" id="y" name="y" /> 
                    <input type="hidden" id="w" name="w" /> 
                    <input type="hidden" id="h" name="h" />
                div>
            div>
        div>

        <div id="preview-pane">
            <div class="preview-container">
                <img src="" class="jcrop-preview" alt="预览">
            div>
        div>

        <div class="modal-footer">
            <button id="submit" onclick="">上传button>
        div>
    form>

    <script type="text/javascript">
        //定义一个全局api,这样操作起来比较灵活
        var api = null, 

        boundx, 
        boundy, 

        $preview = $('#preview-pane'), 
        $pcnt = $('#preview-pane .preview-container'), 
        $pimg = $('#preview-pane .preview-container img'),

        xsize = $pcnt.width(), 
        ysize = $pcnt.height();

        function readURL(input) {
            if (input.files && input.files[0]) {
                var reader = new FileReader();
                reader.readAsDataURL(input.files[0]);
                reader.onload = function(e) {
                    $('#cutimg').removeAttr('src');
                    $('#cutimg').attr('src', e.target.result);
                    $pimg.removeAttr('src');
                    $pimg.attr('src', e.target.result);

                    api = $.Jcrop('#cutimg', {
                        setSelect: [ 20, 20, 200, 200 ],
                        aspectRatio: 1,
                        onSelect: updateCoords,
                        onChange:updateCoords
                    });
                    var bounds = api.getBounds();
                    boundx = bounds[0];
                    boundy = bounds[1];
                    $preview.appendTo(api.ui.holder);
                };
                if (api != undefined) {
                    api.destroy();
                }
            }
            function updateCoords(obj) {
                $("#x").val(obj.x);
                $("#y").val(obj.y);
                $("#w").val(obj.w);
                $("#h").val(obj.h);
                if (parseInt(obj.w) > 0) {
                    var rx = xsize / obj.w;
                    var ry = ysize / obj.h;
                    $pimg.css({
                        width : Math.round(rx * boundx) + 'px',
                        height : Math.round(ry * boundy) + 'px',
                        marginLeft : '-' + Math.round(rx * obj.x) + 'px',
                        marginTop : '-' + Math.round(ry * obj.y) + 'px'
                    });
                }
            }
            ;
        }
    script>
body>
html>

原文链接:http://my.oschina.net/zhengweishan/blog/700677。

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