js如何获取本地图片显示到浏览器并上传至服务器

零到壹度 原创: 2018-04-21 14:53:17 10060浏览

这篇文章介绍的内容是关于浏览器显示本地图片的预览图，调用后端接口将图片上传至服务器，有着一定的参考价值，现在分享给大家，有需要的朋友可以参考一下

一、jsp页面

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%><%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%><!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"><html>
    <head>
        <title></title>
        <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
        <META HTTP-EQUIV="pragma" CONTENT="no-cache"> 
        <META HTTP-EQUIV="Cache-Control" CONTENT="no-cache, must-revalidate"> 
        <META HTTP-EQUIV="expires" CONTENT="0">
        <!-- 引入js -->
        <script type="text/javascript" src="<%=request.getContextPath()%>/js/jquery.js"></script>
        <script type="text/javascript" src="<%=request.getContextPath()%>/js/jquery.min.js"></script>
    <body>

        <p id="enteringInfor">

            <form id="uploadForm" >

               <p class="formItem" style="float:left">
                   <p class="itemBlock">
                        <p style="display:inline-block;float:left" class="selectContainer">
                            <span class="txtBox">姓名</span>
                            <input type="text" class="select"  name="realName" id="realName"  placeholder="请输入姓名" style="width:200px;">
                        </p>
                    </p>
                    <p class="itemBlock">
                         <p style="display:inline-block;float:left" class="selectContainer">
                            <span class="txtBox">性别</span>
                            <select class="select" name="gender" id="gender" >
                                <option value="1">男</option>
                                <option value="2">女</option>
                            </select>
                        </p>
                    </p>
                </p>

                <p class="formItem" style="float:right;margin-top:50px;">
                    <p class="picture">
                        <p class="layui-upload">
                            <p class="layui-upload-list" id="localImag">
                                <img class="layui-upload-img" id="userPic" style="width:330px;height:410px">
                                <p id="demoText"></p>
                            </p>
                            <p class="btn btn-primary fileinput-button"  style="width:332px;position:absolute;bottom:0px">
                                <span class="uploadTxt">上传图片</span>
                                <input class="form-control layui-btn" id="entrustPicUpload" type="file" name="entImg" onchange="getPhoto(this)"  />
                            </p>
                        </p> 
                     </p>
                </p>

            </form>

            <p class="modelEditorBottom" style="padding-left:24px;text-align:center;height:70px;line-height:70px;border:none;width:100%;overflow:hidden;zoom:1">
                <button class="buttons adminButton" onclick="saveUser()">保存</button>
            </p>

            <input type="hidden" name="userId" id="userId"/>
        </p><script>
    var imgurl = "";  
    function getPhoto(node) {  
        var imgURL = "";  
        try{  
            var file = null;  
            if(node.files && node.files[0] ){  
                file = node.files[0];  
            }else if(node.files && node.files.item(0)) {  
                file = node.files.item(0);  
            }  
            //Firefox 因安全性问题已无法直接通过input[file].value 获取完整的文件路径  
            try{  
                imgURL =  file.getAsDataURL();  
            }catch(e){  
                imgRUL = window.URL.createObjectURL(file);  
            }  
        }catch(e){  
            if (node.files && node.files[0]) {  
                var reader = new FileReader();  
                reader.onload = function (e) {  
                    imgURL = e.target.result;  
                };  
                reader.readAsDataURL(node.files[0]);  
            }  
        }
        creatImg(imgRUL);//显示图片
        return imgURL;  
    }  
    function creatImg(imgRUL){  
        document.getElementById("userPic").src = imgRUL;
        $('#userPic').viewer({
            url: 'src',
        });
    } 

    //保存
    function saveUser(){
        //数据判断
        var realName=$("#realName").val();        if(realName==null||realName==''){
            layer.msg('用户名不能为空!',{icon : 7,time:1000});            return ;
        }        var imgSrc = $("#userPic").attr("src");        if(imgSrc == "" || imgSrc==null){
            layer.msg('请上传图片!',{icon : 7,time:1000});            return ;
        }        var formData = new FormData($("#uploadForm")[0]);
        $.ajax({  
            url : "../addUser",  
            type: 'POST',  
            data: formData,  
            async: false,  
            cache: false,  
            contentType: false,  
            processData: false, 
            success : function(data) {
                var obj =  JSON.parse(data);
                layer.msg('保存成功!', {icon : 6,time : 2000});
            },  
            error : function(data) {  
                layer.msg('保存失败!', {icon : 5,time : 2000});
            }
        }); 
    }    </script>
    </body></html>

二、controller接口

/** 
     * 添加用户
     * @param session
     * @param request
     * @param response
     * @throws IOException
     */
    @RequestMapping(value = "/addUser", method = RequestMethod.POST)    
    public void addUser(MultipartFile entImg,HttpSession session, HttpServletRequest request, HttpServletResponse response)       
                throws IOException {
        String realName = request.getParameter("realName");//姓名
        String gender = request.getParameter("gender");// 性别

        //调用工具类上传图片
        String userPic = FileUtils.uploadUser(entImg, request);

        TestUser testUser = new TestUser();
        testUser.setRealName(realName);
        testUser.setGender(Integer.parseInt(gender));
        testUser.setUserPic(userPic);        // 添加人员信息及图片url到数据库
        int res= userService.insertUser(testUser);        if (res > 0) {
            writeJSON(response, res);
        } else {
            writeJSON(response,null);
        }

    }

三、工具类

public class FileUtils {

    FILES_PATH("files_path"); // 此路径存放于jdbc.properties配置文件中，例如：files_path=D:/uploadImgs
    private static final String path = PropertiesUtil.get(FILES_PATH)+"/user";    /**
     * 上传图片URL
     * @param fileName
     * @param request
     * @return
     */
    public static String getPath(String fileName,HttpServletRequest request) {
        String ip=IpUtil.getIP();        int port=request.getLocalPort();
        StringBuilder sb=new StringBuilder();
        sb.append("http://");
        sb.append(ip);
        sb.append(":");
        sb.append(port);
        sb.append("/uploadImgs/user/");
        sb.append(fileName);        return sb.toString();
    }    /**
     * 以时间戳对上传文件进行重新命名
     * @param file
     * @return
     */
    public static String renameFile(MultipartFile file) {        if(file!=null) {
            Long date=new Date().getTime();
            String fileRealName=file.getOriginalFilename();
            String prefix=fileRealName.substring(fileRealName.lastIndexOf(".")+1);
            String fileName = date.toString()+"."+prefix;  
            return fileName;
        }        return null;
    }    /**
     * 图片上传
     * @param file
     * @param fileName
     */
    public static String uploadUser(MultipartFile file, HttpServletRequest request) {        // 重命名
        String renameFile = FileUtils.renameFile(file);        // 图片名
        String picPath = FileUtils.getPath(renameFile, request);        // 上传
        File targetFile = new File(borpath, renameFile);        if (!targetFile.exists() && !targetFile.isDirectory()) {
            targetFile.mkdirs();
        }        try {
            file.transferTo(targetFile);
        } catch (Exception e) {
            e.printStackTrace();
        }        return picPath;

    }


}

四、效果
这里写图片描述