Spring MVC 实现Excel的导入导出功能(2：Excel的导入优化和Excel的导出)

Excel的导入V2优化版

有些时候文件上传这一步骤由前端来处理，只将上传后的 URL 传输给后端（可以参考上一文中的图片上传功能），也就是导入请求中并不会直接处理 MultipartFile 对象，而是通过文件 URL 将其下载，之后进行文件流处理，具体过程如下：

点击 “ 导入V2 ” 按钮，与 V1 按钮不同，此时出现的不是文件选择框，而是一个上传文件的弹框，点击弹框里的 “ 上传 Excel 文件 ” 按钮才会出现文件选择框，选择正确的文件后点击确定，请求完成后同 V1 版本的导入功能效果一样。

前端实现

HTML页面

<!-- Main content -->
    <div class="content">
        <div class="row">
            <div class="col-12">
                <div class="card">
                    <div class="card-body">
                        <div class="grid-btn">
                            <button class="btn btn-info" onclick="userAdd()">
                                <i class="fa fa-plus"></i>&nbsp;新增
                            </button>
                            <button class="btn btn-success" onclick="userEdit()">
                                <i class="fa fa-plus"></i>&nbsp;编辑
                            </button>
                            <button class="btn btn-danger" onclick="deleteUser()">
                                <i class="fa fa-remove"></i>&nbsp;删除
                            </button>
                            <button class="btn btn-default" id="importV1Button">
                                <i class="fa fa-upload"></i>&nbsp;导入ExcelV1
                            </button>
                            <button class="btn btn-default" onclick="importV2()"><i
                                    class="fa fa-upload"></i>&nbsp;导入ExcelV2
                            </button>
                            <button class="btn btn-primary" onclick="window.location.href='/users/export'">
                                <i class="fa fa-download"></i> 导出
                            </button>
                        </div>
                        <table id="jqGrid" class="table table-bordered">
                        </table>
                        <div id="jqGridPager"></div>
                    </div>
                </div>
            </div>
        </div>
    </div>
</div>

HTML模态框(这里用的是Custombox)

<!--导入Excel模态框-->
    <div class="content">
        <div class="modal" id="importV2Modal" tabindex="-1" role="dialog" aria-labelledby="importV2ModalLabel">
            <div class="modal-dialog" role="document">
                <div class="modal-content">
                    <div class="modal-header">
                        <h6 class="modal-title" id="importV2ModalLabel">用户导入</h6>
                    </div>

                    <div class="modal-body">
                        <div class="form-group">
                            <input type="hidden" id="fileUrl" value="">
                            <div class="col-sm-10">
                                <a class="btn btn-default" id="uploadExcelV2">
                                    <i class="fa fa-file">
                                        上传Excel文件
                                    </i>
                                </a>
                            </div>
                        </div>
                    </div>
                    <div class="modal-footer">
                        <button type="button" class="btn btn-default" id="cancelImportV2">取消</button>
                        <button type="button" class="btn btn-primary" id="importV2Button">确认</button>
                    </div>
                </div>
            </div>
        </div>
    </div>

导入的JS

// 用户导入V2
function importV2() {
    var modal = new Custombox.modal({
        content: {
            effect: 'fadein',
            target: '#importV2Modal'
        }
    });
    modal.open();
}

    new AjaxUpload('#uploadExcelV2', {
        action: 'upload/file',
        name: 'file',
        autoSubmit: 'true',
        responseType: 'json',
        onSubmit: function (file, extension) {
            if (!(extension && /^(xlsx)$/.test(extension.toLowerCase()))) {
                alert('只支持xlsx格式的文件！', {
                    icon: "error",
                });
                return false;
            }
        },
        onComplete: function (file, r) {
            if (r.resultCode == 200) {
                $("#fileUrl").val(r.data);
                $("#uploadExcelV2").attr('class','btn-info');
                alert("上传Excel成功，请点击确认添加数据");
                return false;
            } else {
                alert(r.message);
            }
        }
    });
});

这里还是通过上传获取文件的url再通过流处理转换成File类型并把对应的Excel下载到服务器，其他的和V1版本是一样的

当点击确定导入的时候，如果之前上传没错，再访问一次后台

$("#importV2Button").click(function () {
    var fileUrl = $("#fileUrl").val();
    $.ajax({
        type: 'post',
        dataType: 'json',
        url: 'users/importV2?fileUrl=' + fileUrl,
        contentType:'application/json',
        success:function (result) {
                if (result.resultCode==200){
                    closeModal();
                    reload();
                    alert("成功导入"+result.data+"条记录！");
                }else {
                    closeModal();
                    alert(result.message);
                };
        },
        error:function () {
            reset();
            alert("操作失败！");
        }
    });
});

后端逻辑

控制层

package com.ssm.demo.controller;

import com.ssm.demo.common.Result;
import com.ssm.demo.common.ResultGenerator;
import com.ssm.demo.controller.enums.UploadFileTypeEnum;
import com.ssm.demo.utils.FileUtil;
import org.apache.commons.io.FileUtils;
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.bind.annotation.ResponseBody;
import org.springframework.web.multipart.MultipartFile;

import javax.servlet.ServletContext;
import javax.servlet.http.HttpServletRequest;
import java.io.File;
import java.io.IOException;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Random;

import static com.ssm.demo.common.Constants.FILE_PRE_URL;

/**
 * Created by 13 on 2017/7/17.
 */
@Controller
@RequestMapping("/upload")
public class UploadFileController {

    /**
     * 通用 文件上传接口(可以上传图片、视频、excel等文件，具体格式可在UploadFileTypeEnum中进行配置)
     *
     * @return
     */
    @RequestMapping(value = "/file", method = RequestMethod.POST)
    @ResponseBody
    public Result uploadFile(HttpServletRequest request, @RequestParam("file") MultipartFile file) {
        ServletContext sc = request.getSession().getServletContext();
        String type = file.getOriginalFilename().substring(file.getOriginalFilename().lastIndexOf(".") + 1, file.getOriginalFilename().length());
        String fileName = null;
        UploadFileTypeEnum uploadFileTypeEnum = UploadFileTypeEnum.getFileEnumByType(type);
        if (uploadFileTypeEnum == UploadFileTypeEnum.ERROR_TYPE) {
            //格式错误则不允许上传，直接返回错误提示
            return ResultGenerator.genFailResult("请检查文件格式！");
        } else {
            //生成文件名称通用方法
            SimpleDateFormat sdf = new SimpleDateFormat("yyyyMMdd_HHmmss");
            Random r = new Random();
            StringBuilder tempName = new StringBuilder();
            tempName.append(sdf.format(new Date())).append(r.nextInt(100)).append(".").append(type);
            fileName = tempName.toString();
        }
        try {
            String dir = sc.getRealPath("/upload");
            FileUtils.writeByteArrayToFile(new File(dir, fileName), file.getBytes());
        } catch (IOException e) {
            //文件上传异常
            return ResultGenerator.genFailResult("文件上传失败！");
        }
        Result result = ResultGenerator.genSuccessResult();
        //返回文件的全路径
        StringBuilder fileUrl = new StringBuilder();
        fileUrl.append(FILE_PRE_URL).append("/upload/").append(fileName);
        result.setData(fileUrl.toString());
        return result;
    }

    /**
     * @param chunks 当前所传文件的分片总数
     * @param chunk  当前所传文件的当前分片数
     * @return
     * @Description: 大文件上传前分片检查
     * @author: 13
     */
    @ResponseBody
    @RequestMapping(value = "/checkChunk")
    public Result checkChunk(HttpServletRequest request, String guid, Integer chunks, Integer chunk, String fileName) {
        try {
            String uploadDir = FileUtil.getRealPath(request);
            String ext = fileName.substring(fileName.lastIndexOf("."));
            // 判断文件是否分块
            if (chunks != null && chunk != null) {
                //文件路径
                StringBuilder tempFileName = new StringBuilder();
                tempFileName.append(uploadDir).append(File.separator).append("temp").append(File.separator).append(guid).append(File.separator).append(chunk).append(ext);
                File tempFile = new File(tempFileName.toString());
                //是否已存在分片,如果已存在分片则返回SUCCESS结果
                if (tempFile.exists()) {
                    return ResultGenerator.genSuccessResult("分片已经存在！跳过此分片！");
                }
            }
        } catch (Exception ex) {
            ex.printStackTrace();
            return ResultGenerator.genFailResult("error");
        }
        return ResultGenerator.genNullResult("不存在分片");
    }

    /**
     * @param chunks 当前所传文件的分片总数
     * @param chunk  当前所传文件的当前分片数
     * @return
     * @Description: 大文件分片上传
     * @author: 13
     */
    @ResponseBody
    @RequestMapping(value = "/files")
    public Result upload(HttpServletRequest request, String guid, Integer chunks, Integer chunk, String name, MultipartFile file) {
        String filePath = null;
        //上传存储路径
        String uploadDir = FileUtil.getRealPath(request);
        //后缀名
        String ext = name.substring(name.lastIndexOf("."));
        StringBuilder tempFileName = new StringBuilder();
        //等价于 uploadDir + "\\temp\\" + guid + "\\" + chunk + ext
        tempFileName.append(uploadDir).append(File.separator).append("temp").append(File.separator).append(guid).append(File.separator).append(chunk).append(ext);
        File tempFile = new File(tempFileName.toString());
        // 判断文件是否分块
        if (chunks != null && chunk != null) {
            //根据guid 创建一个临时的文件夹
            if (!tempFile.exists()) {
                tempFile.mkdirs();
            }
            try {
                //保存每一个分片
                file.transferTo(tempFile);
            } catch (Exception e) {
                e.printStackTrace();
            }
            //如果当前是最后一个分片，则合并所有文件
            if (chunk == (chunks - 1)) {
                StringBuilder tempFileFolder = new StringBuilder();
                //等价于 uploadDir + "\\temp\\" + guid + File.separator
                tempFileFolder.append(uploadDir).append(File.separator).append("temp").append(File.separator).append(guid).append(File.separator);
                String newFileName = FileUtil.mergeFile(chunks, ext, tempFileFolder.toString(), request);
                filePath = "upload/chunked/" + newFileName;
            }
        } else {
            //不用分片的文件存储到files文件夹中
            StringBuilder destPath = new StringBuilder();
            destPath.append(uploadDir).append(File.separator).append("files").append(File.separator);
            String newName = System.currentTimeMillis() + ext;// 文件新名称
            try {
                FileUtil.saveFile(destPath.toString(), newName, file);
            } catch (IOException e) {
                e.printStackTrace();
            }
            filePath = "upload/files/" + newName;
        }
        Result result = ResultGenerator.genSuccessResult();
        result.setData(filePath);
        return result;
    }
}

FileUtil工具类

package com.ssm.demo.utils;

import org.apache.commons.io.FileUtils;
import org.springframework.web.multipart.MultipartFile;

import javax.servlet.ServletContext;
import javax.servlet.http.HttpServletRequest;
import java.io.*;
import java.net.URL;
import java.net.URLConnection;
import java.util.UUID;

public class FileUtil {
    /**
     * 转换MultipartFile对象为java.io.File类型
     *
     * @param multipartFile
     * @return
     */
    public static File convertMultipartFileToFile(MultipartFile multipartFile) {
        File result = null;
        try {
            /**
             * UUID.randomUUID().toString()是javaJDK提供的一个自动生成主键的方法。
             * UUID(Universally Unique Identifier)全局唯一标识符,是指在一台机器上生成的数字，
             * 它保证对在同一时空中的所有机器都是唯一的，是由一个十六位的数字组成,表现出来的形式。
             * 由以下几部分的组合：当前日期和时间(UUID的第一个部分与时间有关，如果你在生成一个UUID之后，
             * 过几秒又生成一个UUID，则第一个部分不同，其余相同)，时钟序列，
             * 全局唯一的IEEE机器识别号（如果有网卡，从网卡获得，没有网卡以其他方式获得），
             * UUID的唯一缺陷在于生成的结果串会比较长。
             *
             *
             * File.createTempFile和File.createNewFile()的区别：
             *  后者只是创建文件，而前者可以给文件名加前缀和后缀
             */
            //这里对生成的文件名加了UUID随机生成的前缀,后缀是null
            result = File.createTempFile(UUID.randomUUID().toString(), null);
            multipartFile.transferTo(result);
            result.deleteOnExit();
        } catch (Exception e) {
            e.printStackTrace();
        }
        return result;
    }

    /**
     * 根据url获取文件对象
     *
     * @param fileUrl
     * @return
     */
    public static File downloadFile(String fileUrl) {
        File result = null;
        try {
            result = File.createTempFile(UUID.randomUUID().toString(), null);
            URL url = new URL(fileUrl);
            URLConnection connection = url.openConnection();
            connection.setConnectTimeout(3000);
            BufferedInputStream bis = new BufferedInputStream(connection.getInputStream());
            BufferedOutputStream bos = new BufferedOutputStream(new FileOutputStream(result));
            byte[] car = new byte[1024];
            int l = 0;
            while ((l = bis.read(car)) != -1) {
                bos.write(car, 0, l);
            }
            bis.close();
            bos.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
        return result;
    }

    /**
     * @param request
     * @return
     */
    public static String getRealPath(HttpServletRequest request) {
        ServletContext sc = request.getSession().getServletContext();
        String uploadDir = sc.getRealPath("/upload");
        return uploadDir;
    }

    public static boolean saveFile(String savePath, String fileFullName, MultipartFile file) throws IOException {
        File uploadFile = new File(savePath + fileFullName);
        FileUtils.writeByteArrayToFile(new File(savePath, fileFullName), file.getBytes());
        return uploadFile.exists();
    }

    public static String mergeFile(int chunksNumber, String ext, String uploadFolderPath,
                                   HttpServletRequest request) {
        //合并分片流
        String mergePath = uploadFolderPath;
        String destPath = getRealPath(request);// 文件路径
        String newName = System.currentTimeMillis() + ext;// 文件新名称
        SequenceInputStream s;
        InputStream s1;
        try {
            s1 = new FileInputStream(mergePath + 0 + ext);
            String tempFilePath;
            InputStream s2 = new FileInputStream(mergePath + 1 + ext);
            s = new SequenceInputStream(s1, s2);
            for (int i = 2; i < chunksNumber; i++) {
                tempFilePath = mergePath + i + ext;
                InputStream s3 = new FileInputStream(tempFilePath);
                s = new SequenceInputStream(s, s3);
            }
            //分片文件存储到/upload/chunked目录下
            StringBuilder filePath = new StringBuilder();
            filePath.append(destPath).append(File.separator).append("chunked").append(File.separator);
            saveStreamToFile(s, filePath.toString(), newName);
            // 删除保存分块文件的文件夹
            deleteFolder(mergePath);
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (Exception e) {
            e.printStackTrace();
        }
        return newName;
    }

    private static boolean deleteFolder(String mergePath) {
        File dir = new File(mergePath);
        File[] files = dir.listFiles();
        if (files != null) {
            for (File file : files) {
                try {
                    file.delete();
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        }
        return dir.delete();
    }

    private static void saveStreamToFile(SequenceInputStream inputStream, String filePath, String newName)
            throws Exception {
        File fileDirectory = new File(filePath);
        synchronized (fileDirectory) {
            if (!fileDirectory.exists()) {
                if (!fileDirectory.mkdir()) {
                    throw new Exception("文件夹创建失败,路径为：" + fileDirectory);
                }
            }
            if (!fileDirectory.exists()) {
                if (!fileDirectory.mkdir()) {
                    throw new Exception("文件夹创建失败,路径为：" + fileDirectory);
                }
            }
        }
        OutputStream outputStream = new FileOutputStream(filePath + newName);
        byte[] buffer = new byte[1024];
        int len = 0;
        try {
            while ((len = inputStream.read(buffer)) != -1) {
                outputStream.write(buffer, 0, len);
                outputStream.flush();
            }
        } catch (Exception e) {
            e.printStackTrace();
            throw e;
        } finally {
            outputStream.close();
            inputStream.close();
        }
    }
}

其他的和V1版本是一样的

mapper

  <update id="deleteUser">
          update tb_admin_user set is_deleted = 1
           where id in
           <foreach collection="array" item="id" open="(" separator="," close=")">
                  #{id}
           </foreach>
    </update>

效果展示

Excel的导出实现

前端实现

    <button class="btn btn-primary"
           onclick="window.location.href='/users/export'">
               <i class="fa fa-download"></i> 导出
                 </button>

点击的时候会直接访问到Controller层来获取下载

后端逻辑

/**
     * 导出功能
     */
    @RequestMapping(value = "/export", method = RequestMethod.GET)
    public void exportUsers(HttpServletRequest request, HttpServletResponse response) {
        List<AdminUser> userList = adminUserService.getUsersForExport();
        //单元格表头
        String[] excelHeader = {"用户id", "用户名", "账号状态", "添加时间"};
        //字段名称
        String[] fileds = {"userId", "userName", "status", "createTime"};
        //单元格宽度内容格式
        int[] formats = {4, 2, 1, 1};
        //单元格宽度
        int[] widths = {256 * 14, 512 * 14, 256 * 14, 512 * 14};
        try {
            List<Map<String, Object>> excelData = new ArrayList<Map<String, Object>>();
            SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
            if (CollectionUtils.isNotEmpty(userList)) {
                for (AdminUser user : userList) {
                    Map<String, Object> map = new HashMap<>();
                    map.put("userId", user.getId());
                    map.put("userName", user.getUserName());
                    map.put("status", user.getIsDeleted() == 0 ? "正常账号" : "废弃账号");
                    map.put("createTime", formatter.format(user.getCreateTime()));
                    excelData.add(map);
                }
            }
            String excelName = "用户数据_" + System.currentTimeMillis();
            PoiUtil.exportFile(excelName, excelHeader, fileds, formats, widths, excelData, request, response);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

注：这里的一些工具类在上一篇写过了