springboot easyexcel 提取Excel中图片 spring excel导入导出

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数据大侠客 2024-02-19 08:13:18

文章标签 spring boot java servlet List apache 文章分类 架构后端开发

文章目录

前言
导出excel
导入excel
上传文件获取文件名(中文文件名问题)
xls和xlsx文件的区别

前言

web开发项目，经常会有导出和导出excel文件的需求。如何导出(下载到excel文件)和导入excel(从excel向系统导入数据)?

excel文件的类型有

.xls
excel 2007之前的格式，包含2007
.xlsx
excel 2007之后的格式，内存占用更小。
.csv
该文件可以以txt形式读取，内容之间用英文逗号隔开。

注意:本文只涉及到xls和xlsx文件的导入和导出。csv文件的实质就是txt，所以本文不做介绍。

导出excel

添加依赖

<!-- excel导入导出插件 -->
		<dependency>
			<groupId>com.alibaba</groupId>
			<artifactId>easyexcel</artifactId>
			<version>2.2.8</version>
		</dependency>
				<dependency>
			<groupId>commons-collections</groupId>
			<artifactId>commons-collections</artifactId>
			<version>3.2.1</version>
		</dependency>

编写excel导出工具类

package com.it2.springbootweb2.util;

import com.alibaba.excel.ExcelWriter;
import com.alibaba.excel.support.ExcelTypeEnum;

import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.net.URLEncoder;
import java.nio.charset.StandardCharsets;
import java.text.SimpleDateFormat;
import java.util.*;
import java.util.Map.Entry;

import org.apache.commons.collections.CollectionUtils;
import com.alibaba.excel.metadata.Sheet;
import com.alibaba.excel.metadata.Table;

/**
 * Excel导出
 *
 * @author leng
 */
public class ExcelExportUtils {

    /**
     * 导出Excel
     *
     * @param headList  Excel表头列表
     * @param dataList  Excel内容列表
     * @param sheetName Excel工作表名称
     * @param fileName 文件名
     * @param response  响应对象
     * @throws IOException
     */
    public static void exportExcel(List<String> headList, List<LinkedHashMap<String, Object>> dataList, String sheetName, String fileName, HttpServletResponse response)
            throws IOException {
        ServletOutputStream servletOutputStream = null;
        try {
            servletOutputStream = response.getOutputStream();
            response.setContentType("multipart/form-data");
            response.setCharacterEncoding("utf-8");
            if (null == fileName|| fileName.trim().equals("")) { //如果不设置文件名，则默认
                fileName = new String((sheetName + new SimpleDateFormat("yyyy-MM-dd").format(new Date())).getBytes(), StandardCharsets.UTF_8);
            }
            response.setHeader("Content-Disposition", "attachment;filename=" + URLEncoder.encode(fileName, "UTF-8") + ".xlsx");
            ExcelWriter writer = new ExcelWriter(servletOutputStream, ExcelTypeEnum.XLSX, true);
            Sheet sheet = new Sheet(1, 0);
            sheet.setSheetName(sheetName);

            Table table = new Table(1);
            List<List<String>> head = new ArrayList<>();
            if (!CollectionUtils.isEmpty(headList)) {
                headList.forEach(headName -> head.add(Arrays.asList(headName)));
            }
            table.setHead(head);

            List<List<String>> data = new ArrayList<>();
            if (!CollectionUtils.isEmpty(dataList)) {
                dataList.forEach(map -> {
                    List<String> list = new ArrayList<>();
//                    for (Entry<String, Object> entry : map.entrySet()) {
//                        Object value = entry.getValue();
//                        list.add(value == null ? null : value.toString());
//                    }
                    for (String title:headList) {
                        Object value = map.get(title);
//                        Object value = entry.getValue();
                        list.add(value == null ? null : value.toString());
                    }
                    data.add(list);
                });
            }

            writer.write0(data, sheet, table);
            writer.finish();
            servletOutputStream.flush();
        } catch (IOException e) {
            throw new IOException(e.toString());
        } finally {
            if (servletOutputStream != null) {
                servletOutputStream.close();
            }
        }
    }
}

编写controller测试

package com.it2.springbootweb2.controller;

import com.it2.springbootweb2.util.ExcelExportUtils;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.LinkedHashMap;
import java.util.List;

/**
 * 导出excel
 */
@Controller
public class ExportExcelController {

    @RequestMapping("/exportExcel")
    public void exportExcel(HttpServletRequest request, HttpServletResponse response) throws IOException {
        List<String> headList = Arrays.asList("姓名", "地址");
        List<LinkedHashMap<String, Object>> dataList = new ArrayList<>();
        for (int i = 0; i < 10; i++) {
            LinkedHashMap<String, Object> map = new LinkedHashMap<>();
            map.put("姓名", "张三" + i);
            map.put("地址", "北京" + i);
            dataList.add(map);
        }

        ExcelExportUtils.exportExcel(headList, dataList, "学生名单1", "某校学生名单", response);
    }

}

启动项目测试，访问http://localhost:8081/exportExcel，即可导出文件。

导入excel

添加依赖

<!-- excel导入导出插件 -->
		<dependency>
			<groupId>com.alibaba</groupId>
			<artifactId>easyexcel</artifactId>
			<version>2.2.8</version>
		</dependency>
				<dependency>
			<groupId>commons-collections</groupId>
			<artifactId>commons-collections</artifactId>
			<version>3.2.1</version>
		</dependency>

编写excel工具类

package com.it2.springbootweb2.util;

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import org.apache.poi.hssf.usermodel.HSSFCell;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.ss.usermodel.Cell;
import org.apache.poi.ss.usermodel.Row;
import org.apache.poi.ss.usermodel.Sheet;
import org.apache.poi.ss.usermodel.Workbook;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;

/**
 * Excel读取,支持xls和xlsx
 *
 * @author leng
 */
public class ExcelReadUtil {

    /**
     * excel读取器
     */
    private static final ExcelReadUtil excelReader = new ExcelReadUtil();

    /**
     * 总行数
     */
    private int totalRows = 0;
    /**
     * 总列数
     */
    private int totalCells = 0;
    /**
     * 错误信息
     */
    private String errorInfo;

    /**
     * 构造方法
     */
    public ExcelReadUtil() {
    }

    public int getTotalRows() {
        return totalRows;
    }

    public int getTotalCells() {
        return totalCells;
    }

    public String getErrorInfo() {
        return errorInfo;
    }

    public boolean validateExcel(String filePath) {
        /** 检查文件名是否为空或者是否是Excel格式的文件 */
        if (filePath == null || !(isExcel2003(filePath) || isExcel2007(filePath))) {
            errorInfo = "not excel," + filePath;
            return false;
        }
        /** 检查文件是否存在 */
        File file = new File(filePath);
        if (file == null || !file.exists()) {
            errorInfo = "not exist," + filePath;
            return false;
        }
        return true;
    }

    private List<List<String>> read(String filePath) {
        List<List<String>> dataLst = new ArrayList<List<String>>();
        InputStream is = null;
        try {
            /** 验证文件是否合法 */
            if (!validateExcel(filePath)) {
                System.out.println(errorInfo);
                return null;
            }
            /** 判断文件的类型，是2003还是2007 */
            boolean isExcel2003 = true;
            if (isExcel2007(filePath)) {
                isExcel2003 = false;
            }
            /** 调用本类提供的根据流读取的方法 */
            File file = new File(filePath);
            is = new FileInputStream(file);
            dataLst = read(is, isExcel2003);
            is.close();
        } catch (Exception ex) {
            ex.printStackTrace();
        } finally {
            if (is != null) {
                try {
                    is.close();
                } catch (IOException e) {
                    is = null;
                    e.printStackTrace();
                }
            }
        }
        /** 返回最后读取的结果 */
        return dataLst;
    }

    public List<List<String>> read(InputStream inputStream, boolean isExcel2003) {
        List<List<String>> dataLst = null;
        try {
            /** 根据版本选择创建Workbook的方式 */
            Workbook wb = null;
            if (isExcel2003) {
                wb = new HSSFWorkbook(inputStream);
            } else {
                wb = new XSSFWorkbook(inputStream);
            }
            dataLst = read(wb);
        } catch (IOException e) {

            e.printStackTrace();
        }
        return dataLst;
    }

    private List<List<String>> read(Workbook wb) {
        List<List<String>> dataLst = new ArrayList<List<String>>();
        /** 得到第一个shell */
        Sheet sheet = wb.getSheetAt(0);
        /** 得到Excel的行数 */
        this.totalRows = sheet.getPhysicalNumberOfRows();
        /** 得到Excel的列数 */
        if (this.totalRows >= 1 && sheet.getRow(0) != null) {
            this.totalCells = sheet.getRow(0).getPhysicalNumberOfCells();
        }
        /** 循环Excel的行 */
        for (int r = 0; r < this.totalRows; r++) {
            Row row = sheet.getRow(r);
            if (row == null) {
                continue;
            }
            List<String> rowLst = new ArrayList<String>();
            /** 循环Excel的列 */
            for (int c = 0; c < this.getTotalCells(); c++) {
                Cell cell = row.getCell(c);
                String cellValue = "";
                if (null != cell) {
                    // 以下是判断数据的类型
                    switch (cell.getCellType()) {
                        case HSSFCell.CELL_TYPE_NUMERIC: // 数字
                            cellValue = cell.getNumericCellValue() + "";
                            break;
                        case HSSFCell.CELL_TYPE_STRING: // 字符串
                            cellValue = cell.getStringCellValue();
                            break;
                        case HSSFCell.CELL_TYPE_BOOLEAN: // Boolean
                            cellValue = cell.getBooleanCellValue() + "";
                            break;
                        case HSSFCell.CELL_TYPE_FORMULA: // 公式
                            cellValue = cell.getCellFormula() + "";
                            break;
                        case HSSFCell.CELL_TYPE_BLANK: // 空值
                            cellValue = "";
                            break;
                        case HSSFCell.CELL_TYPE_ERROR: // 故障
                            cellValue = "非法字符";
                            break;
                        default:
                            cellValue = "未知类型";
                            break;
                    }
                }
                rowLst.add(cellValue);
            }
            /** 保存第r行的第c列 */
            dataLst.add(rowLst);
        }
        return dataLst;
    }

    public static void main(String[] args) throws Exception {
        List<List<String>> list = ExcelReadUtil.readExcel("D:\\readExcel.xls");
        if (list != null) {
            for (int i = 0; i < list.size(); i++) {
                System.out.print("第" + (i) + "行");
                List<String> cellList = list.get(i);
                for (int j = 0; j < cellList.size(); j++) {
                    // System.out.print(" 第" + (j + 1) + "列值：");
                    System.out.print("    " + cellList.get(j));
                }
                System.out.println();
            }
        }
    }

    /**
     * 读取excel,首列如果内容前缀为##,则不会被读取
     *
     * @param filePath
     * @return
     */
    public static List<List<String>> readExcel(String filePath) {
        synchronized (excelReader) {
            List<List<String>> list = excelReader.read(filePath);
            if (null != list && list.size() > 0) {
                List<Integer> deleteList = new ArrayList<>();// 需要删除的行

                for (int i = 0; i < list.size(); i++) {
                    List<String> row = list.get(i);
                    if (null != row && row.size() > 0) {
                        String firstRow = row.get(0);
                        if (firstRow.startsWith("##")) {
                            deleteList.add(i);
                        }
                    }
                }

                for (int i = deleteList.size() - 1; i >= 0; i--) {
                    int index = deleteList.get(i);
                    list.remove(index);
                }
            }

            return list;
        }
    }

    /**
     * 读取excel,首列如果内容前缀为##,则不会被读取
     *
     * @param filePath
     * @return
     */
    public static List<String[]> readExcel2(String filePath) {
        List<List<String>> list = readExcel(filePath);
        List<String[]> resultList = new ArrayList<>(list.size());
        for (List<String> listTemp : list) {
            String[] strArr = new String[listTemp.size()];
            for (int i = 0; i < listTemp.size(); i++) {
                strArr[i] = listTemp.get(i);
            }
            resultList.add(strArr);
        }
        return resultList;
    }

    /**
     * 读取excel,首列如果内容前缀为##,则不会被读取
     *
     * @param filePath
     * @return
     */
    public static List<Map<String, String>> readExcel3(String filePath) {
        List<List<String>> list = readExcel(filePath);
        if (null == list || list.size() <= 1) {
            return null;
        }

        List<Map<String, String>> listMap = new ArrayList<>(list.size() - 1);
        List<String> title = list.get(0);

        for (int i = 1; i < list.size(); i++) {
            Map<String, String> map = new HashMap<>();
            List<String> childList = list.get(i);
            for (int j = 0; j < title.size(); j++) {
                map.put(title.get(j), childList.get(j));
            }
            listMap.add(map);
        }
        return listMap;
    }

    /**
     * 是否是xls文件,95~2003的excel文件
     *
     * @param filePath
     * @return
     */
    public static boolean isExcel2003(String filePath) {
        return filePath.matches("^.+\\.(?i)(xls)$");
    }

    /**
     * 是否能是xlsx文件,excel2017以上的格式
     *
     * @param filePath
     * @return
     */
    public static boolean isExcel2007(String filePath) {
        return filePath.matches("^.+\\.(?i)(xlsx)$");
    }

}

编写controller测试

package com.it2.springbootweb2.controller;

import com.it2.springbootweb2.util.ExcelReadUtil;
import com.it2.springbootweb2.util.UnicodeUtils;
import org.apache.commons.lang3.StringEscapeUtils;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.multipart.MultipartFile;

import javax.servlet.http.HttpServletRequest;
import java.net.URLDecoder;
import java.util.List;

/**
 * 导入excel
 */
@Controller
public class ImportExcelController {

    @PostMapping("/uploadFile")
    @ResponseBody
    public String uploadFile(HttpServletRequest request, MultipartFile file) throws Exception {
        String fileName = request.getParameter("fileName");
        System.out.println("从file获取的文件名:"+ UnicodeUtils.webUnicodeToString(file.getOriginalFilename()));
        System.out.println("前端提交的文件名:"+ URLDecoder.decode(fileName,"UTF-8"));
        List<List<String>> list = new ExcelReadUtil().read(file.getInputStream(), false);
        list.forEach(li -> {
            System.out.println(li);
        });
        return "ok";
    }

}

webunicode转中文

package com.it2.springbootweb2.util;

/**
 * Unicode
 *
 * @author leng
 */
public class UnicodeUtils {

    /*
     * web类型的unicode转string
     */
    public static String webUnicodeToString(String input) {
        String str = "";
        String[] array = input.split(";");
        for (String st : array) {
            int idx = st.lastIndexOf("&#");
            if (idx > -1) {
                String str1 = st.substring(0, idx);
                String str2 = st.substring(idx + 2);
                if (st.length() > 2) {
                    str = str + str1;
                    str = str + (char) Integer.parseInt(str2);
                }
            } else {
                str = str + st;
            }
        }
        return str;
    }
}

编写一个index.html页面用于上传excel文件，文件位置位于resources/static目录下

<html>
<meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=1.0, minimum-scale=1.0, user-scalable=no">
<head>
    <title>example</title>
</head>
<script src="http://libs.baidu.com/jquery/2.0.0/jquery.min.js"></script>
<body>
<hr>
<h1>import excel</h1>
<form action="/uploadFile"
      enctype="multipart/form-data" method="post">
    file <input type="file" name="file" id="file" onchange='$("#fileName").val(encodeURI($("#file").val()));'>
    <input type="hidden" value="" id="fileName" name="fileName" >
    <br><br>
    <input type="submit" value="submit">
</form>
<hr>
</body>
</html>