Springboot实现导入导出Excel的方法

目录

• 一、添加poi的maven依赖
• 二、自定义注解(Excel属性标题、位置等)
• 三、CustomExcelUtils编写
• 四、定义导出实体类
• 五、Controller层代码编写

一、添加poi的maven依赖

<dependency>
    <groupId>org.apache.poi</groupId>
    <artifactId>poi</artifactId>
    <version>3.13</version>
</dependency>
<dependency>
    <groupId>org.apache.poi</groupId>
    <artifactId>poi-ooxml</artifactId>
    <version>3.13</version>
</dependency>

二、自定义注解(Excel属性标题、位置等)

package com.cloud.core.annotation;

import java.lang.annotation.*;

/**
 * 自定义实体类所需要的bean(Excel属性标题、位置等)
 * Copyright: Copyright (C) 2021 DLANGEL, Inc. All rights reserved.
 * Company: 大连安琪科技有限公司
 *
 * @author Rex
 * @since 2021/5/19 9:30
 */
@Target({ElementType.FIELD})
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface ExcelColumn {
    /**
     * Excel标题
     *
     * @return
     * @author Rex
     */
    String value() default "";

    /**
     * Excel从左往右排列位置，第一个是0
     *
     * @return
     * @author Rex
     */
    int col() default 0;
}

三、CustomExcelUtils编写

package com.cloud.core.utils;

import com.baomidou.mybatisplus.core.toolkit.CollectionUtils;
import com.cloud.core.annotation.ExcelColumn;
import com.cloud.core.common.CommonConst;
import org.apache.commons.lang.BooleanUtils;
import org.apache.commons.lang.CharUtils;
import org.apache.commons.lang.StringUtils;
import org.apache.commons.lang.math.NumberUtils;
import org.apache.poi.hssf.usermodel.HSSFDateUtil;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.ss.usermodel.*;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.http.MediaType;
import org.springframework.web.multipart.MultipartFile;

import javax.servlet.http.HttpServletResponse;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.lang.reflect.Constructor;
import java.lang.reflect.Field;
import java.math.BigDecimal;
import java.net.URLEncoder;
import java.util.*;
import java.util.concurrent.atomic.AtomicInteger;
import java.util.stream.Collectors;
import java.util.stream.Stream;

/**
 * 自定义导入导出Excel文件类
 * Copyright: Copyright (C) 2021 DLANGEL, Inc. All rights reserved.
 * Company: 大连安琪科技有限公司
 *
 * @author Rex
 * @since 2021/5/19 9:31
 */
public class CustomExcelUtils {
    private final static Logger log = LoggerFactory.getLogger(CustomExcelUtils.class);

    private final static String EXCEL2003 = "xls";
    private final static String EXCEL2007 = "xlsx";

    /**
     * 读取Excel
     *
     * @param path     为了测试文件用，实际为空
     * @param cls      类
     * @param startRow 起始行
     * @param file     文件
     * @return
     * @author Rex
     */
    public static <T> List<T> readExcel(String path, Class<T> cls, int startRow, MultipartFile file) {

        String fileName = file.getOriginalFilename();
        if (!fileName.matches(CommonConst.Regex.FILE_EXT_XLS) && !fileName.matches(CommonConst.Regex.FILE_EXT_XLSX)) {
            log.error("上传文件格式不正确");
        }
        List<T> dataList = new ArrayList<>();
        Workbook workbook = null;
        try {
            InputStream is = file.getInputStream();
            if (fileName.endsWith(EXCEL2007)) {
//                FileInputStream is = new FileInputStream(new File(path));
                workbook = new XSSFWorkbook(is);
            }
            if (fileName.endsWith(EXCEL2003)) {
//                FileInputStream is = new FileInputStream(new File(path));
                workbook = new HSSFWorkbook(is);
            }
            if (workbook != null) {
                //类映射  注解 value-->bean columns
                Map<String, List<Field>> classMap = new HashMap<>();
                List<Field> fields = Stream.of(cls.getDeclaredFields()).collect(Collectors.toList());
                fields.forEach(
                        field -> {
                            ExcelColumn annotation = field.getAnnotation(ExcelColumn.class);
                            if (annotation != null) {
                                String value = annotation.value();
                                if (StringUtils.isBlank(value)) {
                                    // return起到的作用和continue是相同的 语法
                                    return;
                                }
                                if (!classMap.containsKey(value)) {
                                    classMap.put(value, new ArrayList<>());
                                }
                                field.setAccessible(true);
                                classMap.get(value).add(field);
                            }
                        }
                );
                //索引-->columns
                Map<Integer, List<Field>> reflectionMap = new HashMap<>(16);
                //默认读取第一个sheet
                Sheet sheet = workbook.getSheetAt(0);

                boolean firstRow = true;
                for (int i = startRow; i <= sheet.getLastRowNum(); i++) {
                    Row row = sheet.getRow(i);
                    // 提取注解
                    if (firstRow) {
                        for (int j = row.getFirstCellNum(); j <= row.getLastCellNum(); j++) {
                            Cell cell = row.getCell(j);
                            String cellValue = getCellValue(cell);
                            if (classMap.containsKey(cellValue)) {
                                reflectionMap.put(j, classMap.get(cellValue));
                            }
                        }
                        if (reflectionMap.size() > 0) {
                            firstRow = false;
                        }
                    } else {
                        //忽略空白行
                        if (row == null) {
                            continue;
                        }
                        try {
                            T t = cls.newInstance();
                            //判断是否为空白行
                            boolean allBlank = true;
                            for (int j = row.getFirstCellNum(); j <= row.getLastCellNum(); j++) {
                                if (reflectionMap.containsKey(j)) {
                                    Cell cell = row.getCell(j);
                                    String cellValue = getCellValue(cell);
                                    if (StringUtils.isNotBlank(cellValue)) {
                                        allBlank = false;
                                    }
                                    List<Field> fieldList = reflectionMap.get(j);
                                    fieldList.forEach(
                                            x -> {
                                                try {
                                                    handleField(t, cellValue, x);
                                                } catch (Exception e) {
                                                    log.error(String.format("reflect field:%s value:%s exception!", x.getName(), cellValue), e);
                                                }
                                            }
                                    );
                                }
                            }
                            if (!allBlank) {
                                dataList.add(t);
                            } else {
                                log.warn(String.format("row:%s is blank ignore!", i));
                            }
                        } catch (Exception e) {
                            log.error(String.format("parse row:%s exception!", i), e);
                        }
                    }
                }
            }
        } catch (Exception e) {
            log.error(String.format("parse excel exception!"), e);
        } finally {
            if (workbook != null) {
                try {
                    workbook.close();
                } catch (Exception e) {
                    log.error(String.format("parse excel exception!"), e);
                }
            }
        }
        return dataList;
    }

    private static <T> void handleField(T t, String value, Field field) throws Exception {
        Class<?> type = field.getType();
        if (type == null || type == void.class || StringUtils.isBlank(value)) {
            return;
        }
        if (type == Object.class) {
            field.set(t, value);
            //数字类型
        } else if (type.getSuperclass() == null || type.getSuperclass() == Number.class) {
            if (type == int.class || type == Integer.class) {
                field.set(t, NumberUtils.toInt(value));
            } else if (type == long.class || type == Long.class) {
                field.set(t, NumberUtils.toLong(value));
            } else if (type == byte.class || type == Byte.class) {
                field.set(t, NumberUtils.toByte(value));
            } else if (type == short.class || type == Short.class) {
                field.set(t, NumberUtils.toShort(value));
            } else if (type == double.class || type == Double.class) {
                field.set(t, NumberUtils.toDouble(value));
            } else if (type == float.class || type == Float.class) {
                field.set(t, NumberUtils.toFloat(value));
            } else if (type == char.class || type == Character.class) {
                field.set(t, CharUtils.toChar(value));
            } else if (type == boolean.class) {
                field.set(t, BooleanUtils.toBoolean(value));
            } else if (type == BigDecimal.class) {
                field.set(t, new BigDecimal(value));
            }
        } else if (type == Boolean.class) {
            field.set(t, BooleanUtils.toBoolean(value));
        } else if (type == Date.class) {
            //
            field.set(t, value);
        } else if (type == String.class) {
            field.set(t, value);
        } else {
            Constructor<?> constructor = type.getConstructor(String.class);
            field.set(t, constructor.newInstance(value));
        }
    }

    private static String getCellValue(Cell cell) {
        if (cell == null) {
            return "";
        }
        if (cell.getCellType() == Cell.CELL_TYPE_NUMERIC) {
            if (HSSFDateUtil.isCellDateFormatted(cell)) {
                return HSSFDateUtil.getJavaDate(cell.getNumericCellValue()).toString();
            } else {
                return new BigDecimal(cell.getNumericCellValue()).toString();
            }
        } else if (cell.getCellType() == Cell.CELL_TYPE_STRING) {
            return StringUtils.trimToEmpty(cell.getStringCellValue());
        } else if (cell.getCellType() == Cell.CELL_TYPE_FORMULA) {
            return StringUtils.trimToEmpty(cell.getCellFormula());
        } else if (cell.getCellType() == Cell.CELL_TYPE_BLANK) {
            return "";
        } else if (cell.getCellType() == Cell.CELL_TYPE_BOOLEAN) {
            return String.valueOf(cell.getBooleanCellValue());
        } else if (cell.getCellType() == Cell.CELL_TYPE_ERROR) {
            return "ERROR";
        } else {
            return cell.toString().trim();
        }

    }

    public static <T> void writeExcel(HttpServletResponse response, List<T> dataList, Class<T> cls) {
        Field[] fields = cls.getDeclaredFields();
        List<Field> fieldList = Arrays.stream(fields)
                .filter(field -> {
                    ExcelColumn annotation = field.getAnnotation(ExcelColumn.class);
                    if (annotation != null && annotation.col() > 0) {
                        field.setAccessible(true);
                        return true;
                    }
                    return false;
                }).sorted(Comparator.comparing(field -> {
                    int col = 0;
                    ExcelColumn annotation = field.getAnnotation(ExcelColumn.class);
                    if (annotation != null) {
                        col = annotation.col();
                    }
                    return col;
                })).collect(Collectors.toList());

        Workbook wb = new XSSFWorkbook();
        Sheet sheet = wb.createSheet("Sheet1");
        AtomicInteger ai = new AtomicInteger();
        {
            Row row = sheet.createRow(ai.getAndIncrement());
            AtomicInteger aj = new AtomicInteger();
            //写入头部
            fieldList.forEach(field -> {
                ExcelColumn annotation = field.getAnnotation(ExcelColumn.class);
                String columnName = "";
                if (annotation != null) {
                    columnName = annotation.value();
                }
                Cell cell = row.createCell(aj.getAndIncrement());

                CellStyle cellStyle = wb.createCellStyle();
                cellStyle.setFillForegroundColor(IndexedColors.WHITE.getIndex());
                cellStyle.setFillPattern(CellStyle.SOLID_FOREGROUND);
                cellStyle.setAlignment(CellStyle.ALIGN_CENTER);

                Font font = wb.createFont();
                font.setBoldweight(Font.BOLDWEIGHT_NORMAL);
                cellStyle.setFont(font);
                cell.setCellStyle(cellStyle);
                cell.setCellValue(columnName);
            });
        }
        if (CollectionUtils.isNotEmpty(dataList)) {
            dataList.forEach(t -> {
                Row row1 = sheet.createRow(ai.getAndIncrement());
                AtomicInteger aj = new AtomicInteger();
                fieldList.forEach(field -> {
                    Class<?> type = field.getType();
                    Object value = "";
                    try {
                        value = field.get(t);
                    } catch (Exception e) {
                        e.printStackTrace();
                    }
                    Cell cell = row1.createCell(aj.getAndIncrement());
                    if (value != null) {
                        if (type == Date.class) {
                            cell.setCellValue(value.toString());
                        } else {
                            cell.setCellValue(value.toString());
                        }
                        cell.setCellValue(value.toString());
                    }
                });
            });
        }
        //冻结窗格
        wb.getSheet("Sheet1").createFreezePane(0, 1, 0, 1);
        //浏览器下载excel
        buildExcelDocument("导出数据.xlsx", wb, response);
        //生成excel文件
//        buildExcelFile(".\\default.xlsx", wb);
    }

    /**
     * 浏览器下载excel
     *
     * @param fileName
     * @param wb
     * @param response
     */

    private static void buildExcelDocument(String fileName, Workbook wb, HttpServletResponse response) {
        try {
            response.setContentType(MediaType.APPLICATION_OCTET_STREAM_VALUE);
            response.setHeader("Content-Disposition", "attachment;filename=" + URLEncoder.encode(fileName, "utf-8"));
            response.flushBuffer();
            wb.write(response.getOutputStream());
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    /**
     * 生成excel文件
     *
     * @param path 生成excel路径
     * @param wb
     */
    private static void buildExcelFile(String path, Workbook wb) {

        File file = new File(path);
        if (file.exists()) {
            file.delete();
        }
        try {
            wb.write(new FileOutputStream(file));
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

四、定义导出实体类

主要是使用这里的@ExcelColumn注解，其中的col从0开始的。

package com.cloud.library.model.role;

import com.cloud.core.annotation.ExcelColumn;
import lombok.Data;

/**
 * 导入角色用
 * Copyright: Copyright (C) 2021 DLANGEL, Inc. All rights reserved.
 * Company: 大连安琪科技有限公司
 *
 * @author Rex
 * @since 2021/5/19 16:13
 */
@Data
public class SysRoleExcel {
    @ExcelColumn(value = "姓名", col = 1)
    private String name;
    @ExcelColumn(value = "描述", col = 2)
    private String description;
}

Excel对应的模板参考

五、Controller层代码编写

//region 导入数据

    /**
     * 导入数据
     *
     * @param file
     * @return
     * @author Rex
     */
    @RequestMapping(value = "/readExcel", method = RequestMethod.POST)
    public void readExcel(@RequestParam(value = "uploadFile", required = false) MultipartFile file) {
        List<SysRoleExcel> list = CustomExcelUtils.readExcel("", SysRoleExcel.class, 0, file);
        List<SysRole> sysRoleList = new ArrayList<>();
        list.forEach(e -> {
            SysRole sysRole = new SysRole();
            BeanUtils.copyProperties(e, sysRole);
            sysRoleList.add(sysRole);
        });
        sysRoleService.saveBatch(sysRoleList);
    }
    // endregion

这里发现了，这个saveBatch可以直接使用雪花的id来保存数据，因为这里用的是mybatis-plus，单条数据保存使用的是它的配置。然后试了下，批量导入也是可以的，另外，这个批量保存，理论上没有条数限制，这个还等待后续测试。

到此这篇关于Springboot实现导入导出Excel的方法的文章就介绍到这了,更多相关Springboot导入导出Excel内容请搜索我们以前的文章或继续浏览下面的相关文章希望大家以后多多支持我们！