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)@Documentedpublic @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 */@Datapublic 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。
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