先看一下导出效果，
controller
表头数据一定要放在最前面
List
List<List
sheetDataList.add(head);
/** * 导出报名列表 */@GetMapping("/export")public void export(HttpServletResponse response, ExMessage exMessage) throws MalformedURLException {List list = exMessageService.selectExMessageList(exMessage);// 表头数据ListExcelUtils
package com.ruoyi.expo.controller;import com.alibaba.fastjson2.JSONArray;import com.alibaba.fastjson2.JSONObject;import org.apache.poi.hssf.usermodel.HSSFDataValidation;import org.apache.poi.hssf.usermodel.HSSFWorkbook;import org.apache.poi.poifs.filesystem.POIFSFileSystem;import org.apache.poi.ss.usermodel.*;import org.apache.poi.ss.usermodel.ClientAnchor.AnchorType;import org.apache.poi.ss.util.CellRangeAddress;import org.apache.poi.ss.util.CellRangeAddressList;import org.apache.poi.xssf.streaming.SXSSFWorkbook;import org.apache.poi.xssf.usermodel.XSSFClientAnchor;import org.apache.poi.xssf.usermodel.XSSFWorkbook;import org.springframework.web.multipart.MultipartFile;import javax.servlet.ServletOutputStream;import javax.servlet.http.HttpServletResponse;import java.io.*;import java.lang.reflect.Field;import java.math.BigDecimal;import java.math.RoundingMode;import java.net.URL;import java.text.NumberFormat;import java.text.SimpleDateFormat;import java.util.*;import java.util.Map.Entry;import java.util.regex.Pattern;/** * Excel导入导出工具类 * 原文链接（不定时增加新功能）: https://zyqok.blog.csdn.net/article/details/121994504 * * @author: cyf * @Date: 2023/3/16 15:53 */@SuppressWarnings("unused")public class ExcelUtils {private static final String XLSX = ".xlsx";private static final String XLS = ".xls";public static final String ROW_MERGE = "row_merge";public static final String COLUMN_MERGE = "column_merge";private static final String DATE_FORMAT = "yyyy-MM-dd HH:mm:ss";private static final String ROW_NUM = "rowNum";private static final String ROW_DATA = "rowData";private static final String ROW_TIPS = "rowTips";private static final int CELL_OTHER = 0;private static final int CELL_ROW_MERGE = 1;private static final int CELL_COLUMN_MERGE = 2;private static final int IMG_HEIGHT = 30;private static final int IMG_WIDTH = 30;private static final char LEAN_LINE = '/';private static final int BYTES_DEFAULT_LENGTH = 10240;private static final NumberFormat NUMBER_FORMAT = NumberFormat.getNumberInstance();public static List readFile(File file, Class clazz) throws Exception {JSONArray array = readFile(file);return getBeanList(array, clazz);}public static List readMultipartFile(MultipartFile mFile, Class clazz) throws Exception {JSONArray array = readMultipartFile(mFile);return getBeanList(array, clazz);}public static JSONArray readFile(File file) throws Exception {return readExcel(null, file);}public static JSONArray readMultipartFile(MultipartFile mFile) throws Exception {return readExcel(mFile, null);}public static Map readFileManySheet(File file) throws Exception {return readExcelManySheet(null, file);}public static Map readFileManySheet(MultipartFile file) throws Exception {return readExcelManySheet(file, null);}private static List getBeanList(JSONArray array, Class clazz) throws Exception {List list = new ArrayList();Map uniqueMap = new HashMap(16);for (int i = 0; i < array.size(); i++) {list.add(getBean(clazz, array.getJSONObject(i), uniqueMap));}return list;}/** * 获取每个对象的数据 */private static T getBean(Class c, JSONObject obj, Map uniqueMap) throws Exception {T t = c.newInstance();Field[] fields = c.getDeclaredFields();List errMsgList = new ArrayList();boolean hasRowTipsField = false;StringBuilder uniqueBuilder = new StringBuilder();int rowNum = 0;for (Field field : fields) {// 行号if (field.getName().equals(ROW_NUM)) {rowNum = obj.getInteger(ROW_NUM);field.setAccessible(true);field.set(t, rowNum);continue;}// 是否需要设置异常信息if (field.getName().equals(ROW_TIPS)) {hasRowTipsField = true;continue;}// 原始数据if (field.getName().equals(ROW_DATA)) {field.setAccessible(true);field.set(t, obj.toString());continue;}// 设置对应属性值setFieldValue(t, field, obj, uniqueBuilder, errMsgList);}// 数据唯一性校验if (uniqueBuilder.length() > 0) {if (uniqueMap.containsValue(uniqueBuilder.toString())) {Set rowNumKeys = uniqueMap.keySet();for (Integer num : rowNumKeys) {if (uniqueMap.get(num).equals(uniqueBuilder.toString())) {errMsgList.add(String.format("数据唯一性校验失败,(%s)与第%s行重复)", uniqueBuilder, num));}}} else {uniqueMap.put(rowNum, uniqueBuilder.toString());}}// 失败处理if (errMsgList.isEmpty() && !hasRowTipsField) {return t;}StringBuilder sb = new StringBuilder();int size = errMsgList.size();for (int i = 0; i < size; i++) {if (i == size - 1) {sb.append(errMsgList.get(i));} else {sb.append(errMsgList.get(i)).append(";");}}// 设置错误信息for (Field field : fields) {if (field.getName().equals(ROW_TIPS)) {field.setAccessible(true);field.set(t, sb.toString());}}return t;}private static void setFieldValue(T t, Field field, JSONObject obj, StringBuilder uniqueBuilder, List errMsgList) {// 获取 ExcelImport 注解属性ExcelImport annotation = field.getAnnotation(ExcelImport.class);if (annotation == null) {return;}String cname = annotation.value();if (cname.trim().length() == 0) {return;}// 获取具体值String val = null;if (obj.containsKey(cname)) {val = getString(obj.getString(cname));}if (val == null) {return;}field.setAccessible(true);// 判断是否必填boolean require = annotation.required();if (require && val.isEmpty()) {errMsgList.add(String.format("[%s]不能为空", cname));return;}// 数据唯一性获取boolean unique = annotation.unique();if (unique) {if (uniqueBuilder.length() > 0) {uniqueBuilder.append("--").append(val);} else {uniqueBuilder.append(val);}}// 判断是否超过最大长度int maxLength = annotation.maxLength();if (maxLength > 0 && val.length() > maxLength) {errMsgList.add(String.format("[%s]长度不能超过%s个字符(当前%s个字符)", cname, maxLength, val.length()));}// 判断当前属性是否有映射关系LinkedHashMap kvMap = getKvMap(annotation.kv());if (!kvMap.isEmpty()) {boolean isMatch = false;for (String key : kvMap.keySet()) {if (kvMap.get(key).equals(val)) {val = key;isMatch = true;break;}}if (!isMatch) {errMsgList.add(String.format("[%s]的值不正确(当前值为%s)", cname, val));return;}}// 其余情况根据类型赋值String fieldClassName = field.getType().getSimpleName();try {if ("String".equalsIgnoreCase(fieldClassName)) {field.set(t, val);} else if ("boolean".equalsIgnoreCase(fieldClassName)) {field.set(t, Boolean.valueOf(val));} else if ("int".equalsIgnoreCase(fieldClassName) || "Integer".equals(fieldClassName)) {try {field.set(t, Integer.valueOf(val));} catch (NumberFormatException e) {errMsgList.add(String.format("[%s]的值格式不正确(当前值为%s)", cname, val));}} else if ("double".equalsIgnoreCase(fieldClassName)) {field.set(t, Double.valueOf(val));} else if ("long".equalsIgnoreCase(fieldClassName)) {field.set(t, Long.valueOf(val));} else if ("BigDecimal".equalsIgnoreCase(fieldClassName)) {field.set(t, new BigDecimal(val));} else if ("Date".equalsIgnoreCase(fieldClassName)) {try {field.set(t, new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").parse(val));} catch (Exception e) {field.set(t, new SimpleDateFormat("yyyy-MM-dd").parse(val));}}} catch (Exception e) {e.printStackTrace();}}private static Map readExcelManySheet(MultipartFile mFile, File file) throws IOException {Workbook book = getWorkbook(mFile, file);if (book == null) {return Collections.emptyMap();}Map map = new LinkedHashMap();for (int i = 0; i < book.getNumberOfSheets(); i++) {Sheet sheet = book.getSheetAt(i);JSONArray arr = readSheet(sheet);map.put(sheet.getSheetName(), arr);}book.close();return map;}private static JSONArray readExcel(MultipartFile mFile, File file) throws IOException {Workbook book = getWorkbook(mFile, file);if (book == null) {return new JSONArray();}JSONArray array = readSheet(book.getSheetAt(0));book.close();return array;}private static Workbook getWorkbook(MultipartFile mFile, File file) throws IOException {boolean fileNotExist = (file == null || !file.exists());if (mFile == null && fileNotExist) {return null;}// 解析表格数据InputStream in;String fileName;if (mFile != null) {// 上传文件解析in = mFile.getInputStream();fileName = getString(mFile.getOriginalFilename()).toLowerCase();} else {// 本地文件解析in = new FileInputStream(file);fileName = file.getName().toLowerCase();}Workbook book;if (fileName.endsWith(XLSX)) {book = new XSSFWorkbook(in);} else if (fileName.endsWith(XLS)) {POIFSFileSystem poifsFileSystem = new POIFSFileSystem(in);book = new HSSFWorkbook(poifsFileSystem);} else {return null;}in.close();return book;}private static JSONArray readSheet(Sheet sheet) {// 首行下标int rowStart = sheet.getFirstRowNum();// 尾行下标int rowEnd = sheet.getLastRowNum();// 获取表头行Row headRow = sheet.getRow(rowStart);if (headRow == null) {return new JSONArray();}int cellStart = headRow.getFirstCellNum();int cellEnd = headRow.getLastCellNum();Map keyMap = new HashMap();for (int j = cellStart; j < cellEnd; j++) {// 获取表头数据String val = getCellValue(headRow.getCell(j));if (val != null && val.trim().length() != 0) {keyMap.put(j, val);}}// 如果表头没有数据则不进行解析if (keyMap.isEmpty()) {return (JSONArray) Collections.emptyList();}// 获取每行JSON对象的值JSONArray array = new JSONArray();// 如果首行与尾行相同，表明只有一行，返回表头数据if (rowStart == rowEnd) {JSONObject obj = new JSONObject();// 添加行号obj.put(ROW_NUM, 1);for (int i : keyMap.keySet()) {obj.put(keyMap.get(i), "");}array.add(obj);return array;}for (int i = rowStart + 1; i <= rowEnd; i++) {Row eachRow = sheet.getRow(i);JSONObject obj = new JSONObject();// 添加行号obj.put(ROW_NUM, i + 1);StringBuilder sb = new StringBuilder();for (int k = cellStart; k 0) {array.add(obj);}}return array;}private static String getCellValue(Cell cell) {// 空白或空if (cell == null || cell.getCellTypeEnum() == CellType.BLANK) {return "";}// String类型if (cell.getCellTypeEnum() == CellType.STRING) {String val = cell.getStringCellValue();if (val == null || val.trim().length() == 0) {return "";}return val.trim();}// 数字类型if (cell.getCellTypeEnum() == CellType.NUMERIC) {String s = cell.getNumericCellValue() + "";// 去掉尾巴上的小数点0if (Pattern.matches(".*\\.0*", s)) {return s.split("\\.")[0];} else {return s;}}// 布尔值类型if (cell.getCellTypeEnum() == CellType.BOOLEAN) {return cell.getBooleanCellValue() + "";}// 错误类型return cell.getCellFormula();}public static void exportTemplate(HttpServletResponse response, String fileName, Class clazz) {exportTemplate(response, fileName, fileName, clazz, false);}public static void exportTemplate(HttpServletResponse response, String fileName, String sheetName,Class clazz) {exportTemplate(response, fileName, sheetName, clazz, false);}public static void exportTemplate(HttpServletResponse response, String fileName, Class clazz,boolean isContainExample) {exportTemplate(response, fileName, fileName, clazz, isContainExample);}public static void exportTemplate(HttpServletResponse response, String fileName, String sheetName,Class clazz, boolean isContainExample) {// 获取表头字段List headFieldList = getExcelClassFieldList(clazz);// 获取表头数据和示例数据List<ListExcelImport
package com.ruoyi.expo.controller;import java.lang.annotation.ElementType;import java.lang.annotation.Retention;import java.lang.annotation.RetentionPolicy;import java.lang.annotation.Target;/** * @author: cyf * @Date: 2023/3/16 15:55 */@Target(ElementType.FIELD)@Retention(RetentionPolicy.RUNTIME)public @interface ExcelImport {/** 字段名称 */String value();/** 导出映射，格式如：0-未知;1-男;2-女 */String kv() default "";/** 是否为必填字段（默认为非必填） */boolean required() default false;/** 最大长度（默认255） */int maxLength() default 255;/** 导入唯一性验证（多个字段则取联合验证） */boolean unique() default false;}ExcelExport
package com.ruoyi.expo.controller;import java.lang.annotation.ElementType;import java.lang.annotation.Retention;import java.lang.annotation.RetentionPolicy;import java.lang.annotation.Target;/** * @author: cyf * @Date: 2023/3/16 15:56 */@Target(ElementType.FIELD)@Retention(RetentionPolicy.RUNTIME)public @interface ExcelExport {/** 字段名称 */String value();/** 导出排序先后: 数字越小越靠前（默认按Java类字段顺序导出） */int sort() default 0;/** 导出映射，格式如：0-未知;1-男;2-女 */String kv() default "";/** 导出模板示例值（有值的话，直接取该值，不做映射） */String example() default "";}ExcelClassField
package com.ruoyi.expo.controller;import java.util.LinkedHashMap;/** * @author: cyf * @Date: 2023/3/16 15:55 */public class ExcelClassField {/** 字段名称 */private String fieldName;/** 表头名称 */private String name;/** 映射关系 */private LinkedHashMap kvMap;/** 示例值 */private Object example;/** 排序 */private int sort;/** 是否为注解字段：0-否，1-是 */private int hasAnnotation;public String getFieldName() {return fieldName;}public void setFieldName(String fieldName) {this.fieldName = fieldName;}public String getName() {return name;}public void setName(String name) {this.name = name;}public LinkedHashMap getKvMap() {return kvMap;}public void setKvMap(LinkedHashMap kvMap) {this.kvMap = kvMap;}public Object getExample() {return example;}public void setExample(Object example) {this.example = example;}public int getSort() {return sort;}public void setSort(int sort) {this.sort = sort;}public int getHasAnnotation() {return hasAnnotation;}public void setHasAnnotation(int hasAnnotation) {this.hasAnnotation = hasAnnotation;}}