一 、环境准备

maven依赖

本次工具类的封装主要依赖于阿里巴巴的JSON包，以及表格处理的POI包，所以我们需要导入这两个库的依赖包，另外，我们还需要文件上传的相关包，毕竟我们在浏览器页面，做Excel导入时，是上传的Excel文件

    <!--excel工具依赖 start--><dependency><groupId>org.apache.httpcomponents</groupId><artifactId>httpmime</artifactId><version>4.5.7</version></dependency><!-- JSON --><dependency><groupId>com.alibaba</groupId><artifactId>fastjson</artifactId><version>1.2.83</version></dependency><!-- POI --><dependency><groupId>org.apache.poi</groupId><artifactId>poi-ooxml</artifactId><version>3.16</version></dependency><!--excel工具依赖 end-->

引进knife，方便进行测试

        <dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-web</artifactId><version>2.7.8</version></dependency><!--knife4j start--><dependency><groupId>com.github.xiaoymin</groupId><artifactId>knife4j-spring-boot-starter</artifactId><version>2.0.9</version></dependency><!--knife4j end-->

 相关util工具类

public class ExcelClassField {/** 字段名称 */private String fieldName;/** 表头名称 */private String name;/** 映射关系 */private LinkedHashMap<String, String> 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<String, String> getKvMap() {return kvMap;}public void setKvMap(LinkedHashMap<String, String> 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;}}

@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 "";}

@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;}

/*** Excel导入导出工具类**/
@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 <T> List<T> readFile(File file, Class<T> clazz) throws Exception {JSONArray array = readFile(file);return getBeanList(array, clazz);}public static <T> List<T> readMultipartFile(MultipartFile mFile, Class<T> 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<String, JSONArray> readFileManySheet(File file) throws Exception {return readExcelManySheet(null, file);}public static Map<String, JSONArray> readFileManySheet(MultipartFile file) throws Exception {return readExcelManySheet(file, null);}private static <T> List<T> getBeanList(JSONArray array, Class<T> clazz) throws Exception {List<T> list = new ArrayList<>();Map<Integer, String> uniqueMap = new HashMap<>(16);for (int i = 0; i < array.size(); i++) {T bean = getBean(clazz, array.getJSONObject(i), uniqueMap);list.add(bean);}return list;}/*** 获取每个对象的数据*/private static <T> T getBean(Class<T> c, JSONObject obj, Map<Integer, String> uniqueMap) throws Exception {T t = c.newInstance();Field[] fields = c.getDeclaredFields();List<String> 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<Integer> 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 <T> void setFieldValue(T t, Field field, JSONObject obj, StringBuilder uniqueBuilder, List<String> 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<String, String> 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<String, JSONArray> readExcelManySheet(MultipartFile mFile, File file) throws IOException {Workbook book = getWorkbook(mFile, file);if (book == null) {return Collections.emptyMap();}Map<String, JSONArray> 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<Integer, String> 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 < cellEnd; k++) {if (eachRow != null) {String val = getCellValue(eachRow.getCell(k));// 所有数据添加到里面，用于判断该行是否为空sb.append(val);obj.put(keyMap.get(k), val);}}if (sb.length() > 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 <T> void exportTemplate(HttpServletResponse response, String fileName, Class<T> clazz) {exportTemplate(response, fileName, fileName, clazz, false);}public static <T> void exportTemplate(HttpServletResponse response, String fileName, String sheetName,Class<T> clazz) {exportTemplate(response, fileName, sheetName, clazz, false);}public static <T> void exportTemplate(HttpServletResponse response, String fileName, Class<T> clazz,boolean isContainExample) {exportTemplate(response, fileName, fileName, clazz, isContainExample);}public static <T> void exportTemplate(HttpServletResponse response, String fileName, String sheetName,Class<T> clazz, boolean isContainExample) {// 获取表头字段List<ExcelClassField> headFieldList = getExcelClassFieldList(clazz);// 获取表头数据和示例数据List<List<Object>> sheetDataList = new ArrayList<>();List<Object> headList = new ArrayList<>();List<Object> exampleList = new ArrayList<>();Map<Integer, List<String>> selectMap = new LinkedHashMap<>();for (int i = 0; i < headFieldList.size(); i++) {ExcelClassField each = headFieldList.get(i);headList.add(each.getName());exampleList.add(each.getExample());LinkedHashMap<String, String> kvMap = each.getKvMap();if (kvMap != null && kvMap.size() > 0) {selectMap.put(i, new ArrayList<>(kvMap.values()));}}sheetDataList.add(headList);if (isContainExample) {sheetDataList.add(exampleList);}// 导出数据export(response, fileName, sheetName, sheetDataList, selectMap);}private static <T> List<ExcelClassField> getExcelClassFieldList(Class<T> clazz) {// 解析所有字段Field[] fields = clazz.getDeclaredFields();boolean hasExportAnnotation = false;Map<Integer, List<ExcelClassField>> map = new LinkedHashMap<>();List<Integer> sortList = new ArrayList<>();for (Field field : fields) {ExcelClassField cf = getExcelClassField(field);if (cf.getHasAnnotation() == 1) {hasExportAnnotation = true;}int sort = cf.getSort();if (map.containsKey(sort)) {map.get(sort).add(cf);} else {List<ExcelClassField> list = new ArrayList<>();list.add(cf);sortList.add(sort);map.put(sort, list);}}Collections.sort(sortList);// 获取表头List<ExcelClassField> headFieldList = new ArrayList<>();if (hasExportAnnotation) {for (Integer sort : sortList) {for (ExcelClassField cf : map.get(sort)) {if (cf.getHasAnnotation() == 1) {headFieldList.add(cf);}}}} else {headFieldList.addAll(map.get(0));}return headFieldList;}private static ExcelClassField getExcelClassField(Field field) {ExcelClassField cf = new ExcelClassField();String fieldName = field.getName();cf.setFieldName(fieldName);ExcelExport annotation = field.getAnnotation(ExcelExport.class);// 无 ExcelExport 注解情况if (annotation == null) {cf.setHasAnnotation(0);cf.setName(fieldName);cf.setSort(0);return cf;}// 有 ExcelExport 注解情况cf.setHasAnnotation(1);cf.setName(annotation.value());String example = getString(annotation.example());if (!example.isEmpty()) {if (isNumeric(example) && example.length() < 8) {cf.setExample(Double.valueOf(example));} else {cf.setExample(example);}} else {cf.setExample("");}cf.setSort(annotation.sort());// 解析映射String kv = getString(annotation.kv());cf.setKvMap(getKvMap(kv));return cf;}private static LinkedHashMap<String, String> getKvMap(String kv) {LinkedHashMap<String, String> kvMap = new LinkedHashMap<>();if (kv.isEmpty()) {return kvMap;}String[] kvs = kv.split(";");if (kvs.length == 0) {return kvMap;}for (String each : kvs) {String[] eachKv = getString(each).split("-");if (eachKv.length != 2) {continue;}String k = eachKv[0];String v = eachKv[1];if (k.isEmpty() || v.isEmpty()) {continue;}kvMap.put(k, v);}return kvMap;}/*** 导出表格到本地** @param file      本地文件对象* @param sheetData 导出数据*/public static void exportFile(File file, List<List<Object>> sheetData) {if (file == null) {System.out.println("文件创建失败");return;}if (sheetData == null) {sheetData = new ArrayList<>();}Map<String, List<List<Object>>> map = new HashMap<>();map.put(file.getName(), sheetData);export(null, file, file.getName(), map, null);}/*** 导出表格到本地** @param <T>      导出数据类似，和K类型保持一致* @param filePath 文件父路径（如：D:/doc/excel/）* @param fileName 文件名称（不带尾缀，如：学生表）* @param list     导出数据* @throws IOException IO异常*/public static <T> File exportFile(String filePath, String fileName, List<T> list) throws IOException {File file = getFile(filePath, fileName);List<List<Object>> sheetData = getSheetData(list);exportFile(file, sheetData);return file;}/*** 获取文件** @param filePath filePath 文件父路径（如：D:/doc/excel/）* @param fileName 文件名称（不带尾缀，如：用户表）* @return 本地File文件对象*/private static File getFile(String filePath, String fileName) throws IOException {String dirPath = getString(filePath);String fileFullPath;if (dirPath.isEmpty()) {fileFullPath = fileName;} else {// 判定文件夹是否存在，如果不存在，则级联创建File dirFile = new File(dirPath);if (!dirFile.exists()) {boolean mkdirs = dirFile.mkdirs();if (!mkdirs) {return null;}}// 获取文件夹全名if (dirPath.endsWith(String.valueOf(LEAN_LINE))) {fileFullPath = dirPath + fileName + XLSX;} else {fileFullPath = dirPath + LEAN_LINE + fileName + XLSX;}}System.out.println(fileFullPath);File file = new File(fileFullPath);if (!file.exists()) {boolean result = file.createNewFile();if (!result) {return null;}}return file;}private static <T> List<List<Object>> getSheetData(List<T> list) {// 获取表头字段List<ExcelClassField> excelClassFieldList = getExcelClassFieldList(list.get(0).getClass());List<String> headFieldList = new ArrayList<>();List<Object> headList = new ArrayList<>();Map<String, ExcelClassField> headFieldMap = new HashMap<>();for (ExcelClassField each : excelClassFieldList) {String fieldName = each.getFieldName();headFieldList.add(fieldName);headFieldMap.put(fieldName, each);headList.add(each.getName());}// 添加表头名称List<List<Object>> sheetDataList = new ArrayList<>();sheetDataList.add(headList);// 获取表数据for (T t : list) {Map<String, Object> fieldDataMap = getFieldDataMap(t);Set<String> fieldDataKeys = fieldDataMap.keySet();List<Object> rowList = new ArrayList<>();for (String headField : headFieldList) {if (!fieldDataKeys.contains(headField)) {continue;}Object data = fieldDataMap.get(headField);if (data == null) {rowList.add("");continue;}ExcelClassField cf = headFieldMap.get(headField);// 判断是否有映射关系LinkedHashMap<String, String> kvMap = cf.getKvMap();if (kvMap == null || kvMap.isEmpty()) {rowList.add(data);continue;}String val = kvMap.get(data.toString());if (isNumeric(val)) {rowList.add(Double.valueOf(val));} else {rowList.add(val);}}sheetDataList.add(rowList);}return sheetDataList;}private static <T> Map<String, Object> getFieldDataMap(T t) {Map<String, Object> map = new HashMap<>();Field[] fields = t.getClass().getDeclaredFields();try {for (Field field : fields) {String fieldName = field.getName();field.setAccessible(true);Object object = field.get(t);map.put(fieldName, object);}} catch (IllegalArgumentException | IllegalAccessException e) {e.printStackTrace();}return map;}public static void exportEmpty(HttpServletResponse response, String fileName) {List<List<Object>> sheetDataList = new ArrayList<>();List<Object> headList = new ArrayList<>();headList.add("导出无数据");sheetDataList.add(headList);export(response, fileName, sheetDataList);}public static void export(HttpServletResponse response, String fileName, List<List<Object>> sheetDataList) {export(response, fileName, fileName, sheetDataList, null);}public static void exportManySheet(HttpServletResponse response, String fileName, Map<String, List<List<Object>>> sheetMap) {export(response, null, fileName, sheetMap, null);}public static void export(HttpServletResponse response, String fileName, String sheetName,List<List<Object>> sheetDataList) {export(response, fileName, sheetName, sheetDataList, null);}public static void export(HttpServletResponse response, String fileName, String sheetName,List<List<Object>> sheetDataList, Map<Integer, List<String>> selectMap) {Map<String, List<List<Object>>> map = new HashMap<>();map.put(sheetName, sheetDataList);export(response, null, fileName, map, selectMap);}public static <T, K> void export(HttpServletResponse response, String fileName, List<T> list, Class<K> template) {// list 是否为空boolean lisIsEmpty = list == null || list.isEmpty();// 如果模板数据为空，且导入的数据为空，则导出空文件if (template == null && lisIsEmpty) {exportEmpty(response, fileName);return;}// 如果 list 数据，则导出模板数据if (lisIsEmpty) {exportTemplate(response, fileName, template);return;}// 导出数据List<List<Object>> sheetDataList = getSheetData(list);export(response, fileName, sheetDataList);}public static void export(HttpServletResponse response, String fileName, List<List<Object>> sheetDataList, Map<Integer, List<String>> selectMap) {export(response, fileName, fileName, sheetDataList, selectMap);}private static void export(HttpServletResponse response, File file, String fileName,Map<String, List<List<Object>>> sheetMap, Map<Integer, List<String>> selectMap) {// 整个 Excel 表格 book 对象SXSSFWorkbook book = new SXSSFWorkbook();// 每个 Sheet 页Set<Entry<String, List<List<Object>>>> entries = sheetMap.entrySet();for (Entry<String, List<List<Object>>> entry : entries) {List<List<Object>> sheetDataList = entry.getValue();Sheet sheet = book.createSheet(entry.getKey());Drawing<?> patriarch = sheet.createDrawingPatriarch();// 设置表头背景色（灰色）CellStyle headStyle = book.createCellStyle();headStyle.setFillForegroundColor(IndexedColors.GREY_80_PERCENT.index);headStyle.setFillPattern(FillPatternType.SOLID_FOREGROUND);headStyle.setAlignment(HorizontalAlignment.CENTER);headStyle.setFillForegroundColor(IndexedColors.GREY_25_PERCENT.index);// 设置表身背景色（默认色）CellStyle rowStyle = book.createCellStyle();rowStyle.setAlignment(HorizontalAlignment.CENTER);rowStyle.setVerticalAlignment(VerticalAlignment.CENTER);// 设置表格列宽度（默认为15个字节）sheet.setDefaultColumnWidth(15);// 创建合并算法数组int rowLength = sheetDataList.size();int columnLength = sheetDataList.get(0).size();int[][] mergeArray = new int[rowLength][columnLength];for (int i = 0; i < sheetDataList.size(); i++) {// 每个 Sheet 页中的行数据Row row = sheet.createRow(i);List<Object> rowList = sheetDataList.get(i);for (int j = 0; j < rowList.size(); j++) {// 每个行数据中的单元格数据Object o = rowList.get(j);int v = 0;if (o instanceof URL) {// 如果要导出图片的话, 链接需要传递 URL 对象setCellPicture(book, row, patriarch, i, j, (URL) o);} else {Cell cell = row.createCell(j);if (i == 0) {// 第一行为表头行，采用灰色底背景v = setCellValue(cell, o, headStyle);} else {// 其他行为数据行，默认白底色v = setCellValue(cell, o, rowStyle);}}mergeArray[i][j] = v;}}// 合并单元格mergeCells(sheet, mergeArray);// 设置下拉列表setSelect(sheet, selectMap);}// 写数据if (response != null) {// 前端导出try {write(response, book, fileName);} catch (IOException e) {e.printStackTrace();}} else {// 本地导出FileOutputStream fos;try {fos = new FileOutputStream(file);ByteArrayOutputStream ops = new ByteArrayOutputStream();book.write(ops);fos.write(ops.toByteArray());fos.close();} catch (Exception e) {e.printStackTrace();}}}/*** 合并当前Sheet页的单元格** @param sheet      当前 sheet 页* @param mergeArray 合并单元格算法*/private static void mergeCells(Sheet sheet, int[][] mergeArray) {// 横向合并for (int x = 0; x < mergeArray.length; x++) {int[] arr = mergeArray[x];boolean merge = false;int y1 = 0;int y2 = 0;for (int y = 0; y < arr.length; y++) {int value = arr[y];if (value == CELL_COLUMN_MERGE) {if (!merge) {y1 = y;}y2 = y;merge = true;} else {merge = false;if (y1 > 0) {sheet.addMergedRegion(new CellRangeAddress(x, x, (y1 - 1), y2));}y1 = 0;y2 = 0;}}if (y1 > 0) {sheet.addMergedRegion(new CellRangeAddress(x, x, (y1 - 1), y2));}}// 纵向合并int xLen = mergeArray.length;int yLen = mergeArray[0].length;for (int y = 0; y < yLen; y++) {boolean merge = false;int x1 = 0;int x2 = 0;for (int x = 0; x < xLen; x++) {int value = mergeArray[x][y];if (value == CELL_ROW_MERGE) {if (!merge) {x1 = x;}x2 = x;merge = true;} else {merge = false;if (x1 > 0) {sheet.addMergedRegion(new CellRangeAddress((x1 - 1), x2, y, y));}x1 = 0;x2 = 0;}}if (x1 > 0) {sheet.addMergedRegion(new CellRangeAddress((x1 - 1), x2, y, y));}}}private static void write(HttpServletResponse response, SXSSFWorkbook book, String fileName) throws IOException {response.setContentType("application/vnd.openxmlformats-officedocument.spreadsheetml.sheet");response.setCharacterEncoding("utf-8");String name = new String(fileName.getBytes("GBK"), "ISO8859_1") + XLSX;response.addHeader("Content-Disposition", "attachment;filename=" + name);ServletOutputStream out = response.getOutputStream();book.write(out);out.flush();out.close();}private static int setCellValue(Cell cell, Object o, CellStyle style) {// 设置样式cell.setCellStyle(style);// 数据为空时if (o == null || o.equals("")) {cell.setCellType(CellType.STRING);cell.setCellValue("");return CELL_OTHER;}// 是否为字符串if (o instanceof String) {String s = o.toString();// 当数字类型长度超过8位时，改为字符串类型显示（Excel数字超过一定长度会显示为科学计数法）if (isNumeric(s) && s.length() < 8) {cell.setCellType(CellType.NUMERIC);cell.setCellValue(Double.parseDouble(s));return CELL_OTHER;} else {cell.setCellType(CellType.STRING);cell.setCellValue(s);}if (s.equals(ROW_MERGE)) {return CELL_ROW_MERGE;} else if (s.equals(COLUMN_MERGE)) {return CELL_COLUMN_MERGE;} else {return CELL_OTHER;}}// 是否为字符串if (o instanceof Integer || o instanceof Long || o instanceof Double || o instanceof Float) {cell.setCellType(CellType.NUMERIC);cell.setCellValue(Double.parseDouble(o.toString()));return CELL_OTHER;}// 是否为Booleanif (o instanceof Boolean) {cell.setCellType(CellType.BOOLEAN);cell.setCellValue((Boolean) o);return CELL_OTHER;}// 如果是BigDecimal，则默认3位小数if (o instanceof BigDecimal) {cell.setCellType(CellType.NUMERIC);cell.setCellValue(((BigDecimal) o).setScale(3, RoundingMode.HALF_UP).doubleValue());return CELL_OTHER;}// 如果是Date数据，则显示格式化数据if (o instanceof Date) {cell.setCellType(CellType.STRING);cell.setCellValue(formatDate((Date) o));return CELL_OTHER;}// 如果是其他，则默认字符串类型cell.setCellType(CellType.STRING);cell.setCellValue(o.toString());return CELL_OTHER;}private static void setCellPicture(SXSSFWorkbook wb, Row sr, Drawing<?> patriarch, int x, int y, URL url) {// 设置图片宽高sr.setHeight((short) (IMG_WIDTH * IMG_HEIGHT));// （jdk1.7版本try中定义流可自动关闭）try (InputStream is = url.openStream(); ByteArrayOutputStream outputStream = new ByteArrayOutputStream()) {byte[] buff = new byte[BYTES_DEFAULT_LENGTH];int rc;while ((rc = is.read(buff, 0, BYTES_DEFAULT_LENGTH)) > 0) {outputStream.write(buff, 0, rc);}// 设置图片位置XSSFClientAnchor anchor = new XSSFClientAnchor(0, 0, 0, 0, y, x, y + 1, x + 1);// 设置这个，图片会自动填满单元格的长宽anchor.setAnchorType(AnchorType.MOVE_AND_RESIZE);patriarch.createPicture(anchor, wb.addPicture(outputStream.toByteArray(), HSSFWorkbook.PICTURE_TYPE_JPEG));} catch (Exception e) {e.printStackTrace();}}private static String formatDate(Date date) {if (date == null) {return "";}SimpleDateFormat format = new SimpleDateFormat(DATE_FORMAT);return format.format(date);}private static void setSelect(Sheet sheet, Map<Integer, List<String>> selectMap) {if (selectMap == null || selectMap.isEmpty()) {return;}Set<Entry<Integer, List<String>>> entrySet = selectMap.entrySet();for (Entry<Integer, List<String>> entry : entrySet) {int y = entry.getKey();List<String> list = entry.getValue();if (list == null || list.isEmpty()) {continue;}String[] arr = new String[list.size()];for (int i = 0; i < list.size(); i++) {arr[i] = list.get(i);}DataValidationHelper helper = sheet.getDataValidationHelper();CellRangeAddressList addressList = new CellRangeAddressList(1, 65000, y, y);DataValidationConstraint dvc = helper.createExplicitListConstraint(arr);DataValidation dv = helper.createValidation(dvc, addressList);if (dv instanceof HSSFDataValidation) {dv.setSuppressDropDownArrow(false);} else {dv.setSuppressDropDownArrow(true);dv.setShowErrorBox(true);}sheet.addValidationData(dv);}}private static boolean isNumeric(String str) {if (Objects.nonNull(str) && "0.0".equals(str)) {return true;}for (int i = str.length(); --i >= 0; ) {if (!Character.isDigit(str.charAt(i))) {return false;}}return true;}private static String getString(String s) {if (s == null) {return "";}if (s.isEmpty()) {return s;}return s.trim();}}

二、数据导入

1、导入解析为JSON

创建一个学生信息的一个表格：

 Controller 代码：

@RestController
@RequestMapping("/excel")
@Api(tags = "EXCEL模块")
public class ExcelController {/****************************** 导入 ************************************/@PostMapping("/import1")@ApiOperationSupport(order = 1)@ApiOperation(value = "导入解析为JSON", notes = "导入解析为JSON")@ApiImplicitParams({@ApiImplicitParam(name = "file", value = "文件流对象", required = true,dataType = "MultipartFile")})public JSONArray import1(@RequestPart("file") MultipartFile file) throws Exception {JSONArray array = ExcelUtils.readMultipartFile(file);System.out.println("导入数据为:" + array);return array;}}

测试效果：

 2、导入解析为对象（字段自动映射）

首先，你需要创建一个与导入表格对应的Java实体对象，并打上对应的Excel解析的导入注解，@ExcelImport注解的value则为表头名称

对于有的枚举数据，通常我们导入的时候，表格中的数据是值，而在数据保存时，往往用的是键，比如：我们用sex=1可以表示为男，sex=2表示为女，那么我们通过配置也可以达到导入时，数据的自动映射。

那么，我们只需要将Java实体中的对象sex字段的类型改为对应的数字类型Integer，然后再注解中配置好 kv 属性（属性格式为：键1-值1;键2-值2;键3-值3;.....）

@Data
@ApiModel(value = "用户导入类")
public class UserImport {@ApiModelProperty(value = "姓名")@ExcelImport(value = "姓名")private String name;@ApiModelProperty(value = "年龄")@ExcelImport(value = "年龄")private Integer age;@ApiModelProperty(value = "性别")@ExcelImport(value = "性别" , kv="1-男;2-女")private Integer sex;@ApiModelProperty(value = "电话")@ExcelImport(value = "电话")private String phone;@ApiModelProperty(value = "城市")@ExcelImport(value = "城市")private String city;@ApiModelProperty(value = "头像")@ExcelImport(value = "头像")private String avatar;}

    @PostMapping("/import2")@ApiOperationSupport(order = 2)@ApiOperation(value = "导入解析为对象", notes = "导入解析为对象")@ApiImplicitParams({@ApiImplicitParam(name = "file", value = "文件流对象", required = true,dataType = "MultipartFile")})public List<User> import2(@RequestPart("file")MultipartFile file) throws Exception {List<User> users = ExcelUtils.readMultipartFile(file, User.class);System.out.println("导入数据为:" + users);return users;}

测试效果：

 3、导入解析为对象（获取行号）

我们在做页面数据导入时，有时候可能需要获取行号，好追踪导入的数据。

那么，我们只需要在对应的实体中加入一个 int 类型的 rowNum 字段即可。

private int rowNum;  //行号

 测试效果：

 4、 导入解析为对象（获取原始数据）

在做页面数据导入的时候，如果某行存在错误，一般我们会将原始的数据拿出来分析，为什么会造成数据错误。那么，我们在实体类中，增加一个 String 类型的 rowData 字段即可。

private String rowData;     //原始数据

 测试效果

5、导入解析为对象（获取错误提示）

当我们在导入数据的时候，如果某行数据存在，字段类型不正确，长度超过最大限制，必填字段验证，数据唯一性验证 等一些错误时候，我们可以往对象中添加一个 String 类型的 rowTips 字段，则可以直接拿到对应的错误信息。

private String rowTips;     //错误提示

比如，我们将表格中小明的性别改为F（F并不是映射数据），将小红的年龄改为二十八（不能转换为Integer类型数据）

 测试效果：可以看到，我们可以通过 rowTips 直接拿到对应的错误数据提示。

 6、导入解析为对象（限制字段长度）

比如，我们手机通常为11为长度，那么不妨限制电话的最大长度位数为11位。

对应的做法，就是在 @ExcelImport 注解中，设置 maxLength = 11 即可。

    @ApiModelProperty(value = "电话")@ExcelImport(value = "电话",maxLength = 11)private String phone;

比如，我们小明的电话长度设置为超过11位数的一个字符串

 测试效果：

7、导入解析为对象（必填字段验证） 

我们在做数据导入的时候，往往还会有一些必填字段，比如用户的名称，电话。

那么，我们只需要在 @ExcelImport 注解属性中，加上 required = true 即可

    @ApiModelProperty(value = "姓名")@ExcelImport(value = "姓名", required = true)private String name;

我们将小明和小红的姓名去掉，进行测试。 

 测试效果 

8、导入解析为对象（数据唯一性验证）

1、单字段唯一性验证

我们在导入数据的时候，某个字段是具有唯一性的，比如我们这里假设规定姓名不能重复，那么则可以在对应字段的 @ExcelImport 注解上加上 unique = true 属性

    @ApiModelProperty(value = "姓名")@ExcelImport(value = "姓名", required = true,unique = true)private String name;

 这里我们构建2条姓名一样的数据进行测试

 测试效果：

 2、多字段唯一性验证

如果你导入的数据存在多字段唯一性验证这种情况，只需要将每个对应字段的 @ExcelImport 注解属性中，都加上 unique = true 即可。

比如：我们将姓名和电话两个字段进行联合唯一性验证（即不能存在有名称和电话都一样的数据，单个字段属性重复允许）

 使用刚才的数据 

 测试效果：可以看到，虽然名称有相同，但电话不相同，所以这里并没有提示唯一性验证错误。

 现在，我们将小明的电话改成一样

 测试效果：可以看到，我们的联合唯一性验证生效了

9、导入多Sheet页

如果你的导入表格存在多个sheet页（如下图），并想解析每个sheet页的数据，那么也是可以的

 Controller 代码：

    @PostMapping("/import3")@ApiOperationSupport(order = 3)@ApiOperation(value = "导入多Sheet页", notes = "导入多Sheet页")@ApiImplicitParams({@ApiImplicitParam(name = "file", value = "文件流对象", required = true,dataType = "MultipartFile")})public Map<String, JSONArray> import3(@RequestPart("file") MultipartFile file) throws Exception {Map<String, JSONArray> map = ExcelUtils.readFileManySheet(file);map.forEach((key, value) -> {System.out.println("Sheet名称：" + key);System.out.println("Sheet数据：" + value);System.out.println("----------------------");});return map;}

 测试效果

 三、数据导出

1、动态导出（带图片）

如果你的导出中，需要将对应图片链接直接显示为图片的话，那么，这里也是可以的，只需要将对应的类型转为 java.net.URL 类型即可（注意：转的时候有异常处理，为了方便演示，我这里直接抛出）

    @GetMapping("/export4")@ApiOperationSupport(order = 4)@ApiOperation(value = "动态导出(带图片)", notes = "动态导出(带图片)", produces = MediaType.APPLICATION_OCTET_STREAM_VALUE)public void export4(HttpServletResponse response) throws MalformedURLException {// 表头数据List<Object> head = Arrays.asList("姓名","年龄","性别","头像");// 用户1数据List<Object> user1 = new ArrayList<>();user1.add("诸葛亮");user1.add(60);user1.add("男");user1.add(new URL("https://c-ssl.dtstatic.com/uploads/blog/202101/11/20210111220519_7da89.thumb.1000_0.jpeg"));  //显示图片// 用户2数据List<Object> user2 = new ArrayList<>();user2.add("大乔");user2.add(28);user2.add("女");user2.add(new URL("https://c-ssl.dtstatic.com/uploads/blog/202112/02/20211202113803_9ba69.thumb.1000_0.png"));  //显示图片// 将数据汇总List<List<Object>> sheetDataList = new ArrayList<>();sheetDataList.add(head);sheetDataList.add(user1);sheetDataList.add(user2);// 导出数据ExcelUtils.export(response,"用户表", sheetDataList);}

测试效果

2、动态导出（带下拉列表）

我们在做一些数据导出的时候，可能要对某一行的下拉数据进行约束限制。

比如，当我们下载一个导入模版的时候，我们可以将性别，城市对应的列设置为下拉选择。

    @GetMapping("/export5")@ApiOperationSupport(order = 5)@ApiOperation(value = "动态导出(带下拉列表)", notes = "动态导出(带下拉列表)", produces = MediaType.APPLICATION_OCTET_STREAM_VALUE)public void export5(HttpServletResponse response) throws MalformedURLException {// 表头数据List<Object> head = Arrays.asList("姓名","年龄","性别","城市");// 用户1数据List<Object> user1 = new ArrayList<>();user1.add("诸葛亮");user1.add(60);user1.add("男");user1.add("北京");// 用户2数据List<Object> user2 = new ArrayList<>();user2.add("大乔");user2.add(28);user2.add("女");user2.add("上海");// 将数据汇总List<List<Object>> sheetDataList = new ArrayList<>();sheetDataList.add(head);sheetDataList.add(user1);sheetDataList.add(user2);//设置下拉列表,键为第几列(从0开始),值为下拉数据Map<Integer,List<String>> selectMap = new HashMap<>(1);selectMap.put(2,Arrays.asList("男","女"));selectMap.put(3,Arrays.asList("北京","上海","广州"));// 导出数据ExcelUtils.export(response,"用户表", sheetDataList,selectMap);}

测试效果：

3、动态导出（横向合并）

比如，我们将表头横向合并，只需要将合并的单元格设置为 ExcelUtils.COLUMN_MERGE 即可。

    @GetMapping("/export6")@ApiOperationSupport(order = 6)@ApiOperation(value = "动态导出(横向合并)", notes = "动态导出(横向合并)", produces = MediaType.APPLICATION_OCTET_STREAM_VALUE)public void export6(HttpServletResponse response) throws MalformedURLException {// 表头数据List<Object> head = Arrays.asList("姓名","年龄","性别","地址",ExcelUtils.COLUMN_MERGE);// 用户1数据List<Object> user1 = new ArrayList<>();user1.add("诸葛亮");user1.add(60);user1.add("男");user1.add("北京");user1.add("门头沟区12号");// 用户2数据List<Object> user2 = new ArrayList<>();user2.add("大乔");user2.add(28);user2.add("女");user2.add("上海");user2.add("黄埔区24号");// 将数据汇总List<List<Object>> sheetDataList = new ArrayList<>();sheetDataList.add(head);sheetDataList.add(user1);sheetDataList.add(user2);// 导出数据ExcelUtils.export(response,"用户表", sheetDataList);}

测试效果

4、动态导出（纵向合并） 

除了横向合并，我们还可以进行纵向合并，只需要将合并的单元格设为 ExcelUtils.ROW_MERGE 即可。

    @GetMapping("/export7")@ApiOperationSupport(order = 7)@ApiOperation(value = "动态导出(纵向合并)", notes = "动态导出(纵向合并)", produces = MediaType.APPLICATION_OCTET_STREAM_VALUE)public void export7(HttpServletResponse response) throws MalformedURLException {// 表头数据List<Object> head = Arrays.asList("归属地","姓名","年龄","性别","地址");// 用户1数据List<Object> user1 = new ArrayList<>();user1.add("蜀国");user1.add("诸葛亮");user1.add(60);user1.add("男");user1.add("北京门头沟区12号");// 用户2数据List<Object> user2 = new ArrayList<>();user2.add("吴国");user2.add("大乔");user2.add(28);user2.add("女");user2.add("上海黄埔区24号");// 用户3数据List<Object> user3 = new ArrayList<>();user3.add(ExcelUtils.ROW_MERGE);user3.add("小乔");user3.add(26);user3.add("女");user3.add("上海金山区30号");// 将数据汇总List<List<Object>> sheetDataList = new ArrayList<>();sheetDataList.add(head);sheetDataList.add(user1);sheetDataList.add(user2);sheetDataList.add(user3);// 导出数据ExcelUtils.export(response,"用户表", sheetDataList);}

测试效果

5、导出模板(附示例数据)

我们在做数据导入的时候，往往首先会提供一个模版供其下载，这样用户在导入的时候才知道如何去填写数据。导出模板除了可以用上面的动态导出，这里还提供了一种更加便捷的写法。只需要创建一个类，然后再对应字段上打上 @ExcelExport 注解类即可。

我们在做模版下载时候，有时往往会携带一条样本数据，好提示用户数据格式是什么，那么我们只需要在对应字段加上example

@Data
@ApiModel(value = "用户导出类")
public class UserExport {@ApiModelProperty(value = "姓名")@ExcelExport(value = "姓名",example = "张三")private String name;@ApiModelProperty(value = "年龄")@ExcelExport(value = "年龄",example = "20")private Integer age;@ApiModelProperty(value = "性别")@ExcelExport(value = "性别",example = "男")private Integer sex;@ApiModelProperty(value = "电话")@ExcelExport(value = "电话",example = "18888888888")private String phone;@ApiModelProperty(value = "城市")@ExcelExport(value = "城市",example = "上海")private String city;}

 Controller 代码：如果不需要显示example，将最后一个参数改为false

    @GetMapping("/export8")@ApiOperationSupport(order = 8)@ApiOperation(value = "导出模板(附示例数据)", notes = "导出模板(附示例数据)", produces = MediaType.APPLICATION_OCTET_STREAM_VALUE)public void export8(HttpServletResponse response) {ExcelUtils.exportTemplate(response, "用户表", UserExport.class,true);}

测试效果：

 6、按对象导出

我们还可以通过 List 对象，对数据直接进行导出。首先，同样需要在对应类的字段上，设置导出名称。

    @GetMapping("/export9")@ApiOperationSupport(order = 9)@ApiOperation(value = "按对象导出", notes = "按对象导出", produces = MediaType.APPLICATION_OCTET_STREAM_VALUE)public void export9(HttpServletResponse response) {//构建数据List<UserExport> userList = new ArrayList<>();UserExport user1 = new UserExport();user1.setName("张三");user1.setAge(18);user1.setSex(1);user1.setCity("成都");user1.setPhone("19999999999");UserExport user2 = new UserExport();user2.setName("李四");user2.setAge(25);user2.setSex(2);user2.setCity("西安");user2.setPhone("18888888888");userList.add(user1);userList.add(user2);ExcelUtils.export(response, "用户表", userList,UserExport.class);}

 测试效果

 7、按对象导出（数据映射）

在上面 的导出中，我们可以看到，性别数据导出来是1和2，这个不利于用户体验，应该需要转换为对应的中文，我们可以在字段注解上进行对应的配置KV

@Data
@ApiModel(value = "用户导出类")
public class UserExport {@ApiModelProperty(value = "姓名")@ExcelExport(value = "姓名",example = "张三")private String name;@ApiModelProperty(value = "年龄")@ExcelExport(value = "年龄",example = "20")private Integer age;@ApiModelProperty(value = "性别")@ExcelExport(value = "性别",example = "男",kv="1-男;2-女")private Integer sex;@ApiModelProperty(value = "电话")@ExcelExport(value = "电话",example = "18888888888")private String phone;@ApiModelProperty(value = "城市")@ExcelExport(value = "城市",example = "上海")private String city;}

测试效果：可以看到1和2显示为了对应的男和女

8、按对象导出（调整表头顺序） 

 如果你需要对表头字段进行排序，有两种方式：

第一种：按照表格的顺序，排列Java类中的字段；

第二种：在 @ExcelExport 注解中，指定 sort 属性，其值越少，排名越靠前。 

测试效果：可以看到，此时导出数据的表头顺序，和我们指定的顺序完全一致。

9、多Sheet页导出

Controller 代码：

    @GetMapping("/export10")@ApiOperationSupport(order = 10)@ApiOperation(value = "多Sheet页导出", notes = "多Sheet页导出", produces = MediaType.APPLICATION_OCTET_STREAM_VALUE)public void export10(HttpServletResponse response) {// 第 1 个 Sheet 页List<List<Object>> sheet1 = new ArrayList<>();List<Object> sheet1Head = new ArrayList<>();sheet1Head.add("姓名");sheet1Head.add("数学");sheet1Head.add("英语");sheet1.add(sheet1Head);List<Object> row1 = new ArrayList<>();row1.add("Jack");row1.add(85);row1.add(100);sheet1.add(row1);List<Object> row2 = new ArrayList<>();row2.add("Marry");row2.add(85);row2.add(100);sheet1.add(row2);// 第 2 个 Sheet 页List<List<Object>> sheet2 = new ArrayList<>();List<Object> sheet2Head = new ArrayList<>();sheet2Head.add("姓名");sheet2Head.add("音乐");sheet2Head.add("美术");sheet2.add(sheet2Head);List<Object> row01 = new ArrayList<>();row01.add("Jack");row01.add(77);row01.add(66);sheet2.add(row01);List<Object> row02 = new ArrayList<>();row02.add("Marry");row02.add(99);row02.add(88);sheet2.add(row02);// 将两个 Sheet 页添加到集合中Map<String, List<List<Object>>> sheets = new LinkedHashMap<>();sheets.put("文化课", sheet1);sheets.put("艺术课", sheet2);// 导出数据ExcelUtils.exportManySheet(response, "学生成绩表", sheets);}

测试效果：

第一个 Sheet 页 

第二个 Sheet 页  

 

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疑问解答

关于身份证导入显示科学计数法的问题

首先，当我们把身份证输入到表格中的时候，表格会默认为数字类型，由于数字太大，这时候Excel 会自动显示为科学计数法。

 那么这个时候，我们进行导入的话，确实会显示为科学计数法，如下图所示：

那么，如果要解决这个问题，需要从根源解决掉，即让 Excel 表格不能显示为科学计数法。 

这个时候，我们需要将该列设置为文本格式：

 然后设置为文本格式。

 当设置完成后，你再重新输入身份证后，就会原封不动的显示了。

 这个时候，你再导入就会完全显示了