列表信息导出为Excel文件，依赖pom： ```XML Sheet, Row: org.apache.poi poi XSSFWorkbook org.apache.poi poi-ooxml ``` ``` 实现代码： ``` override表示是否覆盖现有文件，false，追加；true，覆盖。 ```java private void exportExcelToLocal(List list, Class clazz) throws IOException { if (CollectionUtils.isEmpty(list)) { return; } XSSFWorkbook workbook = null; File file = new File("src/main/resources/xxx.xlsx"); FileInputStream fis = null; if (!file.exists()) { file.createNewFile(); } else { if (!override) { fis = new FileInputStream(file); workbook = new XSSFWorkbook(fis); } } XSSFWorkbook workbookResult = ExcelUtils.exportExcelData(new XSSFWorkbook(), list, clazz, false); if (Objects.nonNull(workbook)) { Integer index = workbookResult.getSheetAt(0).getLastRowNum() + 1; Sheet sheet = workbookResult.getSheetAt(0); Sheet lastSheet = workbook.getSheetAt(0); for (int i = 1; i <= lastSheet.getLastRowNum(); ++i) { Row row = sheet.createRow(index++); for (int cellIndex = 0; cellIndex < lastSheet.getRow(i).getLastCellNum(); ++cellIndex) { String value = lastSheet.getRow(i).getCell(cellIndex).getStringCellValue(); row.createCell(cellIndex).setCellValue(value); } } } FileOutputStream fos = new FileOutputStream(file); workbookResult.write(fos); fos.flush(); fos.close(); if (Objects.nonNull(fis)) { fis.close(); } } ``` ExcelUtils：单次导出操作 ```java public static XSSFWorkbook exportExcelData(XSSFWorkbook workbook, List data, Class clazz, boolean template) { XSSFSheet sheet = workbook.createSheet(); Row rowHeader = sheet.createRow(0); Map fieldMap = analysisAnnotation(clazz); for(int i = 0; i < fieldMap.size(); ++i) { Cell cell = rowHeader.createCell(i); Field field = (Field)fieldMap.get(i + 1); ExcelBind ea = (ExcelBind)field.getAnnotation(ExcelBind.class); cell.setCellValue(ea.columnName()); cell.setCellStyle(setRowHeaderStyle(workbook)); cell.setCellType(CellType.STRING); } if (!template) { analysisData(sheet, data, clazz, fieldMap); } return workbook; } // 数据导出 private static void analysisData(Sheet sheet, List data, Class clazz, Map fieldMap) { for(int i = 0; i < data.size(); ++i) { Row row = sheet.createRow(i + 1); T t = data.get(i); Class aClass = t.getClass(); for(int j = 0; j < fieldMap.size(); ++j) { Field declaredField = (Field)fieldMap.get(j + 1); declaredField.setAccessible(true); String key = declaredField.getName(); Object value = ""; try { value = declaredField.get(t) == null ? "" : declaredField.get(t); } catch (IllegalAccessException var13) { var13.printStackTrace(); } if ("java.util.Date".equals(declaredField.getType().getName())) { ExcelBind ea = (ExcelBind)declaredField.getAnnotation(ExcelBind.class); if (StringUtils.isNotEmpty(ea.dateFormat())) { value = (new SimpleDateFormat(ea.dateFormat())).format(value); } } row.createCell(j).setCellValue(value.toString()); } } } ```