poi导出excel并下载工具类（含有demo）

package com.aisino.cxtj.utils; import java.io.ByteArrayOutputStream; import java.io.IOException; import java.text.SimpleDateFormat; import java.util.Date; import java.util.LinkedHashMap; import java.util.List; import java.util.Map.Entry; import java.util.Set; import org.apache.poi.hssf.usermodel.HSSFCell; import org.apache.poi.hssf.usermodel.HSSFRichTextString; import org.apache.poi.hssf.usermodel.HSSFRow; import org.apache.poi.hssf.usermodel.HSSFSheet; import org.apache.poi.hssf.usermodel.HSSFWorkbook; import org.apache.poi.ss.usermodel.CellStyle; import org.apache.poi.ss.usermodel.Font; import org.apache.poi.ss.usermodel.IndexedColors; import org.apache.poi.ss.util.CellRangeAddress; import org.apache.poi.ss.util.Region; /** * Excel工具类 * @ClassName: ExcelUtil * @author CXJ * @date 2016年8月3日 */ public class TjExcelUtil { private static HSSFWorkbook wb; private static CellStyle titleStyle; // 标题行样式 private static Font titleFont; // 标题行字体 private static CellStyle dateStyle; // 日期行样式 private static Font dateFont; // 日期行字体 private static CellStyle headStyle; // 表头行样式 private static Font headFont; // 表头行字体 private static CellStyle contentStyle; // 内容行样式 private static Font contentFont; // 内容行字体 /** * 导出文件 * * @param setInfo * @param outputExcelFileName * @return * @throws IOException */ public static boolean export2File(ExcelExportData setInfo, String outputExcelFileName,String tjlx) throws Exception { return FileUtil.write(outputExcelFileName, export2ByteArray(setInfo,tjlx),true, true); } /** * 导出到byte数组 * * @param setInfo * @return * @throws Exception */ public static byte[] export2ByteArray(ExcelExportData setInfo, String tjlx) throws Exception { return export2Stream(setInfo,tjlx).toByteArray(); } /** * 导出到流 * * @param setInfo * @return * @throws Exception */ public static ByteArrayOutputStream export2Stream(ExcelExportData setInfo, String tjlx) throws Exception { init(); ByteArrayOutputStream outputStream = new ByteArrayOutputStream(); Set<Entry<String, List<?>>> set = setInfo.getDataMap().entrySet(); String[] sheetNames = new String[setInfo.getDataMap().size()]; int sheetNameNum = 0; for (Entry<String, List<?>> entry : set) { sheetNames[sheetNameNum] = entry.getKey(); sheetNameNum++; } HSSFSheet[] sheets = getSheets(setInfo.getDataMap().size(), sheetNames); int sheetNum = 0; for (Entry<String, List<?>> entry : set) { // Sheet List<?> objs = entry.getValue(); // 标题行 createTableTitleRow(setInfo, sheets, sheetNum); // 日期行 (导出日期) createTableDateRow(setInfo, sheets, sheetNum ,tjlx); // 表头 //creatTableHeadRow(setInfo, sheets, sheetNum); // 表体 String[] fieldNames = setInfo.getFieldNames().get(sheetNum); int rowNum = 4; for (Object obj : objs) { HSSFRow contentRow = sheets[sheetNum].createRow(rowNum); contentRow.setHeight((short) 300); HSSFCell[] cells = getCells(contentRow, setInfo.getFieldNames().get(sheetNum).length); int cellNum = 1; // 去掉一列序号，因此从1开始 if (fieldNames != null) { for (int num = 0; num < fieldNames.length; num++) { Object value = ReflectionUtil.invokeGetterMethod(obj,fieldNames[num]); cells[cellNum].setCellValue(value == null ? "" : value.toString()); cellNum++; } } rowNum++; } adjustColumnSize(sheets, sheetNum, fieldNames); // 自动调整列宽 sheetNum++; } wb.write(outputStream); outputStream.flush(); outputStream.close(); return outputStream; } /** * @Description: 初始化 */ private static void init() { wb = new HSSFWorkbook(); titleFont = wb.createFont(); titleStyle = wb.createCellStyle(); dateStyle = wb.createCellStyle(); dateFont = wb.createFont(); headStyle = wb.createCellStyle(); headFont = wb.createFont(); contentStyle = wb.createCellStyle(); contentFont = wb.createFont(); initTitleCellStyle(); initTitleFont(); initDateCellStyle(); initDateFont(); initHeadCellStyle(); initHeadFont(); initContentCellStyle(); initContentFont(); } /** * @Description: 自动调整列宽 */ private static void adjustColumnSize(HSSFSheet[] sheets, int sheetNum, String[] fieldNames) { for (int i = 0; i < fieldNames.length + 1; i++) { sheets[sheetNum].autoSizeColumn(i, true); } } /** * @Description: 创建标题行(需合并单元格) */ private static void createTableTitleRow(ExcelExportData setInfo, HSSFSheet[] sheets, int sheetNum) { CellRangeAddress titleRange = new CellRangeAddress(0, 0, 0, setInfo .getFieldNames().get(sheetNum).length); sheets[sheetNum].addMergedRegion(titleRange); HSSFRow titleRow = sheets[sheetNum].createRow(0); titleRow.setHeight((short) 600); HSSFCell titleCell = titleRow.createCell(0); titleCell.setCellStyle(titleStyle); titleCell.setCellValue(setInfo.getTitles()[sheetNum]); } /** * @Description: 创建日期行(需合并单元格) */ private static void createTableDateRow(ExcelExportData setInfo, HSSFSheet[] sheets, int sheetNum, String tjlx) { CellRangeAddress dateRange = new CellRangeAddress(1, 1, 0, setInfo .getFieldNames().get(sheetNum).length); sheets[sheetNum].addMergedRegion(dateRange); HSSFRow dateRow = sheets[sheetNum].createRow(1); dateRow.setHeight((short) 350); HSSFCell dateCell = dateRow.createCell(0); dateCell.setCellStyle(dateStyle); if (null==setInfo.getExportExcelDate()||"".equals(setInfo.getExportExcelDate())) { dateCell.setCellValue("统计日期："+new SimpleDateFormat("yyyy-MM-dd").format(new Date())); }else{ dateCell.setCellValue("统计日期："+setInfo.getExportExcelDate()); } //创建workbook HSSFWorkbook workbook = new HSSFWorkbook(); //创建sheet页 //HSSFSheet sheet = workbook.createSheet("学生表"); //创建单元格 HSSFRow row = sheets[0].createRow(2);//---------------------第一行 row.setHeight((short) 350); HSSFCell c0 = row.createCell(1); if(tjlx.equals("aswjtj")){ c0.setCellValue(new HSSFRichTextString("税局")); }else{ c0.setCellValue(new HSSFRichTextString("开票月份")); } c0.setCellStyle(dateStyle); HSSFCell c1 = row.createCell(2); c1.setCellValue(new HSSFRichTextString("数量(张)")); //1 c1.setCellStyle(dateStyle); HSSFCell c2 = row.createCell(5); c2.setCellValue(new HSSFRichTextString("金额(元)")); //2 c2.setCellStyle(dateStyle); HSSFCell c3 = row.createCell(8); c3.setCellValue(new HSSFRichTextString("税额(元)")); //3 c3.setCellStyle(dateStyle); HSSFCell c4 = row.createCe