一、介绍
常常有客户这样子要求：你要把我们的报表直接用Excel打开(电信系统、银行系统)。或者是：我们已经习惯用Excel打印。这样在我们实际的开发中，很多时候需要实现导入、导出Excel的应用。
目前，比较常用的实现Java导入、导出Excel的技术有:Jakarta POI、freemarker和Java Excel
下面我就分别讲解一下如何使用这些技术实现导入、导出Excel
二、使用Jakarta POI导入、导出Excel
Jakarta POI 是一套用于访问微软格式文档的Java API。Jakarta POI有很多组件组成，其中有用于操作Excel格式文件的HSSF和用于操作Word的HWPF，
在各种组件中目前只有用于操作Excel的HSSF相对成熟。官方主页http://poi.apache.org/index.html，API文档http://poi.apache.org/apidocs/index.html
1.环境配置
下载jar
官方下载：http://poi.apache.org/download.html这里可以下载到它的最新版本和文档，目前最新版本是3.7，这里使用比较稳定的3.6版。
加入jar包
将根目录下的poi-3.6-20091214.jar和Lib目录下三个通用包 commons-logging-1.1.jar junit-3.8.1.jar log4j-1.2.13.jar拷贝到项目的Lib下
2.Jakarta POI HSSF API组件
HSSF（用于操作Excel的组件）提供给用户使用的对象在rg.apache.poi.hssf.usermodel包中,主要部分包括Excel对象，样式和格式，还有辅助操作。有以下几种对象：
常用组件：
HSSFWorkbook excel的文档对象
HSSFSheet excel的表单
HSSFRow excel的行
HSSFCell excel的格子单元
HSSFFont excel字体
HSSFDataFormat 日期格式
HSSFHeader sheet头
HSSFFooter sheet尾（只有打印的时候才能看到效果）
样式：
HSSFCellStyle cell样式
辅助操作包括：
HSSFDateUtil 日期
HSSFPrintSetup 打印
HSSFErrorConstants 错误信息表
3. 基本操作步骤
首先，理解一下一个Excel的文件的组织形式，一个Excel文件对应于一个workbook(HSSFWorkbook)，一个workbook可以有多个sheet（HSSFSheet）组成，一个sheet是由多个row（HSSFRow）组成，一个row是由多个cell（HSSFCell）组成。
基本操作步骤：
a、用HSSFWorkbook打开或者创建“Excel文件对象”
b、用HSSFWorkbook对象返回或者创建Sheet对象
c、用Sheet对象返回行对象，用行对象得到Cell对象
d、对Cell对象读写。
4.我自己写的测试用例
import java.io.FileOutputStream; import java.util.ArrayList; import java.util.List; import org.apache.poi.hssf.usermodel.HSSFCell; import org.apache.poi.hssf.usermodel.HSSFCellStyle; import org.apache.poi.hssf.usermodel.HSSFFont; 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.hssf.util.Region; public class POIExportExcel { public HSSFWorkbook generateExcel1(List list, HSSFWorkbook wb, String title) { //行的数量 int rows = 0; HSSFSheet sheet = wb.createSheet("Sheet1"); // 数据格样式 HSSFCellStyle dataCellStyle = createDataCellStyle(wb); // 小标题样式 HSSFCellStyle cellStyle = createCellStyle(wb); sheet.setDefaultRowHeight((short) 400);//设置所有行高为400 //设置列宽 sheet.setColumnWidth((short) 1, (short) 2800); sheet.setColumnWidth((short) 2, (short) 2800); sheet.setColumnWidth((short) 3, (short) 2800); sheet.setColumnWidth((short) 4, (short) 2800); sheet.setColumnWidth((short) 5, (short) 2800); sheet.setColumnWidth((short) 6, (short) 2800); sheet.setColumnWidth((short) 7, (short) 2800); sheet.setColumnWidth((short) 8, (short) 2800); sheet.setColumnWidth((short) 9, (short) 2800); sheet.setColumnWidth((short) 10, (short) 3200); sheet.setColumnWidth((short) 11, (short) 3200); sheet.setColumnWidth((short) 12, (short) 3200); sheet.setColumnWidth((short) 13, (short) 3200); //标题行 HSSFRow row1 = sheet.createRow((short) (rows++)); row1.setHeight((short) 500); sheet.addMergedRegion(new Region(0, (short) 0, 0, (short) 13));//横跨1-14列 createCell(row1, (short) 0, cellStyle, title); //表头行(1,2列合并；3,4,5,6,7列合并；8,9列合并) HSSFRow row2 = sheet.createRow((short) (rows++)); sheet.addMergedRegion(new Region(1, (short) 0, 1, (short) 1)); sheet.addMergedRegion(new Region(1, (short) 2, 1, (short) 6)); sheet.addMergedRegion(new Region(1, (short) 7, 1, (short) 8)); sheet.addMergedRegion(new Region(1, (short) 9, 1, (short) 9)); sheet.addMergedRegion(new Region(1, (short) 10, 1, (short) 10)); sheet.addMergedRegion(new Region(1, (short) 11, 1, (short) 11)); sheet.addMergedRegion(new Region(1, (short) 12, 1, (short) 12)); sheet.addMergedRegion(new Region(1, (short) 13, 1, (short) 13)); createCell(row2, (short) 0, dataCellStyle, "name1"); createNullCell(row2, (short) 1, dataCellStyle); createCell(row2, (short) 2, dataCellStyle, "name2"); createNullCell(row2, (short) 3, dataCellStyle); createNullCell(row2, (short) 4, dataCellStyle); createNullCell(row2, (short) 5, dataCellStyle); createNullCell(row2, (short) 6, dataCellStyle); createCell(row2, (short) 7, dataCellStyle, "name3"); createNullCell(row2, (short) 8, dataCellStyle); createCell(row2, (short) 9, dataCellStyle, "name4"); createCell(row2, (short) 10, dataCellStyle, "name5"); createCell(row2, (short) 11, dataCellStyle, "name6"); createCell(row2, (short) 12, dataCellStyle, "name7"); createCell(row2, (short) 13, dataCellStyle, "name8"); //遍历集合,保存数据到单元格 for(int i=0;i<list.size();i++){ Object javaBean = list.get(i); //具体的数据值通过对象去获取，这里简单给值 String variable1 = "value1"+"_"+i; String variable2 = "value2"+"_"+i; String variable3 = "value3"+"_"+i; String variable4 = "value4"+"_"+i; String variable5 = "value5"+"_"+i; String variable6 = "value6"+"_"+i; String variable7 = "value7"+"_"+i; String variable8 = "value8"+"_"+i; HSSFRow rowi = sheet.createRow((short) (rows++)); sheet.addMergedRegion(new Region(i+2, (short) 0, i+2, (short) 1)); sheet.addMergedRegion(new Region(i+2, (short) 2, i+2, (short) 6)); sheet.addMergedRegion(new Region(i+2, (short) 7, i+2, (short) 8)); sheet.addMergedRegion(new Region(i+2, (short) 9, i+2, (short) 9)); sheet.addMergedRegion(new Region(i+2, (short) 10, i+2, (short) 10)); sheet.addMergedRegion(new Region(i+2, (short) 11, i+2, (short) 11)); sheet.addMergedRegion(new Region(i+2, (short) 12, i+2, (short) 12)); sheet.addMergedRegion(new Region(i+2, (short) 13, i+2, (short) 13)); createCell(rowi, (short) 0, dataCellStyle, variable1); createNullCell(rowi, (short) 1, dataCellStyle); createCell(rowi, (short) 2, dataCellStyle, variable2); createNullCell(rowi, (short) 3, dataCellStyle); createNullCell(rowi, (short) 4, dataCellStyle); createNullCell(rowi, (short) 5, dataCellStyle); createNullCell(rowi, (short) 6, dataCellStyle); createCell(rowi, (short) 7, dataCellStyle, variable3); createNullCell(rowi, (short) 8, dataCellStyle); createCell(rowi, (short) 9, dataCellStyle, variable4); createCell(rowi, (short) 10, dataCellStyle, variable5); createCell(rowi, (short) 11, dataCellStyle, variable6); createCell(rowi, (short) 12, dataCellStyle, variable7); createCell(rowi, (short) 13, dataCellStyle, variable8); } return wb; } /** * 创建单元格 * @param row * @param id * @param style * @param value */ private void createCell(HSSFRow row, short id, HSSFCellStyle style, String value) { HSSFCell cell = row.createCell((short) id); // cell.setEncoding(HSSFCell.ENCODING_UTF_16); cell.setCellValue(value); cell.setCellStyle(style); } /** * 创建空的单元格 */ private HSSFCell createNullCell(HSSFRow row, short id, HSSFCellStyle style) { HSSFCell null1Cell = row.createCell(id); null1Cell.setCellStyle(style); return null1Cell; } /** * 设置数据单元格样式 * @param wb * @return */ private HSSFCellStyle createDataCellStyle(HSSFWorkbook wb) { HSSFCellStyle dataCellStyle = wb.createCellStyle(); // 水平居中 dataCellStyle.setAlignment(HSSFCellStyle.ALIGN_LEFT); dataCellStyle.setBorderBottom(HSSFCellStyle.BORDER_THIN); dataCellStyle.setBorderLeft(HSSFCellStyle.BORDER_THIN); dataCellStyle.setBorderRight(HSSFCellStyle.BORDER_THIN); dataCellStyle.setBorderTop(HSSFCellStyle.BORDER_THIN); return dataCellStyle; } /** * 设置单元格样式 * @param wb * @return */ private HSSFCellStyle createCellStyle(HSSFWorkbook wb) { // 小标题样式 HSSFCellStyle cellStyle = wb.createCellStyle(); // 水平居中 cellStyle.setAlignment(HSSFCellStyle.ALIGN_CENTER); // 字体 HSSFFont littleFont = wb.createFont(); // 设置字体为粗体 littleFont.setBoldweight(HSSFFont.BOLDWEIGHT_BOLD); // 然后将字体关联到样式 cellStyle.setFont(littleFont); cellStyle.setBorderBottom(HSSFCellStyle.BORDER_THIN); cellStyle.setBorderLeft(HSSFCellStyle.BORDER_THIN); cellStyle.setBorderRight(HSSFCellStyle.BORDER_THIN); cellStyle.setBorderTop(HSSFCellStyle.BORDER_THIN); cellStyle.setAlignment(HSSFCellStyle.ALIGN_CENTER); return cellStyle; } public static void main(String[] args){ /*String serverPath = request.getSession().getServletContext().getRealPath("/")+"exportExcel"; //在服务器端创建文件夹 File file = new File(serverPath+path); if(!file.exists()){ file.mkdir(); } SimpleDateFormat sfm = new SimpleDateFormat("yyyy-MM-dd"); String filename = "excel" + "_" + sfm.format(new java.util.Date()); String encodedfileName = new String(filename.getBytes(), "GBK"); FileOutputStream out = new FileOutputStream(serverPath+path+"/"+encodedfileName+".xls"); */ new POIExportExcel(); String title = "POI导出excel"; List list = new ArrayList<String>(); //加入两条做个测试 list.add(new String()); list.add(new String()); try { FileOutputStream out = new FileOutputStream("D:/"+title+".xls"); HSSFWorkbook wb =new HSSFWorkbook(); wb = new POIExportExcel().generateExcel1(list,wb,title); wb.write(out); /*List srcfile=new ArrayList(); srcfile.add(new File(serverPath+path+"/"+encodedfileName+".xls")); //将服务器上存放Excel的文件夹打成zip包 File zipfile = new File(serverPath+path+".zip"); ZipUtil.zipFiles(srcfile, zipfile); //弹出下载框供用户下载 this.downFile(response,serverPath, path+".zip");*/ } catch (Exception e) { // TODO Auto-generated catch block e.printStackTrace(); } } }
结果如下图：
三、使用freemarker导出excel
参考文章:
http://blog.csdn.net/jerehedu/article/details/45195359
原文：http://www.cnblogs.com/zhaoyhBlog/p/6255998.html
