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导出Excel通用工具类

导出Excel的两种方法:

一,POI

导入poi包

poi-3.11-beta3-20141111.jar

技术分享
 1 /** 2 *  3 */ 4 package com.car.ots.mpckp.utils; 5  6 import java.io.OutputStream; 7 import java.net.URLEncoder; 8 import java.util.List; 9 10 import javax.servlet.http.HttpServletRequest;11 import javax.servlet.http.HttpServletResponse;12 13 import org.apache.commons.beanutils.BeanUtils;14 import org.apache.poi.hssf.usermodel.HSSFCell;15 import org.apache.poi.hssf.usermodel.HSSFCellStyle;16 import org.apache.poi.hssf.usermodel.HSSFRow;17 import org.apache.poi.hssf.usermodel.HSSFSheet;18 import org.apache.poi.hssf.usermodel.HSSFWorkbook;19 20 /**21 * @author cora.guo22 * 23 */24 public class ExportUtils {25 26 public static void createExcel(HttpServletRequest req,27 HttpServletResponse resp, List<Object> datas, String sheetName,28 List<String> headers, List<String> colunmValueNames)29 throws Exception {30 OutputStream out = null;31 try {32 // 第一步,创建一个webbook,对应一个Excel文件33 resp.setContentType("application/vnd.ms-excel");34 resp.setCharacterEncoding("UTF-8");35 if (req.getHeader("User-Agent").toLowerCase().indexOf("msie") != -1) {36 resp.setHeader("Content-Disposition", "attachment;filename="37 + URLEncoder.encode(sheetName, "utf-8") + ".xls");38 } else {39 resp.setHeader("Content-Disposition", "attachment;filename="40 + new String(sheetName.getBytes("utf-8"), "ISO-8859-1")41 + ".xls");42 }43 resp.setHeader("Cache-Control", "max-age=0");44 HSSFWorkbook wb = new HSSFWorkbook();45 46 // 第二步,在webbook中添加一个sheet,对应Excel文件中的sheet47 HSSFSheet sheet = wb.createSheet(sheetName);48 // 第三步,在sheet中添加表头第0行,注意老版本poi对Excel的行数列数有限制short49 HSSFRow row = sheet.createRow(0);50 // 第四步,创建单元格,并设置值表头 设置表头居中51 HSSFCellStyle style = wb.createCellStyle();52 // 创建居中样式53 style.setAlignment(HSSFCellStyle.ALIGN_CENTER);54 HSSFCell cell = null;55 if (headers != null && headers.size() > 0) {56 for (int i = 0; i < headers.size(); i++) {57 cell = row.createCell(i);58 cell.setCellValue(headers.get(i));59 cell.setCellStyle(style);60 }61 }62 // 第五步,写入实体数据 实际应用中这些数据从数据库得到,63 if (datas != null && datas.size() != 0) {64 for (int r = 0; r < datas.size(); r++) {65 Object obj = datas.get(r);66 row = sheet.createRow(r+1);67 if (colunmValueNames != null68 && colunmValueNames.size() != 0) {69 for (int j = 0; j < colunmValueNames.size(); j++) {70 String name = colunmValueNames.get(j);71 String value =http://www.mamicode.com/ BeanUtils.getProperty(obj, name);72 // 创建单元格,设置值73 cell = row.createCell(j);74 cell.setCellStyle(style);75 cell.setCellValue(value);76 }77 }78 }79 }80 out = resp.getOutputStream();81 wb.write(out);82 } catch (Exception e) {83 // TODO Auto-generated catch block84 throw new Exception(e);85 } finally {86 out.close();87 }88 }89 }
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二,JXl

导入包

技术分享
 1 package com.car.ots.uis.utils; 2  3 import java.net.URLEncoder; 4 import java.util.List; 5  6 import javax.servlet.http.HttpServletRequest; 7 import javax.servlet.http.HttpServletResponse; 8  9 import jxl.Workbook;10 import jxl.format.Alignment;11 import jxl.format.VerticalAlignment;12 import jxl.write.Label;13 import jxl.write.WritableCellFormat;14 import jxl.write.WritableFont;15 import jxl.write.WritableSheet;16 import jxl.write.WritableWorkbook;17 18 import org.apache.commons.beanutils.BeanUtils;19 20 public class ExportUtil {21   public static void export(HttpServletRequest req, HttpServletResponse resp, List<Object> datas,22       String sheetName, List<String> headers, List<String> colunmValueNames) throws Exception {23     // 写入excel24     WritableWorkbook wb = null;25     WritableSheet ws = null;26     Label label = null;27 28     try {29       resp.setContentType("application/vnd.ms-excel");30       resp.setCharacterEncoding("UTF-8");31       if (req.getHeader("User-Agent").toLowerCase().indexOf("msie") != -1) {32         resp.setHeader("Content-Disposition",33             "attachment;filename=" + URLEncoder.encode(sheetName, "utf-8") + ".xls");34       } else {35         resp.setHeader("Content-Disposition",36             "attachment;filename=" + new String(sheetName.getBytes("utf-8"), "ISO-8859-1") + ".xls");37       }38       resp.setHeader("Cache-Control", "max-age=0");39       wb = Workbook.createWorkbook(resp.getOutputStream());40 41       ws = wb.createSheet(sheetName, 0);42 43       WritableFont bold_font = new WritableFont(WritableFont.ARIAL, 10, WritableFont.BOLD);44       WritableCellFormat f = new WritableCellFormat(bold_font);45       f.setVerticalAlignment(VerticalAlignment.CENTRE);46       f.setAlignment(Alignment.CENTRE);47       if(headers!=null&headers.size()!=0){48           for (int i = 0; i < headers.size(); i++) {49               ws.setColumnView(i, 25);50               label = new Label(i, 0, headers.get(i), f);51               ws.addCell(label);52           }53       }54 55       WritableFont nobold_font = new WritableFont(WritableFont.ARIAL, 10, WritableFont.NO_BOLD);56       f = new WritableCellFormat(nobold_font);57       f.setVerticalAlignment(VerticalAlignment.CENTRE);58       f.setAlignment(Alignment.CENTRE);59       if(datas!=null&&datas.size()!=0){60           for (int r = 0; r < datas.size(); r++) {61               Object obj = datas.get(r);62               if (colunmValueNames!=null&&colunmValueNames.size()!=0) {63                   for (int j = 0; j < colunmValueNames.size(); j++) {64                       String name = colunmValueNames.get(j);65                       String value =http://www.mamicode.com/ BeanUtils.getProperty(obj, name);66                       label = new Label(j, r + 1, value, f);67                       ws.addCell(label);68                   }69             }70           }71       }72       wb.write();73     } catch (Exception e) {74       throw new Exception(e);75     } finally {76       wb.write();77       wb.close();78 79     }80   }81 82 }
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两者区别:

POI为apache公司的一个子项目,主要是提供一组操作windows文档的Java API
JavaExcel俗称jxl是一开放源码项目,通过它开发人员可以读取Excel文件的内容、创建新的Excel文件、更新已经存在的Excel文件。使用该API非Windows操作系统也可以通过纯Java应用来处理Excel数据表。因为是使用Java编写的,所以我们在Web应用中可以通过JSP、Servlet来调用API实现对Excel数据表的访问。

JVM虚拟机内存消耗的情况:

数据量3000条数据,每条60列.JVM虚拟机内存大小64M.
使用POI:运行到2800条左右就报内存溢出.
使用JXL:3000条全部出来,并且内存还有21M的空间.
可想而知,在对内存的消耗方面差距还是挺大的.
也许是由于JXL在对资源回收利用方面做的不错.

效率方面:

也是基于大数据量而言的,数据量小的话基本上差别不大,也不难被发觉.但是大的数据量,POI消耗的JVM内存远比JXL消耗的多.但相比提供的功能的话,JXL又相对弱了点.所以如果要实现的功能比较复杂的情况下可以考虑使用POI,但如果只想生成一些大数据量可以考虑使用JXL

导出Excel通用工具类