没事做就想到做这个东西
首先要说明的是excel03 每个sheet最多放65535行所以，每行不能超过这个数，如果想放的多，可以考虑生成excel2007，
好像excel2007可以放100W多行数据
大数据量生成excel我只想到三种方法，当然基本也是网上看到的
1 生成多个excel打包 2 利用xml方式生成 3 用最新的包
现在讲的是第一种 第二种也可以以后会做下测试 第三种好像不行，一直内存溢出
直接上代码
这个是servlet：
package servlets;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.hssf.util.CellRangeAddress;
import org.apache.poi.ss.usermodel.Cell;
import org.apache.poi.ss.usermodel.CellStyle;
import org.apache.poi.ss.usermodel.Row;
import org.apache.poi.ss.usermodel.Sheet;
import org.apache.poi.ss.usermodel.Workbook;
import util.DBConnectionManager;
import domain.Person;public class exportExcel extends HttpServlet {
private String fileName;
public void destroy() {
super.destroy(); // Just puts "destroy" string in log
// Put your code here
}
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
// 文件名获取
Date date = new Date();
SimpleDateFormat format = new SimpleDateFormat("yyyyMMddHHmmss");
String f = "Person-" + format.format(date);
this.fileName = f;
setResponseHeader(response);
OutputStream out = null;
try {
System.out.println("导出excel开始~~~"+System.currentTimeMillis());
long startTime = System.currentTimeMillis(); out = response.getOutputStream(); DBConnectionManager db = new DBConnectionManager();//该部分是用于链接数据库 List<Person> list = db.queryDataList(" select * from TEST_EXPORT ");//查询数据集合toExcel(list, request, 50000, f, out);
System.out.println("导出excel结束~~~"+System.currentTimeMillis()); long endTime = System.currentTimeMillis(); System.out.println("导出excel共花费时间~~~"+(endTime-startTime)/1000); } catch (IOException e1) {e1.printStackTrace();
} finally {
try {
out.flush();
out.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
/** 设置响应头 */
public void setResponseHeader(HttpServletResponse response) {
try {
response.setContentType("application/octet-stream;charset=UTF-8");
response.setHeader("Content-Disposition", "attachment;filename="
+ java.net.URLEncoder.encode(this.fileName, "UTF-8")
+ ".zip");
response.addHeader("Pargam", "no-cache");
response.addHeader("Cache-Control", "no-cache");
} catch (Exception ex) {
ex.printStackTrace();
}
}
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doGet(request, response);
}
public void init() throws ServletException {
// Put your code here
}
@SuppressWarnings("deprecation")
public void toExcel(List<Person> list, HttpServletRequest request,int length, String f, OutputStream out) throws IOException {
List<String> fileNames = new ArrayList();// 用于存放生成的文件名称s
File zip = new File(request.getRealPath("/excel") + f + ".zip");// 压缩文件
// 生成excel
for (int j = 0, n = list.size() / length + 1; j < n; j++) {
Workbook book = new HSSFWorkbook();
Sheet sheet = book.createSheet("person");
double d = 0;// 用来统计
String file = request.getRealPath("/excel") + "/" + f + "-" + j
+ ".xls";
fileNames.add(file);
FileOutputStream o = null;
try {
o = new FileOutputStream(file);
// sheet.addMergedRegion(new
// CellRangeAddress(list.size()+1,0,list.size()+5,6));
Row row = sheet.createRow(0);
row.createCell(0).setCellValue("ID");
row.createCell(1).setCellValue("NAME");
row.createCell(2).setCellValue("REMARK");
int m = 1;for (int i = 1, min = (list.size() - j * length + 1) > (length + 1) ? (length + 1)
: (list.size() - j * length + 1); i < min; i++) {
m++;
Person user = list.get(length * (j) + i - 1);
row = sheet.createRow(i);row.createCell(0).setCellValue(user.getId());
row.createCell(1).setCellValue(user.getName());
row.createCell(2).setCellValue(user.getRemark());
}
// CellStyle cellStyle2 = book.createCellStyle();
//// cellStyle2.setAlignment(CellStyle.ALIGN_CENTER);//// row = sheet.createRow(m);//// Cell cell0 = row.createCell(0);//// cell0.setCellValue("Total");//// cell0.setCellStyle(cellStyle2);//// Cell cell4 = row.createCell(4);//// cell4.setCellValue(d);//// cell4.setCellStyle(cellStyle2);//// sheet.addMergedRegion(new CellRangeAddress(m, m, 0, 3));} catch (Exception e) {
e.printStackTrace();
}
try {
book.write(o);
} catch (Exception ex) {
ex.printStackTrace();
} finally {
if (o != null){
o.flush();o.close();
}}
}
File srcfile[] = new File[fileNames.size()];
for (int i = 0, n = fileNames.size(); i < n; i++) {
srcfile[i] = new File(fileNames.get(i));
}
util.FileZip.ZipFiles(srcfile, zip);
FileInputStream inStream = new FileInputStream(zip);
byte[] buf = new byte[4096];
int readLength;
while (((readLength = inStream.read(buf)) != -1)) {
out.write(buf, 0, readLength);
}
inStream.close();}
}
实体类
package domain;
public class Person {
private String id; private String name; private String remark; public String getId() { return id; } public void setId(String id) { this.id = id; } public String getName() { return name; } public void setName(String name) { this.name = name; } public String getRemark() { return remark; } public void setRemark(String remark) { this.remark = remark; } }
这个是打包的工具类
package util;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.zip.ZipEntry;
import java.util.zip.ZipOutputStream;
public class FileZip {/**
*
* srcfile 文件名数组
* zipfile 压缩后文件
*/
public static void ZipFiles(java.io.File[] srcfile, java.io.File zipfile) {
byte[] buf = new byte[1024];
try {
ZipOutputStream out = new ZipOutputStream(new FileOutputStream(
zipfile));
for (int i = 0; i < srcfile.length; i++) {
FileInputStream in = new FileInputStream(srcfile[i]);
out.putNextEntry(new ZipEntry(srcfile[i].getName()));
int len;
while ((len = in.read(buf)) > 0) {
out.write(buf, 0, len);
}
out.closeEntry();
in.close();
}
out.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
jsp我就传了，
另外这个也是我从别的地方转载的，修改了一些地方，也有很多不完善的地方，如果在项目中最好再做优化