POI生成Excel并通过Servlet下载示例_poi 将生成excel 写入到 servletoutputstream-优快云博客

本文提供了一个使用Java实现的简单示例，展示如何通过Apache POI库创建并导出Excel文件。该示例创建了一个包含固定数据的工作表，并通过Servlet将文件发送给客户端。

[java]view plaincopyprint? 
   
 Java代码    
 package com.ljz;  
 import java.io.BufferedInputStream;  
 import java.io.BufferedOutputStream;  
 import java.io.ByteArrayInputStream;  
 import java.io.ByteArrayOutputStream;  
 import java.io.IOException;  
 import java.io.InputStream;  
 import javax.servlet.ServletException;  
 import javax.servlet.ServletOutputStream;  
 import javax.servlet.http.HttpServlet;  
 import javax.servlet.http.HttpServletRequest;  
 import javax.servlet.http.HttpServletResponse;  
 import org.apache.poi.hssf.usermodel.HSSFCell;  
 import org.apache.poi.hssf.usermodel.HSSFRow;  
 import org.apache.poi.hssf.usermodel.HSSFSheet;  
 import org.apache.poi.hssf.usermodel.HSSFWorkbook;  
 public class downloadExcelServletextends HttpServlet {  
 private static final long serialVersionUID = 1L;  
 public downloadExcelServlet() {  
 super();  
 }  
 public void destroy() {  
 super.destroy();  
 }  
 private InputStream getInputStream() {  
 HSSFWorkbook wb = new HSSFWorkbook();  
 HSSFSheet sheet = wb.createSheet("sheet1");  
 HSSFRow row = sheet.createRow(0);  
 HSSFCell cell = row.createCell((short) 0);  
 cell.setEncoding(HSSFCell.ENCODING_UTF_16);  
 cell.setCellValue("序号");  
 cell = row.createCell((short) 1);  
 cell.setEncoding(HSSFCell.ENCODING_UTF_16);  
 cell.setCellValue("姓");  
 cell = row.createCell((short) 2);  
 cell.setEncoding(HSSFCell.ENCODING_UTF_16);  
 cell.setCellValue("名");  
 cell = row.createCell((short) 3);  
 cell.setEncoding(HSSFCell.ENCODING_UTF_16);  
 cell.setCellValue("年龄");  
 //创建一行记录  
 row = sheet.createRow(1);  
 cell = row.createCell((short) 0);  
 cell.setEncoding(HSSFCell.ENCODING_UTF_16);  
 cell.setCellValue("1");  
 cell = row.createCell((short) 1);  
 cell.setEncoding(HSSFCell.ENCODING_UTF_16);  
 cell.setCellValue("刘");  
 cell = row.createCell((short) 2);  
 cell.setEncoding(HSSFCell.ENCODING_UTF_16);  
 cell.setCellValue("继忠");  
 cell = row.createCell((short) 3);  
 cell.setEncoding(HSSFCell.ENCODING_UTF_16);  
 cell.setCellValue("25");  
 // List<User> list = this.findAll();  
 //  
 // for (int i = 0; i < list.size(); ++i)  
 // {  
 // User user = list.get(i);  
 //  
 // row = sheet.createRow(i + 1);  
 //  
 // cell = row.createCell((short) 0);  
 // cell.setEncoding(HSSFCell.ENCODING_UTF_16);  
 // cell.setCellValue(i + 1);  
 //  
 // cell = row.createCell((short) 1);  
 // cell.setEncoding(HSSFCell.ENCODING_UTF_16);  
 // cell.setCellValue(user.getFirstname());  
 //  
 // cell = row.createCell((short) 2);  
 // cell.setEncoding(HSSFCell.ENCODING_UTF_16);  
 // cell.setCellValue(user.getLastname());  
 //  
 // cell = row.createCell((short) 3);  
 // cell.setEncoding(HSSFCell.ENCODING_UTF_16);  
 // cell.setCellValue(user.getAge());  
 // }  
 ByteArrayOutputStream os = new ByteArrayOutputStream();  
 try {  
 wb.write(os);  
 } catch (IOException e) {  
 e.printStackTrace();  
 }  
 byte[] content = os.toByteArray();  
 InputStream is = new ByteArrayInputStream(content);  
 return is;  
 }  
 public void doGet(HttpServletRequest request, HttpServletResponse response)  
 throws ServletException, IOException {  
 response.reset();  
 response.setContentType("application/vnd.ms-excel;charset=utf-8");  
 response.setHeader("Content-Disposition", "attachment;filename="  
 + new String("系统日志.xls".getBytes(),"iso-8859-1"));  
 ServletOutputStream out = response.getOutputStream();  
 BufferedInputStream bis = null;  
 BufferedOutputStream bos = null;  
 try {  
 bis = new BufferedInputStream(new FileInputStream(file);  
 bos = new BufferedOutputStream(out);  
 byte[] buff = new byte[2048];  
 int bytesRead;  
 // Simple read/write loop.  
 while (-1 != (bytesRead = bis.read(buff,0, buff.length))) {  
 bos.write(buff, 0, bytesRead);  
 }  
 } catch (final IOException e) {  
 System.out.println("IOException.");  
 throw e;  
 } finally {  
 if (bis != null)  
 bis.close();  
 if (bos != null)  
 bos.close();  
 }  
 }  
 public void doPost(HttpServletRequest request, HttpServletResponse response)  
 throws ServletException, IOException {  
 }  
 public void init() throws ServletException {  
 // Put your code here  
 }  
 }    

public class UploadAction{
	private TPoiService ts;
	
	public TPoiService getTs() {
		return ts;
	}

	public void setTs(TPoiService ts) {
		this.ts = ts;
	}

	public File getNewFile(String path){
		File file=new File(path);
		File[] dir=file.listFiles();
		System.out.println(dir.length);
		int[] newfiles=new int[dir.length];
		for (int i = 0; i < dir.length; i++) {
//			System.out.println(dir[i]);
			newfiles[i]=Integer.parseInt(dir[i].getName().substring(0,dir[i].getName().indexOf(".")));
		}
		int num1=newfiles[0];
		for (int j = 0; j < newfiles.length; j++) {
			if(newfiles[j]>num1){
				num1=newfiles[j];
			}
		}
		System.out.println(num1);
		return new File(path+"\\"+num1+".xls");
	}
	
	@Action(value="upload",className="upload",results={@Result(name="success",location="/upload.jsp",type="dispatcher"),
			@Result(name="error",location="/Page/error.jsp",type="dispatcher")})
	public String upload() throws IOException{
		System.out.println("this is upload");
		HttpServletResponse response=ServletActionContext.getResponse();
//		PrintWriter out = response.getWriter();
		File file=getNewFile(ServletActionContext.getRequest().getRealPath("xls"));
		response.setContentType("application/vnd.ms-excel;charset=UTF-8");

		response.setHeader("Content-Disposition", "attachment;filename="+ new String("isd.xls".getBytes(), "iso-8859-1"));
		
		ServletOutputStream out = response.getOutputStream();  
		 
		BufferedInputStream bis = null;
		 
		BufferedOutputStream bos = null;
		 
		try {  
		    bis = new BufferedInputStream(new FileInputStream(file) {
		    @Override
		    public int read() throws IOException {
		      // TODO Auto-generated method stub
		        return 0;
		    }
		 });  
		     bos = new BufferedOutputStream(out);  
		 
		     byte[] buff = new byte[2048];  
		 
		     int bytesRead;  
		 
		     // Simple read/write loop.  
		     while (-1 != (bytesRead = bis.read(buff, 0, buff.length))) {  
		            bos.write(buff, 0, bytesRead);  
		        }
		    } catch (final IOException e) {  
		        System.out.println("IOException.");  
		        throw e;  
		    } finally {  
		        if (bis != null)  
		            bis.close();  
		        if (bos != null)  
		            bos.close();  
		    }  
		return null;
	}