本文介紹將一個Excel檔案上傳後，修改Excel表中資料，再從新寫入到新的Excel表

1.使用myeclipse建立web工程，

2.新增struts2 使用struts2的分裝工具將檔案 上傳

3.匯入poi-3.0.2-FINAL-20080204.jar

4.Excel的操作

	try {
			//傳入的檔案
			FileInputStream fileInput = new FileInputStream(file);
			//poi包下的類讀取excel檔案
			POIFSFileSystem ts = new POIFSFileSystem(fileInput);
			// 建立一個webbook，對應一個Excel檔案			
			HSSFWorkbook workbook = new HSSFWorkbook(ts);
			//對應Excel檔案中的sheet，0代表第一個			
			HSSFSheet sh = workbook.getSheetAt(0);
			//修改excle表的第5行資料			
			for(int i=2;i<19;i++){
				//對第五行的資料修改
				sh.getRow(4).getCell((short)i).setCellValue(100210+i);
			}
			//將修改後的檔案寫出到D:\\excel目錄下
			FileOutputStream os = new FileOutputStream("D:\\excel\\輔機1.xls");
			os.flush();
			//將Excel寫出		
			workbook.write(os);
			//關閉流
			fileInput.close();
			os.close();
		} catch (IOException e) {
			e.printStackTrace();
		}
 

<struts>
	<package name="upload" extends="struts-default">  
      <action name="upFile" class="excelAction.Excel">  
          <!-- 上傳成功後跳轉到success.jsp頁面 -->  
          <result name="success">/sucess.jsp</result>  
           <result name="error">/error.jsp</result>  
      </action>  
      </package>
</struts>   
 

   private File upload;  
	    private String uploadContentType;  
	    private String uploadFileName;  
	    public File getUpload() {  
	       return upload;  
	  
	    }  
	    public void setUpload(File upload) {  
	       this.upload = upload;  
	    }  
	    public String getUploadContentType() {  
	       return uploadContentType;  
	    }  
	  
	    public void setUploadContentType(String uploadContentType) {  
	       this.uploadContentType = uploadContentType;  
	    }  
	    public String getUploadFileName() {  
	       return uploadFileName;  
	    }  
	  
	    public void setUploadFileName(String uploadFileName) {  
	  
	       this.uploadFileName = uploadFileName;  
	  
	    }  
	    public String execute() throws Exception {  
		    	FileUpload.upload(upload,uploadContentType,uploadFileName);
	      return SUCCESS;  
	    }  
 

7.jsp頁面(form必須新增enctype="multipart/form-data"

 <form action="${pageContext.request.contextPath }/upFile.action" enctype="multipart/form-data" method="post">  
	       	 檔案:<input type="file" name="upload"/><br/>  
	        <input type="submit" value="Excel">"  

</form>