在生成报表时需要将数据转成excel的文件形式进行下载用,这类方法网上有很多,自己总结一下,方便后期自己查看。

Jsp:


<a href=’${pageContext.request.contextPath}/user/exportAllUser.
Action’>导出全部</a>

Action

/**
     * 导出所有用户信息到Excel
     * @throws Exception
     */
    @Action(value = "/user/exportAllUser")
	public void exportAllUser() {
    	userService.allUserToExcel(response);
	}

Service

/**
	 * 导出所有用户数据到extcel文件
	 * @createDate 2013-12-23
	 */
	//导出数据库全部信息到excel文件
	public void allUserToExcel(HttpServletResponse response) {
		//需要导出的数据
		List<User> listUser = userDao.listAll();
		//下载是显示给用户的文件名(如果是中文需要作一定处理,否则会有乱码)
		String fileName="allUser.xls";
		//调用导出的具体实现方法
		try {
			exportToExc(listUser,fileName,response);
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}

public void exportToExc(List<User> listUser, String fileName, HttpServletResponse response) throws IOException {
		AjaxResponse.responseName(fileName, response);
        String[] header = {"用户Id","用户名","密码","真实姓名","手机号码","单位","下属旅游局Id","用户等级",
        		"创建时间","修改时间","状态","区域"};
        ExportExcel<User> ex = new ExportExcel<User>();
        OutputStream out = response.getOutputStream();         
        ex.exportExcel(header, listUser, out);
        out.close();
	}

具体方法ExportExcel.java

public void exportExcel(String title, String[] headers,Collection<T> dataset, OutputStream out, String pattern) {  
        // 声明一个工作薄  
        HSSFWorkbook workbook = new HSSFWorkbook();  
        // 生成一个表格  
        HSSFSheet sheet = workbook.createSheet(title);  
        // 设置表格默认列宽度为15个字节  
        sheet.setDefaultColumnWidth((short) 15);
        // 生成一个样式  
        HSSFCellStyle style = workbook.createCellStyle();  
        // 设置这些样式  
        style.setFillForegroundColor(HSSFColor.SKY_BLUE.index);  
        style.setFillPattern(HSSFCellStyle.SOLID_FOREGROUND);  
        style.setBorderBottom(HSSFCellStyle.BORDER_THIN);  
        style.setBorderLeft(HSSFCellStyle.BORDER_THIN);  
        style.setBorderRight(HSSFCellStyle.BORDER_THIN);  
        style.setBorderTop(HSSFCellStyle.BORDER_THIN);  
        style.setAlignment(HSSFCellStyle.ALIGN_CENTER);
        // 生成一个字体  
        HSSFFont font = workbook.createFont();  
        font.setColor(HSSFColor.VIOLET.index);  
        font.setFontHeightInPoints((short) 12);  
        font.setBoldweight(HSSFFont.BOLDWEIGHT_BOLD);
        // 把字体应用到当前的样式  
        style.setFont(font);
        // 生成并设置另一个样式  
        HSSFCellStyle style2 = workbook.createCellStyle();  
        style2.setFillForegroundColor(HSSFColor.LIGHT_YELLOW.index);  
        style2.setFillPattern(HSSFCellStyle.SOLID_FOREGROUND);  
        style2.setBorderBottom(HSSFCellStyle.BORDER_THIN);  
        style2.setBorderLeft(HSSFCellStyle.BORDER_THIN);  
        style2.setBorderRight(HSSFCellStyle.BORDER_THIN);  
        style2.setBorderTop(HSSFCellStyle.BORDER_THIN);  
        style2.setAlignment(HSSFCellStyle.ALIGN_CENTER);  
        style2.setVerticalAlignment(HSSFCellStyle.VERTICAL_CENTER);  
        // 生成另一个字体  
        HSSFFont font2 = workbook.createFont();  
        font2.setBoldweight(HSSFFont.BOLDWEIGHT_NORMAL);  
        // 把字体应用到当前的样式  
        style2.setFont(font2);  
          
        // 声明一个画图的顶级管理器  
        HSSFPatriarch patriarch = sheet.createDrawingPatriarch();
        // 定义注释的大小和位置,详见文档  
        HSSFComment comment = patriarch.createComment(new HSSFClientAnchor(0, 0, 0, 0, (short) 4, 2, (short) 6, 5));  
        // 设置注释内容  
        comment.setString(new HSSFRichTextString("可以在POI中添加注释!"));  
        // 设置注释作者,当鼠标移动到单元格上是可以在状态栏中看到该内容.  
        comment.setAuthor("leno");
     
        //产生表格标题行  
        HSSFRow row = sheet.createRow(0);  
        for (short i = 0; i < headers.length; i++) {
           HSSFCell cell = row.createCell(i);
           cell.setCellStyle(style);
           HSSFRichTextString text = new HSSFRichTextString(headers[i]);  
           cell.setCellValue(text);
        }

        //遍历集合数据,产生数据行  
        Iterator<T> it = dataset.iterator();
        int index = 0;
        while (it.hasNext()) {
           index++;
           row = sheet.createRow(index);  
           T t = (T) it.next();  
           //利用反射,根据javabean属性的先后顺序,动态调用getXxx()方法得到属性值  
           Field[] fields = t.getClass().getDeclaredFields();  
          
           for (short i = 1; i < fields.length; i++) {  
              HSSFCell cell = row.createCell(i-1);
              cell.setCellStyle(style2);  
              Field field = fields[i];  
              String fieldName = field.getName(); 
              if(!"serialVersionUID".equals(fieldName)) {
	              String getMethodName = "get" + fieldName.substring(0, 1).toUpperCase() + fieldName.substring(1);  
	              try {  
	                  Class<? extends Object> tCls = t.getClass();
	                 
	                  Method getMethod = tCls.getMethod(getMethodName, new Class[] {}); 
	                  Object value = getMethod.invoke(t, new Object[] {});
	                  
	                  //判断值的类型后进行强制类型转换  
	                  String textValue = "";
	                  value = dealData(t,value,fieldName);  //处理关联表中的数据

	                  if (value instanceof Boolean) {  
	                     boolean bValue = (Boolean) value;  
	                     textValue = "男";  
	                     if (!bValue) {  
	                        textValue ="女";  
	                     }  
	                  } else if (value instanceof Date) {  
	                     Date date = (Date) value;  
	                     SimpleDateFormat sdf = new SimpleDateFormat(pattern);  
	                     textValue = sdf.format(date);  
	                  }  else if (value instanceof byte[]) {  
	                     // 有图片时,设置行高为60px;  
	                     row.setHeightInPoints(60);  
	                     // 设置图片所在列宽度为80px,注意这里单位的一个换算  
	                     sheet.setColumnWidth(i, (short) (35.7 * 80));  
	                     // sheet.autoSizeColumn(i);  
	                     byte[] bsValue = (byte[]) value;  
	                     HSSFClientAnchor anchor = new HSSFClientAnchor(0, 0,  
	                           1023, 255, (short) 6, index, (short) 6, index);  
	                     anchor.setAnchorType(2);  
	                     patriarch.createPicture(anchor, workbook.addPicture(  
	                           bsValue, HSSFWorkbook.PICTURE_TYPE_JPEG));  
	                  } else {
	                     //其它数据类型都当作字符串简单处理 
	                	  if(null != value) {
	                		  textValue = value.toString();  
	                	  }
	                  }  
	                  //如果不是图片数据,就利用正则表达式判断textValue是否全部由数字组成  
	                  if(textValue!=null){  
	                     Pattern p = Pattern.compile("^//d+(//.//d+)?$");     
	                     Matcher matcher = p.matcher(textValue);  
	                     if(matcher.matches()){  
	                        //是数字当作double处理  
	                        cell.setCellValue(Double.parseDouble(textValue));  
	                     }else{  
	                        HSSFRichTextString richString = new HSSFRichTextString(textValue);  
	                        HSSFFont font3 = workbook.createFont();  
	                        font3.setColor(HSSFColor.BLUE.index);  
	                        richString.applyFont(font3);  
	                        cell.setCellValue(richString);  
	                     }
	                  }
              } catch (SecurityException e) {  
                  // TODO Auto-generated catch block  
                  e.printStackTrace();  
              } catch (NoSuchMethodException e) {  
                  // TODO Auto-generated catch block  
                  e.printStackTrace();  
              } catch (IllegalArgumentException e) {  
                  // TODO Auto-generated catch block  
                  e.printStackTrace();  
              } catch (IllegalAccessException e) {  
                  // TODO Auto-generated catch block  
                  e.printStackTrace();  
              } catch (InvocationTargetException e) {  
                  // TODO Auto-generated catch block  
                  e.printStackTrace();  
              } finally {  
                  //清理资源  
              } 
              }
           }
        }  
        try {
           workbook.write(out);  
        } catch (IOException e) {  
           // TODO Auto-generated catch block  
           e.printStackTrace();  
        }
     }



内部参数可以根据自己的需求进行修改,希望可以帮助大家,不明白的可以留言。