poi 导出Excel 工具类详解编程语言

import java.io.OutputStream; 
import java.lang.reflect.Method; 
import java.text.SimpleDateFormat; 
import java.util.Collection; 
import java.util.Date; 
import java.util.regex.Matcher; 
import java.util.regex.Pattern; 
 
import org.apache.poi.hssf.usermodel.HSSFCell; 
import org.apache.poi.hssf.usermodel.HSSFCellStyle; 
import org.apache.poi.hssf.usermodel.HSSFClientAnchor; 
import org.apache.poi.hssf.usermodel.HSSFFont; 
import org.apache.poi.hssf.usermodel.HSSFPatriarch; 
import org.apache.poi.hssf.usermodel.HSSFRichTextString; 
import org.apache.poi.hssf.usermodel.HSSFRow; 
import org.apache.poi.hssf.usermodel.HSSFSheet; 
import org.apache.poi.hssf.usermodel.HSSFWorkbook; 
import org.apache.poi.hssf.util.HSSFColor; 
import org.apache.poi.hssf.util.Region; 
/** 
 * 
 * @author Bruce Xu 
 * 
 * @param <T> 
 */ 
public class ExcelUtil<T> {    
    
    /**  
     * 导出Excel的方法  
     * @param title excel中的sheet名称  
     * @param headers 表头  
     * @param result 结果集  
     * @param out 输出流  
     * @param pattern 时间格式  
     * @throws Exception  
     */    
    public void exportExcel(String title, String[] headers,String[] columns, Collection<T> result, OutputStream out, String pattern) throws Exception{    
        // 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20个字节    
        sheet.setDefaultColumnWidth((short)20);    
            
            
        // 生成一个样式    
        HSSFCellStyle style = workbook.createCellStyle();    
        // 设置这些样式    
        style.setFillForegroundColor(HSSFColor.GOLD.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);    
            
        // 指定当单元格内容显示不下时自动换行    
        style.setWrapText(true);    
          
        // 声明一个画图的顶级管理器   
        HSSFPatriarch patriarch = sheet.createDrawingPatriarch();  
        /*  
           
         以下可以用于设置导出的数据的样式  
            
        // 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    
        //表头的样式  
        HSSFCellStyle titleStyle = workbook.createCellStyle();// 创建样式对象  
        titleStyle.setAlignment(HSSFCellStyle.ALIGN_CENTER_SELECTION);// 水平居中  
        titleStyle.setVerticalAlignment(HSSFCellStyle.VERTICAL_CENTER);// 垂直居中  
        // 设置字体  
        HSSFFont titleFont = workbook.createFont(); // 创建字体对象  
        titleFont.setFontHeightInPoints((short) 15); // 设置字体大小  
        titleFont.setBoldweight(HSSFFont.BOLDWEIGHT_BOLD);// 设置粗体  
      //  titleFont.setFontName("黑体"); // 设置为黑体字  
        titleStyle.setFont(titleFont);  
        sheet.addMergedRegion(new Region(0,(short)0,0,(short)(headers.length-1)));//指定合并区域   
        HSSFRow rowHeader = sheet.createRow(0);    
        HSSFCell cellHeader = rowHeader.createCell((short)0);   //只能往第一格子写数据，然后应用样式，就可以水平垂直居中  
        HSSFRichTextString textHeader = new HSSFRichTextString(title);    
        cellHeader.setCellStyle(titleStyle);  
        cellHeader.setCellValue(textHeader);  
          
        HSSFRow row = sheet.createRow(1);    
        for (int i = 0; i < headers.length; i++) {    
            HSSFCell cell = row.createCell((short)i);    
            cell.setCellStyle(style);    
            HSSFRichTextString text = new HSSFRichTextString(headers[i]);    
            cell.setCellValue(text);    
         }    
         // 遍历集合数据，产生数据行    
         if(result != null){    
             int index = 2;    
             for(T t:result){   
             //  Field[] fields = t.getClass().getDeclaredFields();  
                 row = sheet.createRow(index);    
                 index++;  
                 for(short i = 0; i < columns.length; i++) {  
                     HSSFCell cell = row.createCell(i);  
//                   Field field = fields[i];  
//                   String fieldName = field.getName();  
                     String fieldName = columns[i];  
                     String getMethodName = "get"  
                         + fieldName.substring(0, 1).toUpperCase() + fieldName.substring(1);  
                     Class tCls = t.getClass();  
                     Method getMethod = tCls.getMethod(getMethodName, new Class[]{});  
                    // getMethod.getReturnType().isInstance(obj); 
                     Object value = getMethod.invoke(t, new Class[]{});  
                     String textValue = null;  
                     if(value == null) {  
                         textValue = "";  
                     }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  
                         textValue = value.toString();  
                      }  
                       
                     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);  
                         }  
                      }  
                 }  
             }       
         }    
         workbook.write(out);    
     }    
 }   
 
 

调用示例：以springmvc为例，导出数据库记录到Excel,弹出下载对话框

@RequestMapping(value="/exprotExcel") 
 public @ResponseBody String exprotExcel(HttpServletResponse response,NjWorkLog njWorkLog,@RequestParam(value="createUserIds",required=false) String createUserIds,@RequestParam(value="workLogGrantUsersName",required=false)String workLogGrantUsersName,@RequestParam(value="strWorkEndDate",required=false)String strWorkEndDate) 
 { 
   
  ExcelUtil<NjWorkLog> excelUtil=new ExcelUtil<NjWorkLog>(); 
  OutputStream out=null; 
  try 
  { 
   out = response.getOutputStream();// 取得输出流   
   //out.flush(); 
             response.reset();// 清空输出流   
 
             response.setHeader("Content-disposition", "attachment; filename="+new String("工作日志".getBytes("GB2312"),"8859_1")+".xls");// 设定输出文件头   
             response.setContentType("application/msexcel");// 定义输出类型 
 
  }  catch (IOException e) 
  { 
   e.printStackTrace(); 
  }  
  String[] headers ={"跟踪目标","工作时间","事项类型","项目名称","完成情况自述","工作量","进度","配合人员","加班","作者","附件名称"}; 
  String[]columns={ "strTarget", "strWorkDate", "dictTypeId", "projectId", "strDesc", "bdWorkload", "strSchedule", "strCooperate","isOverTime","createUserId", "strFileName"}; 
  if("on".equals(njWorkLog.getIsOverTime())) 
   njWorkLog.setIsOverTime("1"); 
  else 
   njWorkLog.setIsOverTime(""); 
  if(StringUtils.isNotBlank(createUserIds)) 
   njWorkLog.setTempArray(createUserIds.split(",")); 
  List<NjWorkLog> dataset=njWorkLogService.findMyAttentionExcel(njWorkLog); 
   
  try 
  { 
   excelUtil.exportExcel("工作日志", headers, columns, dataset, out, ""); 
    
  } catch (Exception e1) 
  { 
   e1.printStackTrace(); 
  } 
  try 
  { 
   out.close(); 
  } catch (IOException e) 
  { 
   e.printStackTrace(); 
  } 
  return null; 
 }