poi 导出Excel 工具类，poiexcel,import java.

poi 导出Excel 工具类，poiexcel,import java.

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; }