Java XSSF 导出excel 工具类

参数解释： title：导出excel标题、headers 导出到excel显示的列头、
　　　　　　columns 对应数据库字段 、list 导出数据

public void expoortExcelx(String title, String[] headers, String[] columns,
            List<T> list, OutputStream out, String pattern) throws NoSuchMethodException, Exception{
//创建工作薄
            XSSFWorkbook workbook=new XSSFWorkbook();
//创建表格
            Sheet sheet=workbook.createSheet(title);
//设置默认宽度
            sheet.setDefaultColumnWidth(25);
//创建样式
            XSSFCellStyle style=workbook.createCellStyle();
//设置样式
            style.setFillForegroundColor(IndexedColors.GOLD.index);
            style.setFillPattern(CellStyle.SOLID_FOREGROUND);
            style.setBorderBottom(CellStyle.BORDER_THIN);
            style.setBorderLeft(CellStyle.BORDER_THIN);
            style.setBorderRight(CellStyle.BORDER_THIN);
            style.setBorderTop(CellStyle.BORDER_THIN);
//生成字体
            XSSFFont font=workbook.createFont();
            font.setColor(IndexedColors.VIOLET.index);
            font.setBoldweight(XSSFFont.BOLDWEIGHT_BOLD);
//应用字体
            style.setFont(font);

//自动换行
            style.setWrapText(true);
//声明一个画图的*管理器
            Drawing drawing=(XSSFDrawing) sheet.createDrawingPatriarch();
//表头的样式
            XSSFCellStyle titleStyle=workbook.createCellStyle();//样式对象
            titleStyle.setAlignment(CellStyle.ALIGN_CENTER_SELECTION);//水平居中
            titleStyle.setVerticalAlignment(CellStyle.VERTICAL_CENTER);
//设置字体
            XSSFFont titleFont=workbook.createFont();
            titleFont.setFontHeightInPoints((short)15);
            titleFont.setBoldweight(XSSFFont.BOLDWEIGHT_BOLD);//粗体
            titleStyle.setFont(titleFont);
            sheet.addMergedRegion(new CellRangeAddress(0, 0, 0, headers.length-1));
//指定合并区域
            Row rowHeader = sheet.createRow(0);
//XSSFRow rowHeader=sheet.createRow(0);
            Cell cellHeader=rowHeader.createCell(0);
            XSSFRichTextString textHeader=new XSSFRichTextString(title);
            cellHeader.setCellStyle(titleStyle);
            cellHeader.setCellValue(textHeader);

            Row row=sheet.createRow(1);
for(int i=0;i<headers.length;i++){
                Cell cell=row.createCell(i);
                cell.setCellStyle(style);
                XSSFRichTextString text=new XSSFRichTextString(headers[i]);
                cell.setCellValue(text);
            }
//遍历集合数据，产生数据行
if(list!=null&&list.size()>0){
int index=2;
for(T t:list){
                    row=sheet.createRow(index);
                    index++;
for(short i=0;i<columns.length;i++){
                        Cell cell=row.createCell(i);
                        String filedName=columns[i];
                        String getMethodName="get"+filedName.substring(0,1).toUpperCase()
+filedName.substring(1);
                        Class tCls=t.getClass();
                        Method getMethod=tCls.getMethod(getMethodName,new Class[]{});
                        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[]){
                            row.setHeightInPoints(80);
                            sheet.setColumnWidth(i, 35*100);
byte[] bsValue=(byte[])value;
                            XSSFClientAnchor anchor=new XSSFClientAnchor(0,0,1023,255,6,index,6,index);
                            anchor.setAnchorType(2);
                            drawing.createPicture(anchor, workbook.addPicture(bsValue, XSSFWorkbook.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 {
                                XSSFRichTextString richString = new XSSFRichTextString(
                                        textValue);
// HSSFFont font3 = workbook.createFont();
// font3.setColor(HSSFColor.BLUE.index);
// richString.applyFont(font3);
                                cell.setCellValue(richString);
                            }
                        }

                    }
                }
            }
            workbook.write(out);

    }