一个poi操作实现导出功能的类

public class ExportExcel<T> {
public void exportExcel(Collection<T> dataset, OutputStream out) {
// exportExcel("测试POI导出EXCEL文档", null, dataset, out, "yyyy-MM-dd");
}

public static void main(String[] args) {
try {
String path2 = "d://123.png";
List<User> bs = new ArrayList<User>();
User u = new User();
u.setLoginName(QRCodeUtil.getRnNumber() + "");
u.setQrCodePath(path2);
bs.add(u); bs.add(u); bs.add(u); bs.add(u);

String path = "E://";

//导出excel
OutputStream out2 = new FileOutputStream(path+QRCodeUtil.getRnNumber()+".xls");

String[] headers = {"用户名","二维码"};
List<String> exportFile = new ArrayList<String>();
exportFile.add("loginName");exportFile.add("qrCodePath");

ExportExcel<User> export = new ExportExcel<User>();
export.exportExcel("二维码",headers, bs,exportFile, out2,"yyyy");

out2.close();
JOptionPane.showMessageDialog(null, "导出成功!");
System.out.println("excel导出成功！");
System.exit(0);
} catch (Exception e) {
e.printStackTrace();
}
}

/**往Excel中插入图片
* @param dataSheet 待插入的工作表
* @param col 图片从该列开始
* @param row 图片从该行开始
* @param width 图片所占的列数
* @param height 图片所占的行数
* @param imgFile 要插入的图片文件
*/
public static void insertImg(WritableSheet dataSheet, int col, int row, int width,
int height, File imgFile){
WritableImage img = new WritableImage(col, row, width, height, imgFile);
dataSheet.addImage(img);
}

@SuppressWarnings("unchecked")
public void exportExcel(String title, String[] headers,
List<T> dataset,List<String> exportFile, 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);
// 生成并设置另一个样式
HSSFCellStyle style2 = workbook.createCellStyle();
style2.setVerticalAlignment(HSSFCellStyle.VERTICAL_TOP);

// 声明一个画图的顶级管理器
HSSFPatriarch patriarch = sheet.createDrawingPatriarch();

//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);
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();
int j = 0;
for (short i = 0; i < exportFile.size(); i++) {
try {
String name = exportFile.get(i);
Object value = BeanUtils.getProperty(t, name);
HSSFCell cell = row.createCell(j);
cell.setCellStyle(style2);
j++;
// 判断值的类型后进行强制类型转换
String textValue = null;
/*if (value instanceof Date) {
Date date = (Date) value;
SimpleDateFormat sdf = new SimpleDateFormat(pattern);
textValue = sdf.format(date);
} 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 if(name.equals("qrCodePath")){
//属性名为qrCodePath即为图片路径信息
ByteArrayOutputStream byteArrayOut = new ByteArrayOutputStream();
BufferedImage bufferImg = ImageIO.read(new File(textValue));
ImageIO.write(bufferImg, "PNG", byteArrayOut);
// 有图片时，设置行高为327px;
row.setHeightInPoints(327);
// 设置图片所在列宽度为195px,注意这里单位的一个换算
sheet.setColumnWidth(i, (short) (40 * 195));
// sheet.autoSizeColumn(i);
HSSFClientAnchor anchor = new HSSFClientAnchor(0, 0, 680, 95, (short) i, index, (short) i, index);
HSSFPicture pic = patriarch.createPicture(anchor, workbook.addPicture(byteArrayOut.toByteArray(), HSSFWorkbook.PICTURE_TYPE_PNG));
pic.resize();
}else {
HSSFRichTextString richString = new HSSFRichTextString(textValue);
HSSFFont font3 = workbook.createFont();
font3.setColor(HSSFColor.BLACK.index);
richString.applyFont(font3);
cell.setCellValue(richString);
}
}
} catch (Exception e) {
e.printStackTrace();
} finally {

}
}

}
try {
workbook.write(out);
} catch (IOException e) {
e.printStackTrace();
}

}

/**
* 创建单个sheet
*
* @param sheetName
* 导出的sheet名字
* @param headers
* 列头
* @param dataset
* 需要导出的数据
* @param exportFile
* 需要的导出的字段
* @param response
* @throws IOException
*/
public void exportExcel(String sheetName, String[] headers,
Collection<T> dataset, List<String> exportFile,
HttpServletResponse response) throws IOException {
OutputStream out = null;
response.setContentType("application/vnd.ms-excel");

response.setCharacterEncoding("gbk");
response.setHeader("Content-disposition", "attachment;filename="
+ new String(sheetName.getBytes("GBK"), "ISO-8859-1") + ".xls");
out = response.getOutputStream();
HSSFWorkbook workbook = new HSSFWorkbook();
createSheet(sheetName, headers, dataset, exportFile, out, "yyyy-MM-dd",
workbook);
try {
workbook.write(out);
} catch (IOException e) {
e.printStackTrace();
}
out.flush();
out.close();
}

/**
* 创建多个sheet
*
* @param title
* 文件名
* @param headerMap
* 以sheet名为Key，列头为value
* @param dataMap
* 以sheet名为Key，数据集合为value
* @param cellMap
* 以sheet名为Key，数据列为value
* @param response
* @throws IOException
*/
public void exportExcel(String title, Map<String, Object> headerMap,
Map<String, Object> dataMap, Map<String, Object> cellMap,
HttpServletResponse response) throws IOException {
OutputStream out = null;
response.setContentType("application/vnd.ms-excel");
response.setCharacterEncoding("gbk");
response.setHeader("Content-disposition", "attachment;filename="
+ new String(title.getBytes("GBK"), "ISO-8859-1") + ".xls");
out = response.getOutputStream();
HSSFWorkbook workbook = new HSSFWorkbook();
for (String key : headerMap.keySet()) {
String sheetName = key;
String[] headers = (String[]) headerMap.get(key);
Collection<T> dataSet = (Collection<T>) dataMap.get(key);
List<String> exportFile = (List<String>) cellMap.get(key);
createSheet(sheetName, headers, dataSet, exportFile, out,
"yyyy-MM-dd HH：mm：ss", workbook);
}
try {
workbook.write(out);
} catch (IOException e) {
e.printStackTrace();
}
out.flush();
out.close();
}

/**
* 这是一个通用的方法，利用了JAVA的反射机制，可以将放置在JAVA集合中并且符号一定条件的数据以EXCEL 的形式输出到指定IO设备上
*
* @param sheetName
* 表格sheet名
* @param headers
* 表格属性列名数组
* @param dataset
* 需要显示的数据集合,集合中一定要放置符合javabean风格的类的对象。此方法支持的
* javabean属性的数据类型有基本数据类型及String,Date,byte[](图片数据)
* @param out
* 与输出设备关联的流对象，可以将EXCEL文档导出到本地文件或者网络中
* @param pattern
* 如果有时间数据，设定输出格式。默认为"yyy-MM-dd"
* @param workbook
* 声明一个工作薄
*/
public void createSheet(String sheetName, String[] headers,
Collection<T> dataset, List<String> exportFile, OutputStream out,
String pattern, HSSFWorkbook workbook) {
// 生成一个表格
HSSFSheet sheet = workbook.createSheet(sheetName);
// 设置表格默认列宽度为15个字节
sheet.setDefaultColumnWidth((short) 15);
// 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;
// 设置单元格内容靠上
HSSFCellStyle style = workbook.createCellStyle();
style.setVerticalAlignment(HSSFCellStyle.VERTICAL_TOP);
while (it.hasNext()) {
index++;
row = sheet.createRow(index);
T t = (T) it.next();
int j = 0;
for (short i = 0; i < exportFile.size(); i++) {
try {
String name = exportFile.get(i);
Object value = BeanUtils.getProperty(t, name);
HSSFCell cell = row.createCell(j);
cell.setCellStyle(style);
j++;
// 判断值的类型后进行强制类型转换
String textValue = null;
/*if (value instanceof Date) {
Date date = (Date) value;
SimpleDateFormat sdf = new SimpleDateFormat(pattern);
textValue = sdf.format(date);
} 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 if(name.equals("qrCodePath")){ //属性名为qrCodePath即为图片路径信息
ByteArrayOutputStream byteArrayOut = new ByteArrayOutputStream();
BufferedImage bufferImg = ImageIO.read(new File(textValue));
ImageIO.write(bufferImg, "PNG", byteArrayOut);
// 有图片时，设置行高为327px; 调整高度为120
row.setHeightInPoints(120);
// 设置图片所在列宽度为195px,注意这里单位的一个换算
sheet.setColumnWidth(i, (short) (40 * 195));
// sheet.autoSizeColumn(i);
HSSFClientAnchor anchor = new HSSFClientAnchor(0, 0, 680, 95, (short) i, index, (short) i, index);
HSSFPicture pic = patriarch.createPicture(anchor, workbook.addPicture(byteArrayOut.toByteArray(), HSSFWorkbook.PICTURE_TYPE_PNG));
pic.resize();
} else {
HSSFRichTextString richString = new HSSFRichTextString(
textValue);
HSSFFont font3 = workbook.createFont();
font3.setColor(HSSFColor.BLACK.index);
richString.applyFont(font3);
cell.setCellValue(richString);
}
}
} catch (Exception e) {
e.printStackTrace();
} finally {

}
}
}
}

}