先创建导出Excel的工具类，并带泛型，实体一定要生成属性的get方法，就是普通的Javabean，后面的就是个人发挥了，废话不多说，直接上代码：
public class ExportExcel<T> {
public void exportExcel(Collection<T> dataset, OutputStream out) {
exportExcel("数据导出", null, dataset, out, "yyyy-MM-dd hh:MM:ss");
}
public void exportExcel(String[] headers, Collection<T> dataset,
OutputStream out) {
exportExcel("数据导出", headers, dataset, out, "yyyy-MM-dd hh:MM:ss");
}
public void exportExcel(String[] headers, Collection<T> dataset,
OutputStream out, String pattern) {
exportExcel("数据导出", headers, dataset, out, pattern);
}
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30个字节
sheet.setDefaultColumnWidth(30);
// 生成一个样式
HSSFCellStyle style = workbook.createCellStyle();
// 设置这些样式
style.setFillForegroundColor(HSSFColor.WHITE.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);
// 标题字体
HSSFFont font = workbook.createFont();
font.setColor(HSSFColor.BLACK.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.WHITE.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);
// 内容字体
HSSFFont font2 = workbook.createFont();
font2.setColor(HSSFColor.BLACK.index);
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("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("yuyidi");
//产生表格标题行
HSSFRow row = sheet.createRow(0);
for (int 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 (int i = 0; i < fields.length; i++) {
HSSFCell cell = row.createCell(i);
cell.setCellStyle(style2);
Field field = fields[i];
String fieldName = field.getName();
String getMethodName = "get"
+ fieldName.substring(0, 1).toUpperCase()
+ fieldName.substring(1);
try {
Class 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 = null;
if (value instanceof Date) {
Date date = (Date) value;
SimpleDateFormat sdf = new SimpleDateFormat(pattern);
textValue = sdf.format(date);
}else if (value instanceof Double) {
textValue = formatter.format(value);
} 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 = objToString(value);
}
//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);
cell.setCellValue(richString);
}
}
} catch (SecurityException e) {
e.printStackTrace();
} catch (NoSuchMethodException e) {
e.printStackTrace();
} catch (IllegalArgumentException e) {
e.printStackTrace();
} catch (IllegalAccessException e) {
e.printStackTrace();
} catch (InvocationTargetException e) {
e.printStackTrace();
} finally {
//清理资源
}
}
}
try {
workbook.write(out);
} catch (IOException e) {
e.printStackTrace();
}
}
private String objToString(Object obj){
return (obj == null) ? "" : obj.toString();
}
}