以下代码是动态填充数据，这些数据是从数据库取得的批量的，并合并单元格，最终导出excel。但是有一点需要注意，一定是先填充数据在合并单元格，而且每个单元格的样式都是提前设置好的 。
举个例子：合并单元格，第一行的第一个单元格是靠左的，第二个单元格你想居中，第三个单元格是靠右，这样是没法实现的。
下面代码可以直接使用，分为四部分，标题，head部分，内容，foot部分。
public void export(List headerList, List middleList, List footList, List data, String title, GlobalDto globalDto, HttpServletResponse response) throws Exception {
try {
// 创建一个workbook，对应一个Excel文件
HSSFWorkbook workbook = new HSSFWorkbook();
// 在webbook中添加一个sheet,对应Excel文件中的sheet
HSSFSheet hssfSheet = workbook.createSheet("sheet1");
// 设置head单元格的格式
HSSFCellStyle style1 = workbook.createCellStyle();
// style1.setFillPattern(FillPatternType.ALT_BARS);
// 设置边框的线条
style1.setBorderBottom(BorderStyle.THIN);
style1.setBorderLeft(BorderStyle.THIN);
style1.setBorderRight(BorderStyle.THIN);
style1.setBorderTop(BorderStyle.THIN);
// 设置边框的颜色为白色（默认是黑色）
if ("0".equals(globalDto.getHeaderBorder())) {
style1.setBottomBorderColor(IndexedColors.WHITE.getIndex());
style1.setLeftBorderColor(IndexedColors.WHITE.getIndex());
style1.setRightBorderColor(IndexedColors.WHITE.getIndex());
style1.setTopBorderColor(IndexedColors.WHITE.getIndex());
}
style1.setAlignment(HorizontalAlignment.CENTER);
style1.setVerticalAlignment(VerticalAlignment.CENTER);
style1.setWrapText(true);
// 生成并设置另一个样式:文本样式 标题的格式
HSSFCellStyle style2 = workbook.createCellStyle();
style2.setFillForegroundColor(IndexedColors.WHITE.getIndex());
// style2.setFillPattern(FillPatternType.ALT_BARS);
style2.setBorderBottom(BorderStyle.THIN);
style2.setBorderLeft(BorderStyle.THIN);
style2.setBorderRight(BorderStyle.THIN);
style2.setBorderTop(BorderStyle.THIN);
style2.setAlignment(HorizontalAlignment.CENTER);
style2.setVerticalAlignment(VerticalAlignment.CENTER);
style2.setWrapText(true);
// 设置foot单元格的格式
HSSFCellStyle style3 = workbook.createCellStyle();
// 设置边框的线条
style3.setBorderBottom(BorderStyle.THIN);
style3.setBorderLeft(BorderStyle.THIN);
style3.setBorderRight(BorderStyle.THIN);
style3.setBorderTop(BorderStyle.THIN);
// 设置边框的颜色为白色（默认是黑色）
if ("0".equals(globalDto.getFooterBorder())) {
style3.setBottomBorderColor(IndexedColors.WHITE.getIndex());
style3.setLeftBorderColor(IndexedColors.WHITE.getIndex());
style3.setRightBorderColor(IndexedColors.WHITE.getIndex());
style3.setTopBorderColor(IndexedColors.WHITE.getIndex());
}
style3.setAlignment(HorizontalAlignment.CENTER);
style3.setVerticalAlignment(VerticalAlignment.CENTER);
// 生成一个字体
// HSSFFont font = workbook.createFont();
// font.setFontHeightInPoints((short) 12);
// font.setBold(true);
// style3.setFont(font);
style3.setWrapText(true);
// 设置标题的格式
HSSFCellStyle style4 = workbook.createCellStyle();
// 设置边框的线条
style4.setBorderBottom(BorderStyle.THIN);
style4.setBorderLeft(BorderStyle.THIN);
style4.setBorderRight(BorderStyle.THIN);
style4.setBorderTop(BorderStyle.THIN);
// 设置边框的颜色为白色（默认是黑色）
style4.setBottomBorderColor(IndexedColors.WHITE.getIndex());
style4.setLeftBorderColor(IndexedColors.WHITE.getIndex());
style4.setRightBorderColor(IndexedColors.WHITE.getIndex());
style4.setTopBorderColor(IndexedColors.WHITE.getIndex());
style4.setAlignment(HorizontalAlignment.CENTER);
style4.setVerticalAlignment(VerticalAlignment.CENTER);
// 生成一个字体
HSSFFont font = workbook.createFont();
font.setFontHeightInPoints((short) 12);
font.setBold(true);
style4.setFont(font);
style4.setWrapText(true);
// 获取表的最大的列
int length = middleList.size();
int size = 0;
List<HeaderDto> hList = null;
List<FootDto> fList = null;
// 记录行
int count = 0;
// 在sheet中添加表头第0行,注意老版本poi对Excel的行数列数有限制short
HSSFRow row = null;
HSSFCell hssfCell = null;
// 写标题
row = hssfSheet.createRow(count++);
hssfCell = row.createCell(0);
setCellValue(hssfCell, title, style4);
// 获取data的第一个数据 方便用来取头部和底部文本的数据源数据
Map generate = (Map) data.get(0);
Date now = new Date();
// 1.写header部分的数据(与写foot部分的写法一样，怎么去封装)
for (int i = 0; i < headerList.size(); i++) {
List<Integer> mergeCountList = new ArrayList<>();
row = hssfSheet.createRow(count++);
hList = (List<HeaderDto>) headerList.get(i);
// 这里可以判断是否为null
size = hList.size();
// 记录写入列的位置
int k = 0;
if (size <= (length / 2) + 1) {
for (int j = 0; j < length; j++) {
String cellText = "";
// String align = "center";
if ((j + 1) % 2 != 0) {
if (k < size) {
mergeCountList.add(j);
HeaderDto head = hList.get(k);
// 1、常量文本 2、数据源字段 3、打印信息
if ("2".equals(head.getCellType())) {
// 从数据源中取数据(有可能是)
cellText = formatData(generate.get(head.getCellText()));
} else if ("1".equals(head.getCellType())) {
cellText = head.getCellText();
} else if ("3".equals(head.getCellType())) {
// 1、打印时间 2、打印日期
if ("1".equals(head.getCellText())) {
cellText = new SimpleDateFormat("HH:mm:ss").format(now);
} else if ("2".equals(head.getCellText())) {
cellText = new SimpleDateFormat("yyyy-MM-dd").format(now);
} else {
cellText = "";
}
} else {
cellText = "";
}
// align = head.getAlign();
k++;
}
}
HSSFCell cell = row.createCell(j);
setCellValue(cell, cellText, style1);
}
logger.info("i:{}, mergeCountList:{}, length:{}", i, JSON.toJSONString(mergeCountList), length);
for (Integer mergeCount : mergeCountList) {
if (mergeCountList.get(mergeCountList.size() - 1).equals(mergeCount)) {
// 最后一个单元格firstCol<lastCol,否则异常，不能导出
if (mergeCount.compareTo(length - 1) < 0) {
// 遍历到的mergeCount就是list的最后一个元素
hssfSheet.addMergedRegion(new CellRangeAddress(count - 1, count - 1, mergeCount, length - 1));
}
} else {
hssfSheet.addMergedRegion(new CellRangeAddress(count - 1, count - 1, mergeCount, mergeCount + 1));
}
}
} else {
for (int j = 0; j < length; j++) {
String cellText = "";
// String align = "center";
if (k < size) {
HeaderDto head = hList.get(k);
// 1、常量文本 2、数据源字段 3、打印信息
if ("2".equals(head.getCellType())) {
// 从数据源中取数据(有可能是)
cellText = formatData(generate.get(head.getCellText()));
} else if ("1".equals(head.getCellType())) {
cellText = head.getCellText();
} else if ("3".equals(head.getCellType())) {
// 1、打印时间 2、打印日期
if ("1".equals(head.getCellText())) {
cellText = new SimpleDateFormat("HH:mm:ss").format(now);
} else if ("2".equals(head.getCellText())) {
cellText = new SimpleDateFormat("yyyy-MM-dd").format(now);
} else {
cellText = "";
}
} else {
cellText = "";
}
// align = head.getAlign();
k++;
}
HSSFCell cell = row.createCell(j);
setCellValue(cell, cellText, style1);
}
logger.info("i:{}, size:{}, length:{}", i, size, length);
if (size < length) {
hssfSheet.addMergedRegion(new CellRangeAddress(count - 1, count - 1, size - 1, length - 1));
}
}
// 删除list，防止过多的创建list导致内存溢出
mergeCountList.clear();
}
// 2.写middle部分的数据
row = hssfSheet.createRow(count++);
for (int i = 0; i < middleList.size(); i++) {
MiddleDto mDto = (MiddleDto) middleList.get(i);
hssfCell = row.createCell(i);
hssfCell.setCellValue(mDto.getCellText());
hssfCell.setCellStyle(style2);
}
// 3.写data数据,获取map中的list集合
for (int i = 0; i < data.size(); i++) {
row = hssfSheet.createRow(count++);
Map ddMap = (Map) data.get(i);
// 写数据
for (int j = 0; j < length; j++) {
// 创建单元格
HSSFCell cell = row.createCell(j);
cell.setCellStyle(style2);
MiddleDto mDto = (MiddleDto) middleList.get(j);
if ("序号".equals(mDto.getCellText())) {
int z = i + 1;
cell.setCellValue(z + "");
} else {
// 设置单元格的值
MiddleDto temp = (MiddleDto) middleList.get(j);
// String filed = ddMap.get(temp.getKey())+"";
String filed = formatData(ddMap.get(temp.getKey()));
cell.setCellValue(filed);
}
}
}
// 4.写foot数据
for (int i = 0; i < footList.size(); i++) {
List<Integer> mergeCountList = new ArrayList<>();
row = hssfSheet.createRow(count++);
fList = (List<FootDto>) footList.get(i);
// 这里可以判断是否为null
size = fList.size();
// 记录写入列的位置y
int k = 0;
if (size <= (length / 2) + 1) {
for (int j = 0; j < length; j++) {
String cellText = "";
// String align = "center";
if ((j + 1) % 2 != 0) {
if (k < size) {
mergeCountList.add(j);
FootDto foot = fList.get(k);
// 1、常量文本 2、数据源字段 3、打印信息
if ("2".equals(foot.getCellType())) {
// 从数据源中取数据
cellText = formatData(generate.get(foot.getCellText()));
} else if ("1".equals(foot.getCellType())) {
cellText = foot.getCellText();
} else if ("3".equals(foot.getCellType())) {
// 1、打印时间 2、打印日期
if ("1".equals(foot.getCellText())) {
cellText = new SimpleDateFormat("HH:mm:ss").format(now);
} else if ("2".equals(foot.getCellText())) {
cellText = new SimpleDateFormat("yyyy-MM-dd").format(now);
} else {
cellText = "";
}
} else {
cellText = "";
}
// align = foot.getAlign();
k++;
}
}
HSSFCell cell = row.createCell(j);
setCellValue(cell, cellText, style3);
}
logger.info("i:{}, mergeCountList:{}, length:{}", i, JSON.toJSONString(mergeCountList), length);
for (Integer mergeCount : mergeCountList) {
if (mergeCountList.get(mergeCountList.size() - 1).equals(mergeCount)) {
// 最后一个单元格firstCol<lastCol,否则异常，不能导出
if (mergeCount.compareTo(length - 1) < 0) {
// 遍历到的mergeCount就是list的最后一个元素
hssfSheet.addMergedRegion(new CellRangeAddress(count - 1, count - 1, mergeCount, length - 1));
}
} else {
hssfSheet.addMergedRegion(new CellRangeAddress(count - 1, count - 1, mergeCount, mergeCount + 1));
}
}
} else {
for (int j = 0; j < length; j++) {
String cellText = "";
// String align = "center";
if (k < size) {
FootDto foot = fList.get(k);
// 1、常量文本 2、数据源字段 3、打印信息
if ("2".equals(foot.getCellType())) {
// 从数据源中取数据
cellText = formatData(generate.get(foot.getCellText()));
} else if ("1".equals(foot.getCellType())) {
cellText = foot.getCellText();
} else if ("3".equals(foot.getCellType())) {
// 1、打印时间 2、打印日期
if ("1".equals(foot.getCellText())) {
cellText = new SimpleDateFormat("HH:mm:ss").format(now);
} else if ("2".equals(foot.getCellText())) {
cellText = new SimpleDateFormat("yyyy-MM-dd").format(now);
} else {
cellText = "";
}
} else {
cellText = "";
}
// align = foot.getAlign();
k++;
}
HSSFCell cell = row.createCell(j);
setCellValue(cell, cellText, style3);
}
logger.info("i:{}, size:{}, length:{}", i, size, length);
if (size < length) {
hssfSheet.addMergedRegion(new CellRangeAddress(count - 1, count - 1, size - 1, length - 1));
}
}
// 删除list，防止过多的创建list导致内存溢出
mergeCountList.clear();
}
// 合并单元格
hssfSheet.addMergedRegion(new CellRangeAddress(0, 0, 0, length - 1));
for (int i = 0; i < length; i++) {
// hssfSheet.setColumnWidth(i,(short)(middleList.get(i).getCellText().getBytes().length*256));
hssfSheet.autoSizeColumn(i, true);
}
// 将文件输出到客户端浏览器
response.setContentType("application/octet-stream");
// 默认Excel名称
response.setHeader("Content-Disposition", "attachment;fileName=" + URLEncoder.encode(title + ".xls", "UTF-8"));
try {
response.flushBuffer();
workbook.write(response.getOutputStream());
} catch (Exception e) {
e.printStackTrace();
}
} catch (Exception e) {
throw new Exception("导出信息失败！失败原因:", e);
}
}
/**
* 写单元格数据
*
* @param cell
* @param cellValue
* @param style
*/
private void setCellValue(HSSFCell cell, String cellValue, HSSFCellStyle style, String align) {
logger.info("align:{}", align);
if ("left".equalsIgnoreCase(align)) {
style.setAlignment(HorizontalAlignment.LEFT);
} else if ("center".equalsIgnoreCase(align)) {
style.setAlignment(HorizontalAlignment.CENTER);
} else if ("right".equalsIgnoreCase(align)) {
style.setAlignment(HorizontalAlignment.RIGHT);
}
cell.setCellValue(cellValue);
cell.setCellStyle(style);
}
/**
* 写单元格数据
*
* @param cell
* @param cellValue
* @param style
*/
private void setCellValue(HSSFCell cell, String cellValue, HSSFCellStyle style) {
cell.setCellValue(cellValue);
cell.setCellStyle(style);
}
/**
* 数据格式转换
*
* @param o
* @return
*/
public String formatData(Object o) {
String result = "";
if (o == null) {
return "/";
}
if (o instanceof Long) {
// 处理日期类型的数据
SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd");
result = dateFormat.format(new Date((long) o));
} else if (o instanceof BigDecimal) {
// 处理bigDecimal格式
DecimalFormat decimalFormat = new DecimalFormat("#.00");
result = decimalFormat.format((BigDecimal) o);
} else if (o instanceof String) {
result = StringUtils.isBlank((String) o) ? "/" : (String) o;
} else {
result = o.toString();
}
return result;
}
/**
* bean转map：可以直接通过JSON来转，弃用
*
* @param source
* @param <T>
* @return
* @throws IllegalAccessException
*/
public <T> Map<String, Object> beanToMap(T source) throws IllegalAccessException {
Map<String, Object> result = new HashMap<>();
Class<?> sourceClass = source.getClass();
// 拿到所有的字段,不包括继承的字段
Field[] sourceFiled = sourceClass.getDeclaredFields();
for (Field field : sourceFiled) {
field.setAccessible(true);
result.put(field.getName(), field.get(source));
}
return result;
}
/**
* 底部文本
*/
@Data
public static class FootDto {
private String cellType;
private String cellText;
private String align;
private String width;
private String col;
}
/**
* 中部文本
*/
@Data
public static class MiddleDto {
private String cellType;
private String align;
private String width;
private String cellText;
private String key;
private String _index;
private String _rowKey;
}
/**
* 头部文本
*/
@Data
public static class HeaderDto {
private String cellType;
private String cellText;
private String align;
private String width;
private String col;
}
/**
* 全局文本设置
*/
@Data
public static class GlobalDto {
private String paddingTop;
private String paddingLeft;
private String paddingRight;
private String paddingBottom;
private String width;
private String height;
private String headerBorder;
private String footerBorder;
private String showBarCode;
private String barCodeFormAttr;
private String cellType;
private String showFooter;
private String groupTotal;
}