Java POI实现合并单元格
最近碰到个需要合并单元格的需求，要合并相同内容的单元格，前提是合并同一个订单的（第5列）
1.先合并第5列OrderNo的列的单元格
2.读取合并后的单元格，然后合并其它需要合并的列
代码如下：
String[] titles = { "orderList"};
// 对已生成的excel进行合并单元格操作，先合并第5列OrderNo的列的单元格
ExcelUtil.mergeCell(filepath + "/" + filename, 5);
注释：如果只合并一列相同内容的单元格，只调用上面的方法就可以了。如果还要合并其它的列，再调用下面的ExcelUtil.readMergedCell()方法即可。
int[] columns = {0, 1, 2, 3, 4, 6, 7, 8, 9, 10};
// 读取合并后的单元格，然后合并其它需要合并的列
ExcelUtil.readMergedCell(filepath + "/" + filename, titles, columns);
FileUtils.download(filepath + "/" + filename, response);
import org.apache.commons.lang3.StringUtils;
import org.apache.poi.ss.util.CellRangeAddress;
import org.apache.poi.xssf.usermodel.*;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
public class ExcelUtil {
private static final Logger LOGGER = LoggerFactory.getLogger(ExcelUtil.class);
/**
* 合并单元格
*
* @param filePath excel文件路径
* @param mergeNum 要合并的列数
*/
public static void mergeCell(String filePath, int mergeNum) throws Exception{
try {
File file = new File(filePath);
FileInputStream fis = new FileInputStream(file);
XSSFWorkbook workbook = new XSSFWorkbook(fis);
if (workbook != null){
// 设置样式
XSSFCellStyle cellStyle = createCellStyle(workbook);
XSSFFont font = createFont(workbook);
cellStyle.setFont(font);
XSSFSheet sheet = workbook.getSheetAt(0);
if (null != sheet) {
//开始查找的行
int currentRow = 1;
//totalRow 总行数
int totalRow = sheet.getLastRowNum();
String cellValue;
for (int p = 1; p <= totalRow; p++) {
XSSFRow row = sheet.getRow(p);
if (null != row) {
XSSFCell currentCell = row.getCell(mergeNum);
if (null != currentCell) {
String current = getStringCellValue(currentCell);
XSSFCell nextCell = null;
String next = "";
if (p < totalRow + 1) {
XSSFRow nowRow = sheet.getRow(p + 1);
if (nowRow != null) {
nextCell = nowRow.getCell(mergeNum);
next = getStringCellValue(nextCell);
} else {
next = "";
}
} else {
next = "";
}
// 比对是否相同
if (current.equals(next)) {
currentCell.setCellValue("");
continue;
} else {
if (currentRow == p && !current.equals(next)){
currentRow = p + 1;
continue;
}
XSSFCell xssfCell = row.getCell(mergeNum);
cellValue = getStringCellValue(xssfCell);
List list = new ArrayList<>();
for(int i = currentRow; i<= p; i++){
list.add(i);
}
for (Integer rowNum: list) {
XSSFCell cell1 = sheet.getRow(rowNum).getCell(mergeNum);
// 判断是否是几行同一个订单的第一个单元格
if (rowNum.equals(currentRow)){
cell1.setCellValue(cellValue);
cell1.setCellStyle(cellStyle);
} else {
sheet.getRow(rowNum).removeCell(cell1);
}
}
// 合并单元格
sheet.addMergedRegion(new CellRangeAddress(currentRow, p, mergeNum, mergeNum));
XSSFCell nowCell = sheet.getRow(currentRow).getCell(mergeNum);
nowCell.setCellValue(cellValue);
nowCell.setCellStyle(cellStyle);
currentRow = p + 1;
}
}
}
}
}
}
FileOutputStream fos = new FileOutputStream(file);
workbook.write(fos);
fis.close();
fos.close();
workbook.close();
} catch (Exception e) {
LOGGER.error(e.getMessage(), e);
}
}
/**
* 读取合并后的单元格
*
* @param filePath excel文件路径
* @param sheetNames sheet列名称列表，如果只有一个sheet的话，此参数可不传，可使用workbook.getSheetAt(0)获取XSSFSheet对象
* @param mergeColumns 需要合并的列数组
* @return
*/
public static void readMergedCell(String filePath, String[] sheetNames, int[] mergeColumns){
// 读取合并后的订单excel内容
File file;
FileInputStream fis = null;
FileOutputStream fos = null;
XSSFWorkbook workbook = null;
try {
file = new File(filePath);
fis = new FileInputStream(file);
workbook = new XSSFWorkbook(fis);
// 设置样式
XSSFCellStyle cellStyle = createCellStyle(workbook);
XSSFFont font = createFont(workbook);
cellStyle.setFont(font);
for (String sheetName : sheetNames) {
String cellValue;
XSSFSheet sheet = workbook.getSheet(sheetName);
List mergedRegions = sheet.getMergedRegions();
for (CellRangeAddress cellRangeAddress: mergedRegions){
int firstRow = cellRangeAddress.getFirstRow();
int lastRow = cellRangeAddress.getLastRow();
List rowNumList = new ArrayList<>();
for(int i = firstRow; i<= lastRow; i++){
rowNumList.add(i);
}
for (int columnNum: mergeColumns){
XSSFCell cell = sheet.getRow(firstRow).getCell(columnNum);
cellValue = getStringCellValue(cell);
// 合并单元格
for (Integer rowNum: rowNumList) {
XSSFCell cell1 = sheet.getRow(rowNum).getCell(columnNum);
// 判断是否是几行同一个订单的第一个单元格
if (rowNum.equals(firstRow)){
if (Integer.valueOf(XSSFCell.CELL_TYPE_NUMERIC).equals(cell.getCellType())){
cell1.setCellValue(cell.getNumericCellValue());
}else{
cell1.setCellValue(cellValue);
}
cell1.setCellStyle(cellStyle);
} else {
if(sheet.getRow(rowNum) != null && cell1 != null ){
sheet.getRow(rowNum).removeCell(cell1);
}
}
}
sheet.addMergedRegion(new CellRangeAddress(firstRow, lastRow, columnNum, columnNum));
XSSFCell nowCell = sheet.getRow(firstRow).getCell(columnNum);
if (Integer.valueOf(XSSFCell.CELL_TYPE_NUMERIC).equals(cell.getCellType())){
nowCell.setCellValue(cell.getNumericCellValue());
} else{
nowCell.setCellValue(cellValue);
}
nowCell.setCellStyle(cellStyle);
}
}
}
fos = new FileOutputStream(file);
workbook.write(fos);
} catch (IOException e) {
LOGGER.error(e.getMessage(), e);
} catch (Exception e) {
LOGGER.error(e.getMessage(), e);
} finally {
try {
if (fis != null){
fis.close();
}
if (fos != null){
fos.close();
}
if (workbook != null){
workbook.close();
}
} catch (Exception e){
LOGGER.error(e.getMessage(), e);
}
}
}
/**
* 将单元格中的所有值，都转化为String类型的值
*
* @param cell
* @return
*/
public static String getStringCellValue(XSSFCell cell) {
String strCell = "";
if (cell != null) {
switch (cell.getCellType()) {
case XSSFCell.CELL_TYPE_STRING:
strCell = cell.getStringCellValue();
break;
case XSSFCell.CELL_TYPE_NUMERIC:
strCell = String.valueOf(cell.getNumericCellValue());
break;
case XSSFCell.CELL_TYPE_BOOLEAN:
strCell = String.valueOf(cell.getBooleanCellValue());
break;
case XSSFCell.CELL_TYPE_BLANK:
strCell = "";
break;
default:
strCell = "";
break;
}
if (StringUtils.isEmpty(strCell)) {
return "";
}
}
if (cell == null) {
return "";
}
return strCell;
}
/**
* 设置样式
*
* @param workbook
*/
public static XSSFCellStyle createCellStyle(XSSFWorkbook workbook){
// 设置样式
XSSFCellStyle cellStyle = workbook.createCellStyle();
// 居中样式
cellStyle.setAlignment(XSSFCellStyle.ALIGN_CENTER);
// 垂直样式
cellStyle.setVerticalAlignment(XSSFCellStyle.VERTICAL_CENTER);
return cellStyle;
}
/**
* 设置字体
*
* @param workbook
*/
public static XSSFFont createFont(XSSFWorkbook workbook){
// 设置字体:
XSSFFont font = workbook.createFont();
font.setFontName("Calibri");
// 设置字体大小
font.setFontHeightInPoints((short) 11);
return font;
}
}