fix code

hutool-json/src/main/java/org/dromara/hutool/json/serialize/GlobalSerializeMapping.java

@@ -97,7 +97,7 @@ public class GlobalSerializeMapping {
 	 * @return 自定义的序列化器或者{@code null}
 	 */
 	public static JSONSerializer<? extends JSON, ?> getSerializer(final Type type) {
-		if (null == serializerMap) {
+		if (null == serializerMap || null == type) {
 			return null;
 		}
 		return serializerMap.get(ObjUtil.defaultIfNull(type, NullType.INSTANCE));
@@ -110,7 +110,7 @@ public class GlobalSerializeMapping {
 	 * @return 自定义的反序列化器或者{@code null}
 	 */
 	public static JSONDeserializer<?> getDeserializer(final Type type) {
-		if (null == deserializerMap) {
+		if (null == deserializerMap || null == type) {
 			return null;
 		}
 		return deserializerMap.get(ObjUtil.defaultIfNull(type, NullType.INSTANCE));

hutool-poi/src/main/java/org/dromara/hutool/poi/excel/SheetUtil.java

@@ -141,4 +141,21 @@ public class SheetUtil {
 			throw new UnsupportedOperationException("Only XSSFSheet supports addIgnoredErrors");
 		}
 	}
+
+	/**
+	 * 获取指定坐标点对应的合并单元格范围
+	 *
+	 * @param sheet {@link Sheet}
+	 * @param x     x坐标，即列号
+	 * @param y     行号
+	 * @return CellRangeAddress or null
+	 */
+	public static CellRangeAddress getMergedRegion(final Sheet sheet, final int x, final int y) {
+		for (final CellRangeAddress ca : sheet.getMergedRegions()) {
+			if (ca.isInRange(y, x)) {
+				return ca;
+			}
+		}
+		return null;
+	}
 }

hutool-poi/src/main/java/org/dromara/hutool/poi/excel/cell/CellUtil.java

@@ -19,16 +19,15 @@ package org.dromara.hutool.poi.excel.cell;
 import org.apache.poi.ss.usermodel.*;
 import org.apache.poi.ss.util.CellRangeAddress;
 import org.apache.poi.ss.util.CellReference;
-import org.apache.poi.ss.util.RegionUtil;
-import org.apache.poi.ss.util.SheetUtil;
-import org.dromara.hutool.core.util.ObjUtil;
 import org.dromara.hutool.poi.excel.RowUtil;
+import org.dromara.hutool.poi.excel.SheetUtil;
 import org.dromara.hutool.poi.excel.cell.editors.CellEditor;
 import org.dromara.hutool.poi.excel.cell.editors.TrimEditor;
 import org.dromara.hutool.poi.excel.cell.setters.CellSetter;
 import org.dromara.hutool.poi.excel.cell.setters.CellSetterFactory;
 import org.dromara.hutool.poi.excel.cell.values.CompositeCellValue;
 import org.dromara.hutool.poi.excel.style.StyleSet;
+import org.dromara.hutool.poi.excel.style.StyleUtil;
 
 /**
  * Excel表格中单元格工具类
@@ -194,6 +193,18 @@ public class CellUtil {
 
 	// region ----- getCell
 
+	/**
+	 * 获取或创建指定坐标单元格
+	 *
+	 * @param sheet {@link Sheet}
+	 * @param x     X坐标，从0计数，即列号
+	 * @param y     Y坐标，从0计数，即行号
+	 * @return {@link Cell}
+	 */
+	public static Cell getOrCreateCell(final Sheet sheet, final int x, final int y) {
+		return getCell(sheet, x, y, true);
+	}
+
 	/**
 	 * 获取指定坐标单元格，如果isCreateIfNotExist为false，则在单元格不存在时返回{@code null}
 	 *
@@ -318,54 +329,33 @@ public class CellUtil {
 	 * @return 合并后的单元格号
 	 */
 	public static int mergingCells(final Sheet sheet, final CellRangeAddress cellRangeAddress, final CellStyle cellStyle) {
-		setMergeCellStyle(cellStyle, cellRangeAddress, sheet);
+		if (cellRangeAddress.getNumberOfCells() <= 1) {
+			// 非合并单元格，无需合并
+			return -1;
+		}
+		StyleUtil.setBorderStyle(sheet, cellRangeAddress, cellStyle);
 		return sheet.addMergedRegion(cellRangeAddress);
 	}
 
 	/**
-	 * 获取合并单元格的值<br>
+	 * 获取合并单元格中的第一个单元格<br>
-	 * 传入的x,y坐标（列行数）可以是合并单元格范围内的任意一个单元格
+	 * 传入的cell可以是合并单元格范围内的任意一个单元格
-	 *
-	 * @param sheet       {@link Sheet}
-	 * @param locationRef 单元格地址标识符，例如A11，B5
-	 * @return 合并单元格的值
-	 * @since 5.1.5
-	 */
-	public static Object getMergedRegionValue(final Sheet sheet, final String locationRef) {
-		final CellReference cellReference = new CellReference(locationRef);
-		return getMergedRegionValue(sheet, cellReference.getCol(), cellReference.getRow());
-	}
-
-	/**
-	 * 获取合并单元格的值<br>
-	 * 传入的x,y坐标（列行数）可以是合并单元格范围内的任意一个单元格
-	 *
-	 * @param sheet {@link Sheet}
-	 * @param x     列号，从0开始，可以是合并单元格范围中的任意一列
-	 * @param y     行号，从0开始，可以是合并单元格范围中的任意一行
-	 * @return 合并单元格的值
-	 * @since 4.6.3
-	 */
-	public static Object getMergedRegionValue(final Sheet sheet, final int x, final int y) {
-		// 合并单元格的识别在getCellValue已经集成，无需重复获取合并单元格
-		return getCellValue(SheetUtil.getCell(sheet, x, y));
-	}
-
-	/**
-	 * 获取合并单元格<br>
-	 * 传入的x,y坐标（列行数）可以是合并单元格范围内的任意一个单元格
 	 *
 	 * @param cell {@link Cell}
 	 * @return 合并单元格
 	 * @since 5.1.5
 	 */
-	public static Cell getMergedRegionCell(final Cell cell) {
+	public static Cell getFirstCellOfMerged(final Cell cell) {
 		if (null == cell) {
 			return null;
 		}
-		return ObjUtil.defaultIfNull(
+
-			getCellIfMergedRegion(cell.getSheet(), cell.getColumnIndex(), cell.getRowIndex()),
+		final MergedCell mergedCell = getMergedCell(cell.getSheet(), cell.getColumnIndex(), cell.getRowIndex());
-			cell);
+		if (null != mergedCell) {
+			return mergedCell.getFirst();
+		}
+
+		return cell;
 	}
 
 	/**
@@ -378,10 +368,16 @@ public class CellUtil {
 	 * @return 合并单元格，如果非合并单元格，返回坐标对应的单元格
 	 * @since 5.1.5
 	 */
-	public static Cell getMergedRegionCell(final Sheet sheet, final int x, final int y) {
+	public static MergedCell getMergedCell(final Sheet sheet, final int x, final int y) {
-		return ObjUtil.defaultIfNull(
+		if (null == sheet) {
-			getCellIfMergedRegion(sheet, x, y),
+			return null;
-			() -> SheetUtil.getCell(sheet, y, x));
+		}
+
+		final CellRangeAddress mergedRegion = SheetUtil.getMergedRegion(sheet, x, y);
+		if (null != mergedRegion) {
+			return MergedCell.of(getCell(sheet, mergedRegion.getFirstColumn(), mergedRegion.getFirstRow(), false), mergedRegion);
+		}
+		return null;
 	}
 	// endregion
 
@@ -440,46 +436,4 @@ public class CellUtil {
 			cell.getRow().removeCell(cell);
 		}
 	}
-
-	// -------------------------------------------------------------------------------------------------------------- Private method start
-
-	/**
-	 * 获取合并单元格，非合并单元格返回{@code null}<br>
-	 * 传入的x,y坐标（列行数）可以是合并单元格范围内的任意一个单元格
-	 *
-	 * @param sheet {@link Sheet}
-	 * @param x     列号，从0开始，可以是合并单元格范围中的任意一列
-	 * @param y     行号，从0开始，可以是合并单元格范围中的任意一行
-	 * @return 合并单元格，如果非合并单元格，返回{@code null}
-	 * @since 5.4.5
-	 */
-	private static Cell getCellIfMergedRegion(final Sheet sheet, final int x, final int y) {
-		for (final CellRangeAddress ca : sheet.getMergedRegions()) {
-			if (ca.isInRange(y, x)) {
-				return SheetUtil.getCell(sheet, ca.getFirstRow(), ca.getFirstColumn());
-			}
-		}
-		return null;
-	}
-
-	/**
-	 * 根据{@link CellStyle}设置合并单元格边框样式
-	 *
-	 * @param cellStyle        {@link CellStyle}
-	 * @param cellRangeAddress {@link CellRangeAddress}
-	 * @param sheet            {@link Sheet}
-	 */
-	private static void setMergeCellStyle(final CellStyle cellStyle, final CellRangeAddress cellRangeAddress, final Sheet sheet) {
-		if (null != cellStyle) {
-			RegionUtil.setBorderTop(cellStyle.getBorderTop(), cellRangeAddress, sheet);
-			RegionUtil.setBorderRight(cellStyle.getBorderRight(), cellRangeAddress, sheet);
-			RegionUtil.setBorderBottom(cellStyle.getBorderBottom(), cellRangeAddress, sheet);
-			RegionUtil.setBorderLeft(cellStyle.getBorderLeft(), cellRangeAddress, sheet);
-			RegionUtil.setTopBorderColor(cellStyle.getTopBorderColor(), cellRangeAddress, sheet);
-			RegionUtil.setRightBorderColor(cellStyle.getRightBorderColor(), cellRangeAddress, sheet);
-			RegionUtil.setLeftBorderColor(cellStyle.getLeftBorderColor(), cellRangeAddress, sheet);
-			RegionUtil.setBottomBorderColor(cellStyle.getBottomBorderColor(), cellRangeAddress, sheet);
-		}
-	}
-	// -------------------------------------------------------------------------------------------------------------- Private method end
 }

hutool-poi/src/main/java/org/dromara/hutool/poi/excel/cell/MergedCell.java

@@ -0,0 +1,111 @@
+/*
+ * Copyright (c) 2024 Hutool Team and hutool.cn
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.dromara.hutool.poi.excel.cell;
+
+import org.apache.poi.ss.usermodel.Cell;
+import org.apache.poi.ss.usermodel.CellStyle;
+import org.apache.poi.ss.util.CellRangeAddress;
+
+/**
+ * 合并单元格封装
+ *
+ * @author Looly
+ * @since 6.0.0
+ */
+public class MergedCell {
+
+	/**
+	 * 创建MergedCell
+	 *
+	 * @param cell        第一个单元格，即左上角的单元格
+	 * @param rowCount    占用行数
+	 * @param columnCount 占用列数
+	 * @return MergedCell
+	 */
+	public static MergedCell of(final Cell cell, final int rowCount, final int columnCount) {
+		final int rowIndex = cell.getRowIndex();
+		final int columnIndex = cell.getColumnIndex();
+		return of(cell, new CellRangeAddress(
+			rowIndex, rowIndex + rowCount - 1,
+			columnIndex, columnIndex + columnCount - 1));
+	}
+
+	/**
+	 * 创建MergedCell
+	 *
+	 * @param cell  第一个单元格，即左上角的单元格
+	 * @param range 合并单元格范围
+	 * @return MergedCell
+	 */
+	public static MergedCell of(final Cell cell, final CellRangeAddress range) {
+		return new MergedCell(cell, range);
+	}
+
+	private final Cell first;
+	private final CellRangeAddress range;
+
+	/**
+	 * 构造
+	 *
+	 * @param first  第一个单元格，即左上角的单元格
+	 * @param range 合并单元格范围
+	 */
+	public MergedCell(final Cell first, final CellRangeAddress range) {
+		this.first = first;
+		this.range = range;
+	}
+
+	/**
+	 * 获取第一个单元格，即左上角的单元格
+	 *
+	 * @return Cell
+	 */
+	public Cell getFirst() {
+		return this.first;
+	}
+
+	/**
+	 * 获取合并单元格范围
+	 *
+	 * @return CellRangeAddress
+	 */
+	public CellRangeAddress getRange() {
+		return this.range;
+	}
+
+	/**
+	 * 设置单元格样式
+	 *
+	 * @param cellStyle 单元格样式
+	 * @return this
+	 */
+	public MergedCell setCellStyle(final CellStyle cellStyle) {
+		this.first.setCellStyle(cellStyle);
+		return this;
+	}
+
+	/**
+	 * 设置单元格值
+	 *
+	 * @param value 值
+	 * @return this
+	 */
+	public MergedCell setValue(final Object value) {
+		CellUtil.setCellValue(this.first, value);
+		return this;
+	}
+}

hutool-poi/src/main/java/org/dromara/hutool/poi/excel/cell/values/CompositeCellValue.java

@@ -77,7 +77,7 @@ public class CompositeCellValue implements CellValue<Object> {
 		}
 
 		// 尝试获取合并单元格，如果是合并单元格，则重新获取单元格类型
-		final Cell mergedCell = CellUtil.getMergedRegionCell(cell);
+		final Cell mergedCell = CellUtil.getFirstCellOfMerged(cell);
 		if (mergedCell != cell) {
 			cell = mergedCell;
 			cellType = cell.getCellType();

hutool-poi/src/main/java/org/dromara/hutool/poi/excel/style/CellBorderStyle.java

@@ -32,6 +32,24 @@ import java.io.Serializable;
 public class CellBorderStyle implements Serializable {
 	private static final long serialVersionUID = 1L;
 
+	/**
+	 * 根据CellStyle创建单元格边框样式对象。
+	 *
+	 * @param cellStyle 单元格样式
+	 * @return CellBorderStyle
+	 */
+	public static CellBorderStyle of(final CellStyle cellStyle) {
+		return new CellBorderStyle()
+			.setTopStyle(cellStyle.getBorderTop())
+			.setTopColor(cellStyle.getTopBorderColor())
+			.setRightStyle(cellStyle.getBorderRight())
+			.setRightColor(cellStyle.getRightBorderColor())
+			.setBottomStyle(cellStyle.getBorderBottom())
+			.setBottomColor(cellStyle.getBottomBorderColor())
+			.setLeftStyle(cellStyle.getBorderLeft())
+			.setLeftColor(cellStyle.getLeftBorderColor());
+	}
+
 	/**
 	 * 创建单元格边框样式对象，四边框样式保持一致。
 	 *

hutool-poi/src/main/java/org/dromara/hutool/poi/excel/style/StyleSet.java

@@ -37,7 +37,7 @@ public interface StyleSet {
 	 *
 	 * @param reference 单元格引用，包含单元格位置等信息
 	 * @param cellValue 单元格值
-	 * @param isHeader  是否为表头，扁头定义的特殊样式
+	 * @param isHeader  是否为表头，表头定义的特殊样式
 	 * @return 单元格样式
 	 */
 	CellStyle getStyleFor(CellReference reference, Object cellValue, boolean isHeader);

hutool-poi/src/main/java/org/dromara/hutool/poi/excel/style/StyleUtil.java

@@ -17,6 +17,8 @@
 package org.dromara.hutool.poi.excel.style;
 
 import org.apache.poi.ss.usermodel.*;
+import org.apache.poi.ss.util.CellRangeAddress;
+import org.apache.poi.ss.util.RegionUtil;
 import org.apache.poi.xssf.usermodel.XSSFCellStyle;
 import org.apache.poi.xssf.usermodel.XSSFColor;
 import org.dromara.hutool.core.text.StrUtil;
@@ -156,6 +158,41 @@ public class StyleUtil {
 		return cellBorderStyle.setTo(cellStyle);
 	}
 
+	/**
+	 * 根据{@link CellStyle}设置指定范围边框样式
+	 *
+	 * @param sheet            {@link Sheet}
+	 * @param cellRangeAddress 边框样式范围
+	 * @param cellBorderStyle  边框风格，包括边框样式、颜色
+	 */
+	public static void setBorderStyle(final Sheet sheet, final CellRangeAddress cellRangeAddress, final CellBorderStyle cellBorderStyle) {
+		if (null != cellBorderStyle) {
+			RegionUtil.setBorderTop(cellBorderStyle.getTopStyle(), cellRangeAddress, sheet);
+			RegionUtil.setBorderRight(cellBorderStyle.getRightStyle(), cellRangeAddress, sheet);
+			RegionUtil.setBorderBottom(cellBorderStyle.getBottomStyle(), cellRangeAddress, sheet);
+			RegionUtil.setBorderLeft(cellBorderStyle.getLeftStyle(), cellRangeAddress, sheet);
+
+			RegionUtil.setTopBorderColor(cellBorderStyle.getTopColor(), cellRangeAddress, sheet);
+			RegionUtil.setRightBorderColor(cellBorderStyle.getRightColor(), cellRangeAddress, sheet);
+			RegionUtil.setLeftBorderColor(cellBorderStyle.getLeftColor(), cellRangeAddress, sheet);
+			RegionUtil.setBottomBorderColor(cellBorderStyle.getBottomColor(), cellRangeAddress, sheet);
+		}
+	}
+
+	/**
+	 * 根据{@link CellStyle}设置指定范围边框样式
+	 *
+	 * @param sheet            {@link Sheet}
+	 * @param cellRangeAddress {@link CellRangeAddress}
+	 * @param cellStyle        {@link CellStyle}
+	 */
+	public static void setBorderStyle(final Sheet sheet, final CellRangeAddress cellRangeAddress, final CellStyle cellStyle) {
+		if (null != cellStyle) {
+			final CellBorderStyle cellBorderStyle = CellBorderStyle.of(cellStyle);
+			setBorderStyle(sheet, cellRangeAddress, cellBorderStyle);
+		}
+	}
+
 	// region ----- color
 
 	/**

hutool-poi/src/main/java/org/dromara/hutool/poi/excel/writer/ExcelWriter.java

@@ -21,7 +21,6 @@ import org.apache.poi.ss.util.CellRangeAddress;
 import org.apache.poi.ss.util.CellRangeAddressList;
 import org.apache.poi.ss.util.CellReference;
 import org.dromara.hutool.core.bean.BeanUtil;
-import org.dromara.hutool.core.collection.CollUtil;
 import org.dromara.hutool.core.io.IORuntimeException;
 import org.dromara.hutool.core.io.IoUtil;
 import org.dromara.hutool.core.io.file.FileUtil;
@@ -37,7 +36,6 @@ import java.io.File;
 import java.io.IOException;
 import java.io.OutputStream;
 import java.util.Comparator;
-import java.util.List;
 import java.util.Map;
 import java.util.TreeMap;
 
@@ -644,9 +642,7 @@ public class ExcelWriter extends ExcelBase<ExcelWriter, ExcelWriteConfig> {
 	public ExcelWriter merge(final CellRangeAddress cellRangeAddress, final Object content, final CellStyle cellStyle) {
 		checkClosed();
 
-		if(cellRangeAddress.getNumberOfCells() > 1){
 		CellUtil.mergingCells(this.getSheet(), cellRangeAddress, cellStyle);
-		}
 
 		// 设置内容
 		if (null != content) {
@@ -766,41 +762,9 @@ public class ExcelWriter extends ExcelBase<ExcelWriter, ExcelWriteConfig> {
 	 * @param rowGroup 分组行
 	 * @return this
 	 */
-	@SuppressWarnings("resource")
+	public ExcelWriter writeHeader(final int x, final int y, final int rowCount, final RowGroup rowGroup) {
-	public ExcelWriter writeHeader(int x, int y, int rowCount, final RowGroup rowGroup) {
+		checkClosed();
-
+		this.getSheetDataWriter().writeHeader(x, y, rowCount, rowGroup);
-		// 写主标题
-		final String name = rowGroup.getName();
-		final List<RowGroup> children = rowGroup.getChildren();
-		if (null != name) {
-			if(!CollUtil.isEmpty(children)){
-				// 有子节点，标题行只占用除子节点占用的行数
-				rowCount = Math.max(1, rowCount - rowGroup.childrenMaxRowCount());
-				//nameRowCount = 1;
-			}
-
-			// 如果无子节点，则标题行占用所有行
-			final CellRangeAddress cellAddresses = CellRangeUtil.of(y, y + rowCount - 1, x, x + rowGroup.maxColumnCount() - 1);
-			final CellStyle style = rowGroup.getStyle();
-			if(null == style){
-				merge(cellAddresses, name, true);
-			} else{
-				merge(cellAddresses, name, style);
-			}
-			// 子分组写到下N行
-			y += rowCount;
-		}
-
-		// 写分组
-		final int childrenMaxRowCount = rowGroup.childrenMaxRowCount();
-		if(childrenMaxRowCount > 0){
-			for (final RowGroup child : children) {
-				// 子分组行高填充为当前分组最大值
-				writeHeader(x, y, childrenMaxRowCount, child);
-				x += child.maxColumnCount();
-			}
-		}
-
 		return this;
 	}
 	// endregion

hutool-poi/src/main/java/org/dromara/hutool/poi/excel/writer/SheetDataWriter.java

@@ -18,20 +18,26 @@ package org.dromara.hutool.poi.excel.writer;
 
 import org.apache.poi.common.usermodel.Hyperlink;
 import org.apache.poi.ss.usermodel.Cell;
+import org.apache.poi.ss.usermodel.CellStyle;
 import org.apache.poi.ss.usermodel.Row;
 import org.apache.poi.ss.usermodel.Sheet;
+import org.apache.poi.ss.util.CellRangeAddress;
+import org.apache.poi.ss.util.CellReference;
 import org.dromara.hutool.core.bean.BeanUtil;
+import org.dromara.hutool.core.collection.CollUtil;
 import org.dromara.hutool.core.collection.ListUtil;
 import org.dromara.hutool.core.map.MapUtil;
-import org.dromara.hutool.core.map.concurrent.SafeConcurrentHashMap;
 import org.dromara.hutool.core.map.multi.Table;
 import org.dromara.hutool.core.text.StrUtil;
+import org.dromara.hutool.poi.excel.RowGroup;
 import org.dromara.hutool.poi.excel.RowUtil;
+import org.dromara.hutool.poi.excel.cell.CellRangeUtil;
 import org.dromara.hutool.poi.excel.cell.CellUtil;
 import org.dromara.hutool.poi.excel.cell.editors.CellEditor;
 import org.dromara.hutool.poi.excel.style.StyleSet;
 
 import java.util.LinkedHashMap;
+import java.util.List;
 import java.util.Map;
 import java.util.TreeMap;
 import java.util.concurrent.atomic.AtomicInteger;
@@ -53,7 +59,7 @@ public class SheetDataWriter {
 	 * 标题项对应列号缓存，每次写标题更新此缓存<br>
 	 * 此缓存用于用户多次write时，寻找标题位置
 	 */
-	private Map<String, Integer> headLocationCache;
+	private Map<String, Integer> headerLocationCache;
 	/**
 	 * 当前行，用于标记初始可写数据的行和部分写完后当前的行
 	 */
@@ -75,6 +81,7 @@ public class SheetDataWriter {
 
 	/**
 	 * 设置样式表
+	 *
 	 * @param styleSet 样式表
 	 * @return this
 	 */
@@ -83,6 +90,67 @@ public class SheetDataWriter {
 		return this;
 	}
 
+	/**
+	 * 设置标题位置映射缓存
+	 *
+	 * @param headerLocationCache 标题位置映射缓存，key为表明名，value为列号
+	 * @return this
+	 */
+	public SheetDataWriter setHeaderLocationCache(final Map<String, Integer> headerLocationCache) {
+		this.headerLocationCache = headerLocationCache;
+		return this;
+	}
+
+	/**
+	 * 写出分组标题行
+	 *
+	 * @param x        开始的列，下标从0开始
+	 * @param y        开始的行，下标从0开始
+	 * @param rowCount 当前分组行所占行数，此数值为标题占用行数+子分组占用的最大行数，不确定传1
+	 * @param rowGroup 分组行
+	 * @return this
+	 */
+	public SheetDataWriter writeHeader(int x, int y, int rowCount, final RowGroup rowGroup) {
+
+		// 写主标题
+		final String name = rowGroup.getName();
+		final List<RowGroup> children = rowGroup.getChildren();
+		if (null != name) {
+			if(CollUtil.isNotEmpty(children)){
+				// 有子节点，标题行只占用除子节点占用的行数
+				rowCount = Math.max(1, rowCount - rowGroup.childrenMaxRowCount());
+				//nameRowCount = 1;
+			}
+
+			// 如果无子节点，则标题行占用所有行
+			final CellRangeAddress cellRangeAddresses = CellRangeUtil.of(y, y + rowCount - 1, x, x + rowGroup.maxColumnCount() - 1);
+			CellStyle style = rowGroup.getStyle();
+			if (null == style && null != this.styleSet) {
+				style = styleSet.getStyleFor(new CellReference(cellRangeAddresses.getFirstRow(), cellRangeAddresses.getFirstColumn()), name, true);
+			}
+			CellUtil.mergingCells(this.sheet, cellRangeAddresses, style);
+			final Cell cell = CellUtil.getOrCreateCell(this.sheet, cellRangeAddresses.getFirstColumn(), cellRangeAddresses.getFirstRow());
+			if(null != cell){
+				CellUtil.setCellValue(cell, name, style, this.config.getCellEditor());
+			}
+
+			// 子分组写到下N行
+			y += rowCount;
+		}
+
+		// 写分组
+		final int childrenMaxRowCount = rowGroup.childrenMaxRowCount();
+		if(childrenMaxRowCount > 0){
+			for (final RowGroup child : children) {
+				// 子分组行高填充为当前分组最大值
+				writeHeader(x, y, childrenMaxRowCount, child);
+				x += child.maxColumnCount();
+			}
+		}
+
+		return this;
+	}
+
 	/**
 	 * 写出一行，根据rowBean数据类型不同，写出情况如下：
 	 *
@@ -153,13 +221,13 @@ public class SheetDataWriter {
 			// 记录原数据key和别名对应列号
 			int i = 0;
 			for (final Object key : aliasTable.rowKeySet()) {
-				this.headLocationCache.putIfAbsent(StrUtil.toString(key), i);
+				this.headerLocationCache.putIfAbsent(StrUtil.toString(key), i);
 				i++;
 			}
 		}
 
 		// 如果已经写出标题行，根据标题行找对应的值写入
-		if (MapUtil.isNotEmpty(this.headLocationCache)) {
+		if (MapUtil.isNotEmpty(this.headerLocationCache)) {
 			final Row row = RowUtil.getOrCreateRow(this.sheet, this.currentRow.getAndIncrement());
 			final CellEditor cellEditor = this.config.getCellEditor();
 			Integer columnIndex;
@@ -176,7 +244,7 @@ public class SheetDataWriter {
 	}
 
 	/**
-	 * 写出一行标题数据<br>
+	 * 写出一行标题数据，标题数据不替换别名<br>
 	 * 本方法只是将数据写入Workbook中的Sheet，并不写出到文件<br>
 	 * 写出的起始行为当前行号，可使用{@link #getCurrentRow()}方法调用，根据写出的的行数，当前行号自动+1
 	 *
@@ -184,21 +252,20 @@ public class SheetDataWriter {
 	 * @return this
 	 */
 	public SheetDataWriter writeHeaderRow(final Iterable<?> rowData) {
-		this.headLocationCache = new SafeConcurrentHashMap<>();
-
 		final int rowNum = this.currentRow.getAndIncrement();
 		final Row row = this.config.insertRow ? this.sheet.createRow(rowNum) : RowUtil.getOrCreateRow(this.sheet, rowNum);
 
+		final Map<String, Integer> headerLocationCache = new LinkedHashMap<>();
 		final CellEditor cellEditor = this.config.getCellEditor();
 		int i = 0;
 		Cell cell;
 		for (final Object value : rowData) {
 			cell = CellUtil.getOrCreateCell(row, i);
 			CellUtil.setCellValue(cell, value, this.styleSet, true, cellEditor);
-			this.headLocationCache.put(StrUtil.toString(value), i);
+			headerLocationCache.put(StrUtil.toString(value), i);
 			i++;
 		}
-		return this;
+		return setHeaderLocationCache(headerLocationCache);
 	}
 
 	/**
@@ -217,6 +284,7 @@ public class SheetDataWriter {
 	}
 
 	// region ----- currentRow ops
+
 	/**
 	 * 获得当前行
 	 *
@@ -275,10 +343,10 @@ public class SheetDataWriter {
 	 */
 	private Integer getColumnIndex(final Table.Cell<?, ?, ?> cell) {
 		// 首先查找原名对应的列号
-		Integer location = this.headLocationCache.get(StrUtil.toString(cell.getRowKey()));
+		Integer location = this.headerLocationCache.get(StrUtil.toString(cell.getRowKey()));
 		if (null == location) {
 			// 未找到，则查找别名对应的列号
-			location = this.headLocationCache.get(StrUtil.toString(cell.getColumnKey()));
+			location = this.headerLocationCache.get(StrUtil.toString(cell.getColumnKey()));
 		}
 		return location;
 	}

hutool-poi/src/test/java/org/dromara/hutool/poi/excel/writer/ExcelWriteTest.java

@@ -213,6 +213,17 @@ public class ExcelWriteTest {
 		writer.close();
 	}
 
+	@Test
+	@Disabled
+	public void mergeNotExistCellTest(){
+		final ExcelWriter writer = ExcelUtil.getWriter()
+			.merge(5);
+
+		writer
+			.flush(FileUtil.file("d:/test/mergeNotExist.xlsx"), true)
+			.close();
+	}
+
 	@Test
 	@Disabled
 	public void mergeTest2() {