upadte 优化Excel单元格合并代码逻辑，明确处理类职责

ruoyi-common/ruoyi-common-excel/src/main/java/org/dromara/common/excel/core/CellMergeHandler.java

@@ -0,0 +1,152 @@
+package org.dromara.common.excel.core;
+
+import cn.hutool.core.collection.CollUtil;
+import cn.hutool.core.util.ReflectUtil;
+import cn.hutool.core.util.StrUtil;
+import cn.idev.excel.annotation.ExcelIgnore;
+import cn.idev.excel.annotation.ExcelIgnoreUnannotated;
+import cn.idev.excel.annotation.ExcelProperty;
+import lombok.SneakyThrows;
+import org.apache.poi.ss.util.CellRangeAddress;
+import org.dromara.common.core.utils.reflect.ReflectUtils;
+import org.dromara.common.excel.annotation.CellMerge;
+
+import java.lang.reflect.Field;
+import java.util.*;
+
+/**
+ * 单元格合并处理器
+ *
+ * @author Lion Li
+ */
+public class CellMergeHandler {
+
+    private final boolean hasTitle;
+    private int rowIndex;
+
+    private CellMergeHandler(final boolean hasTitle) {
+        this.hasTitle = hasTitle;
+        // 行合并开始下标
+        this.rowIndex = hasTitle ? 1 : 0;
+    }
+
+    @SneakyThrows
+    public List<CellRangeAddress> handle(List<?> list) {
+        List<CellRangeAddress> cellList = new ArrayList<>();
+        if (CollUtil.isEmpty(list)) {
+            return cellList;
+        }
+        Class<?> clazz = list.get(0).getClass();
+        boolean annotationPresent = clazz.isAnnotationPresent(ExcelIgnoreUnannotated.class);
+        Field[] fields = ReflectUtils.getFields(clazz, field -> {
+            if ("serialVersionUID".equals(field.getName())) {
+                return false;
+            }
+            if (field.isAnnotationPresent(ExcelIgnore.class)) {
+                return false;
+            }
+            return !annotationPresent || field.isAnnotationPresent(ExcelProperty.class);
+        });
+
+        // 有注解的字段
+        List<Field> mergeFields = new ArrayList<>();
+        List<Integer> mergeFieldsIndex = new ArrayList<>();
+        for (int i = 0; i < fields.length; i++) {
+            Field field = fields[i];
+            if (field.isAnnotationPresent(CellMerge.class)) {
+                CellMerge cm = field.getAnnotation(CellMerge.class);
+                mergeFields.add(field);
+                mergeFieldsIndex.add(cm.index() == -1 ? i : cm.index());
+                if (hasTitle) {
+                    ExcelProperty property = field.getAnnotation(ExcelProperty.class);
+                    rowIndex = Math.max(rowIndex, property.value().length);
+                }
+            }
+        }
+
+        Map<Field, RepeatCell> map = new HashMap<>();
+        // 生成两两合并单元格
+        for (int i = 0; i < list.size(); i++) {
+            Object rowObj = list.get(i);
+            for (int j = 0; j < mergeFields.size(); j++) {
+                Field field = mergeFields.get(j);
+                Object val = ReflectUtils.invokeGetter(rowObj, field.getName());
+
+                int colNum = mergeFieldsIndex.get(j);
+                if (!map.containsKey(field)) {
+                    map.put(field, new RepeatCell(val, i));
+                } else {
+                    RepeatCell repeatCell = map.get(field);
+                    Object cellValue = repeatCell.value();
+                    if (cellValue == null || "".equals(cellValue)) {
+                        // 空值跳过不合并
+                        continue;
+                    }
+
+                    if (!cellValue.equals(val)) {
+                        if ((i - repeatCell.current() > 1)) {
+                            cellList.add(new CellRangeAddress(repeatCell.current() + rowIndex, i + rowIndex - 1, colNum, colNum));
+                        }
+                        map.put(field, new RepeatCell(val, i));
+                    } else if (i == list.size() - 1) {
+                        if (!isMerge(list, i, field)) {
+                            // 如果最后一行不能合并，检查之前的数据是否需要合并
+                            if (i - repeatCell.current() > 1) {
+                                cellList.add(new CellRangeAddress(repeatCell.current() + rowIndex, i + rowIndex - 1, colNum, colNum));
+                            }
+                        } else if (i > repeatCell.current()) {
+                            // 如果最后一行可以合并，则直接合并到最后
+                            cellList.add(new CellRangeAddress(repeatCell.current() + rowIndex, i + rowIndex, colNum, colNum));
+                        }
+                    } else if (!isMerge(list, i, field)) {
+                        if ((i - repeatCell.current() > 1)) {
+                            cellList.add(new CellRangeAddress(repeatCell.current() + rowIndex, i + rowIndex - 1, colNum, colNum));
+                        }
+                        map.put(field, new RepeatCell(val, i));
+                    }
+                }
+            }
+        }
+        return cellList;
+    }
+
+    private boolean isMerge(List<?> list, int i, Field field) {
+        boolean isMerge = true;
+        CellMerge cm = field.getAnnotation(CellMerge.class);
+        final String[] mergeBy = cm.mergeBy();
+        if (StrUtil.isAllNotBlank(mergeBy)) {
+            //比对当前list(i)和list(i - 1)的各个属性值一一比对 如果全为真 则为真
+            for (String fieldName : mergeBy) {
+                final Object valCurrent = ReflectUtil.getFieldValue(list.get(i), fieldName);
+                final Object valPre = ReflectUtil.getFieldValue(list.get(i - 1), fieldName);
+                if (!Objects.equals(valPre, valCurrent)) {
+                    //依赖字段如有任一不等值,则标记为不可合并
+                    isMerge = false;
+                }
+            }
+        }
+        return isMerge;
+    }
+
+    record RepeatCell(Object value, int current) {}
+
+    /**
+     * 创建一个单元格合并处理器实例
+     *
+     * @param hasTitle 是否合并标题
+     * @return 单元格合并处理器
+     */
+    public static CellMergeHandler of(final boolean hasTitle) {
+        return new CellMergeHandler(hasTitle);
+    }
+
+    /**
+     * 创建一个单元格合并处理器实例（默认不合并标题）
+     *
+     * @return 单元格合并处理器
+     */
+    public static CellMergeHandler of() {
+        return new CellMergeHandler(false);
+    }
+
+}

ruoyi-common/ruoyi-common-excel/src/main/java/org/dromara/common/excel/core/CellMergeStrategy.java

@@ -1,26 +1,15 @@
 package org.dromara.common.excel.core;
 
 import cn.hutool.core.collection.CollUtil;
-import cn.hutool.core.util.ReflectUtil;
-import cn.hutool.core.util.StrUtil;
-import cn.idev.excel.annotation.ExcelIgnore;
-import cn.idev.excel.annotation.ExcelIgnoreUnannotated;
-import cn.idev.excel.annotation.ExcelProperty;
 import cn.idev.excel.metadata.Head;
 import cn.idev.excel.write.handler.WorkbookWriteHandler;
 import cn.idev.excel.write.handler.context.WorkbookWriteHandlerContext;
 import cn.idev.excel.write.merge.AbstractMergeStrategy;
-import lombok.AllArgsConstructor;
-import lombok.Data;
-import lombok.SneakyThrows;
 import lombok.extern.slf4j.Slf4j;
 import org.apache.poi.ss.usermodel.Cell;
 import org.apache.poi.ss.usermodel.Sheet;
 import org.apache.poi.ss.util.CellRangeAddress;
-import org.dromara.common.core.utils.reflect.ReflectUtils;
-import org.dromara.common.excel.annotation.CellMerge;
 
-import java.lang.reflect.Field;
 import java.util.*;
 
 /**
@@ -32,145 +21,39 @@ import java.util.*;
 public class CellMergeStrategy extends AbstractMergeStrategy implements WorkbookWriteHandler {
 
     private final List<CellRangeAddress> cellList;
-    private final boolean hasTitle;
-    private int rowIndex;
+
+    public CellMergeStrategy(List<CellRangeAddress> cellList) {
+        this.cellList = cellList;
+    }
 
     public CellMergeStrategy(List<?> list, boolean hasTitle) {
-        this.hasTitle = hasTitle;
-        // 行合并开始下标
-        this.rowIndex = hasTitle ? 1 : 0;
-        this.cellList = handle(list, hasTitle);
+        this.cellList = CellMergeHandler.of(hasTitle).handle(list);
     }
 
     @Override
     protected void merge(Sheet sheet, Cell cell, Head head, Integer relativeRowIndex) {
+        if (CollUtil.isEmpty(cellList)){
+            return;
+        }
         //单元格写入了,遍历合并区域,如果该Cell在区域内,但非首行,则清空
         final int rowIndex = cell.getRowIndex();
-        if (CollUtil.isNotEmpty(cellList)){
-            for (CellRangeAddress cellAddresses : cellList) {
-                final int firstRow = cellAddresses.getFirstRow();
-                if (cellAddresses.isInRange(cell) && rowIndex != firstRow){
-                    cell.setBlank();
-                }
+        for (CellRangeAddress cellAddresses : cellList) {
+            final int firstRow = cellAddresses.getFirstRow();
+            if (cellAddresses.isInRange(cell) && rowIndex != firstRow){
+                cell.setBlank();
             }
         }
     }
 
     @Override
     public void afterWorkbookDispose(final WorkbookWriteHandlerContext context) {
-        //当前表格写完后，统一写入
-        if (CollUtil.isNotEmpty(cellList)){
-            for (CellRangeAddress item : cellList) {
-                context.getWriteContext().writeSheetHolder().getSheet().addMergedRegion(item);
-            }
-        }
-    }
-
-    @SneakyThrows
-    private List<CellRangeAddress> handle(List<?> list, boolean hasTitle) {
-        List<CellRangeAddress> cellList = new ArrayList<>();
-        if (CollUtil.isEmpty(list)) {
-            return cellList;
-        }
-        Class<?> clazz = list.get(0).getClass();
-        boolean annotationPresent = clazz.isAnnotationPresent(ExcelIgnoreUnannotated.class);
-        Field[] fields = ReflectUtils.getFields(clazz, field -> {
-            if ("serialVersionUID".equals(field.getName())) {
-                return false;
-            }
-            if (field.isAnnotationPresent(ExcelIgnore.class)) {
-                return false;
-            }
-            return !annotationPresent || field.isAnnotationPresent(ExcelProperty.class);
-        });
-
-        // 有注解的字段
-        List<Field> mergeFields = new ArrayList<>();
-        List<Integer> mergeFieldsIndex = new ArrayList<>();
-        for (int i = 0; i < fields.length; i++) {
-            Field field = fields[i];
-            if (field.isAnnotationPresent(CellMerge.class)) {
-                CellMerge cm = field.getAnnotation(CellMerge.class);
-                mergeFields.add(field);
-                mergeFieldsIndex.add(cm.index() == -1 ? i : cm.index());
-                if (hasTitle) {
-                    ExcelProperty property = field.getAnnotation(ExcelProperty.class);
-                    rowIndex = Math.max(rowIndex, property.value().length);
-                }
-            }
+        if (CollUtil.isEmpty(cellList)){
+            return;
         }
-
-        Map<Field, RepeatCell> map = new HashMap<>();
-        // 生成两两合并单元格
-        for (int i = 0; i < list.size(); i++) {
-            Object rowObj = list.get(i);
-            for (int j = 0; j < mergeFields.size(); j++) {
-                Field field = mergeFields.get(j);
-                Object val = ReflectUtils.invokeGetter(rowObj, field.getName());
-
-                int colNum = mergeFieldsIndex.get(j);
-                if (!map.containsKey(field)) {
-                    map.put(field, new RepeatCell(val, i));
-                } else {
-                    RepeatCell repeatCell = map.get(field);
-                    Object cellValue = repeatCell.getValue();
-                    if (cellValue == null || "".equals(cellValue)) {
-                        // 空值跳过不合并
-                        continue;
-                    }
-
-                    if (!cellValue.equals(val)) {
-                        if ((i - repeatCell.getCurrent() > 1)) {
-                            cellList.add(new CellRangeAddress(repeatCell.getCurrent() + rowIndex, i + rowIndex - 1, colNum, colNum));
-                        }
-                        map.put(field, new RepeatCell(val, i));
-                    } else if (i == list.size() - 1) {
-                        if (!isMerge(list, i, field)) {
-                            // 如果最后一行不能合并，检查之前的数据是否需要合并
-                            if (i - repeatCell.getCurrent() > 1) {
-                                cellList.add(new CellRangeAddress(repeatCell.getCurrent() + rowIndex, i + rowIndex - 1, colNum, colNum));
-                            }
-                        } else if (i > repeatCell.getCurrent()) {
-                            // 如果最后一行可以合并，则直接合并到最后
-                            cellList.add(new CellRangeAddress(repeatCell.getCurrent() + rowIndex, i + rowIndex, colNum, colNum));
-                        }
-                    } else if (!isMerge(list, i, field)) {
-                        if ((i - repeatCell.getCurrent() > 1)) {
-                            cellList.add(new CellRangeAddress(repeatCell.getCurrent() + rowIndex, i + rowIndex - 1, colNum, colNum));
-                        }
-                        map.put(field, new RepeatCell(val, i));
-                    }
-                }
-            }
-        }
-        return cellList;
-    }
-
-    private boolean isMerge(List<?> list, int i, Field field) {
-        boolean isMerge = true;
-        CellMerge cm = field.getAnnotation(CellMerge.class);
-        final String[] mergeBy = cm.mergeBy();
-        if (StrUtil.isAllNotBlank(mergeBy)) {
-            //比对当前list(i)和list(i - 1)的各个属性值一一比对 如果全为真 则为真
-            for (String fieldName : mergeBy) {
-                final Object valCurrent = ReflectUtil.getFieldValue(list.get(i), fieldName);
-                final Object valPre = ReflectUtil.getFieldValue(list.get(i - 1), fieldName);
-                if (!Objects.equals(valPre, valCurrent)) {
-                    //依赖字段如有任一不等值,则标记为不可合并
-                    isMerge = false;
-                }
-            }
+        //当前表格写完后，统一写入
+        for (CellRangeAddress item : cellList) {
+            context.getWriteContext().writeSheetHolder().getSheet().addMergedRegion(item);
         }
-        return isMerge;
     }
 
-    @Data
-    @AllArgsConstructor
-    static class RepeatCell {
-
-        private Object value;
-
-        private int current;
-
-    }
 }