upadte 优化Excel单元格合并处理器代码逻辑分支

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

@@ -31,12 +31,89 @@ public class CellMergeHandler {
     }
 
     @SneakyThrows
-    public List<CellRangeAddress> handle(List<?> list) {
-        List<CellRangeAddress> cellList = new ArrayList<>();
-        if (CollUtil.isEmpty(list)) {
-            return cellList;
+    public List<CellRangeAddress> handle(List<?> rows) {
+        // 如果入参为空集合则返回空集
+        if (CollUtil.isEmpty(rows)) {
+            return Collections.emptyList();
         }
-        Class<?> clazz = list.get(0).getClass();
+
+        // 获取有合并注解的字段
+        Map<Field, FieldColumnIndex> mergeFields = getFieldColumnIndexMap(rows.get(0).getClass());
+        // 如果没有需要合并的字段则返回空集
+        if (CollUtil.isEmpty(mergeFields)) {
+            return Collections.emptyList();
+        }
+
+        // 结果集
+        List<CellRangeAddress> result = new ArrayList<>();
+
+        // 生成两两合并单元格
+        Map<Field, RepeatCell> rowRepeatCellMap = new HashMap<>();
+        for (Map.Entry<Field, FieldColumnIndex> item : mergeFields.entrySet()) {
+            Field field = item.getKey();
+            FieldColumnIndex itemValue = item.getValue();
+            int colNum = itemValue.colIndex();
+            CellMerge cellMerge = itemValue.cellMerge();
+
+            for (int i = 0; i < rows.size(); i++) {
+                // 当前行数据
+                Object currentRowObj = rows.get(i);
+                // 当前行数据字段值
+                Object currentRowObjFieldVal = ReflectUtils.invokeGetter(currentRowObj, field.getName());
+
+                // 空值跳过不处理
+                if (currentRowObjFieldVal == null || "".equals(currentRowObjFieldVal)) {
+                    continue;
+                }
+
+                // 单元格合并Map是否存在数据，如果不存在则添加当前行的字段值
+                if (!rowRepeatCellMap.containsKey(field)) {
+                    rowRepeatCellMap.put(field, RepeatCell.of(currentRowObjFieldVal, i));
+                    continue;
+                }
+
+                // 获取 单元格合并Map 中字段值
+                RepeatCell repeatCell = rowRepeatCellMap.get(field);
+                Object cellValue = repeatCell.value();
+                int current = repeatCell.current();
+
+                // 检查是否满足合并条件
+                // currentRowObj 当前行数据
+                // rows.get(i - 1) 上一行数据 注：由于 if (!rowRepeatCellMap.containsKey(field)) 条件的存在，所以该 i 必不可能小于1
+                // cellMerge 当前行字段合并注解
+                boolean merge = isMerge(currentRowObj, rows.get(i - 1), cellMerge);
+
+                // 是否添加到结果集
+                boolean isAddResult = false;
+                // 最新行
+                int lastRow = i + rowIndex - 1;
+
+                // 如果当前行字段值和缓存中的字段值不相等，或不满足合并条件，则替换
+                if (!currentRowObjFieldVal.equals(cellValue) || !merge) {
+                    rowRepeatCellMap.put(field, RepeatCell.of(currentRowObjFieldVal, i));
+                    isAddResult = true;
+                }
+
+                // 如果最后一行不能合并，检查之前的数据是否需要合并；如果最后一行可以合并，则直接合并到最后
+                if (i == rows.size() - 1) {
+                    isAddResult = true;
+                    if (i > current) {
+                        lastRow = i + rowIndex;
+                    }
+                }
+
+                if (isAddResult && i > current) {
+                    result.add(new CellRangeAddress(current + rowIndex, lastRow, colNum, colNum));
+                }
+            }
+        }
+        return result;
+    }
+
+    /**
+     * 获取带有合并注解的字段列索引和合并注解信息Map集
+     */
+    private Map<Field, FieldColumnIndex> getFieldColumnIndexMap(Class<?> clazz) {
         boolean annotationPresent = clazz.isAnnotationPresent(ExcelIgnoreUnannotated.class);
         Field[] fields = ReflectUtils.getFields(clazz, field -> {
             if ("serialVersionUID".equals(field.getName())) {
@@ -49,86 +126,57 @@ public class CellMergeHandler {
         });
 
         // 有注解的字段
-        List<Field> mergeFields = new ArrayList<>();
-        List<Integer> mergeFieldsIndex = new ArrayList<>();
+        Map<Field, FieldColumnIndex> mergeFields = new HashMap<>();
         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 (!field.isAnnotationPresent(CellMerge.class)) {
+                continue;
             }
-        }
+            CellMerge cm = field.getAnnotation(CellMerge.class);
+            int index = cm.index() == -1 ? i : cm.index();
+            mergeFields.put(field, FieldColumnIndex.of(index, cm));
 
-        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));
-                    }
-                }
+            if (hasTitle) {
+                ExcelProperty property = field.getAnnotation(ExcelProperty.class);
+                rowIndex = Math.max(rowIndex, property.value().length);
             }
         }
-        return cellList;
+        return mergeFields;
     }
 
-    private boolean isMerge(List<?> list, int i, Field field) {
-        boolean isMerge = true;
-        CellMerge cm = field.getAnnotation(CellMerge.class);
-        final String[] mergeBy = cm.mergeBy();
+    private boolean isMerge(Object currentRow, Object preRow, CellMerge cellMerge) {
+        final String[] mergeBy = cellMerge.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
+            //比对当前行和上一行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);
+                final Object valCurrent = ReflectUtil.getFieldValue(currentRow, fieldName);
+                final Object valPre = ReflectUtil.getFieldValue(preRow, 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 false;
                 }
             }
         }
-        return isMerge;
+        return true;
+    }
+
+    /**
+     * 单元格合并
+     */
+    record RepeatCell(Object value, int current) {
+        static RepeatCell of(Object value, int current) {
+            return new RepeatCell(value, current);
+        }
     }
 
-    record RepeatCell(Object value, int current) {}
+    /**
+     * 字段列索引和合并注解信息
+     */
+    record FieldColumnIndex(int colIndex, CellMerge cellMerge) {
+        static FieldColumnIndex of(int colIndex, CellMerge cellMerge) {
+            return new FieldColumnIndex(colIndex, cellMerge);
+        }
+    }
 
     /**
      * 创建一个单元格合并处理器实例