支持树形结构的导出

easyexcel-core/src/main/java/com/alibaba/excel/write/executor/ExcelWriteAddExecutor.java

@@ -1,12 +1,7 @@
 package com.alibaba.excel.write.executor;
 
 import java.lang.reflect.Field;
-import java.util.ArrayList;
-import java.util.Collection;
-import java.util.HashSet;
-import java.util.Map;
-import java.util.Set;
-import java.util.TreeMap;
+import java.util.*;
 
 import com.alibaba.excel.context.WriteContext;
 import com.alibaba.excel.enums.HeadKindEnum;
@@ -22,12 +17,14 @@ import com.alibaba.excel.write.handler.context.RowWriteHandlerContext;
 import com.alibaba.excel.write.metadata.CollectionRowData;
 import com.alibaba.excel.write.metadata.MapRowData;
 import com.alibaba.excel.write.metadata.RowData;
+import com.alibaba.excel.write.metadata.WriteTreeData;
 import com.alibaba.excel.write.metadata.holder.WriteHolder;
 import com.alibaba.excel.write.metadata.holder.WriteSheetHolder;
 
 import org.apache.commons.collections4.CollectionUtils;
 import org.apache.poi.ss.usermodel.Cell;
 import org.apache.poi.ss.usermodel.Row;
+import org.apache.poi.ss.usermodel.Sheet;
 import org.springframework.cglib.beans.BeanMap;
 
 /**
@@ -50,14 +47,37 @@ public class ExcelWriteAddExecutor extends AbstractExcelWriteExecutor {
         if (writeSheetHolder.isNew() && !writeSheetHolder.getExcelWriteHeadProperty().hasHead()) {
             newRowIndex += writeContext.currentWriteHolder().relativeHeadRowIndex();
         }
-        // BeanMap is out of order, so use sortedAllFieldMap
-        Map<Integer, Field> sortedAllFieldMap = new TreeMap<>();
         int relativeRowIndex = 0;
         for (Object oneRowData : data) {
+            relativeRowIndex = loopDataByLevel(oneRowData, relativeRowIndex, newRowIndex);
+        }
+    }
+
+    private int loopDataByLevel(Object oneRowData, int relativeRowIndex, int newRowIndex) {
+        // BeanMap is out of order, so use sortedAllFieldMap
+        Map<Integer, Field> sortedAllFieldMap = new TreeMap<>();
         int lastRowIndex = relativeRowIndex + newRowIndex;
+        if (oneRowData instanceof WriteTreeData) {
+            addOneRowOfDataToExcel(((WriteTreeData<?, ?>) oneRowData).getParentData(), lastRowIndex, relativeRowIndex, sortedAllFieldMap);
+            relativeRowIndex++;
+            List<?> childList = ((WriteTreeData<?, ?>) oneRowData).getChildDataList();
+            if (CollectionUtils.isNotEmpty(childList)) {
+                int fromRow = relativeRowIndex;
+                for (Object childData : childList) {
+                    relativeRowIndex = loopDataByLevel(childData, relativeRowIndex, newRowIndex);
+                }
+                setGroup(fromRow, relativeRowIndex);
+            }
+        } else {
             addOneRowOfDataToExcel(oneRowData, lastRowIndex, relativeRowIndex, sortedAllFieldMap);
             relativeRowIndex++;
         }
+        return relativeRowIndex;
+    }
+
+    private void setGroup(int fromRow, int toRow) {
+        Sheet sheet = writeContext.writeSheetHolder().getSheet();
+        sheet.groupRow(fromRow + 1, toRow);
     }
 
     private void addOneRowOfDataToExcel(Object oneRowData, int rowIndex, int relativeRowIndex,
@@ -156,7 +176,6 @@ public class ExcelWriteAddExecutor extends AbstractExcelWriteExecutor {
                 if (!beanKeySet.contains(name)) {
                     continue;
                 }
-
                 ExcelContentProperty excelContentProperty = ClassUtils.declaredExcelContentProperty(beanMap,
                     currentWriteHolder.excelWriteHeadProperty().getHeadClazz(), name);
                 CellWriteHandlerContext cellWriteHandlerContext = WriteHandlerUtils.createCellWriteHandlerContext(

easyexcel-core/src/main/java/com/alibaba/excel/write/metadata/WriteTreeData.java

@@ -0,0 +1,26 @@
+package com.alibaba.excel.write.metadata;
+
+import lombok.EqualsAndHashCode;
+import lombok.Getter;
+import lombok.Setter;
+
+import java.util.List;
+
+/**
+ * 用来显示树形结构
+ * childDataList 类型支持 WriteTreeData进行嵌套
+ * @author Wish
+ * @version 1.0 2022/5/14
+ */
+@Getter
+@Setter
+@EqualsAndHashCode
+public class WriteTreeData<T, E> {
+    T parentData;
+    List<E> childDataList;
+
+    public WriteTreeData(T parentData, List<E> childDataList) {
+        this.parentData = parentData;
+        this.childDataList = childDataList;
+    }
+}

easyexcel-test/src/test/java/com/alibaba/easyexcel/test/demo/write/WriteTest.java

@@ -3,11 +3,7 @@ package com.alibaba.easyexcel.test.demo.write;
 import java.io.File;
 import java.io.InputStream;
 import java.net.URL;
-import java.util.ArrayList;
-import java.util.Date;
-import java.util.HashSet;
-import java.util.List;
-import java.util.Set;
+import java.util.*;
 
 import com.alibaba.easyexcel.test.util.TestFileUtil;
 import com.alibaba.excel.EasyExcel;
@@ -35,6 +31,7 @@ import com.alibaba.excel.write.handler.context.CellWriteHandlerContext;
 import com.alibaba.excel.write.merge.LoopMergeStrategy;
 import com.alibaba.excel.write.metadata.WriteSheet;
 import com.alibaba.excel.write.metadata.WriteTable;
+import com.alibaba.excel.write.metadata.WriteTreeData;
 import com.alibaba.excel.write.metadata.style.WriteCellStyle;
 import com.alibaba.excel.write.metadata.style.WriteFont;
 import com.alibaba.excel.write.style.HorizontalCellStyleStrategy;
@@ -794,6 +791,16 @@ public class WriteTest {
         EasyExcel.write(fileName).head(head()).sheet("模板").doWrite(dataList());
     }
 
+    /**
+     * 支持树形结构的写
+     */
+    @Test
+    public void treeWrite() {
+        String fileName = TestFileUtil.getPath() + "treeWrite" + System.currentTimeMillis() + ".xlsx";
+        // 这里 需要指定写用哪个class去写，然后写到第一个sheet，名字为模板 然后文件流会自动关闭
+        EasyExcel.write(fileName, DemoData.class).sheet("模板").doWrite(treeData());
+    }
+
     private List<LongestMatchColumnWidthData> dataLong() {
         List<LongestMatchColumnWidthData> list = ListUtils.newArrayList();
         for (int i = 0; i < 10; i++) {
@@ -858,4 +865,43 @@ public class WriteTest {
         return list;
     }
 
+    private List<WriteTreeData> treeData() {
+        List<WriteTreeData> list = ListUtils.newArrayList();
+        for (int i = 0; i < 10; i++) {
+            DemoData school = new DemoData();
+            school.setString("XX学校" + i);
+            school.setDate(new Date());
+            school.setDoubleData(0.56);
+
+            DemoData grade1 = new DemoData();
+            grade1.setString("1年级" + i);
+            grade1.setDate(new Date());
+            grade1.setDoubleData(1.0);
+            DemoData grade2 = new DemoData();
+            grade2.setString("2年级" + i);
+            grade2.setDate(new Date());
+            grade2.setDoubleData(2.0);
+            List<WriteTreeData> gradeWithClass = ListUtils.newArrayList();
+
+            List<DemoData> classList = ListUtils.newArrayList();
+            DemoData class1 = new DemoData();
+            class1.setString("1班级" + i);
+            class1.setDate(new Date());
+            class1.setDoubleData(1.0);
+            DemoData class2 = new DemoData();
+            class2.setString("2班级" + i);
+            class2.setDate(new Date());
+            class2.setDoubleData(1.0);
+
+            classList.add(class1);
+            classList.add(class2);
+
+            gradeWithClass.add(new WriteTreeData(grade1, classList));
+            gradeWithClass.add(new WriteTreeData(grade2, classList));
+
+            WriteTreeData parentData = new WriteTreeData(school, gradeWithClass);
+            list.add(parentData);
+        }
+        return list;
+    }
 }