树结构关系的数据导出为excel Java实现

可以使用Apache POI库来实现树形数据导出为Excel。

首先，需要定义一个节点类，包含节点名称、父节点、子节点等属性。例如：

public class Node {
    private String name;
    private Node parent;
    private List<Node> children;
    
    // getter and setter methods
}

接下来，可以使用递归方式将树形结构转换为Excel表格。具体实现步骤如下：

1. 创建一个Workbook对象。

Workbook workbook = new XSSFWorkbook();

2. 创建一个Sheet对象。

Sheet sheet = workbook.createSheet("Sheet1");

3. 定义表头。

Row headerRow = sheet.createRow(0);
headerRow.createCell(0).setCellValue("节点名称");
headerRow.createCell(1).setCellValue("父节点名称");

4. 递归遍历树形结构，将节点数据写入Excel表格中。

private int rowIndex = 1; // 从第二行开始写入数据

public void writeNodeToExcel(Node node, Row row) {
    row.createCell(0).setCellValue(node.getName());
    row.createCell(1).setCellValue(node.getParent() == null ? "" : node.getParent().getName());
    
    if (node.getChildren() != null) {
        for (Node child : node.getChildren()) {
            Row childRow = sheet.createRow(rowIndex++);
            writeNodeToExcel(child, childRow);
        }
    }
}

// 在主程序中调用
Node root = // 根节点
Row rootRow = sheet.createRow(rowIndex++);
writeNodeToExcel(root, rootRow);

5. 将Workbook对象写入文件。

FileOutputStream outputStream = new FileOutputStream("output.xlsx");
workbook.write(outputStream);
outputStream.close();

完整代码示例：

import org.apache.poi.ss.usermodel.*;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;

import java.io.FileOutputStream;
import java.util.List;

public class TreeToExcel {
    private Sheet sheet;
    private int rowIndex = 1;

    public void exportToExcel(Node root, String filePath) throws Exception {
        Workbook workbook = new XSSFWorkbook();
        sheet = workbook.createSheet("Sheet1");

        Row headerRow = sheet.createRow(0);
        headerRow.createCell(0).setCellValue("节点名称");
        headerRow.createCell(1).setCellValue("父节点名称");

        Row rootRow = sheet.createRow(rowIndex++);
        writeNodeToExcel(root, rootRow);

        FileOutputStream outputStream = new FileOutputStream(filePath);
        workbook.write(outputStream);
        outputStream.close();
    }

    private void writeNodeToExcel(Node node, Row row) {
        row.createCell(0).setCellValue(node.getName());
        row.createCell(1).setCellValue(node.getParent() == null ? "" : node.getParent().getName());

        if (node.getChildren() != null) {
            for (Node child : node.getChildren()) {
                Row childRow = sheet.createRow(rowIndex++);
                writeNodeToExcel(child, childRow);
            }
        }
    }

    public static class Node {
        private String name;
        private Node parent;
        private List<Node> children;

        public Node(String name) {
            this.name = name;
        }

        public String getName() {
            return name;
        }

        public void setName(String name) {
            this.name = name;
        }

        public Node getParent() {
            return parent;
        }

        public void setParent(Node parent) {
            this.parent = parent;
        }

        public List<Node> getChildren() {
            return children;
        }

        public void setChildren(List<Node> children) {
            this.children = children;
        }
    }
}