public class DepartmentResp { private String bumenbm; private String fbumenbm; private String bumenmch; private List<DepartmentResp> children = new ArrayList<DepartmentResp>(); } 如何使用递归取到 children中的最底层的DepartmentResp并设置每个bumenmch

可以通过递归遍历children列表来找到最底层的DepartmentResp对象，并设置每个bumenmch属性。

示例代码如下：

public void setBumenmchForChildren(DepartmentResp departmentResp, String bumenmch) {
    if (departmentResp.getChildren() != null && !departmentResp.getChildren().isEmpty()) {
        for (DepartmentResp child : departmentResp.getChildren()) {
            setBumenmchForChildren(child, bumenmch);
        }
    } else {
        departmentResp.setBumenmch(bumenmch);
    }
}

使用方法如下：

DepartmentResp rootDepartment = ...; // 根节点
setBumenmchForChildren(rootDepartment, "最底层的部门名称");

这样就可以递归遍历children列表，找到最底层的DepartmentResp对象，并设置每个bumenmch属性。

相关问题

现在有两个实体类对象分别是 public class DepartmentResp { @ApiModelProperty("部门编码") private String bumenbm; @ApiModelProperty("部门名称") private String bumenmch; @ApiModelProperty(value = "子节点") private List<DepartmentResp> children = new ArrayList<DepartmentResp>(); @ApiModelProperty(value = "分区子节点信息节点") private List<Area> areaList; } 和 public class Area { @ApiModelProperty("片区id") private String pianquid; @ApiModelProperty("部门编码") private String bumenbm; @ApiModelProperty("片区名称") private String name; @ApiModelProperty("片区名称") private LocalDate createTime; } 现在需要当DepartmentResp中的bumenbm等于Area中的bumenbm时，就把 Area添加到这一层级的areaList的中，直到递归到children最小层级中的每一个DepartmentResp，

您的问题是如何将Area对象添加到DepartmentResp的areaList中，当DepartmentResp的bumenbm等于Area的bumenbm时，直到递归到children最小层级中的每一个DepartmentResp。

您可以使用递归函数来实现这个过程。具体步骤如下：

1. 遍历DepartmentResp中的每个子节点，如果子节点有children，则递归调用该函数，直到遍历到最小层级的子节点。

2. 在每个子节点中，遍历Area列表，如果Area的bumenbm等于子节点的bumenbm，则将Area添加到该子节点的areaList中。

3. 返回最终的DepartmentResp对象，其中包含了所有的Area信息。

示例代码如下：

public DepartmentResp addAreaToDepartment(DepartmentResp department) {
    List<DepartmentResp> children = department.getChildren();
    List<Area> areaList = department.getAreaList();

    // 遍历子节点
    for (DepartmentResp child : children) {
        // 递归调用该函数
        addAreaToDepartment(child);

        // 遍历Area列表
        for (Area area : areaList) {
            // 如果Area的bumenbm等于子节点的bumenbm，则将Area添加到该子节点的areaList中
            if (area.getBumenbm().equals(child.getBumenbm())) {
                child.getAreaList().add(area);
            }
        }
    }

    return department;
}

使用示例：

DepartmentResp department = new DepartmentResp();

// 添加一些children和areaList信息

DepartmentResp result = addAreaToDepartment(department);

注意：该函数会直接修改DepartmentResp对象，因此建议在调用该函数之前先对原始数据进行备份。

java使用builder设计模式解析这段xml：<?xml version="1.0" encoding="UTF-8"?><bookstore> <book category="children"> <title lang="en">Harry Potter</title> <author>J.K. Rowling</author> <year>2005</year> <price>29.99</price> </book> <book category="web"> <title lang="en">Learning XML</title> <author>Erik T. Ray</author> <year>2003</year> <price>39.95</price> </book></bookstore>

首先，我们需要定义一个Book类来表示XML中的每个书籍。这个类需要有四个属性：category、title、author和price。

然后，我们可以定义一个BookBuilder类来构建Book对象。BookBuilder类应该具有以下方法：

1. setCategory(String category)：设置book的category属性。
2. setTitle(String title)：设置book的title属性。
3. setAuthor(String author)：设置book的author属性。
4. setYear(int year)：设置book的year属性。
5. setPrice(double price)：设置book的price属性。
6. build()：构建一个Book对象并返回。

接下来，我们可以定义一个Bookstore类来表示整个XML文档。这个类应该具有一个List<Book>属性来存储所有的书籍。

最后，我们需要创建一个BookstoreBuilder类来解析XML文档并构建Bookstore对象。BookstoreBuilder类应该具有以下方法：

1. parseDocument(InputStream inputStream)：解析XML文档并返回一个Bookstore对象。

下面是完整的代码实现：

Book.java

public class Book {
    private String category;
    private String title;
    private String author;
    private int year;
    private double price;

    public Book(String category, String title, String author, int year, double price) {
        this.category = category;
        this.title = title;
        this.author = author;
        this.year = year;
        this.price = price;
    }

    // getters and setters
}

BookBuilder.java

public class BookBuilder {
    private String category;
    private String title;
    private String author;
    private int year;
    private double price;

    public BookBuilder setCategory(String category) {
        this.category = category;
        return this;
    }

    public BookBuilder setTitle(String title) {
        this.title = title;
        return this;
    }

    public BookBuilder setAuthor(String author) {
        this.author = author;
        return this;
    }

    public BookBuilder setYear(int year) {
        this.year = year;
        return this;
    }

    public BookBuilder setPrice(double price) {
        this.price = price;
        return this;
    }

    public Book build() {
        return new Book(category, title, author, year, price);
    }
}

Bookstore.java

import java.util.ArrayList;
import java.util.List;

public class Bookstore {
    private List<Book> books;

    public Bookstore() {
        books = new ArrayList<>();
    }

    public void addBook(Book book) {
        books.add(book);
    }

    // getters and setters
}

BookstoreBuilder.java

import org.xml.sax.Attributes;
import org.xml.sax.SAXException;
import org.xml.sax.helpers.DefaultHandler;

import javax.xml.parsers.ParserConfigurationException;
import javax.xml.parsers.SAXParser;
import javax.xml.parsers.SAXParserFactory;
import java.io.IOException;
import java.io.InputStream;

public class BookstoreBuilder {
    public Bookstore parseDocument(InputStream inputStream) {
        Bookstore bookstore = new Bookstore();

        try {
            SAXParserFactory factory = SAXParserFactory.newInstance();
            SAXParser saxParser = factory.newSAXParser();
            DefaultHandler handler = new DefaultHandler() {
                private BookBuilder bookBuilder;
                private String currentElement;

                @Override
                public void startElement(String uri, String localName, String qName, Attributes attributes) throws SAXException {
                    switch (qName) {
                        case "book":
                            bookBuilder = new BookBuilder();
                            bookBuilder.setCategory(attributes.getValue("category"));
                            break;
                        case "title":
                        case "author":
                        case "year":
                        case "price":
                            currentElement = qName;
                            break;
                    }
                }

                @Override
                public void endElement(String uri, String localName, String qName) throws SAXException {
                    switch (qName) {
                        case "book":
                            bookstore.addBook(bookBuilder.build());
                            bookBuilder = null;
                            break;
                        case "title":
                        case "author":
                        case "year":
                        case "price":
                            currentElement = null;
                            break;
                    }
                }

                @Override
                public void characters(char[] ch, int start, int length) throws SAXException {
                    if (currentElement != null) {
                        String value = new String(ch, start, length);
                        switch (currentElement) {
                            case "title":
                                bookBuilder.setTitle(value);
                                break;
                            case "author":
                                bookBuilder.setAuthor(value);
                                break;
                            case "year":
                                bookBuilder.setYear(Integer.parseInt(value));
                                break;
                            case "price":
                                bookBuilder.setPrice(Double.parseDouble(value));
                                break;
                        }
                    }
                }
            };
            saxParser.parse(inputStream, handler);
        } catch (ParserConfigurationException | SAXException | IOException e) {
            e.printStackTrace();
        }

        return bookstore;
    }
}

现在我们可以使用以下代码来解析XML文档并获取所有的书籍：

InputStream inputStream = new FileInputStream("bookstore.xml");
BookstoreBuilder bookstoreBuilder = new BookstoreBuilder();
Bookstore bookstore = bookstoreBuilder.parseDocument(inputStream);

List<Book> books = bookstore.getBooks();
for (Book book : books) {
    System.out.println(book.getTitle() + " by " + book.getAuthor());
}