java 递归反序列化树形json数据

下面是一个 Java 递归反序列化树形 JSON 数据的示例代码：

import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

import com.fasterxml.jackson.core.JsonParseException;
import com.fasterxml.jackson.databind.JsonMappingException;
import com.fasterxml.jackson.databind.JsonNode;
import com.fasterxml.jackson.databind.ObjectMapper;

public class JsonTreeDeserializer {
    private static ObjectMapper mapper = new ObjectMapper();
    
    public static void main(String[] args) {
        String json = "{\"id\":1,\"name\":\"root\",\"children\":[{\"id\":2,\"name\":\"child1\",\"children\":[{\"id\":3,\"name\":\"grandchild1\"},{\"id\":4,\"name\":\"grandchild2\"}]},{\"id\":5,\"name\":\"child2\",\"children\":[{\"id\":6,\"name\":\"grandchild3\"},{\"id\":7,\"name\":\"grandchild4\"}]}]}";
        try {
            JsonNode rootNode = mapper.readTree(json);
            Node tree = deserialize(rootNode);
            System.out.println(tree);
        } catch (JsonParseException e) {
            e.printStackTrace();
        } catch (JsonMappingException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
    
    public static Node deserialize(JsonNode node) {
        int id = node.get("id").asInt();
        String name = node.get("name").asText();
        Node tree = new Node(id, name);
        JsonNode childrenNode = node.get("children");
        if (childrenNode != null && childrenNode.isArray()) {
            for (JsonNode childNode : childrenNode) {
                Node child = deserialize(childNode);
                tree.addChild(child);
            }
        }
        return tree;
    }
}

class Node {
    private int id;
    private String name;
    private List<Node> children;
    
    public Node(int id, String name) {
        this.id = id;
        this.name = name;
        this.children = new ArrayList<Node>();
    }
    
    public void addChild(Node node) {
        this.children.add(node);
    }
    
    @Override
    public String toString() {
        return "Node [id=" + id + ", name=" + name + ", children=" + children + "]";
    }
}

这个示例代码使用了 Jackson 库来进行 JSON 反序列化。首先读取 JSON 数据，然后递归地反序列化每个节点，并构建树形结构。最后输出树形结构。