在Jackson中将内部JSON对象提取为字符串

import com.fasterxml.jackson.databind.JsonNode;
import com.fasterxml.jackson.databind.ObjectMapper;

import java.io.IOException;

public class Main {
    public static void main(String[] args) {
        // 示例JSON字符串
        String json = "{\"externalObject\": \"value\", \"internalObject\": {\"key1\": \"value1\", \"key2\": \"value2\"}}";

        try {
            // 创建一个ObjectMapper实例
            ObjectMapper objectMapper = new ObjectMapper();

            // 将JSON字符串解析为JsonNode对象
            JsonNode rootNode = objectMapper.readTree(json);

            // 提取内部JSON对象
            JsonNode internalObject = rootNode.get("internalObject");

            // 将内部JSON对象转换为字符串
            String internalObjectAsString = objectMapper.writeValueAsString(internalObject);

            // 输出结果
            System.out.println("内部JSON对象为: " + internalObjectAsString);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

内部JSON对象为: {"key1":"value1","key2":"value2"}