Java读取JSON文件并将其中元素转为JSON对象输出的方式

[
	{"123":"libai","245":"zhangfei","444":"qipa"},
	{"133":"libi","205":"zhanfei","494":"qipai"}
]

        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>fastjson</artifactId>
            <version>1.2.83</version>
        </dependency>

package com.xiucong.vihicle;

import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONArray;
import com.alibaba.fastjson.JSONObject;
import java.io.File;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Paths;

/**
 * @func:
 * @author: LiBai
 * @version: v1.0
 * @createTime: 2025/4/15 15:14
 */
public class ExcelInsertRecordsController {

    public static void main(String[] args) {

        // JSON文件路径
        String filePath = "D:\\xiucong\\test.json";
        File file = new File(filePath);

        try {
            // 读取文件内容为字符串
            String content = new String(Files.readAllBytes(Paths.get(file.getPath())));

            // 将字符串解析为JSONArray对象
            JSONArray jsonArray = JSON.parseArray(content);

            // 打印数组内容，以验证结果
            for (int i = 0; i < jsonArray.size(); i++) {
                // System.out.println(jsonArray.get(i));
                JSONObject obj = (JSONObject) jsonArray.get(i);
                System.out.println(i+"==============================================>");

            }

        } catch (IOException e) {
            e.printStackTrace();
        }

    }

}

<dependency>
    <groupId>com.fasterxml.jackson.core</groupId>
    <artifactId>jackson-databind</artifactId>
    <version>2.15.0</version>
</dependency>

<dependency>
    <groupId>com.google.code.gson</groupId>
    <artifactId>gson</artifactId>
    <version>2.10.1</version>
</dependency>

// JDK 内置（JDK 11+）
// 或手动引入：
<dependency>
    <groupId>org.json</groupId>
    <artifactId>json</artifactId>
    <version>20231013</version>
</dependency>

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

public class ReadJsonFile {
    public static void main(String[] args) {
        ObjectMapper mapper = new ObjectMapper();
        try {
            // 从文件路径读取JSON
            JsonNode rootNode = mapper.readTree(new File("data.json"));
            
            // 直接输出整个JSON对象
            System.out.println(rootNode.toPrettyString());

            // 访问具体字段
            String name = rootNode.get("name").asText();
            int age = rootNode.get("age").asInt();
            System.out.println("Name: " + name + ", Age: " + age);

        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

public class User {
    private String name;
    private int age;
    private List<String> hobbies;
    
    // 必须有无参构造器和getter/setter
    // ...
}

User user = mapper.readValue(new File("data.json"), User.class);
System.out.println(user.getHobbies());

import com.google.gson.Gson;
import com.google.gson.JsonObject;
import com.google.gson.JsonParser;

public class GsonExample {
    public static void main(String[] args) {
        Gson gson = new Gson();
        try {
            // 读取文件内容为字符串
            String jsonStr = Files.readString(Paths.get("data.json"));
            
            // 转换为JsonObject
            JsonObject jsonObject = JsonParser.parseString(jsonStr).getAsJsonObject();
            
            // 访问字段
            String name = jsonObject.get("name").getAsString();
            System.out.println("Name: " + name);

            // 反序列化为对象
            User user = gson.fromJson(jsonStr, User.class);
            System.out.println(user.getAge());

        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

import org.json.JSONObject;
import org.json.JSONTokener;

public class JsonOrgExample {
    public static void main(String[] args) {
        try (FileReader reader = new FileReader("data.json")) {
            // 从文件读取JSON
            JSONObject jsonObject = new JSONObject(new JSONTokener(reader));
            
            // 访问字段
            String name = jsonObject.getString("name");
            JSONArray hobbies = jsonObject.getJSONArray("hobbies");
            
            System.out.println("Hobbies: " + hobbies.toString(2)); // 格式化输出

        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

{
  "name": "Alice",
  "age": 30,
  "hobbies": ["Reading", "Hiking"],
  "address": {
    "city": "Shanghai",
    "postcode": "200000"
  }
}

JsonNode addressNode = rootNode.get("address");
String city = addressNode.get("city").asText();

JsonNode hobbies = rootNode.get("hobbies");
hobbies.forEach(hobby -> System.out.println(hobby.asText()));

import com.fasterxml.jackson.databind.JsonNode;
import com.fasterxml.jackson.databind.ObjectMapper;
import java.io.File;
import java.io.IOException;

public class JsonReader {
    public static void main(String[] args) {
        ObjectMapper mapper = new ObjectMapper();
        try {
            JsonNode root = mapper.readTree(new File("data.json"));
            
            // 输出完整JSON
            System.out.println("完整JSON内容:\n" + root.toPrettyString());
            
            // 提取嵌套字段
            String city = root.get("address").get("city").asText();
            System.out.println("城市: " + city);
            
            // 遍历数组
            System.out.println("爱好:");
            root.get("hobbies").forEach(hobby -> 
                System.out.println(" - " + hobby.asText())
            );

        } catch (IOException e) {
            System.err.println("读取文件失败: " + e.getMessage());
        }
    }
}