JSON相关操作(Java)



1 Java中创建JSON

import com.google.gson.JsonArray;
import com.google.gson.JsonObject;

public class CreateJSON {

    public static void main(String[] args) {
        JsonObject object = new JsonObject();
        object.addProperty("cat", "it");
        
        JsonArray array = new JsonArray();
        
        JsonObject lan1 = new JsonObject();
        lan1.addProperty("id", 1);
        lan1.addProperty("name", "Java");
        lan1.addProperty("ide", "Eclipse");
        array.add(lan1);
        
        JsonObject lan2 = new JsonObject();
        lan2.addProperty("id", 2);
        lan2.addProperty("name", "Swift");
        lan2.addProperty("ide", "XCode");
        array.add(lan2);
        
        JsonObject lan3 = new JsonObject();
        lan3.addProperty("id", 3);
        lan3.addProperty("name", "C#");
        lan3.addProperty("ide", "Visual Studio");
        array.add(lan3);
        
        object.add("languages", array);
        object.addProperty("pop", true);
        
        System.out.println(object.toString());
    }
}

将Console输出的文本保存成test.json,内容如下:


2 Java中读取JSON文件

import java.io.FileNotFoundException;
import java.io.FileReader;

import com.google.gson.JsonArray;
import com.google.gson.JsonIOException;
import com.google.gson.JsonObject;
import com.google.gson.JsonParser;
import com.google.gson.JsonSyntaxException;

public class ReadJSON {

    public static void main(String[] args) {
        try {
            JsonParser parser = new JsonParser();
            JsonObject object = (JsonObject) parser.parse(new FileReader("test.json"));
            System.out.println("cat="+object.get("cat").getAsString());
            System.out.println("pop="+object.get("pop").getAsBoolean());
            
            JsonArray array = object.get("languages").getAsJsonArray();
            for (int i = 0; i < array.size(); i++) {
                System.out.println("------------");
                JsonObject subObject = array.get(i).getAsJsonObject();
                System.out.println("id="+subObject.get("id").getAsInt());
                System.out.println("name="+subObject.get("name").getAsString());
                System.out.println("ide="+subObject.get("ide").getAsString());
            }
            
        } catch (JsonIOException | JsonSyntaxException | FileNotFoundException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }
}

代码运行效果:


 
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