jason by gson复习

矫情吗；* 2022-06-18 09:18 116阅读 0赞

把gson-x.x.x.jar添加到工程。  
jason读：

test.json

{
        "cat":"it",
        "languages":[ {"id":1,"ide":"eclipse","name":"java"}, {"id":2,"ide":"xcode","name":"swift"}, {"id":3,"ide":"visual studio","name":"c#"} ],
        "pop":true }

java代码读取json文件：

package test;
    
    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 ReadJason {
    
        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 e) {
                e.printStackTrace();
            } catch (JsonSyntaxException e) {
                e.printStackTrace();
            } catch (FileNotFoundException e) {
                e.printStackTrace();
            }
        }
    
    }

结果输出：

cat=it
    pop=true ------------
    id=1
    name=java
    ide=eclipse ------------
    id=2
    name=swift
    ide=xcode ------------
    id=3
    name=c#
    ide=visual studio

json写出上式test.json文件:注意**jre不可过低**，否则部分方法出问题。

package test;
    import com.google.gson.JsonArray;
    import com.google.gson.JsonObject;
    
    public class JsonWrite {
        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());
    
        }
    
    }