java converts json string to json array

Sometimes we need to convert the json string into an array, and only take some attribute values ​​for the assignment of the next method, which involves the conversion of the json string,

There are two forms of json string, one is {A,B,C}, and the other is [{A},{B},{C}]. But many times it is a combination of the two.

First import the jar package

        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>fastjson</artifactId>
            <version>1.2.47</version>
        </dependency>

If it is the first type, you only need to add the following code, note that str is a json string

        JSONObject json=(JSONObject)JSONObject.toJSON(JSON.parse(str));
        System.out.println("facesets:"+json.getString("facesets"));

is the second with the following code

        JSONArray temp=JSONArray.parseArray(json.getString("facesets"));
        for(int i=0;i<temp.size();i++){
            JSONObject obj=(JSONObject)temp.get(i);
                System.out.println(obj.getString("faceset_token"));
        }

Often it is a combination of the two

        JSONObject json=(JSONObject)JSONObject.toJSON(JSON.parse(str));
        System.out.println("facesets:"+json.getString("facesets"));

        JSONArray temp=JSONArray.parseArray(json.getString("facesets"));
        for(int i=0;i<temp.size();i++){
            JSONObject obj=(JSONObject)temp.get(i);
                System.out.println(obj.getString("faceset_token"));
        }

You can look at the output

 Hope it helps you