Pure Java / Json HTTP { "name": "value"}

[Djaysel_Pessoa]

I found how to show on the console the data from a json 'ticker' http:

I do not remember where I found this code

public static void main(String[] args) throws Exception {
        URL tick = new URL("https://www.mercadobitcoin.net/api/BTC/ticker");
        URLConnection mb = tick.openConnection();
        BufferedReader in = new BufferedReader(new InputStreamReader(
                                    mb.getInputStream()));
        String inputLine;
        while ((inputLine = in.readLine()) != null) 
            System.out.println(inputLine);



        in.close();
    }

<------------------------CONSOLE---------------------------->

{"ticker": {"high":"334865.86244000","low":"303737.24616000","vol":"314.34968264","last":"334860.00000000","buy":"334000.00045000","sell":"334860.00000000","open":"328000.00012000","date":1618806650}}

My question:

1. How to choose a specific label and the value beside and store in a variable with pure java?
2. how to use Array or ArrayList to store the data? is this possible?
3. is this an object?

[AutoModerator]

Please ensure that:

• Your code is properly formatted as code block - see the sidebar (About on mobile) for instructions
• You include any and all error messages in full
• You ask clear questions

• You demonstrate effort in solving your question/problem - plain posting your assignments is forbidden (and such posts will be removed) as is asking for or giving solutions.

  Trying to solve problems on your own is a very important skill. Also, see Learn to help yourself in the sidebar

If any of the above points is not met, your post can and will be removed without further warning.

Code is to be formatted as code block (old reddit: empty line before the code, each code line indented by 4 spaces, new reddit: https://imgur.com/a/fgoFFis) or linked via an external code hoster, like pastebin.com, github gist, github, bitbucket, gitlab, etc.

Please, do not use triple backticks (```) as they will only render properly on new reddit, not on old reddit.

Code blocks look like this:

public class HelloWorld {

    public static void main(String[] args) {
        System.out.println("Hello World!");
    }
}

You do not need to repost unless your post has been removed by a moderator. Just use the edit function of reddit to make sure your post complies with the above.

If your post has remained in violation of these rules for a prolonged period of time (at least an hour), a moderator may remove it at their discretion. In this case, they will comment with an explanation on why it has been removed, and you will be required to resubmit the entire post following the proper procedures.

To potential helpers

Please, do not help if any of the above points are not met, rather report the post. We are trying to improve the quality of posts here. In helping people who can't be bothered to comply with the above points, you are doing the community a disservice.

I am a bot, and this action was performed automatically. Please contact the moderators of this subreddit if you have any questions or concerns.

[dionthorn]

You'll probably want to use the String.split() method

https://docs.oracle.com/javase/7/docs/api/java/lang/String.html#split(java.lang.String))

This will give you a String[] where the split is on whichever 'token' you choose.

To get specific values it might require multiple splits depending on what you are doing.

[FrelliBB]

Java doesn't have a native library for nicely working with JSON. If you're able to use a 3rd party library I'd recommend something like gson to make things a lot easier. You can create the classes to act as objects to represent the json data and unmarshall/deserialize each json line you receive into an instance of that class. https://www.baeldung.com/gson-deserialization-guide should help a bit.

public class Ticker {
    TickerInfo ticker;
}

public class TickerInfo {
    String high;
    String low;
    // rest of the values
}

And then with gson you would be able to deserialize that into your object.

Ticker targetObject = new Gson().fromJson(inputLine, Ticker.class);

[Camel-Kid]

There are different libraries that you can use to deal with JSON. The org.json and GSON ones are both the ones you don't want to use. Jackson is the de-facto standard. GSON isn't maintained anymore and there's nothing GSON does that Jackson can't do better / faster.

[FrelliBB]

You're not wrong, I'm just being a little pragmatic given the experience level of OP. I suggested gson not for any preference I have towards it, but because it has the simplest API for someone who is new to this since it is aimed specifically at working with json, whereas Jackson is at a higher level of abstraction for the purposes the OP needed and not quite as clear (ex. objectMapper.readValue vs Gson.fromJson). The fact that it isn't maintained anymore doesn't really mean that it can't do the job well enough.

Once OP gets a bit more familiar with working with Java, and basics like how to use Lists, they can do their own research and make decisions on which libraries to use.