How to Parse JSON in Java – Know Before You Go!

How to Parse JSON in Java

Want to know how to parse JSON in Java by using different libraries, then just give a read to this post to unfold this fact! JSON is an acronym for JavaScript Object Notation that depends on a subset of JS or JavaScript. 

JSON is loaded with a data-exchange format that is widely used in web programming. In this post, we have decided to show how to parse JSON in Java by using the org.json library.

Remember that a JSON code is an unordered set of key/value pairs, and its array is an ordered collection of values. No doubt, these values themselves could be objects or arrays. 

Swipe down!

How to Parse JSON in Java:

Parse JSON Using org.json:

To use org.json to parse JSON in Java, you ought to add the library as a dependency. However, this can be fetched from the Maven repository.

First of all, you ought to convert the JSON string into a Json online object by simply using JSONObject class.

Also, you have to remember that “pageInfo” is a JSON Object, so you can use the getJSONObject method.

Likewise, “posts” is said to be as a JSON Array, so you ought to use the getJSONArray method.

Parse JSON Using Gson:

If you want to use the Gson to parse JSON in Java, then you ought to add the library as a dependency. Yes, you can attain the latest version from the Maven repository.

Parse JSON Using JsonPATH:

With the ease of the above parameters, there is a need to complete deserialization of the JSON into a Java object before accessing the value in the property of interest. The other alternative that doesn’t go such a route has to account for JsonPATH, which is referred to the same as the XPath for JSON and allows traversing of JSON objects efficiently. 

Yes, here you need to add JSONPATH as a dependency that you can fetch from Maven repository.

Fast-Facts About JSON Parsing:

Remember that Gson JSON Parser class can readily Parse a JSON string or even stream it into a tree structure of Java objects. Also, Gson contains two other parsers – the GSON JSON Parser that can readily parse JSON into Java objects, and the other is JSONReader that can readily parse a JSON string or stream into tokens (that is a pull parser). 

Creating a JsonParser:

SO, before using the Gson JSON parser, you should have to create a JSON parser instance. Well, let’s take a look at an example of creating a JSON parser instance:

JsonParser jsonParser = new JsonParser();

Parsing JSON Into a Tree Structure:

Once you have created a JSON parser, you can readily parse JSON into a tree structure with it. Let’s take a look at an example of parsing a JSON string into a tree structure of GSON objects with the ease of JSON Parser:

JsonParser parser = new JsonParser();

String json = “{ \”f1\”:\”Hello\”,\”f2\”:{\”f3:\”:\”World\”}}”;

JsonElement jsonTree = parser.parse(json);

You can see that the parsing of the JSON occurs in the third line of code, by calling parse() on the JSON Parser, it just passes as a parameter, which means a reference to the JSON string (or stream) to parse.

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