Jackson Json Parser

How to Create Jackson JSON Parser?

In essence, the Jackson JSON parser is a low-level parser of the JSON module. If compared regarding features and overall outlook, then it will seem to be almost similar to Java StAX of XML. However, unlike the latter, the JSON parser helps you in parsing JSON.

Because of being a low-level parser, the Jackson module usually operates at a much lower level than ObjectMapper. Due to this reason, it is pretty quick and works without making any fuss about the overall progression.

However, creating it can be a little bit cumbersome for you, especially if you are new in this aspect. So, through this write-up, we will try to walk you through the whole procedure as clearly as possible. Hopefully, it will help you out.

The Creation Procedure of JSON Parser

In order to build a brand new Jackson excel JSON parser, you will, first, have to create a specific JSON Factory. It will contain a wide array of “createParser ()” methods. And, each of them will take a different source of JSON, which will work as its parameter.

The following is an example that can help you to understand the procedure of creating a proper JSON parser that can parse JSON from strings.

String carJson =

        “{ \”brand\” : \”Mercedes\”, \”doors\” : 5 }”;

JsonFactory factory = new JsonFactory();

JsonParser  parser  = factory.createParser(carJson);

Aside from this, you may also pass an “InputStream”, “Reader”, “byte array”, or “URL” to create the Jackson JSON parsing example. However, it might, sometimes, overload the whole procedure massively.

How to Parse JSON with the Parser?

Have you already created the JSON parser? Then, you are now ready to use it for parsing JSON files. But how will it work in this aspect? Well, it does so by breaking the file into a specific sequence of tokens and printing everything out through “system.out”. Here is an example that might help you to understand it.

String carJson =        “{ \”brand\” : \”Mercedes\”, \”doors\” : 5 }”; JsonFactory factory = new JsonFactory();JsonParser  parser  = factory.createParser(carJson); while(!parser.isClosed()){    JsonToken jsonToken = parser.nextToken();     System.out.println(“jsonToken = ” + jsonToken);}

In this example, you can see that the JSON file has been broken into different tokens. Moreover, it also exhibits the fundamentals of looping through the tokens. If the “isClosed ()” method of parsing has returned with a false result, you will, then, have to use the other tokens from the source.

However, if you wish to have a look at the javascript parse JSON data again, then you can use the “nextToken ()” method of JSON parser. The types of tokens can be understood through a set of constants. These are –


You can employ this to find out the type of token that you are currently dealing with!

As stated previously, working with a Jackson JSON parsing module can be pretty difficult. But, if you do follow the tips we have mentioned, then, hopefully, you will not have any issue at all.