Convert Java object to JSON

This tutorial shows 2 ways for converting Java objects to JSON.

This kind of conversion is normally done via third-party libraries as it’s not supported by the JDK itself and requires a hard work to do it manually.

1- Gson

The most popular library used for converting Java objects to JSON is the Google Gson library.

Using Gson, you can get a JSON String out of an object through one line as the following:

All you have to do is to include gson jar in the classpath.

P.S: It’s worth to mention that toJson() method accepts also Hashmap, ArrayList and Arrays. 

2- Jackson

Another popular library is Jackson.

In order to convert Java objects to JSON using Jackson, you have to include 3 libraries: jackson-annotations, jackson-core and jackson-databind.

Here is the way:

P.S: writeValueAsString() method accepts also Hashmap, ArrayList and Arrays.