Json to Java Object

This is a simple repo made to help demonstrate the steps for creating a Java object from a json format file or response.

Please look under the test directory to see different ways of creating a POJO from json.

You can find the blog to this repo here: How to create a Java Object from a JSON object

SimplePojo Class

This class contains a simple java object with relevant getter methods. In the test you can see I have created a json object which is being passed into the gson.fromJson() method and assigned to a SimplePojo object.

In my tests I am asserting that the getter methods of the SimplePojo instance are returning the correct values from the original json object.

AnnotationPojo Class

This class is another simple java object with the addition of annotations from the Gson library com.google.gson.annotations.SerializedName. You might wonder why you would use this class. One of the reasons you might use this library is when you have specific domain language and your models are created around this. If you are consuming third party api's which most likely be in the form of a json response you may come across 'keys' in a key : value that don't conform to your model.

So instead of changing your model you use the serialized name provided in the json response inside the annotation. So when your pojo is instantiated using the gson library it will automatically assign the value from the json object to the correct instance variable of your pojo.

In my test as above I am asserting that the getter methods of the AnnotationPojo instance are returning the correct values from the original json object.

Example:

json response

{
    "custom_field_102": "Lee"
}

model

class SomeClass

   @SerializedName("custom_field_102") String name;

Disclaimer

This is a MIT licensed repo. Please let me know if there are any errors and if you have any feedback. I will add to this repo other complicated json structures over time.