Jackson is a well-known library for JSON utilities. It has a wide area of features. One of them is case insensitive deserialization for field names. It's available since 2.5.0. In this post, I'll give an example of such case.

Here is a sample POJO class:

public class CarInfo {
	private String model;
    private String year;
	//getter, setter, constructor
}

And here are two JSON messages we'd like to deserialize. First:

{
	"model":"Tesla",
    "year":"2015"
}

This JSON string is a valid one and it can be easily deserialized by following code snippet:

ObjectMapper objectMapper = new ObjectMapper();
CarInfo info = objectMapper.readValue(data, CarInfo.class); //'data' contains JSON string

Below is the second JSON message:

{
	"ModeL":"Tesla",
    "YeaR":"2015"
}

Normally, default ObjectMapper cannot deserialize this message into a CarInfo object. With following configuration, it's possible:

ObjectMapper objectMapper = new ObjectMapper();
objectMapper.configure(MapperFeature.ACCEPT_CASE_INSENSITIVE_PROPERTIES, true);
CarInfo info = objectMapper.readValue(data, CarInfo.class); //'data' contains JSON string

This deserialization is valid.