One post tagged with "json"

Sometimes, the JSON naming conventions used in an API may differ from the naming strategy within your application.

{
  "Title": "Frozen",
  "Year": "2013",
  "Type": "movie",
  "Poster": "https://m.media-amazon.com/images/M/MV5BMTQ1MjQwMTE5OF5BMl5BanBnXkFtZTgwNjk3MTcyMDE@._V1_SX300.jpg",
  "imdbID": "tt2294629"
}

private String title;
private String year;
private String imdbId;
private String type;
private String poster;

If the variable names do not match the JSON keys, the data will not be populated.

In such cases, you can use @JsonProperty(value) to map the data without changing the variable names in the project. However, if there are many fields with different naming strategies, using @JsonProperty(value) on each field can clutter the code with too many annotations.

This is where the @JsonNaming annotation comes in handy, allowing you to change the naming strategy of a class at once.

@JsonNaming​

Before v2.12​

You can elegantly solve this as follows:

@Data
@JsonNaming(value = PropertyNamingStrategy.UpperCamelCaseStrategy.class)
public class Movie {

    private String title;
    private String year;

    @JsonProperty("imdbID")  // Only where needed!
    private String imdbId;
    private String type;
    private String poster;

}

This method is deprecated and marked with a strikethrough.

However, this method has been deprecated since Jackson 2.12, so let's explore the newer approach.

After v2.12​

Starting from version 2.12, you should use PropertyNamingStrategies.

@JsonNaming(value = PropertyNamingStrategies.UpperCamelCaseStrategy.class)

While a detailed explanation of the internal implementation may be too lengthy and off-topic, it is recommended to take a look as it is quite interestingly implemented!