I apologize for any confusion, there is no such class in Apache Commons IO library called JsonRootName. The class JsonRootName is from Jackson library, not from Apache Commons IO.

Here is an example of using the JsonRootName annotation from the Jackson library to specify the root name of an object when serializing it to JSON:

import com.fasterxml.jackson.annotation.JsonRootName;

@JsonRootName("my_root")
public class MyClass {
    private String field;

    public MyClass(String field) {
        this.field = field;
    }

    public String getField() {
        return field;
    }
}

In this example, the MyClass is annotated with @JsonRootName("my_root") which will be used as the root name when serializing the MyClass object to JSON.

Make sure that you are using jackson as serializer.