How to parse a JSON object into a custom object using Gson?

I have the following JSON object as a String:

[{"Add1":"101","Description":null,"ID":1,"Name":"Bundesverfassung","Short":"BV"},{"Add1":"220","Description":null,"ID":2,"Name":"Obligationenrecht","Short":"OR"},{"Add1":"210","Description":null,"ID":3,"Name":"Schweizerisches Zivilgesetzbuch","Short":"ZGB"},{"Add1":"311_0","Description":null,"ID":4,"Name":"Schweizerisches Strafgesetzbuch","Short":null}]

Now i created a class that represents one of the results:

public class Book {

    private int number;
    pri开发者_开发技巧vate String description;
    private int id;
    private String name;
    private String abbrevation;

    public Book(int number, String description, int id, String name, String abbrevation) {
        this.number = number;
        this.description = description;
        this.id = id;
        this.name = name;
        this.abbrevation = abbrevation;
    }

}

Now I want to use Gson to parse the JSON object into a list of Book objects. I tried it this way, but obviously it doesn't work. How can I fix that?

public static Book[] fromJSONtoBook(String response) {
        Gson gson = new Gson();
        return gson.fromJson(response, Book[].class);
    }

The answer is quite simple, you have to use the annotation SerializedName to indicated which part of the JSON object is used to parse the JSON object to a Book object:

public class Book {

    @SerializedName("Add1")
    private String number;

    @SerializedName("Description")
    private String description;

    @SerializedName("ID")
    private int id;

    @SerializedName("Name")
    private String name;

    @SerializedName("Short")
    private String abbrevation;

    public Book(String number, String description, int id, String name, String abbrevation) {
        this.number = number;
        this.description = description;
        this.id = id;
        this.name = name;
        this.abbrevation = abbrevation;
    }

}

I am not sure that GSON knows how to map your JSONArray of JSONObjects to your Book class. I have a couple observations about this setup.

• If you notice, the JSONObjects which make up the JSONArray contain the properties "Add1" and "Short", but your Book class does not have properties that have the same names.

• The types should be noted. I am guessing that "Add1" is going to map to the number property (purely a guess), and the type is String in the JSONObject, but it is an int in the Book class.

• I am wondering whether the case of the Book class properties need to match the case of the JSONObject.

• Your Book class does not contain a public default constructor, which I think GSON needs to map.

The above are just a couple suggestions I have, which are not necessarily correct or complete as I have not used GSON before.