GSonを使いJSONのシリアライズとデシリアライズをするプログラムをJavaで創る

やりたいこと

JSONでシリアライズとデシリアライズをしたい

実装

pom.xml
<dependency> <groupId>com.google.code.gson</groupId> <artifactId>gson</artifactId> <version>2.8.6</version> </dependency>

JsonDemo.java
package jp.ne.yonem; import com.google.gson.Gson; import lombok.Data; import java.util.ArrayList; import java.util.List; public class JsonDemo { public static void main(String[] args) { Shelf shelf = new Shelf("漫画"); Book comic1 = new Book("ONE PIECE", "Eiichirou Oda"); Book comic2 = new Book("DRAGON BALL", "Akira Toriyama"); List<Book> list = shelf.getBooks(); list.add(comic1); list.add(comic2); Gson gson = new Gson(); String jsonShelf = gson.toJson(shelf); System.out.println("◆ Java -> JSON"); System.out.println(gson.toJson(comic1)); System.out.println(gson.toJson(comic2)); System.out.println(jsonShelf); System.out.println("◆ JSON -> Java"); Shelf shelfFromJson = gson.fromJson(jsonShelf, Shelf.class); System.out.println(shelfFromJson.getCategory()); shelfFromJson.getBooks().stream().forEach(System.out::println); } @Data private static class Shelf { Shelf(String category) { this.category = category; } private String category; private List<Book> books = new ArrayList<>(); } @Data private static class Book { Book(String name, String author) { this.name = name; this.author = author; } private String name; private String author; } }

実行結果

◆ Java -> JSON {"name":"ONE PIECE","author":"Eiichirou Oda"} {"name":"DRAGON BALL","author":"Akira Toriyama"} {"category":"漫画","books":[{"name":"ONE PIECE","author":"Eiichirou Oda"},{"name":"DRAGON BALL","author":"Akira Toriyama"}]} ◆ JSON -> Java 漫画 JsonDemo.Book(name=ONE PIECE, author=Eiichirou Oda) JsonDemo.Book(name=DRAGON BALL, author=Akira Toriyama) プロセスは終了コード 0 で完了しました