java 里面的 Gson 问题

Question

@Test
publicvoidtestGetInt(){
Usersusers=usersDAO.get(3);
StringjsonUsers=gson.toJson(users);
System.out.println("jsonUsers:"+jsonUsers);
intavatarId=users.getAvatarId();
Avataravatar=avatarDAO.get(avatarId);
StringjsonAvatar=gson.toJson(avatar);
System.out.println("jsonAvatar:"+jsonAvatar);
}
打印的数据：
jsonUsers:
{"user_id":3,"username":"Tony","urlname":"comq"}
jsonAvatar:
{"id":3,"farm":"farm1","bucket":"hbimg","key":"e925755184a-aSvujx","type":"image/jpeg","width":100,"height":100,"frames":1}
怎么把jsonAvatar数据放到jsonUsers里面，变成：
{"user_id":3,"username":"Tony","urlname":"comq","avatar":{"id":3,"farm":"farm1","bucket":"hbimg","key":"e925755184a-aSvujx","type":"image/jpeg","width":100,"height":100,"frames":1}}

Answer 1

packagecom;importcom.google.gson.Gson;publicclassTestGson{publicstaticvoidmain(Stringargs[]){StringjsonAvatar="";//你的json数据Useruser=newUser();user.setUser_id(3);user.setUsername("Tony");user.setUrlname("comq");user.setAvatar(jsonAvatar);Gsongson=newGson();Stringresult=gson.toJson(user);System.out.println(result);}}packagecom;publicclassUser{privateintuser_id;privateStringusername;privateStringurlname;privateStringavatar;publicintgetUser_id(){returnuser_id;}publicvoidsetUser_id(intuser_id){this.user_id=user_id;}publicStringgetUsername(){returnusername;}publicvoidsetUsername(Stringusername){this.username=username;}publicStringgetUrlname(){returnurlname;}publicvoidsetUrlname(Stringurlname){this.urlname=urlname;}publicStringgetAvatar(){returnavatar;}publicvoidsetAvatar(Stringavatar){this.avatar=avatar;}}

Answer 2

似乎GSON将对象序列化是一次性的，然后我平时如果遇到这类问题的话我会这样做classAvatarUserextendsUsers{Avataravatar;}然后再对AvatarUser进行序列化，这样做的一个好处是方便以后的反序列化。UPDATE:新建一个类UPDATE:谢谢DontpublicclassAvatarUserextendsUsers{publicAvataravatar;publicAvatarUser(){}publicAvatarUser(Usersuser){setUserId(user.getUserId());setUserName(user.getUserName());setUrlName(user.getUrlName());}}@TestpublicvoidtestGetInt(){Usersuser=usersDAO.get(3);AvatarUseravatarUser=newAvartarUser(user);//AvatarUser的getter/setter来自父类Users//UPDATE直接在子类构造器做好赋值工作，就不用每次都重复编码了@DontintavatarId=user.getAvatarId();Avataravatar=avatarDAO.get(avatarId);avatarUser.avatar=avatar;StringjsonAvatar=gson.toJson(avatarUser);System.out.println("jsonAvatar:"+jsonAvatar);}