How to save data with gson in a json file?

Question

In my web application I succeed in displaying data in html table using mybatis. Now I want to save the records of the Mysql table in a json file and create an array of users, I

Answer 1

Quick fix to your code:

SqlSession session = MyBatisSqlSessionFactory.getSession();
List users = session.selectList("dao.UserDao.findAll");
try {
    JsonWriter writer = new JsonWriter(new FileWriter("C:\\file.json"));
    writer.beginObject();
    writer.name("data");
    writer.beginArray();
    for (User u : users) {
        writer.beginObject();
        writer.name("id").value(t.getId());
        writer.name("name").value(t.getNom());
        writer.endObject();
    }
    writer.endArray();
    writer.endObject();
    writer.close();
} catch (IOException e) {
    e.printStackTrace();
}

However, in the case that your User class looks like this:

public class User {
    String id;
    String name;
}

Then you don't need to code the adapter as Gson is able to automatically generate the JSON code for a class that only has primitives (ints, Strings, etc.). So your code would look as @roy-shmuli but only if you omit the data and keep only the array as List can be completely generated without an adapter. The JSON code generated would look like this:

[
    {"id":1, "name": "Mike"},
    {"id":2, "name": "Lucy"}
]

Hope it helps to the beginners.