Question

我有一个名为Teacher的java类：

public class Teacher {
private String _tCode;
private String _tName;
private String[] _teacherLessons;
private int _maxHoursPerDay;
private int _maxHoursPerWeek;

public String get_T_Code(){return this._tCode;}
public String get_T_Name(){return this._tName;}
public String[] get_Teacher_Lessons(){return this._teacherLessons;}
public int    get_Max_Hours_Per_Day(){return this._maxHoursPerDay;}
public int    get_Max_Hours_Per_Week(){return this._maxHoursPerWeek;}

public void set_T_Code(String tCode){this._tCode=tCode;}
public void set_T_Name(String tName){this._tName=tName;}
public void set_Teacher_Lessons(String[] teacherLessons){this._teacherLessons =teacherLessons;}
public void set_Max_Hours_Per_Day(int maxHoursPerDay){this._maxHoursPerDay=maxHoursPerDay;}
public void set_Max_Hours_Per_Week(int maxHoursPerWeek){this._maxHoursPerWeek=maxHoursPerWeek;}

public void teacher (String tCode, String tName, String[] teacherLessons, int maxHoursPerDay, int maxHoursPerWeek){
    this._tCode=tCode;
    this._tName=tName;
    this._teacherLessons=teacherLessons;
    this._maxHoursPerDay=maxHoursPerDay;
    this._maxHoursPerWeek=maxHoursPerWeek;
}
@Override
public String toString(){ return "Code:\t"+this._tCode+"\nName:\t"+this._tName+"\nTeacher Lessons:\t"+this._teacherLessons+
        "\nMax hours per day:\t"+this._maxHoursPerDay+"\nMax hours per week:\t"+this._maxHoursPerWeek;}

}

我希望我的主类从json文件中读取并创建Teacher对象，但我不确定将数据写入json文件的最佳方法是什么。这是我到目前为止所尝试的：

[{
    "Teacher Code": "1",
    "Teacher Name": "john",
    "MaxHoursPerDay":5,
    "MaxHoursPerWeek":18,
    "Teacher Lessons": [
       "Maths"
    ]
},
{
    "Teacher Code": "2",
    "Teacher Name": "Bill",
    "MaxHoursPerDay":5,
    "MaxHoursPerWeek":18,
    "Teacher Lessons": [
       "Maths",
       "Physics
    ]
}]

我创建这样的对象：

JSONArray a = (JSONArray) parser.parse(new FileReader("c:\\file1.txt"));

  for (Object o : a)
 {
      JSONObject person = (JSONObject) o;

String code= (String) person.get("code");

String name= (String) person.get("name");

int maxHoursD= (int) person.get("MaxHourPerDay");
int maxHoursW= (int) person.get("MaxHourPerWeek");


JSONArray lessons = (JSONArray) person.get("Teacher Lessons");

for (Object c : lessons)
{
  Teacher t = new Teacher(code, name, maxHoursD, maxHoursW, c);
}
}

是否有更简单的方法来读取json数据并创建对象？此外，是否可以像我的构造函数一样将json数组（教师课程）存储在java数组中？

Answer 1

Google Gson是一个非常好的第三方库，可以很容易地与您的代码一起使用。它完全符合您的要求。将对象转换为JSON，反之亦然。

import com.google.gson.Gson;
import com.google.gson.GsonBuilder;

public static void main(String[] args) {
    Gson gson = new GsonBuilder().setPrettyPrinting().create();
    Teacher teacher = new Teacher("001", "John Doe", 8, 40, "History", "Civics");
    System.out.println("Teacher Object :\n" + gson.toJson(teacher));

    Teacher teacher1 = new Teacher("002", "Ali G", 8, 40, "English Literature", "English Language");
    Teachers teachers = new Teachers(teacher, teacher1);
    System.out.println("Teachers Object :\n" + gson.toJson(teachers));

}

public static class Teachers {
    private Teacher[] teachers;

    public Teachers(Teacher... teachers) {
        this.teachers = teachers;
    }

}

public static class Teacher {
    private String _tCode;
    private String _tName;
    private String[] _teacherLessons;
    private int _maxHoursPerDay;
    private int _maxHoursPerWeek;

    public Teacher(String _tCode, String _tName, int _maxHoursPerDay, int _maxHoursPerWeek,
            String... _teacherLessons) {
        this._tCode = _tCode;
        this._tName = _tName;
        this._teacherLessons = _teacherLessons;
        this._maxHoursPerDay = _maxHoursPerDay;
        this._maxHoursPerWeek = _maxHoursPerWeek;
        this._teacherLessons = _teacherLessons;
    }

}

以上代码的结果如下：

Teacher Object :
{
  "_tCode": "001",
  "_tName": "John Doe",
  "_teacherLessons": [
    "History",
    "Civics"
  ],
  "_maxHoursPerDay": 8,
  "_maxHoursPerWeek": 40
}
Teachers Object :
{
  "teachers": [
    {
      "_tCode": "001",
      "_tName": "John Doe",
      "_teacherLessons": [
        "History",
        "Civics"
      ],
      "_maxHoursPerDay": 8,
      "_maxHoursPerWeek": 40
    },
    {
      "_tCode": "002",
      "_tName": "Ali G",
      "_teacherLessons": [
        "English Literature",
        "English Language"
      ],
      "_maxHoursPerDay": 8,
      "_maxHoursPerWeek": 40
    }
  ]
}

输出应该告诉您应该如何根据模型对象构建JSON。

如何在java中读取json文件并创建对象？

1 个答案: