School, save data to shared preferences fils

Student.java
------------
package com.example.mohamadpc.savedataexample;

import android.content.Context;
import android.content.SharedPreferences;
import android.util.Log;

/**
 * Created by MOHAMADPC on 17/10/2017.
 */

public class Student {
    private String name;
    private String clas;
    private String password;
    private int idNo;

    public Student(String name, String clas, String password, int idNo) {
        this.name = name;
        this.clas = clas;
        this.password = password;
        this.idNo = idNo;
    }


    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getClas() {
        return clas;
    }

    public void setClas(String clas) {
        this.clas = clas;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }

    public int getIdNo() {
        return idNo;
    }

    public void setIdNo(int idNo) {
        this.idNo = idNo;
    }

    @Override
    public String toString() {
        return "Student{" +
                "name='" + name + '\'' +
                ", clas='" + clas + '\'' +
                ", password='" + password + '\'' +
                ", idNo=" + idNo +
                '}';
    }


}


Utils.java
----------
package com.example.mohamadpc.savedataexample;

import android.content.Context;
import android.content.SharedPreferences;
import android.util.Log;

import static android.R.attr.name;
import static android.R.attr.password;

/**
 * Created by MOHAMADPC on 17/10/2017.
 */

public class Utils {

    public static int[] getAllIdNo(Context context) {
        SharedPreferences sp = context.getSharedPreferences("StudentsSp", Context.MODE_PRIVATE);
        Object[] keys = sp.getAll().keySet().toArray();

        int[] res = new int[keys.length];
        for (int i = 0; i < res.length; i += 1) {
            res[i] = Integer.parseInt(keys[i].toString());
        }

        return res;
    }

    public static boolean checkLogin(Context context, int idNo, String password) {
        SharedPreferences sp = context.getSharedPreferences("StudentsSp", Context.MODE_PRIVATE);
        return sp.getString(idNo + "", "").split("\\|")[2].equals(password);
    }

    public static boolean save(Context context, Student st) {
        SharedPreferences sp = context.getSharedPreferences("StudentsSp", Context.MODE_PRIVATE);
        String dataStr;
        dataStr = st.getName() + "|" + st.getClas() + "|" + st.getPassword();

        return sp.edit().putString(st.getIdNo() + "", dataStr).commit();
    }

    public Student load(Context context, int idNo) {
        SharedPreferences sp = context.getSharedPreferences("StudentsSp", Context.MODE_PRIVATE);
        String dataStr = sp.getString(idNo + "", "");

        String[] parts = dataStr.split("\\|");

        if (parts.length == 3) {
            return new Student(parts[0], parts[1], parts[2], idNo);
        }
        return null;
    }
}