Android Quiz

Table of contents

• General info
• Technologies
• Roadmap
• Features
• Code Parts
• DB Parts
• Related

General info

Android Quiz -- quiz project with login and registration system, it connected to DB where saved information about users and questions, all results will be saved also in DB.

Technologies

Project is created with:

• Android Studio: 4.2.1
• Android Api: 29
• SQLite Database

Roadmap

• DB Connecting
• Login/Registration System
• Quiz Menu
• Create Quiz System
• Quiz part
• Register Results
• LeaderBoard
• Settings

Features

• DB Connecting
  • Created project settings where place connecting string
• Login/Registration System
  • Make Login and Registration system with password and profile
• Quiz Menu
  • List of Quizzes
  • Public Quizzes
  • User Quizzes
  • Manage user-created Quizzes
    • Create
    • Update
    • Remove
    • Make Private (using password)
    • Make Public
    • Is show correct ansver Flag
  • Search By Name or By Quiz ID
• Create Quiz System
  • Get random questions from DB
  • Get answers for this question and random variants
  • Check answers
• Quiz part
  • Text Quiz with one answer
  • Calculate points and update data in DB
  • Show correct (if Flag )
• Register Results
  • At the end of Quiz show Results
• Leaderboard
  • Show Leaderboard of Quiz
• Settings
  • Colors

Code Parts

Models

User Model

public class User {
    public int id;
    public String name;
    public String password;  
    private UserSetting settings;
    public void setSetting(int settingId){}
    public UserSetting getSetting(){return settings;}
}

Quiz Model

public class Quiz {
    public int id;
    public int ownerId;
    public String name;
    public String password;
    public bool isPasswordRequered;
    public bool isPublic;  
    public int maxQuestions; 
    public bool showCorrect; 
    private List<Question> questionsDone;
    private List<Question> questions;
    public void initQuestions(){}
    public Question GetQuestion(){} 
}

Question Model

public class Question {
    public int id; 
    public String description;
    public String answer; 
    public List<String> variants;   
    public bool isCorrect; 
}

Settings Model

public class Settings {
    public int id; 
    public int ownerId; 
    //different settings
    public void Init(){} 
    public void Save(){}
    public void Read(){}
}

DB Parts

It this part you can read about DB tables and relations between them

Here is a simple flow chart:

erDiagram
    USER ||..|| SETTINGS : ownerId
    USER ||--|{ USERQUIZLIST : userId
    USER ||--|{ RANKING : userId
    QUIZ ||--|{ RANKING : quizId
    QUIZ ||--|{ USERQUIZLIST : quizId
    QUIZ ||--|{ QUESTTION : quizId 

Loading

Connection to DB

Connection was created only to show how DB can be connected to Androi App, it should not be used in comercial becouse of security problem if you whant secure your app pleas use server with RestAPI

Connection to DB

Before you will add this code need add mysql-connector-java-5.1.20-bin.jar to your lib folder (app/libs/mysql-connector-java-5.1.20-bin.jar) Download only version 5.1.20 from site [downloads.mysql.com archives](https://downloads.mysql.com/archives/c-j/)

In url enter server in format "jdbc:mysql://[DB Server]/[DB Name]" If you run on local PC your DB Server should be your PC IP, it will be also work if PC in same network where android device

In username enter DB User with access from all IP (values '%' or '0:0:0:0')

    private static final String LOG = "DEBUG";
    private static String classjdbcDriver = "net.sourceforge.jtds.jdbc.Driver";

    private static String url = "jdbc:mysql://192.168.1.20/android_quiz";
    private static String username = "java";
    private static String password = "password";
    String res = "";
    private static Connection connection() {
        StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();
        StrictMode.setThreadPolicy(policy);

        try {
            Class.forName("com.mysql.jdbc.Driver"); // Add DB Driver to program
            System.out.println("Driver loaded!");
            Connection connection = DriverManager.getConnection(url, username, password);
            System.out.println("Database connected!");
            return connection;
        } catch (SQLException | ClassNotFoundException e) {
            throw new IllegalStateException("Cannot connect the database!", e);
        }
    }

SQL Requests

Select Request

    public static User LogIn( String login, String password){

        try{
            Connection con = connection(); //Get DB Connection 
            String sql;
            sql  = "SELECT Id,Name FROM users WHERE Name =? And Password = ?"; // '?' places for parameters
            PreparedStatement prest = con.prepareStatement(sql);
            prest.setString(1,login);
            prest.setString(2,password);
            User result = new User();
            ResultSet rs = prest.executeQuery(); 
            if (rs.next()){
                result.Id = rs.getInt("Id");
                result.Login = rs.getString("Name");

                System.out.println(result.Id + "\t" + "- " + result.Login);

            }
            prest.close(); // important to close reader
            con.close();// important to close connections
            return result;
        }
        catch (SQLException s){
            System.out.println("SQL statement is not executed!");
            System.out.println(s.getMessage());

        }

        return null;
    }

Related

Here are some related projects

geeksforgeeks/android-tutorial

tutorialspoint/android_sqlite_database

developer.android/layout-editor

code.tutsplus/build-an-interactive-quiz-app