Previously we seen how to create Simple Registration Form with GUI Connection with MySQL Database :   Simple Registration Form using JAVA Swing - Step2 (Connecting GUI with MySQL Database using JDBC)

 Here we are going to create an Application of Objective Test, in this application we show Questions with its options one by one, options will load dynamically. We getting our questions and its options through MySQL database.

This Java program needs some important packages:

·      java.sql.Connection;

·       java.sql.ResultSet;

·      java.sql.Statement;

For connecting java application with the MySQL database, you need to follow steps to perform database connectivity: ( In this example we are using MySQL as the database. So we need to know following informations for the MySQL database ):

·   Driver class:  The driver class for the mysql database is com.mysql.jdbc.Driver.

·      Connection URL:  The connection URL for the mysql database is  jdbc:mysql://localhost:3306/project where jdbc is the API, mysql is the database, localhost is the server name on which mysql is running, we may also use IP address, 3306 is the port number and project is the database name. We may use any database, in such case, you need to replace the project with your database name.

·     Username:  The default username for the mysql database is root.

·     Password:  Password is given by the user at the time of installing the mysql database. In this example, we are going to use root as the password.

[ To connect java application with the MySQL database mysqlconnector.jar file is

required to be loaded.] 

import java.awt.Color; 
import java.awt.Component; import java.awt.FlowLayout; 
import java.awt.Font; 
import java.awt.GridLayout; import java.awt.event.ActionEvent; 
import java.awt.event.ActionListener; 
import java.awt.event.ItemEvent; 
import java.awt.event.ItemListener; 
import java.sql.Connection; 
import java.sql.DriverManager; import java.sql.ResultSet; import java.sql.Statement; import java.util.HashMap; 
import javax.swing.BorderFactory; 
import javax.swing.ButtonGroup; 
import javax.swing.ImageIcon; import javax.swing.JButton; 
import javax.swing.JFrame; 
import javax.swing.JLabel; 
import javax.swing.JOptionPane; 
import javax.swing.JPanel; 
import javax.swing.JRadioButton; import javax.swing.border.Border; import javax.swing.border.TitledBorder;
@SuppressWarnings("serial") 
public class DynamicTest extends JFrame implements ActionListener, ItemListener{
      int frameHight=600,frameWidth=700;       JFrame childFrame;       JPanel questionPanel,optionPanel,buttonPanel,resultPanel;       JButton previousButton,nextButton,childPreviousButton,childNextButton,
 resultButton,describeResultButton,restart,childRestart;       JLabel title,questionLabel,totalQuestion,attemptedQuestion,
 unattemptedQuestion,correct,incorrect; 
      Connection con;       Statement statement;       String[] optionString=null;       ResultSet questionRst;       JRadioButton[] optionsButton = null; 
      ButtonGroup buttonGroup = new ButtonGroup();       HashMap<Long,String> map = new HashMap<Long,String>(); 
      int count=0, nor=0, childCount=0; 
      String correctOption=null; 
      ImageIcon icon,icon1,icon3; 
      DynamicTest(){ 
         super("Objective Questions");          setSize(frameWidth,frameHight); 
         setLayout(null); 
         try{
 //calling connect() method
         connect(); 
 
 //fetching all rows from table
         questionRst = statement.executeQuery("select * from objectivetest");  
 //fetch the last record of the table
         questionRst.last(); 
 
         nor=questionRst.getRow(); 
 
         title = new JLabel("Objective Test"); 
         title.setBounds(frameHight/2,20,200,30);          title.setFont(new Font("Arial", Font.BOLD,20)); 
         add(title);
 
         questionPanel = new JPanel(); 
         questionPanel.setLayout(new FlowLayout(FlowLayout.LEFT)); 
         questionPanel.setBounds(frameWidth/9,90,550,50); 
         questionLabel = new JLabel(".............................."); 
         questionPanel.add(questionLabel); 
         add(questionPanel);
 
 optionPanel = new JPanel(); 
         optionPanel.setLayout(new GridLayout(4,2)); 
         optionPanel.setBounds(frameWidth/7,150,550,160);          add(optionPanel);
 
         buttonPanel = new JPanel(); 
         buttonPanel.setLayout(new GridLayout(2,2,5,5));          buttonPanel.setBounds(frameWidth/9,320,550,70);          previousButton = new JButton("Previous"); 
         previousButton.addActionListener(this); 
         buttonPanel.add(previousButton); 
         nextButton = new JButton("Next"); 
         nextButton.addActionListener(this); 
         buttonPanel.add(nextButton); 
         resultButton = new JButton("Result"); 
         resultButton = new JButton("Result"); 
         resultButton.addActionListener(this); 
         buttonPanel.add(resultButton); 
         describeResultButton = new JButton("Show Result Discription");
         describeResultButton.addActionListener(this); 
         buttonPanel.add(describeResultButton); 
         describeResultButton.setEnabled(false); 
         add(buttonPanel);
 
 //calling showNextRecord() method
         showNextRecord(); 
          resultPanel = new JPanel(); 
         resultPanel.setLayout(new GridLayout(3,2)); 
         resultPanel.setBounds(frameWidth/3,410,250,80); 
         totalQuestion = new JLabel(""); 
         correct = new JLabel(""); 
         attemptedQuestion = new JLabel(""); 
         incorrect = new JLabel(""); 
         unattemptedQuestion = new JLabel(""); 
         resultPanel.add(totalQuestion); 
         resultPanel.add(correct); 
         resultPanel.add(attemptedQuestion); 
         resultPanel.add(incorrect); 
         resultPanel.add(unattemptedQuestion); 
         add(resultPanel); 
         resultPanel.hide();
         restart = new JButton("Restart"); 
         restart.setBounds(frameWidth/3,495,200,40); 
         restart.addActionListener(this); 
         add(restart); 
         restart.hide(); 
         }catch(Exception ex){ 
 System.out.println(ex.getMessage()); 
 }
        setDefaultCloseOperation(EXIT_ON_CLOSE); 
        setVisible(true); 
     } 
 
 // show nextRecord() method
      public void showNextRecord(){ 
            if(count < 1){
                  previousButton.setEnabled(false); 
            }else{
                  previousButton.setEnabled(true); 
            } 
            if(count+1 == nor){ 
                  nextButton.setText("FINISH"); 
            }else{ 
                  nextButton.setEnabled(true); 
                  nextButton.setText("Next"); 
            }
 try{
 //move the cursor to the specified row number
                  questionRst.absolute(count+1); 
 
                  questionLabel.setText((count+1)+". "+questionRst.getString(2));
                  String split = questionRst.getString(3); 
                  optionString = split.split("-"); 
                  optionsButton = new JRadioButton[optionString.length]; 
 
                  for(int i=0; i<optionString.length; i++){ 
                      optionsButton[i] = new JRadioButton(optionString[i]); 
                      optionsButton[i].addItemListener(this); 
                      buttonGroup.add(optionsButton[i]); 
                      optionPanel.add(optionsButton[i]); 
                      if(map.containsKey((questionRst.getLong(1)))){ 
                         if(map.get(questionRst.getLong(1)).equals(optionsButton[i].
 getText()))
 optionsButton[i].setSelected(true); 
                        }else
                              buttonGroup.clearSelection(); 
                  } 
                  add(optionPanel); 
 
            }catch(Exception ex){
 System.out.println(ex.getMessage()); 
 } 
      }
 
 //childFrame() method which creates child frame
      public void childFrame(){ 
            try{
 //creating another Frame to show complete result
                  childFrame = new JFrame(); 
                  childFrame.setSize(frameWidth,frameHight); 
                  childFrame.setLayout(null); 
                  title = new JLabel("Objective Test"); 
                  title.setBounds(frameHight/2,20,200,30); 
                  title.setFont(new Font("Arial", Font.BOLD,20)); 
                  childFrame.add(title); 
 
                  questionPanel = new JPanel(); 
                  questionPanel.setLayout(new FlowLayout(FlowLayout.LEFT)); 
                  questionPanel.setBounds(frameWidth/9,90,550,50); 
                  questionLabel = new JLabel(""); 
                  questionPanel.add(questionLabel); 
                  childFrame.add(questionPanel); 
                  optionPanel = new JPanel(); 
                  optionPanel.setLayout(new GridLayout(4,2)); 
                  optionPanel.setBounds(frameWidth/9,150,550,150); 
                  buttonPanel = new JPanel(); 
                  buttonPanel.setLayout(new GridLayout(1,2,5,5)); 
                  buttonPanel.setBounds(frameWidth/9,320,550,50); 
                  childPreviousButton = new JButton("Previous"); 
                  childPreviousButton.addActionListener(this); 
                  buttonPanel.add(childPreviousButton); 
                  childNextButton = new JButton("Next"); 
                  childNextButton.addActionListener(this); 
                  buttonPanel.add(childNextButton); 
 
                  childFrame.add(buttonPanel); 
                  childRestart = new JButton("Restart"); 
                  childRestart.setBounds(frameWidth/3,410,250,40); 
                  childRestart.addActionListener(this); 
                  childFrame.add(childRestart);
 
 //calling childShowNextRecord()method
                  childShowNextRecord();
 
                  childFrame.setDefaultCloseOperation(EXIT_ON_CLOSE); 
                  childFrame.setVisible(true);    
          
            }catch(Exception ex){
 System.out.println(ex.getMessage()); 
 } 
      } 
 
 // defining childShowNextRecord() method
      public void childShowNextRecord(){ 
            if(childCount<1)  childPreviousButton.setEnabled(false); 
            else  childPreviousButton.setEnabled(true); 
            if(childCount+1 == nor)childNextButton.setEnabled(false); 
            else  childNextButton.setEnabled(true); 
 
            // creating border where no options are selected             Border titleBorder = BorderFactory.createLineBorder(Color.RED); 
            TitledBorder title = BorderFactory.createTitledBorder(titleBorder,
 "Not-Attempted"); 
            title.setTitleJustification(TitledBorder.CENTER); 
            try{
                questionRst.absolute(childCount+1); 
                questionLabel.setText((childCount+1)+". "+questionRst.getString(2));
                String string = questionRst.getString(3);                 String[] optionString = string.split("-"); 
                correctOption = questionRst.getString(4); 
                optionsButton = new JRadioButton[optionString.length]; 
                for(int i=0; i<optionString.length; i++){ 
                    optionsButton[i] = new RadioButton(optionString[i]); 
                    buttonGroup.add(optionsButton[i]); 
                    optionPanel.add(optionsButton[i]); 
                    if(map.containsKey((questionRst.getLong(1)))){ 
                       optionPanel.setBorder(null); 
                       if(map.get(questionRst.getLong(1)).equals(optionsButton[i].
 getText())){ 
                          optionsButton[i].setSelected(true); 
                          icon = new ImageIcon(""); 
                          optionsButton[i].setIcon(icon); 
                          optionsButton[i].setFont(new Font("Arial",Font.BOLD,18));
                         if(!map.get(questionRst.getLong(1)).equals(correctOption)){
                            icon1 = new ImageIcon("C:/Users/MSclient008/Desktop/
 TarunDoc/icons/wrong.gif");
                            optionsButton[i].setIcon(icon1); 
                         }
                        } 
                      }else{ 
                          buttonGroup.clearSelection(); 
                            optionPanel.setBorder(title); 
                   }
                  } 
                  int k=0; 
                  while(k<optionString.length){ 
                        if(correctOption.equals(optionsButton[k].getText())){ 
                           optionsButton[k].setFont(new Font("Arial",Font.BOLD,18));
                           icon3 = new ImageIcon("C:/Users/MSclient008/Desktop/
 TarunDoc/icons/correct.gif");
                           optionsButton[k].setIcon(icon3); 
                        } 
                        k++;
                  } 
                  childFrame.add(optionPanel); 
 
                  Component[] component = optionPanel.getComponents();                   int i=0,j=0; 
                  while(component.length>i){
                        JRadioButton radio = (JRadioButton)component[i]; 
                        if(!radio.isSelected()){ 
                              radio.setEnabled(false); 
                              j++; 
                        }     
                        if(radio.getText().equals(correctOption)) 
                              radio.setEnabled(true); 
                        i++; 
                  } 
                  int x=0; 
                  if(j==i) 
                  { 
                        while(component.length>x){ 
                              JRadioButton radio = (JRadioButton)component[x]; 
                              if(radio.getText().equals(correctOption)){ 
                                 radio.setEnabled(false); 
                              } 
                              x++;
                        }
                  } 
            }catch(Exception ex){
 System.out.println(ex.getMessage());
 } 
      }
 
 // defining actionPerformed() method
      public void actionPerformed(ActionEvent ae){ 
            JButton button = (JButton)ae.getSource();             try{            if(ae.getSource()==previousButton) 
            { 
                  if(count>0) 
                  {
                        count--; 
                        optionPanel.removeAll(); 
                        optionPanel.repaint(); 
                        showNextRecord(); 
                  } 
                  System.out.println("Prev:"+count); 
            } 
            if(ae.getSource()==nextButton) 
            {
                  if(count< nor-1) 
                  {
                        optionPanel.removeAll(); 
                        optionPanel.repaint(); 
                        count++; 
                        showNextRecord();                   }                  else if(button.getText().equals("FINISH")) 
                  { 
                        Object[] options = {"Yes, please","Return!"}; 
 
 // asking confirmation to show result
                        int n = JOptionPane.showOptionDialog(this, "Are you sure,
 want to see result!","Test Result", 
                                    JOptionPane.YES_NO_OPTION, 
                                    JOptionPane.QUESTION_MESSAGE, 
                                    null, 
                                    options, 
                                    options[0]); 
                        if(n ==0){ 
                              previousButton.setEnabled(false); 
                              nextButton.setEnabled(false); 
                              questionLabel.setEnabled(false); 
                              resultButton.setEnabled(false); 
                              showResult(); 
                              describeResultButton.setEnabled(true); 
                        } 
                  } 
                  System.out.println("Next:"+count); 
            }
            if(ae.getSource()==resultButton){ 
 
 // calling showResult() method
                  showResult(); 
 
                  restart.show(); 
                  System.out.println("ResultButton:"); 
            } 
            if(ae.getSource()==describeResultButton) 
            { 
                  this.hide(); 
 
 // calling childFrame() method
                  childFrame(); 
 
                  System.out.println("DescribeButton:"); 
            } 
            if(ae.getSource()==childPreviousButton)
            {
                  if(childCount>0) 
                  {
                        childCount--; 
                        optionPanel.removeAll(); 
                        optionPanel.repaint(); 
                        childShowNextRecord(); 
                        System.out.println("ChildPrev:"+childCount); 
                  } 
            } 
            if(ae.getSource()==childNextButton) 
            {
                  if(childCount < nor-1) 
                  { 
                        optionPanel.removeAll(); 
                        optionPanel.repaint(); 
                        childCount++; 
                        childShowNextRecord(); 
                        System.out.println("ChildNext:"+childCount); 
                  } 
            } 
            if(ae.getSource()==restart) 
            {           
                  this.hide(); 
                  new DynamicTest(); 
            } 
            if(ae.getSource()==childRestart) 
            {           
                  childFrame.hide(); 
                  new DynamicTest(); 
            } 
            }catch(Exception ex){
 System.out.println(ex.getMessage());
 } 
      }
      private void showResult(){ 
            try{ 
                  int size=1, totalQ=0, attemptedQ=0,cor=0,inc=0;                   while(size <= nor){
                        String[] optionString = null; 
                        String correctOption = null; 
                        questionRst.absolute(size);
                        if(map.containsKey(questionRst.getLong(1))){ 
                           String split = questionRst.getString(3); 
                           optionString = split.split("-"); 
                           questionRst.absolute(size); 
                           correctOption = questionRst.getString(4); 
                           if(map.get(questionRst.getLong(1)).equals(correctOption))
                              cor++; 
                           else
                              inc++;
                        }
                        size++;
                  } 
                 totalQuestion.setText("TotalQuestions"+" : "+(totalQ=nor)); 
                 attemptedQuestion.setText("Attempted"+":"+(attemptedQ=map.size())); 
                 unattemptedQuestion.setText("Unattempted"+":"+(totalQ-attemptedQ)); 
                 correct.setText("Correct"+" : "+cor);
                 incorrect.setText("Incorrect"+" : "+inc); 
                 resultPanel.show(); 
                 previousButton.setEnabled(false); 
                 nextButton.setEnabled(false); 
                 questionLabel.setEnabled(false);
                 Component[] component = optionPanel.getComponents(); 
                 int i=0; 
                 while(component.length>i){ 
                       JRadioButton radio = (JRadioButton)component[i]; 
                       if(!radio.isSelected()) 
                          radio.setEnabled(false); 
                       i++; 
                 } 
            }catch(Exception e){
 System.out.print(e.getMessage());
 } 
      }
 
 // defining connect() method to connect with the database
      public void connect(){ 
            try{ 
               Class.forName("com.mysql.jdbc.Driver"); 
               con =DriverManager.getConnection("jdbc:mysql://localhost:3306/test",
 "root","1234"); 
               statement = con.createStatement(); 
               System.out.println("Connected"); 
            }catch(Exception e){
 System.out.print(e.getMessage());
 }
      } 
      public void itemStateChanged(ItemEvent e){             try{
               JRadioButton radioButton = (JRadioButton)e.getSource(); 
               if(radioButton.isSelected()) 
               {
                  map.put(questionRst.getLong(1), radioButton.getText());                   System.out.println("MapSize:"+map.size());
               } 
               System.out.println("CheckedOption:"+map.get(questionRst.getLong(1)));
            }catch(Exception ex){
 System.out.print(ex.getMessage()); 
 } 
      }
 
 //defining main()method
      public static void main(String ...s){
            new DynamicTest(); 
      }
}

Running the Application

 Next, we will learn about : JAVA : Singleton Pattern