[Java ] Implement a FIFO Queue with GUI interface and test it storing String obj
ID: 3847834 • Letter: #
Question
[Java ] Implement a FIFO Queue with GUI interface and test it storing String objects.
Implement a Queue class as outlined below:
class Queue {
private Object data[]; // queue holds an array of Objects
private int in, out, size;
Queue(int c){} // constructor, parameter is queue capacity
public void insert(Object n){}
public Object remove(){}
public Object peek(){} // return next item to come out without removing it
public int getSize(){}
public int getCapacity(){} }
Test the Queue class using a JApplet GUI with buttons to perform the basic queue operations like insert, remove etc. Store String objects in the queue.
Explanation / Answer
Class Queue mplements a simple queue structure.
/**
*
* @author Sam
*/
public class Queue {
String[] arr;
int front,rear;
public Queue(int c) {
arr = new String[c];
front = rear = -1;
}
public void insert (Object n){
if (rear < arr.length - 1)
arr[++rear] = n.toString();
}
public Object remove(){
if (front == rear)
return null;
return arr[++front];
}
public Object peek() {
if (front == rear)
return null;
return arr[front+1];
}
public int getSize() {
return rear-front;
}
public int getCapacity() {
return arr.length;
}
}
class TestQueue implements an GUI to test various properties of Queue class
/**
*
* @author Sam
*/
public class TestQueue extends javax.swing.JFrame {
private Queue queue;
/**
* Creates new form TestQueue
*/
public TestQueue() {
initComponents();
}
/**
* This method is called from within the constructor to initialize the form.
* WARNING: Do NOT modify this code. The content of this method is always
* regenerated by the Form Editor.
*/
@SuppressWarnings("unchecked")
// <editor-fold defaultstate="collapsed" desc="Generated Code">
private void initComponents() {
jButton1 = new javax.swing.JButton();
jTextField1 = new javax.swing.JTextField();
jLabel1 = new javax.swing.JLabel();
jButton2 = new javax.swing.JButton();
jButton3 = new javax.swing.JButton();
jLabel2 = new javax.swing.JLabel();
jLabel3 = new javax.swing.JLabel();
jButton4 = new javax.swing.JButton();
jButton5 = new javax.swing.JButton();
jButton6 = new javax.swing.JButton();
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
jButton1.setText("Initialize");
jButton1.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jButton1ActionPerformed(evt);
}
});
jLabel1.setText("Input");
jButton2.setText("Inset");
jButton2.setEnabled(false);
jButton2.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jButton2ActionPerformed(evt);
}
});
jButton3.setText("Remove");
jButton3.setEnabled(false);
jButton3.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jButton3ActionPerformed(evt);
}
});
jLabel2.setText("Output:");
jLabel3.setText("---");
jButton4.setText("Peek");
jButton4.setEnabled(false);
jButton4.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jButton4ActionPerformed(evt);
}
});
jButton5.setText("Get Capacity");
jButton5.setEnabled(false);
jButton5.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jButton5ActionPerformed(evt);
}
});
jButton6.setText("Get Size");
jButton6.setEnabled(false);
jButton6.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jButton6ActionPerformed(evt);
}
});
javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
getContentPane().setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addContainerGap(22, Short.MAX_VALUE)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(jLabel1)
.addComponent(jTextField1, javax.swing.GroupLayout.PREFERRED_SIZE, 349, javax.swing.GroupLayout.PREFERRED_SIZE))
.addContainerGap(29, Short.MAX_VALUE))
.addGroup(layout.createSequentialGroup()
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
.addComponent(jButton5)
.addGap(28, 28, 28)
.addComponent(jButton6))
.addGroup(layout.createSequentialGroup()
.addGap(19, 19, 19)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(jLabel3)
.addComponent(jLabel2)
.addGroup(layout.createSequentialGroup()
.addComponent(jButton1)
.addGap(18, 18, 18)
.addComponent(jButton2)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
.addComponent(jButton3)
.addGap(18, 18, 18)
.addComponent(jButton4)))))
.addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))
);
layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGap(62, 62, 62)
.addComponent(jLabel1)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addComponent(jTextField1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(18, 18, 18)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(jButton1)
.addComponent(jButton2)
.addComponent(jButton3)
.addComponent(jButton4))
.addGap(18, 18, 18)
.addComponent(jLabel2)
.addGap(18, 18, 18)
.addComponent(jLabel3)
.addGap(18, 18, 18)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(jButton5)
.addComponent(jButton6))
.addContainerGap(24, Short.MAX_VALUE))
);
pack();
}// </editor-fold>
private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {
queue = new Queue(Integer.parseInt(jTextField1.getText()));
jLabel3.setText("---");
jButton2.setEnabled(true);
jButton3.setEnabled(true);
jButton4.setEnabled(true);
jButton5.setEnabled(true);
jButton6.setEnabled(true);
}
private void jButton2ActionPerformed(java.awt.event.ActionEvent evt) {
queue.insert(jTextField1.getText());
jLabel3.setText("---");
}
private void jButton3ActionPerformed(java.awt.event.ActionEvent evt) {
jLabel3.setText(queue.remove().toString());
}
private void jButton4ActionPerformed(java.awt.event.ActionEvent evt) {
jLabel3.setText(queue.peek().toString());
}
private void jButton5ActionPerformed(java.awt.event.ActionEvent evt) {
jLabel3.setText(queue.getCapacity()+"");
}
private void jButton6ActionPerformed(java.awt.event.ActionEvent evt) {
jLabel3.setText(queue.getSize()+"");
}
/**
* @param args the command line arguments
*/
public static void main(String args[]) {
/* Set the Nimbus look and feel */
//<editor-fold defaultstate="collapsed" desc=" Look and feel setting code (optional) ">
try {
for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {
if ("Nimbus".equals(info.getName())) {
javax.swing.UIManager.setLookAndFeel(info.getClassName());
break;
}
}
} catch (ClassNotFoundException ex) {
java.util.logging.Logger.getLogger(TestQueue.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (InstantiationException ex) {
java.util.logging.Logger.getLogger(TestQueue.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (IllegalAccessException ex) {
java.util.logging.Logger.getLogger(TestQueue.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (javax.swing.UnsupportedLookAndFeelException ex) {
java.util.logging.Logger.getLogger(TestQueue.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
}
//</editor-fold>
/* Create and display the form */
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
new TestQueue().setVisible(true);
}
});
}
// Variables declaration - do not modify
private javax.swing.JButton jButton1;
private javax.swing.JButton jButton2;
private javax.swing.JButton jButton3;
private javax.swing.JButton jButton4;
private javax.swing.JButton jButton5;
private javax.swing.JButton jButton6;
private javax.swing.JLabel jLabel1;
private javax.swing.JLabel jLabel2;
private javax.swing.JLabel jLabel3;
private javax.swing.JTextField jTextField1;
// End of variables declaration
}
Please Note that the QUEUE used in this example is Simple queue that does not have provition of reusing the blocks already used for storing data