Java tutorial
/* * To change this license header, choose License Headers in Project Properties. * To change this template file, choose Tools | Templates * and open the template in the editor. */ package numerical; import com.itextpdf.text.BaseColor; import com.itextpdf.text.Document; import com.itextpdf.text.DocumentException; import com.itextpdf.text.Font; import com.itextpdf.text.Paragraph; import com.itextpdf.text.pdf.PdfWriter; import java.awt.HeadlessException; import java.awt.event.KeyEvent; import java.io.File; import java.io.FileNotFoundException; import java.io.FileOutputStream; import javax.swing.JFileChooser; import javax.swing.JOptionPane; /** * * @author Cyril */ public class Fibonnaci extends javax.swing.JFrame { long count; /** * Creates new form Fibonnaci */ public Fibonnaci() { 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">//GEN-BEGIN:initComponents private void initComponents() { f_enter = new javax.swing.JButton(); txt_sequence_no = new javax.swing.JTextField(); lbl_sequence_no = new javax.swing.JLabel(); jScrollPane1 = new javax.swing.JScrollPane(); txt_result = new javax.swing.JTextArea(); btn_save = new javax.swing.JButton(); jLabel6 = new javax.swing.JLabel(); jLabel9 = new javax.swing.JLabel(); setDefaultCloseOperation(javax.swing.WindowConstants.DISPOSE_ON_CLOSE); setTitle("Fibonnaci"); setResizable(false); f_enter.setFont(new java.awt.Font("Tahoma", 0, 18)); // NOI18N f_enter.setText("Enter"); f_enter.addActionListener(new java.awt.event.ActionListener() { public void actionPerformed(java.awt.event.ActionEvent evt) { f_enterActionPerformed(evt); } }); txt_sequence_no.setFont(new java.awt.Font("Tahoma", 0, 14)); // NOI18N txt_sequence_no.addKeyListener(new java.awt.event.KeyAdapter() { public void keyPressed(java.awt.event.KeyEvent evt) { txt_sequence_noKeyPressed(evt); } }); lbl_sequence_no.setFont(new java.awt.Font("Tahoma", 0, 14)); // NOI18N lbl_sequence_no.setText("Enter Sequence Number:"); txt_result.setEditable(false); txt_result.setColumns(20); txt_result.setFont(new java.awt.Font("Tahoma", 0, 12)); // NOI18N txt_result.setRows(5); jScrollPane1.setViewportView(txt_result); btn_save.setFont(new java.awt.Font("Tahoma", 0, 14)); // NOI18N btn_save.setText("Save as PDF"); btn_save.setEnabled(false); btn_save.addActionListener(new java.awt.event.ActionListener() { public void actionPerformed(java.awt.event.ActionEvent evt) { btn_saveActionPerformed(evt); } }); jLabel6.setFont(new java.awt.Font("Tahoma", 1, 18)); // NOI18N jLabel6.setText("Result:"); jLabel9.setFont(new java.awt.Font("Tahoma", 1, 18)); // NOI18N jLabel9.setText("Fibonnaci"); 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().addGroup(layout .createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING) .addGroup(layout.createSequentialGroup().addComponent(lbl_sequence_no) .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED) .addComponent(txt_sequence_no, javax.swing.GroupLayout.PREFERRED_SIZE, 204, javax.swing.GroupLayout.PREFERRED_SIZE) .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE) .addComponent(f_enter).addGap(18, 18, 18)) .addGroup( layout.createSequentialGroup().addComponent(jLabel9).addGap(0, 0, Short.MAX_VALUE)) .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup() .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING) .addComponent(jScrollPane1) .addGroup(layout.createSequentialGroup().addGap(0, 0, Short.MAX_VALUE) .addComponent(btn_save)) .addGroup(layout.createSequentialGroup().addComponent(jLabel6).addGap(362, 362, 362))) .addContainerGap())))); layout.setVerticalGroup( layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING) .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup() .addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE) .addComponent(jLabel9).addGap(18, 18, 18) .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE) .addComponent(f_enter).addComponent(lbl_sequence_no) .addComponent(txt_sequence_no, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)) .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED) .addComponent(jLabel6) .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED) .addComponent(jScrollPane1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE) .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED) .addComponent(btn_save).addGap(6, 6, 6))); pack(); setLocationRelativeTo(null); }// </editor-fold>//GEN-END:initComponents private void f_enterActionPerformed(java.awt.event.ActionEvent evt) {//GEN-FIRST:event_f_enterActionPerformed txt_result.setText(""); long n1 = 1, n2 = 1, n3, i; count = Integer.parseInt(txt_sequence_no.getText()); txt_result.append(n1 + ", " + n2);//printing 0 and 1 //loop starts from 2 because 0 and 1 are already printed for (i = 2; i < count; ++i) { n3 = n1 + n2; txt_result.append(", " + n3); n1 = n2; n2 = n3; } btn_save.setEnabled(true); }//GEN-LAST:event_f_enterActionPerformed private void txt_sequence_noKeyPressed(java.awt.event.KeyEvent evt) {//GEN-FIRST:event_txt_sequence_noKeyPressed if (evt.getKeyCode() == KeyEvent.VK_ENTER) { f_enter.doClick(); } }//GEN-LAST:event_txt_sequence_noKeyPressed private void btn_saveActionPerformed(java.awt.event.ActionEvent evt) {//GEN-FIRST:event_btn_saveActionPerformed JFileChooser jfc = new JFileChooser(); jfc.setCurrentDirectory(new File("/My Documents")); int return_val = jfc.showSaveDialog(rootPane); if (return_val == JFileChooser.APPROVE_OPTION) { Document doc = new Document(); try { jfc.getSelectedFile(); PdfWriter writer = PdfWriter.getInstance(doc, new FileOutputStream(jfc.getSelectedFile() + ".pdf")); doc.open(); Font f = new Font(Font.FontFamily.TIMES_ROMAN, 12.0f, Font.NORMAL, BaseColor.BLACK); Font f1 = new Font(Font.FontFamily.TIMES_ROMAN, 18.0f, Font.BOLD, BaseColor.BLACK); Paragraph paragraph = new Paragraph(null, f); Paragraph title = new Paragraph(null, f1); title.add("Fibonnaci\n"); paragraph.add("Sequence number: " + count + "\n"); paragraph.add("Result: "); paragraph.add(txt_result.getText()); doc.add(title); doc.add(paragraph); doc.close(); writer.close(); JOptionPane.showMessageDialog(rootPane, "Successfully saved!"); } catch (FileNotFoundException | DocumentException | HeadlessException e) { System.err.println(e); } } }//GEN-LAST:event_btn_saveActionPerformed /** * @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) "> /* If Nimbus (introduced in Java SE 6) is not available, stay with the default look and feel. * For details see http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html */ 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(Fibonnaci.class.getName()).log(java.util.logging.Level.SEVERE, null, ex); } catch (InstantiationException ex) { java.util.logging.Logger.getLogger(Fibonnaci.class.getName()).log(java.util.logging.Level.SEVERE, null, ex); } catch (IllegalAccessException ex) { java.util.logging.Logger.getLogger(Fibonnaci.class.getName()).log(java.util.logging.Level.SEVERE, null, ex); } catch (javax.swing.UnsupportedLookAndFeelException ex) { java.util.logging.Logger.getLogger(Fibonnaci.class.getName()).log(java.util.logging.Level.SEVERE, null, ex); } //</editor-fold> //</editor-fold> /* Create and display the form */ java.awt.EventQueue.invokeLater(new Runnable() { public void run() { new Fibonnaci().setVisible(true); } }); } // Variables declaration - do not modify//GEN-BEGIN:variables private javax.swing.JButton btn_save; private javax.swing.JButton f_enter; private javax.swing.JLabel jLabel6; private javax.swing.JLabel jLabel9; private javax.swing.JScrollPane jScrollPane1; private javax.swing.JLabel lbl_sequence_no; private javax.swing.JTextArea txt_result; private javax.swing.JTextField txt_sequence_no; // End of variables declaration//GEN-END:variables }