Aplikasi Penentu Nilai Mahasiswa

Membuat Aplikasi Sederhana "Penentu Nilai Mahasiswa" dengan JAVA

untuk para geriyawan yang tak pernah puas akan selalu belajar pemrograman Java, berikut saya tampilkan contoh cara membuat Aplikasi sederhana "Penentu Nilai Mahasiswa" dengan Java...

Yang harus dilakukan yaitu kita menggunakan JAVA GUI

beriktu source code yang bisa anda coba !
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/*
 * To change this template, choose Tools | Templates
 * and open the template in the editor.
 */

/*
 * PenentuNilaiMahasiswa.java
 *
 * Created on Dec 3, 2011, 8:46:14 PM
 */
package PenentuNilaiMahasiswa;

import java.awt.event.KeyEvent;
import java.io.BufferedWriter;
import java.io.FileWriter;
import javax.swing.JOptionPane;
/**
 *
 * @author romadani
 */
public class PenentuNilaiMahasiswa extends javax.swing.JFrame {

    /** Creates new form PenentuNilaiMahasiswa */
    public PenentuNilaiMahasiswa() {
        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() {

        jPanel1 = new javax.swing.JPanel();
        jPanel2 = new javax.swing.JPanel();
        jLabel1 = new javax.swing.JLabel();
        namaTextField = new javax.swing.JTextField();
        jPanel3 = new javax.swing.JPanel();
        jLabel2 = new javax.swing.JLabel();
        utsTextField = new javax.swing.JTextField();
        jLabel3 = new javax.swing.JLabel();
        tmTextField = new javax.swing.JTextField();
        jLabel4 = new javax.swing.JLabel();
        uasTextField = new javax.swing.JTextField();
        jPanel4 = new javax.swing.JPanel();
        namaLabel = new javax.swing.JLabel();
        rerataLabel = new javax.swing.JLabel();
        gradeLabel = new javax.swing.JLabel();
        hasilLabel = new javax.swing.JLabel();
        hitungButton = new javax.swing.JButton();
        bersihkanButton = new javax.swing.JButton();
        simpanButton = new javax.swing.JButton();
        keluarButton = new javax.swing.JButton();

        setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
        setTitle("APLIKASI PENENTU NILAI MAHASISWA");

        jPanel1.setBackground(new java.awt.Color(51, 0, 204));

        jPanel2.setBackground(new java.awt.Color(255, 102, 0));

        jLabel1.setFont(new java.awt.Font("Tahoma", 1, 12)); // NOI18N
        jLabel1.setForeground(new java.awt.Color(255, 255, 255));
        jLabel1.setText("NAMA LENGKAP");

        javax.swing.GroupLayout jPanel2Layout = new javax.swing.GroupLayout(jPanel2);
        jPanel2.setLayout(jPanel2Layout);
        jPanel2Layout.setHorizontalGroup(
            jPanel2Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(jPanel2Layout.createSequentialGroup()
                .addContainerGap()
                .addComponent(jLabel1, javax.swing.GroupLayout.PREFERRED_SIZE, 110, javax.swing.GroupLayout.PREFERRED_SIZE)
                .addGap(30, 30, 30)
                .addComponent(namaTextField, javax.swing.GroupLayout.PREFERRED_SIZE, 192, javax.swing.GroupLayout.PREFERRED_SIZE)
                .addContainerGap(18, Short.MAX_VALUE))
        );
        jPanel2Layout.setVerticalGroup(
            jPanel2Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(jPanel2Layout.createSequentialGroup()
                .addContainerGap()
                .addGroup(jPanel2Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                    .addComponent(jLabel1)
                    .addComponent(namaTextField, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
                .addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))
        );

        jPanel3.setBackground(new java.awt.Color(255, 102, 0));
        jPanel3.setBorder(javax.swing.BorderFactory.createTitledBorder(null, "NILAI", javax.swing.border.TitledBorder.DEFAULT_JUSTIFICATION, javax.swing.border.TitledBorder.DEFAULT_POSITION, new java.awt.Font("Tahoma", 1, 12))); // NOI18N
        jPanel3.setForeground(new java.awt.Color(255, 255, 255));

        jLabel2.setFont(new java.awt.Font("Tahoma", 0, 12)); // NOI18N
        jLabel2.setText("UTS");

        utsTextField.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                utsTextFieldActionPerformed(evt);
            }
        });
        utsTextField.addKeyListener(new java.awt.event.KeyAdapter() {
            public void keyTyped(java.awt.event.KeyEvent evt) {
                utsTextFieldKeyTyped(evt);
            }
        });

        jLabel3.setFont(new java.awt.Font("Tahoma", 0, 12)); // NOI18N
        jLabel3.setText("TM");

        tmTextField.addKeyListener(new java.awt.event.KeyAdapter() {
            public void keyTyped(java.awt.event.KeyEvent evt) {
                tmTextFieldKeyTyped(evt);
            }
        });

        jLabel4.setFont(new java.awt.Font("Tahoma", 0, 12)); // NOI18N
        jLabel4.setText("UAS");

        uasTextField.addKeyListener(new java.awt.event.KeyAdapter() {
            public void keyTyped(java.awt.event.KeyEvent evt) {
                uasTextFieldKeyTyped(evt);
            }
        });

        javax.swing.GroupLayout jPanel3Layout = new javax.swing.GroupLayout(jPanel3);
        jPanel3.setLayout(jPanel3Layout);
        jPanel3Layout.setHorizontalGroup(
            jPanel3Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(jPanel3Layout.createSequentialGroup()
                .addGroup(jPanel3Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                    .addGroup(jPanel3Layout.createSequentialGroup()
                        .addComponent(jLabel2)
                        .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, 36, Short.MAX_VALUE)
                        .addComponent(utsTextField, javax.swing.GroupLayout.PREFERRED_SIZE, 72, javax.swing.GroupLayout.PREFERRED_SIZE))
                    .addGroup(jPanel3Layout.createSequentialGroup()
                        .addComponent(jLabel3)
                        .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, 42, Short.MAX_VALUE)
                        .addComponent(tmTextField, javax.swing.GroupLayout.PREFERRED_SIZE, 72, javax.swing.GroupLayout.PREFERRED_SIZE))
                    .addGroup(jPanel3Layout.createSequentialGroup()
                        .addComponent(jLabel4)
                        .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, 36, Short.MAX_VALUE)
                        .addComponent(uasTextField, javax.swing.GroupLayout.PREFERRED_SIZE, 72, javax.swing.GroupLayout.PREFERRED_SIZE)))
                .addContainerGap())
        );
        jPanel3Layout.setVerticalGroup(
            jPanel3Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(jPanel3Layout.createSequentialGroup()
                .addContainerGap()
                .addGroup(jPanel3Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                    .addComponent(jLabel2)
                    .addComponent(utsTextField, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
                .addGroup(jPanel3Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                    .addComponent(jLabel3)
                    .addComponent(tmTextField, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
                .addGroup(jPanel3Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                    .addComponent(jLabel4)
                    .addComponent(uasTextField, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
                .addContainerGap(33, Short.MAX_VALUE))
        );

        jPanel4.setBackground(new java.awt.Color(255, 102, 0));
        jPanel4.setBorder(javax.swing.BorderFactory.createTitledBorder(null, "HASIL", javax.swing.border.TitledBorder.DEFAULT_JUSTIFICATION, javax.swing.border.TitledBorder.DEFAULT_POSITION, new java.awt.Font("Tahoma", 1, 12))); // NOI18N

        namaLabel.setForeground(new java.awt.Color(255, 255, 255));
        namaLabel.setText("Nama                :");

        rerataLabel.setForeground(new java.awt.Color(255, 255, 255));
        rerataLabel.setText("Nilai Rata-rata  :");

        gradeLabel.setForeground(new java.awt.Color(255, 255, 255));
        gradeLabel.setText("Grade               :");

        hasilLabel.setForeground(new java.awt.Color(255, 255, 255));
        hasilLabel.setText("Hasil                 :");

        javax.swing.GroupLayout jPanel4Layout = new javax.swing.GroupLayout(jPanel4);
        jPanel4.setLayout(jPanel4Layout);
        jPanel4Layout.setHorizontalGroup(
            jPanel4Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, jPanel4Layout.createSequentialGroup()
                .addGroup(jPanel4Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING)
                    .addComponent(hasilLabel, javax.swing.GroupLayout.Alignment.LEADING, javax.swing.GroupLayout.DEFAULT_SIZE, 167, Short.MAX_VALUE)
                    .addComponent(gradeLabel, javax.swing.GroupLayout.Alignment.LEADING, javax.swing.GroupLayout.DEFAULT_SIZE, 167, Short.MAX_VALUE)
                    .addComponent(rerataLabel, javax.swing.GroupLayout.Alignment.LEADING, javax.swing.GroupLayout.DEFAULT_SIZE, 167, Short.MAX_VALUE)
                    .addComponent(namaLabel, javax.swing.GroupLayout.DEFAULT_SIZE, 167, Short.MAX_VALUE))
                .addContainerGap())
        );
        jPanel4Layout.setVerticalGroup(
            jPanel4Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(jPanel4Layout.createSequentialGroup()
                .addContainerGap()
                .addComponent(namaLabel)
                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
                .addComponent(rerataLabel)
                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
                .addComponent(gradeLabel)
                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
                .addComponent(hasilLabel)
                .addContainerGap(26, Short.MAX_VALUE))
        );

        hitungButton.setText("Hitung");
        hitungButton.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                hitungButtonActionPerformed(evt);
            }
        });

        bersihkanButton.setText("Bersihkan");
        bersihkanButton.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                bersihkanButtonActionPerformed(evt);
            }
        });

        simpanButton.setText("Simpan");
        simpanButton.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                simpanButtonActionPerformed(evt);
            }
        });

        keluarButton.setText("Keluar");
        keluarButton.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                keluarButtonActionPerformed(evt);
            }
        });

        javax.swing.GroupLayout jPanel1Layout = new javax.swing.GroupLayout(jPanel1);
        jPanel1.setLayout(jPanel1Layout);
        jPanel1Layout.setHorizontalGroup(
            jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(jPanel1Layout.createSequentialGroup()
                .addContainerGap()
                .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                    .addComponent(jPanel2, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
                    .addGroup(jPanel1Layout.createSequentialGroup()
                        .addComponent(jPanel3, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
                        .addGap(18, 18, 18)
                        .addComponent(jPanel4, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))
                    .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, jPanel1Layout.createSequentialGroup()
                        .addComponent(hitungButton, javax.swing.GroupLayout.DEFAULT_SIZE, 84, Short.MAX_VALUE)
                        .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
                        .addComponent(bersihkanButton)
                        .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
                        .addComponent(simpanButton, javax.swing.GroupLayout.PREFERRED_SIZE, 79, javax.swing.GroupLayout.PREFERRED_SIZE)
                        .addGap(18, 18, 18)
                        .addComponent(keluarButton, javax.swing.GroupLayout.PREFERRED_SIZE, 80, javax.swing.GroupLayout.PREFERRED_SIZE)))
                .addContainerGap())
        );
        jPanel1Layout.setVerticalGroup(
            jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(jPanel1Layout.createSequentialGroup()
                .addContainerGap()
                .addComponent(jPanel2, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
                .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING, false)
                    .addComponent(jPanel3, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
                    .addComponent(jPanel4, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))
                .addGap(18, 18, 18)
                .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                    .addComponent(hitungButton)
                    .addComponent(keluarButton)
                    .addComponent(simpanButton)
                    .addComponent(bersihkanButton))
                .addContainerGap(23, Short.MAX_VALUE))
        );

        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()
                .addComponent(jPanel1, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
                .addContainerGap())
        );
        layout.setVerticalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(layout.createSequentialGroup()
                .addContainerGap()
                .addComponent(jPanel1, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
                .addContainerGap())
        );

        pack();
    }// </editor-fold>                       
        private void filterKeyTyped(java.awt.event.KeyEvent evt) {
        char c = evt.getKeyChar();
        if (!((Character.isDigit(c) ||
               (c == KeyEvent.VK_BACK_SPACE) ||
               (c == KeyEvent.VK_DELETE))
               )){
           getToolkit().beep();
           JOptionPane.showMessageDialog(null, "masukkan hanya 0-9!");
           evt.consume();
         }
        }
    private void simpanButtonActionPerformed(java.awt.event.ActionEvent evt) {                                            
        // TODO add your handling code here:
        try {
            BufferedWriter out = new BufferedWriter(new FileWriter("hitungnilai.txt"));
            String hasil = namaLabel.getText() + '\n' +
                           rerataLabel.getText() + '\n' +
                           gradeLabel.getText() + '\n' +
                           hasilLabel.getText();
            out.write(hasil);
            JOptionPane.showMessageDialog(null, "Berhasil disimpan dalam file");
            out.close();
        }catch (Exception e){
            System.err.println("Error: " + e.getMessage());
        }
    }                                           

    private void hitungButtonActionPerformed(java.awt.event.ActionEvent evt) {                                            
        // TODO add your handling code here:
        if ( !(namaTextField.getText().equals("")) && !(utsTextField.getText().equals(""))
                && !(tmTextField.getText().equals("")) && !(uasTextField.getText().equals("")) ){
               String nama = namaTextField.getText();
               Double uts = Double.parseDouble(utsTextField.getText());
               Double tm = Double.parseDouble(tmTextField.getText());
               Double uas = Double.parseDouble(uasTextField.getText());
               Double rerata = (uts + tm + uas)/3;
               String grade = " ";
               String hasil = " ";

               if ( rerata >= 90 ){
                   grade = "A";
                   hasil = "Lulus";
               }else if ( (rerata >=80) && (rerata < 90)  ) {
                   grade = "B";
                   hasil = "Lulus";
               } else if ( (rerata >= 70) && (rerata < 80) ) {
                   grade = "C";
                   hasil = "Lulus";
               } else if ( rerata < 70 ) {
                   grade = "D";
                   hasil = "Tidak Lulus";
               }

               namaLabel.setText("Nama : " + nama);
               rerataLabel.setText("Nilai Rata - rata " + rerata);
               gradeLabel.setText("Grade : " + grade);
               hasilLabel.setText("Hasil : " + hasil);
        }
    }                                           

    private void utsTextFieldActionPerformed(java.awt.event.ActionEvent evt) {                                            
        // TODO add your handling code here:
       
    }                                           

    private void utsTextFieldKeyTyped(java.awt.event.KeyEvent evt) {                                     
        // TODO add your handling code here:
        filterKeyTyped(evt);
    }                                    

    private void tmTextFieldKeyTyped(java.awt.event.KeyEvent evt) {                                    
        // TODO add your handling code here:
        filterKeyTyped(evt);
    }                                   

    private void uasTextFieldKeyTyped(java.awt.event.KeyEvent evt) {                                     
        // TODO add your handling code here:
        filterKeyTyped(evt);
    }                                    

    private void bersihkanButtonActionPerformed(java.awt.event.ActionEvent evt) {                                               
        // TODO add your handling code here:
        namaTextField.setText("");
        utsTextField.setText("");
        tmTextField.setText("");
        uasTextField.setText("");

        namaLabel.setText("Nama :");
        rerataLabel.setText("Nilai Rata - Rata :");
        gradeLabel.setText("Grade :");
        hasilLabel.setText("Hasil :");
    }                                              

    private void keluarButtonActionPerformed(java.awt.event.ActionEvent evt) {                                            
        // TODO add your handling code here:
        int reply = JOptionPane.showConfirmDialog(null, "Yakin Mau Keluar?",
                                                   "Konfirmasi Keluar Aplikasi", JOptionPane.YES_NO_OPTION);
        if (reply == JOptionPane.YES_OPTION){
            System.exit(0);
        }
    }                                           

    /**
     * @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(PenentuNilaiMahasiswa.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (InstantiationException ex) {
            java.util.logging.Logger.getLogger(PenentuNilaiMahasiswa.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (IllegalAccessException ex) {
            java.util.logging.Logger.getLogger(PenentuNilaiMahasiswa.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (javax.swing.UnsupportedLookAndFeelException ex) {
            java.util.logging.Logger.getLogger(PenentuNilaiMahasiswa.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 PenentuNilaiMahasiswa().setVisible(true);
            }
        });
    }
    // Variables declaration - do not modify                    
    private javax.swing.JButton bersihkanButton;
    private javax.swing.JLabel gradeLabel;
    private javax.swing.JLabel hasilLabel;
    private javax.swing.JButton hitungButton;
    private javax.swing.JLabel jLabel1;
    private javax.swing.JLabel jLabel2;
    private javax.swing.JLabel jLabel3;
    private javax.swing.JLabel jLabel4;
    private javax.swing.JPanel jPanel1;
    private javax.swing.JPanel jPanel2;
    private javax.swing.JPanel jPanel3;
    private javax.swing.JPanel jPanel4;
    private javax.swing.JButton keluarButton;
    private javax.swing.JLabel namaLabel;
    private javax.swing.JTextField namaTextField;
    private javax.swing.JLabel rerataLabel;
    private javax.swing.JButton simpanButton;
    private javax.swing.JTextField tmTextField;
    private javax.swing.JTextField uasTextField;
    private javax.swing.JTextField utsTextField;
    // End of variables declaration                  
}

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maka hasil yang anda peroleh adalah demikian :