This is an Java MySQL example.
Its a simple CRUD app.We shall save items to MySQL,retrieve,update and delete.We shall be using JTextfields,JButtons and JComboBox.We used netbeans in this tutorial.
What we do :
- Connect to MySQL using JDBC.
- User types data into JTextField and clicks save button.
- We then save this data into MySQL.
- We retrieve after saving and bind our data to jcombobox.
- As user enters data he can see the changes he’s made.
- User can select an item from combobox.
- It gets set to the corresponding jtextfield.
- He can change and click update to update.
- Or he can delete and it gets deleted from MySQL database.
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SECTION 1 : Our Database Class
Database CRUD class
Main Responsibility : Perform all CRUD operations.
- INSERTS/SAVES data to MySQL database.
- SELECTS/RETRIEVES data to MySQL.
- UPDATES/EDITS data.
- DELETES data.
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package ComboDataBase; import java.sql.Connection; import java.sql.DriverManager; import java.sql.ResultSet; import java.sql.SQLException; import java.sql.Statement; import javax.swing.DefaultComboBoxModel; public class DBClass { String conString = "jdbc:mysql://localhost:3306/playersdb"; String username = "root"; String password = ""; //INSERT INTO DB public Boolean add(String name) { //SQL STMT String sql = "INSERT INTO playerstb(Name) VALUES('" + name + "')"; try { //CONNECTION" Connection con = DriverManager.getConnection(conString, username, password); //STATEMENT Statement s=con.prepareStatement(sql); //EXECUTE s.execute(sql); return true; } catch (SQLException ex) { ex.printStackTrace(); return false; } } //RETRIEVE DATA public DefaultComboBoxModel retrieve() { DefaultComboBoxModel dm=new DefaultComboBoxModel(); //SQL String sql="SELECT Name FROM playerstb"; try { Connection con=DriverManager.getConnection(conString, username, password); //STATEMENT Statement s=con.prepareStatement(sql); ResultSet rs=s.executeQuery(sql); //LOOP THRU GETTING ALL VALUES while(rs.next()) { //GET VALUES String name=rs.getString(1); dm.addElement(name); } return dm; }catch (SQLException ex) { ex.printStackTrace(); return null; } } //UPDATE DATA public Boolean update(String id,String value) { String sql="UPDATE playerstb SET Name ='" + value + "' WHERE Name='" + id + "'"; try { //GET COONECTION Connection con=DriverManager.getConnection(conString, username, password); //STATEMENT Statement s=con.prepareStatement(sql); //EXECUTE s.execute(sql); return true; }catch (SQLException ex) { ex.printStackTrace(); return false; } } //DELETE public Boolean delete(String id) { String sql="DELETE FROM playerstb WHERE Name ='"+id+"'"; try { //GET COONECTION Connection con=DriverManager.getConnection(conString, username, password); //STATEMENT Statement s=con.prepareStatement(sql); //EXECUTE s.execute(sql); return true; }catch (SQLException ex) { ex.printStackTrace(); return false; } } } |
SECTION 2 : Our GUI Class
GUI and Main class
Main Responsibility : STARTS OUR APPLICATION
- Is our main class.
- Derives from JFrame.
- Handles all GUI interactions such as input of data.
- Instantiates Database class and invokes its database manipulation methods.
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package ComboDataBase; import javax.swing.DefaultComboBoxModel; import javax.swing.JOptionPane; import javax.swing.UIManager; public class GUI_Class extends javax.swing.JFrame { String id=""; public GUI_Class() { initComponents(); } private void retrieve() { DefaultComboBoxModel dm=new DBClass().retrieve(); jComboBox1.setModel(dm); } @SuppressWarnings("unchecked") // <editor-fold defaultstate="collapsed" desc="Generated Code"> private void initComponents() { jLabel2 = new javax.swing.JLabel(); jPanel1 = new javax.swing.JPanel(); jComboBox1 = new javax.swing.JComboBox(); jLabel1 = new javax.swing.JLabel(); nameTxt = new javax.swing.JTextField(); addBtn = new javax.swing.JButton(); retrieveBtn = new javax.swing.JButton(); updateBtn = new javax.swing.JButton(); deleteBtn = new javax.swing.JButton(); clearBtn = new javax.swing.JButton(); setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE); jLabel2.setText("ProgrammingWizards Channel"); jPanel1.setBackground(new java.awt.Color(45, 155, 193)); jComboBox1.addItemListener(new java.awt.event.ItemListener() { public void itemStateChanged(java.awt.event.ItemEvent evt) { jComboBox1ItemStateChanged(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() .addGap(41, 41, 41) .addComponent(jComboBox1, javax.swing.GroupLayout.PREFERRED_SIZE, 129, javax.swing.GroupLayout.PREFERRED_SIZE) .addContainerGap(66, Short.MAX_VALUE)) ); jPanel1Layout.setVerticalGroup( jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING) .addGroup(jPanel1Layout.createSequentialGroup() .addGap(58, 58, 58) .addComponent(jComboBox1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE) .addContainerGap(64, Short.MAX_VALUE)) ); jLabel1.setText("Name"); addBtn.setText("Add"); addBtn.addActionListener(new java.awt.event.ActionListener() { public void actionPerformed(java.awt.event.ActionEvent evt) { addBtnActionPerformed(evt); } }); retrieveBtn.setText("Retrieve"); retrieveBtn.addActionListener(new java.awt.event.ActionListener() { public void actionPerformed(java.awt.event.ActionEvent evt) { retrieveBtnActionPerformed(evt); } }); updateBtn.setText("Update"); updateBtn.addActionListener(new java.awt.event.ActionListener() { public void actionPerformed(java.awt.event.ActionEvent evt) { updateBtnActionPerformed(evt); } }); deleteBtn.setText("Delete"); deleteBtn.addActionListener(new java.awt.event.ActionListener() { public void actionPerformed(java.awt.event.ActionEvent evt) { deleteBtnActionPerformed(evt); } }); clearBtn.setText("Clear"); clearBtn.addActionListener(new java.awt.event.ActionListener() { public void actionPerformed(java.awt.event.ActionEvent evt) { clearBtnActionPerformed(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() .addComponent(jPanel1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE) .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING) .addGroup(layout.createSequentialGroup() .addGap(18, 18, 18) .addComponent(jLabel1) .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED) .addComponent(nameTxt)) .addGroup(layout.createSequentialGroup() .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING) .addGroup(layout.createSequentialGroup() .addGap(8, 8, 8) .addComponent(addBtn) .addGap(18, 18, 18) .addComponent(retrieveBtn)) .addGroup(layout.createSequentialGroup() .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED) .addComponent(updateBtn) .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED) .addComponent(deleteBtn))) .addGap(0, 0, Short.MAX_VALUE))) .addContainerGap()) .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup() .addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE) .addComponent(clearBtn) .addGap(65, 65, 65)) .addGroup(layout.createSequentialGroup() .addGap(115, 115, 115) .addComponent(jLabel2) .addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)) ); layout.setVerticalGroup( layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING) .addGroup(layout.createSequentialGroup() .addGap(31, 31, 31) .addComponent(jLabel2) .addGap(51, 51, 51) .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING) .addComponent(jPanel1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE) .addGroup(layout.createSequentialGroup() .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE) .addComponent(jLabel1) .addComponent(nameTxt, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)) .addGap(58, 58, 58) .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE) .addComponent(addBtn) .addComponent(retrieveBtn)) .addGap(28, 28, 28) .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE) .addComponent(updateBtn) .addComponent(deleteBtn)))) .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED) .addComponent(clearBtn) .addContainerGap(18, Short.MAX_VALUE)) ); pack(); }// </editor-fold> private void jComboBox1ItemStateChanged(java.awt.event.ItemEvent evt) { id=jComboBox1.getSelectedItem().toString(); nameTxt.setText(id); } private void addBtnActionPerformed(java.awt.event.ActionEvent evt) { if(new DBClass().add(nameTxt.getText())) { JOptionPane.showMessageDialog(null, "Successfully Inserted"); retrieve();; //SELECT ADDED ITEM jComboBox1.setSelectedItem(nameTxt.getText()); //CLEAR TXT nameTxt.setText(""); }else { JOptionPane.showMessageDialog(null, "Not Inserted"); } } private void retrieveBtnActionPerformed(java.awt.event.ActionEvent evt) { retrieve(); } private void updateBtnActionPerformed(java.awt.event.ActionEvent evt) { if(new DBClass().update(id,nameTxt.getText())) { JOptionPane.showMessageDialog(null, "Successfully Updated"); retrieve();; //SELECT ADDED ITEM jComboBox1.setSelectedItem(nameTxt.getText()); //CLEAR TXT nameTxt.setText(""); }else { JOptionPane.showMessageDialog(null, "Not Updated"); } } private void deleteBtnActionPerformed(java.awt.event.ActionEvent evt) { if(new DBClass().delete(id)) { JOptionPane.showMessageDialog(null, "Successfully Deleted"); retrieve();; //CLEAR TXT nameTxt.setText(""); }else { JOptionPane.showMessageDialog(null, "Not Deleted"); } } private void clearBtnActionPerformed(java.awt.event.ActionEvent evt) { jComboBox1.setModel(new DefaultComboBoxModel()); } public static void main(String args[]) { java.awt.EventQueue.invokeLater(new Runnable() { public void run() { // try { // // select Look and Feel // UIManager.setLookAndFeel("com.jtattoo.plaf.smart.SmartLookAndFeel"); // // start application // // } catch (Exception ex) { // ex.printStackTrace(); // } new GUI_Class().setVisible(true); } }); } // Variables declaration - do not modify private javax.swing.JButton addBtn; private javax.swing.JButton clearBtn; private javax.swing.JButton deleteBtn; private javax.swing.JComboBox jComboBox1; private javax.swing.JLabel jLabel1; private javax.swing.JLabel jLabel2; private javax.swing.JPanel jPanel1; private javax.swing.JTextField nameTxt; private javax.swing.JButton retrieveBtn; private javax.swing.JButton updateBtn; // End of variables declaration } |
LAST SECTION
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- To see the XML we were parsing and the website itself please have look at the tutorial at our youtbe channel : ProgramminWizards.
- You’ll also find the demo for this example and step by step explanations.
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