I have data in jTable1. I attempted to send them to jTable2 , after calculating by value entered to JOption Pane. But when I clicked on cancelled button on JOption Pane program making error. Line 80 in my code is
BigDecimal quantity = new BigDecimal(JOptionPane.showInputDialog(null,"Enter Quantity", 0));
I need help to solve this problem. Thanks in advance.
Code is shown below
import java.math.BigDecimal; import javax.swing.JOptionPane; import javax.swing.table.DefaultTableModel; public class TableGUI extends javax.swing.JFrame { public TableGUI() { initComponents(); } private void initComponents() { java.awt.GridBagConstraints gridBagConstraints; jScrollPane1 = new javax.swing.JScrollPane(); jTable1 = new javax.swing.JTable(); jScrollPane2 = new javax.swing.JScrollPane(); jTable2 = new javax.swing.JTable(); jButton1 = new javax.swing.JButton(); setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE); getContentPane().setLayout(new java.awt.GridBagLayout()); jTable1.setModel(new javax.swing.table.DefaultTableModel( new Object[][]{ {"1", "Cement", "cwt", "1050.00", "1.00", "2.00", "2100.00"}, {"2", "Sand", "cube", "7500.00", "1.00", "1.50", "11250.00"}, {"3", "Skill labour", "Day", "2500.00", "1.00", "2.50", "6250.00"}, {"4", "Unskill labour", "Day", "1500.00", "1.00", "2.50", "3750.00"} }, new String[]{ "ID", "Name", "Unit", "Rate", "Usage", "Quantity", "Amount" } )); jTable1.setRowHeight(25); jScrollPane1.setViewportView(jTable1); gridBagConstraints = new java.awt.GridBagConstraints(); gridBagConstraints.fill = java.awt.GridBagConstraints.BOTH; gridBagConstraints.weightx = 0.1; gridBagConstraints.weighty = 0.1; gridBagConstraints.insets = new java.awt.Insets(5, 5, 5, 5); getContentPane().add(jScrollPane1, gridBagConstraints); jTable2.setModel(new javax.swing.table.DefaultTableModel( new Object[][]{}, new String[]{ "ID", "Name", "Unit", "Rate", "Usage", "Quantity", "Amount" } )); jTable2.setRowHeight(25); jScrollPane2.setViewportView(jTable2); gridBagConstraints = new java.awt.GridBagConstraints(); gridBagConstraints.fill = java.awt.GridBagConstraints.BOTH; gridBagConstraints.weightx = 0.1; gridBagConstraints.weighty = 0.1; gridBagConstraints.insets = new java.awt.Insets(5, 5, 5, 5); getContentPane().add(jScrollPane2, gridBagConstraints); jButton1.setText("Calculate"); jButton1.addActionListener(new java.awt.event.ActionListener() { public void actionPerformed(java.awt.event.ActionEvent evt) { jButton1ActionPerformed(evt); } }); gridBagConstraints = new java.awt.GridBagConstraints(); gridBagConstraints.gridx = 0; gridBagConstraints.gridy = 1; gridBagConstraints.gridwidth = 2; gridBagConstraints.insets = new java.awt.Insets(5, 5, 5, 5); getContentPane().add(jButton1, gridBagConstraints); pack(); } private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) { BigDecimal quantity = new BigDecimal(JOptionPane.showInputDialog(null,"Enter Quantity", 0)); if (quantity != null && quantity.equals("")) { JOptionPane.showMessageDialog(null, "Calculation Cancelled"); } else { DefaultTableModel model1 = (DefaultTableModel) jTable1.getModel(); for (int i = 0; i < model1.getRowCount(); i++) { Object data1 = jTable1.getValueAt(i, 0); Object data2 = jTable1.getValueAt(i, 1); Object data3 = jTable1.getValueAt(i, 2); BigDecimal data4 = new BigDecimal((String) jTable1.getValueAt(i, 3).toString()); BigDecimal data5 = new BigDecimal((String) jTable1.getValueAt(i, 4).toString()); BigDecimal data6 = quantity.multiply(new BigDecimal((String) jTable1.getValueAt(i,5).toString())); data6 = data6.setScale(2, BigDecimal.ROUND_HALF_UP); BigDecimal data7 = data4.multiply(data5.multiply(data6)); data7 = data7.setScale(2, BigDecimal.ROUND_HALF_UP); Object[] row = {data1, data2, data3, data4, data5, data6, data7}; DefaultTableModel model2 = (DefaultTableModel) jTable2.getModel(); model2.addRow(row); } } } public static void main(String args[]) { java.awt.EventQueue.invokeLater(new Runnable() { public void run() { new TableGUI().setVisible(true); } }); } private javax.swing.JButton jButton1; private javax.swing.JScrollPane jScrollPane1; private javax.swing.JScrollPane jScrollPane2; private javax.swing.JTable jTable1; private javax.swing.JTable jTable2; }
Stack Trace shown below
Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException at java.math.BigDecimal.<init>(BigDecimal.java:806) at soquestion.TableGUI.jButton1ActionPerformed(TableGUI.java:80) at soquestion.TableGUI.access$000(TableGUI.java:7) at soquestion.TableGUI$1.actionPerformed(TableGUI.java:65) at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:2022) at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2348) at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:402) at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:259) at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:252) at java.awt.Component.processMouseEvent(Component.java:6535) at javax.swing.JComponent.processMouseEvent(JComponent.java:3324) at java.awt.Component.processEvent(Component.java:6300) at java.awt.Container.processEvent(Container.java:2236) at java.awt.Component.dispatchEventImpl(Component.java:4891) at java.awt.Container.dispatchEventImpl(Container.java:2294) at java.awt.Component.dispatchEvent(Component.java:4713) at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4888) at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4525) at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4466) at java.awt.Container.dispatchEventImpl(Container.java:2280) at java.awt.Window.dispatchEventImpl(Window.java:2750) at java.awt.Component.dispatchEvent(Component.java:4713) at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:758) at java.awt.EventQueue.access$500(EventQueue.java:97) at java.awt.EventQueue$3.run(EventQueue.java:709) at java.awt.EventQueue$3.run(EventQueue.java:703) at java.security.AccessController.doPrivileged(Native Method) at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:76) at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:86) at java.awt.EventQueue$4.run(EventQueue.java:731) at java.awt.EventQueue$4.run(EventQueue.java:729) at java.security.AccessController.doPrivileged(Native Method) at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:76) at java.awt.EventQueue.dispatchEvent(EventQueue.java:728) at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:201) at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:116) at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:105) at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101) at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:93) at java.awt.EventDispatchThread.run(EventDispatchThread.java:82)
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Answer
I changed my code according to the given opinions. It works well now. Thnaks all who helped me. @QBrute,@Pshemo, @ControlAltDel
String userValue = JOptionPane.showInputDialog("Enter Quantity"); if (userValue != null && !userValue.isEmpty()) { BigDecimal quantity = new BigDecimal(userValue); DefaultTableModel model1 = (DefaultTableModel) jTable1.getModel(); for (int i = 0; i < model1.getRowCount(); i++) { Object data1 = jTable1.getValueAt(i, 0); Object data2 = jTable1.getValueAt(i, 1); Object data3 = jTable1.getValueAt(i, 2); BigDecimal data4 = new BigDecimal((String) jTable1.getValueAt(i, 3).toString()); BigDecimal data5 = new BigDecimal((String) jTable1.getValueAt(i, 4).toString()); BigDecimal data6 = quantity.multiply(new BigDecimal((String) jTable1.getValueAt(i, 5).toString())); data6 = data6.setScale(2, BigDecimal.ROUND_HALF_UP); BigDecimal data7 = data4.multiply(data5.multiply(data6)); data7 = data7.setScale(2, BigDecimal.ROUND_HALF_UP); Object[] row = {data1, data2, data3, data4, data5, data6, data7}; DefaultTableModel model2 = (DefaultTableModel) jTable2.getModel(); model2.addRow(row); } } else { JOptionPane.showMessageDialog(null, "Calculation Cancelled"); }