我在EVT Java Netbeans中有例外

Question

我想，我在这部分中有一个错误，但我不知道修复它。错误的结果是

Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
    at bismillahpata.View.hitungHPP1.selanjutnyaActionPerformed(hitungHPP1.java:381)
    at bismillahpata.View.hitungHPP1.access$800(hitungHPP1.java:28)
    at bismillahpata.View.hitungHPP1$9.actionPerformed(hitungHPP1.java:330)
    at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:2018)
    at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2341)
    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:6505)
    at javax.swing.JComponent.processMouseEvent(JComponent.java:3321)
    at java.awt.Component.processEvent(Component.java:6270)
    at java.awt.Container.processEvent(Container.java:2229)
    at java.awt.Component.dispatchEventImpl(Component.java:4861)
    at java.awt.Container.dispatchEventImpl(Container.java:2287)
    at java.awt.Component.dispatchEvent(Component.java:4687)
    at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4832)
    at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4492)
    at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4422)
    at java.awt.Container.dispatchEventImpl(Container.java:2273)
    at java.awt.Window.dispatchEventImpl(Window.java:2713)
    at java.awt.Component.dispatchEvent(Component.java:4687)
    at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:707)
    at java.awt.EventQueue.access$000(EventQueue.java:101)
    at java.awt.EventQueue$3.run(EventQueue.java:666)
    at java.awt.EventQueue$3.run(EventQueue.java:664)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
    at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:87)
    at java.awt.EventQueue$4.run(EventQueue.java:680)
    at java.awt.EventQueue$4.run(EventQueue.java:678)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
    at java.awt.EventQueue.dispatchEvent(EventQueue.java:677)
    at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:211)
    at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:128)
    at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:117)
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:113)
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:105)
    at java.awt.EventDispatchThread.run(EventDispatchThread.java:90)

这是我的代码

 private void selanjutnyaActionPerformed(java.awt.event.ActionEvent evt) {                                            
        String namaProduk = this.fieldNamaProduk.getText();
        double totalProduk = Double.parseDouble(fieldTotalProduk.getText());
        produk p = new produk();
        p.setNamaProduk(namaProduk);
        p.setJumlah(totalProduk);
        produkController pc = new produkController();
        int res = pc.insertProduct(p);
        if (res > 0){
            new hitungHPP(namaProduk, totalProduk).setVisible(true);
            this.dispose();
        }else{
            JOptionPane.showMessageDialog(null, "Perintah Gagal, silahkan isi ulang!");
        }
        totalHargaBahan = totalHargaBahan + total;
        System.out.println(totalHargaBahan);
    } 

Answer 1

您必须使用catch与代码，

private void selanjutnyaActionPerformed(java.awt.event.ActionEvent evt) {                                            
        String namaProduk = this.fieldNamaProduk.getText();
        double totalProduk = Double.parseDouble(fieldTotalProduk.getText());
        produk p = new produk();
        p.setNamaProduk(namaProduk);
        p.setJumlah(totalProduk);
        produkController pc = new produkController();
        int res = pc.insertProduct(p);
        if (res > 0){
          try{
               new hitungHPP(namaProduk, totalProduk).setVisible(true);
               this.dispose();
              }
          catch(Exception e)
               {
                 System.out.println(e);
               }
        }else{
            JOptionPane.showMessageDialog(null, "Perintah Gagal, silahkan isi ulang!");
        }
        totalHargaBahan = totalHargaBahan + total;
        System.out.println(totalHargaBahan);
    }