java - ClassCastException 从数据库中的组合框中插入数据

Question

我正在尝试插入两个字段(JCombobox 中的优先级及其根据组合中所选选项获取的 ID)并完成其余字段(所有字符串) )提交所有...但我得到这个 Stacktrace:

run:
Exception in thread "AWT-EventQueue-0" java.lang.ClassCastException: br.com.jdbc.victor.model.PriorityDetail cannot be cast to java.lang.String
    at br.com.jdbc.victor.view.FormNewCall.btSubmitActionPerformed(FormNewCall.java:349)
    at br.com.jdbc.victor.view.FormNewCall.access$500(FormNewCall.java:30)
    at br.com.jdbc.victor.view.FormNewCall$6.actionPerformed(FormNewCall.java:151)
    at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:2022)
    at javax.swing.AbstractButton$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:6533)
    at javax.swing.JComponent.processMouseEvent(JComponent.java:3324)
    at java.awt.Component.processEvent(Component.java:6298)
    at java.awt.Container.processEvent(Container.java:2236)
    at java.awt.Component.dispatchEventImpl(Component.java:4889)
    at java.awt.Container.dispatchEventImpl(Container.java:2294)
    at java.awt.Component.dispatchEvent(Component.java:4711)
    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:2746)
    at java.awt.Component.dispatchEvent(Component.java:4711)
    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.pumpEventsForFilter(EventDispatchThread.java:109)
    at java.awt.WaitDispatchSupport$2.run(WaitDispatchSupport.java:184)
    at java.awt.WaitDispatchSupport$4.run(WaitDispatchSupport.java:229)
    at java.awt.WaitDispatchSupport$4.run(WaitDispatchSupport.java:227)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.awt.WaitDispatchSupport.enter(WaitDispatchSupport.java:227)
    at java.awt.Dialog.show(Dialog.java:1084)
    at java.awt.Component.show(Component.java:1671)
    at java.awt.Component.setVisible(Component.java:1623)
    at java.awt.Window.setVisible(Window.java:1014)
    at java.awt.Dialog.setVisible(Dialog.java:1005)
    at br.com.jdbc.victor.view.FormNewCall.lambda$main$0(FormNewCall.java:495)
    at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:311)
    at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:756)
    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.awt.EventQueue.dispatchEvent(EventQueue.java:726)
    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)

在这两行下:

private void btSubmitActionPerformed(java.awt.event.ActionEvent evt) {                                           
        try {                                           
            Call call = new Call();
            MySQLDaoManager man = new MySQLDaoManager("root", "", "localhost", "attendances", 3306);  
            java.util.Date date_util = new java.util.Date();
            java.sql.Date date_sql = new java.sql.Date(date_util.getDate());
            java.sql.Time time_sql = new java.sql.Time(date_util.getTime());

            try {
                //ClassCastException at this line above 
                call.setPriority((String) cbPriorityDetail.getSelectedItem());
                //this one is giving SQL Error and it's flagged by the Catch block of the code
                call.setPriorityDetail(Long.parseLong(tfIdPriorityDetail.getText()));
                call.setInitialDate(date_sql);
                call.setInitialTime(time_sql);
                call.setFinalTime(time_sql);

                man.getCallDAO().insert(call);

                if(tfCallId.getText().length() != 0){
                     call.setCallId(Long.parseLong(tfCallId.getText()));
                     man.getCallDAO().update(call);
                }
                if(tfInitialDate.getValue() != null && tfInitialTime.getValue() != null && tfFinalTime.getValue() != null){
                    JOptionPane.showMessageDialog(rootPane, "Inserted User sucessful!!", "Done", JOptionPane.INFORMATION_MESSAGE);
                    btNewActionPerformed(evt);
                } else {
                    JOptionPane.showMessageDialog(rootPane, "Please fill the fields again", "Isn't possible to insert data", JOptionPane.INFORMATION_MESSAGE);
                    btNewActionPerformed(evt);
                }
            } catch (DAOException ex) {
                JOptionPane.showMessageDialog(rootPane, "MySQL Error", "Error", JOptionPane.ERROR_MESSAGE);
            }
        } catch (SQLException ex) {
            JOptionPane.showMessageDialog(rootPane, "Error to get connection", "Error", JOptionPane.ERROR_MESSAGE);
        }
    }

此表单的工作方式如下:您在 JComboBox cbPriorityDetail 中选择高、中或低之间的一项，然后 tfIdPriorityDetail 获取根据选定的优先级(我已经做了一个函数，它工作正常)并填写接下来的三个字段:初始日期、初始时间和最终时间...如果我注释掉这两行有错误的内容并提交其余部分，效果很好。 我需要帮助了解我的代码出了什么问题？!我无法在 Calls 表中插入选定的组合项和生成的 id，我总是遇到这些错误，非常感谢!

Answer 1

您的组合框似乎管理“PriorityDetail”对象，而不是字符串。您应该将选定的对象转换为“PriorityDetail”，然后从中获取所需的数据。

PriorityDetail pd = (PriorityDetail) cbPriorityDetail.getSelectedItem();
call.setPriority(pd.getTheStringThatYouNeedFromYourModel());

希望有帮助。