How to stop Java from running the entire code with

2019-01-15 20:44发布

问题:

Im fairly new to Java and im just looking for a little help
Im trying to create a program which allows the user to enter as a gui the name and> >location of a department store. It allows this but the program does not wait for the >details to be entered it just initializes the Gui class and simply continues on with the >processing Which is to add the details entered into the Gui into an array list. But the >details have not yet been entered yet so it is creating a null value because it has jumped >ahead.

So how can I make it stop and wait till the values have been entered and then submitted?

Here is the Gui component of the code:

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.util.*;

public class guiDepartment extends JFrame
{



    private String  depName;
    private String  depLocation;
    private static Department newDepartment;
    private JTextField departmentDetails1;
    private JTextField departmentDetails2;
    private JTextField departmentDetails3;


    private Employee worksInInTheDepartment;


    public guiDepartment()
    {
        System.out.println("bob the builder ");

        JButton submit;
        JButton b1;


        JFrame frame = new JFrame();

        departmentDetails1 = new JTextField(10);


        departmentDetails2 = new JTextField(10);


        departmentDetails3 = new JTextField(10);


        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setSize(new Dimension(320, 75));
        frame.setTitle("Department Details");

        frame.setLayout(new FlowLayout());

        frame.add(new JLabel("Please enter department Name: "));
        frame.add(departmentDetails1);
        ButtonListenerDepName dListener = new ButtonListenerDepName();
        System.out.println(depName);

        frame.add(new JLabel("Please enter department location: "));
        frame.add(departmentDetails2);
        ButtonListenerDepName1 dListener1 = new ButtonListenerDepName1(); 




        b1  = new JButton  ("Submit");

        ButtonListener listener = new ButtonListener();
        b1.addActionListener(listener);
        b1.addActionListener(dListener);
        b1.addActionListener(dListener1);
        frame.add(b1);
        frame.pack();
        frame.setSize(300,300);
        frame.setVisible(true);



    }

    public class ButtonListenerDepName implements ActionListener
    {
        public void actionPerformed (ActionEvent e )
        {
            depName = departmentDetails1.getText(); 
            System.out.println("and This is the departments name :"+ depName);      
        } 
    }

    public class ButtonListenerDepName1 implements ActionListener
    {
        public void actionPerformed (ActionEvent e )
        {
            depLocation = departmentDetails2.getText(); 
            System.out.println("and This is the departments location :"+ depLocation);  
        } 
    }


    public class ButtonListener implements ActionListener
    {
        public void actionPerformed (ActionEvent e )
        {
            //create a new department and then adds it to thee system
            newDepartment = new Department(depName, depLocation);
        } 
    }

    public static Department getDepartment()
    {
        return newDepartment;
    }
}

>>and this is the Main class

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.util.*;



public class MainWelcomeGui1 
{

        JFrame frame = new JFrame();

        JButton b1  ;   
        JButton b2  ; 
        JButton b3  ; 
        JButton b4  ;
        JButton b5  ;
        JButton b6  ;
        JButton b7  ;
        JButton b8  ;
        JButton b9  ;
        JButton b10 ;
        JButton b11 ;
        JButton b12 ;

        private String  fName;
        private String  sName;
        private String  gender;
        private String  pLevel;
        private String  empIDnumber;
        private int     dPayLevel;

        private static  ArrayList<Employee> allEmployees = new ArrayList<Employee>(); 
        private static  ArrayList<Department> allDepartments = new ArrayList<Department>(); 




    public MainWelcomeGui1()
    {
        frame.setTitle("Human Resources allocation screen");


        JLabel  hdr = new JLabel ("Welcome to the Human Resources employee control system");


         b1  = new JButton  ("Add a new department");
         ButtonListener listener = new ButtonListener();
         b1.addActionListener(listener);
        // addDepartmentToSystem();

         b2  = new JButton  ("Add a new employee to the system");
         ButtonListener listener1 = new ButtonListener();
         b2.addActionListener(listener1);

         b3  = new JButton  ("Alter a employees details");
         ButtonListener listener2 = new ButtonListener();
         b3.addActionListener(listener2);

         b4  = new JButton  ("Add a employee to a department of my choice");
         ButtonListener listener3 = new ButtonListener();
         b4.addActionListener(listener3);

         b5  = new JButton  ("Assign a employee to a department");
         b6  = new JButton  ("Designate a employee as department head");
         b7  = new JButton  ("Delete a department");
         b8  = new JButton  ("To delete an employee from the system");
         b9  = new JButton  ("To see a list of all employees assigned to a particular department");
         b10 = new JButton  ("To see the amounts needed to be paid fortnightly");
         b11 = new JButton  ("To chane an employees pay level");
         b12 = new JButton  ("To change an employees name");
        frame.setLayout (new GridLayout (6, 6));

        frame.setBackground  (Color.green);


        frame.add(hdr,BorderLayout.NORTH);

        frame.add (b1);
        frame.add (b2);
        frame.add (b3);
        frame.add (b4);
        frame.add (b5);
        frame.add (b6);
        frame.add (b7);
        frame.add (b8);
        frame.add (b9);
        frame.add (b10);
        frame.add (b11);
        frame.add (b12);


        frame.setSize(400, 100);
        frame.pack();
        frame.setVisible(true);
    }

    public static void main(String[] args)
    {
        new MainWelcomeGui1();

    }

    private class ButtonListener implements ActionListener
    {
        public void actionPerformed (ActionEvent e )
        {
            if (e.getSource() == b1)
            {
                guiDepartment guiDepartment = new guiDepartment();
                System.out.println("i should really come after bob the builder");
                addDepartmentToSystem();    
            } 
            else if (e.getSource() == b2)  
            {   
                guiEmployee1 theGuiEmployee = new guiEmployee1();   
            }
            else if (e.getSource() == b3)
            {
                System.out.println("hello1 button 2");
            }
            else if (e.getSource() == b4)
            {
                System.out.println("hello button 3");
            }   
                else if (e.getSource() == b5)  
            {   
                guiEmployee1 theGuiEmployee = new guiEmployee1();   
            }
            else if (e.getSource() == b6)
            {
                System.out.println("hello1 button 2");
            }
            else if (e.getSource() == b7)
            {
                System.out.println("hello button 3");
            }   


        } 
    }

    public  void addDepartmentToSystem()
    {

        Department departmentToAdd = new Department("berel","sam") ; 

        System.out.println("to two");

        System.out.println(departmentToAdd);

        departmentToAdd = guiDepartment.getDepartment();

        System.out.println("got to three");

        allDepartments.add(departmentToAdd);

        System.out.println("to four+");

        System.out.println(allDepartments);
    }

}

回答1:

You shouldn't have a JFrame launching other JFrames, especially if you want the child windows to behave as a modal dialogs -- a dialog that halts the code in the launching window until it has been fully dealt with. When this is the case, make the dialog windows dialogs by using modal JDialogs in place of JFrames for the dialog windows.

For example:

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class MainWelcomeGui2 {
   public static void main(String[] args) {
      final JFrame frame = new JFrame("Main GUI");

      JButton addDeptButtonLaunchJFrame = new JButton(
            "Add a New Department, Launch JFrame");
      JButton addDeptButtonLaunchJDialog = new JButton(
            "Add a New Department, Launch JDialog");

      addDeptButtonLaunchJDialog.addActionListener(new LaunchJDialogListener(
            frame));
      addDeptButtonLaunchJFrame.addActionListener(new LaunchJFrameListener());

      JPanel panel = new JPanel();
      panel.add(addDeptButtonLaunchJDialog);
      panel.add(addDeptButtonLaunchJFrame);

      frame.add(panel);
      frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
      frame.pack();
      frame.setLocationRelativeTo(null);
      frame.setVisible(true);

   }
}

class LaunchJDialogListener implements ActionListener {
   JDialog dialog;

   public LaunchJDialogListener(JFrame parentFrame) {
      JButton doneButton = new JButton(new AbstractAction("Done") {
         public void actionPerformed(ActionEvent e) {
            dialog.dispose();
         }
      });

      JPanel panel = new JPanel();
      panel.setPreferredSize(new Dimension(100, 100));
      panel.add(doneButton);

      dialog = new JDialog(parentFrame, "Dialog", true);
      dialog.add(panel);
      dialog.pack();
      dialog.setLocationRelativeTo(null);
   }

   @Override
   public void actionPerformed(ActionEvent e) {
      System.out.println("called before setting dialog visible");
      dialog.setVisible(true);
      System.out
            .println("called after setting dialog visible. Note that this line doesn't show until the dialog disappears");
   }
}

class LaunchJFrameListener implements ActionListener {
   JFrame frame;

   public LaunchJFrameListener() {
      JButton doneButton = new JButton(new AbstractAction("Done") {
         public void actionPerformed(ActionEvent e) {
            frame.dispose();
         }
      });

      JPanel panel = new JPanel();
      panel.setPreferredSize(new Dimension(100, 100));
      panel.add(doneButton);

      frame = new JFrame("JFrame");
      frame.add(panel);
      frame.pack();
      frame.setLocationRelativeTo(null);
   }

   @Override
   public void actionPerformed(ActionEvent e) {
      System.out.println("called before setting frame visible");
      frame.setVisible(true);
      System.out
            .println("called after setting frame visible.  Note that this line shows up immediately.");
   }
}