DefaultTableModel，标题不会显示。 我怎样才能解决这个问题？

Question

这是我的学生小组的开始。 我试过将JScrollPanes添加到它中，从我读过的内容来看，应该可以使它工作，但它根本不会显示标题。 我可能会错误地添加它们，但我目前还不确定。 任何帮助将不胜感激。 谢谢！

    //Start of student panel
    JPanel stuPanel = new JPanel();
    tabbedPane.addTab("Student", stuPanel);
    JButton stuButton = new JButton("Add Student");
    Object[] stuColumnNames = {"First Name", "Last Name", "Major", "Minor", "GPA"};

    JTable stuTable = new JTable(new DefaultTableModel(data, stuColumnNames)){
        /**
         * 
         */
        private static final long serialVersionUID = 1L;
        //Making it so the cells I want are editable.
        @Override
        public boolean isCellEditable(int row, int column) {
            if (column == 0){
                return false;
            }
            else    
                return true;
        }
    };


    DefaultTableModel stuModel = (DefaultTableModel)stuTable.getModel();
    for(Student tmpS : stuList){
        stuModel.addRow(new Object[]{tmpS.getFirstName(),tmpS.getLastName(), tmpS.getMajor(), tmpS.getMinor(), tmpS.getGpa()});
    }

    stuButton.addActionListener(new ActionListener() {
        public void actionPerformed(ActionEvent arg0) {
            String fName,lName,major,minor;
            float gpa;
            System.out.println("Please enter a first name:");
            fName = in.nextLine();
            System.out.println("Please enter a last name:");
            lName = in.nextLine();
            System.out.println("Please enter a major:");
            major = in.nextLine();
            System.out.println("Please enter a minor:");
            minor = in.nextLine();
            System.out.println("Please enter a GPA:");
            gpa = in.nextFloat();
            in.nextLine();
            stuList.add(new Student(fName, lName, major, minor, gpa));
            stuModel.addRow(new Object[]{fName, lName, major, minor, gpa});
            stuModel.fireTableDataChanged();
        }
    });

    GroupLayout gl_stuPanel = new GroupLayout(stuPanel);
    gl_stuPanel.setHorizontalGroup(
        gl_stuPanel.createParallelGroup(Alignment.LEADING)
            .addGroup(gl_stuPanel.createSequentialGroup()
                .addGroup(gl_stuPanel.createParallelGroup(Alignment.LEADING)
                    .addGroup(gl_stuPanel.createSequentialGroup()
                        .addGap(155)
                        .addComponent(stuButton))
                    .addGroup(gl_stuPanel.createSequentialGroup()
                        .addContainerGap()
                        .addComponent(stuTable, GroupLayout.PREFERRED_SIZE, 408, GroupLayout.PREFERRED_SIZE)))
                .addContainerGap(GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))
    );
    gl_stuPanel.setVerticalGroup(
        gl_stuPanel.createParallelGroup(Alignment.LEADING)
            .addGroup(gl_stuPanel.createSequentialGroup()
                .addContainerGap()
                .addComponent(stuButton)
                .addPreferredGap(ComponentPlacement.RELATED, 11, Short.MAX_VALUE)
                .addComponent(stuTable, GroupLayout.PREFERRED_SIZE, 178, GroupLayout.PREFERRED_SIZE))
    );
    stuPanel.setLayout(gl_stuPanel);
    //End of student panel

Answer 1

首先看一下如何使用表格和如何使用滚动窗格

JTable列标题显示在JScrollPane的标题部分中

您需要将JTable包装在JScrollPane ，类似...

JScrollPane scrollPane = new JScrollPane(stuTable);
gl_stuPanel.setVerticalGroup(
    gl_stuPanel.createParallelGroup(Alignment.LEADING)
        .addGroup(gl_stuPanel.createSequentialGroup()
            .addContainerGap()
            .addComponent(scrollPane)
            .addPreferredGap(ComponentPlacement.RELATED, 11, Short.MAX_VALUE)
            .addComponent(scrollPane, GroupLayout.PREFERRED_SIZE, 178, GroupLayout.PREFERRED_SIZE))
);

例如