为什么没有表头?

Question

代码如下:package com.webmonitor;import java.awt.BorderLayout;
import java.awt.Dimension;import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTable;public class WebMonitor extends JFrame {
    JPanel contentPane;
    BorderLayout borderLayout1 = new BorderLayout();
    String[] columnNames = {"URL","网站名称","Price"};
    Object[][] data =
            {
            {"http://www.google.com", new Integer(5),"5.00"},
            {"http://www.chinaip.net", new Integer(3),"6.00"},
            {"http://www.officebill.net", new Integer(2),"4.00"},
            {"Grapes", new Integer(3),"2.00"},
        };
    JTable jTable1 = new JTable(data,columnNames);    public WebMonitor() {
        try {
            setDefaultCloseOperation(EXIT_ON_CLOSE);
            jbInit();
        } catch (Exception exception) {
            exception.printStackTrace();
        }
    }    private void jbInit() throws Exception {
        contentPane = (JPanel) getContentPane();
        contentPane.setLayout(borderLayout1);
        setTitle("网站监控(WebMonitor) v1.0");
        jTable1.setSize(new Dimension(300, 80));
//        jTable1.setPreferredScrollableViewportSize(new Dimension(300, 80));
        setSize(new Dimension(400, 300));
        this.show();
        contentPane.add(jTable1, java.awt.BorderLayout.CENTER);
    }
    public static void main(String args[])
    {
        new WebMonitor();
    }
}
为什么没有表头?

Answer 1

先把jtable放到JScrollPane就有表头了。