Java DefaultTableModel nullpointerexception
我有一个nullpointerexception,问题来自defaulttablemodel选项卡1,有人知道问题是什么吗Java DefaultTableModel nullpointerexception,java,swing,nullpointerexception,jtable,defaulttablemodel,Java,Swing,Nullpointerexception,Jtable,Defaulttablemodel,我有一个nullpointerexception,问题来自defaulttablemodel选项卡1,有人知道问题是什么吗 package tafel.van.pkg7; import javax.swing.*; public class TafelVan7 extends JFrame { public static void main(String[] args) { JFrame frame = new TafelVan7(); frame.se
package tafel.van.pkg7;
import javax.swing.*;
public class TafelVan7 extends JFrame {
public static void main(String[] args) {
JFrame frame = new TafelVan7();
frame.setSize( 500,800);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setTitle ("quizvragen");
frame.setContentPane( new paneel());
frame.setVisible( true );
}
}
Panel这是一个带有数组和表的面板,该行被添加到for循环中
package tafel.van.pkg7;
import java.awt.Color;
import javax.swing.*;
import javax.swing.table.*;
class paneel extends JPanel {
public static JTable tabel;
public JScrollPane scroll;
static int product = 7;
int uitkomst;
public paneel(){
Object[] Kolom = {"7", "tafel van 7"};
TableModel model = new DefaultTableModel(Kolom,0);
DefaultTableModel tabel1 = (DefaultTableModel) tabel.getModel();
tabel = new JTable(model);
JTableHeader hoofd = tabel.getTableHeader();
hoofd.setBackground(Color.BLACK);
hoofd.setForeground(Color.WHITE);
scroll = new JScrollPane(tabel);
tabel.setFocusable(false);
tabel.setRowSelectionAllowed(false);
this.add(scroll);
int row = 1;
for(int x=1; x<=100;x++){
Integer[] product = new Integer[2];
product[0]= x;
product[1]= x*7;
tabel1.addRow(product);
完全错误
run:
Exception in thread "main" java.lang.NullPointerException
at tafel.van.pkg7.paneel.<init>(paneel.java:19)
at tafel.van.pkg7.TafelVan7.main(TafelVan7.java:12)
Java Result: 1
BUILD SUCCESSFUL (total time: 1 second)
我发现了错误,defaulttablemodel放错地方了 应该是这样的: 面板的一部分
scroll = new JScrollPane(tabel);
tabel.setFocusable(false);
tabel.setRowSelectionAllowed(false);
this.add(scroll);
DefaultTableModel tabel1 = (DefaultTableModel) tabel.getModel();
int row = 1;
for(int x=1; x<=100;x++){
Integer[] product = new Integer[2];
product[0]= x;
product[1]= x*7;
tabel1.addRow(product);
请发布异常堆栈跟踪。很可能您有一个未初始化的组件。