protected  int autoResizeMode 
          确定表是否自动调整列的宽度以占用表的整个宽度，以及如何进行调整。

------解决方案--------------------
用布局管理器,不知道是不是这个意思

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

public class Frame1 extends JFrame  
{
 JScrollPane jScrollPane1 = new JScrollPane();
 JTable table1 = new JTable();
 GridBagLayout gridBagLayout1 = new GridBagLayout();
 Object[] tableheader =new Object[]{"column1","column1","column1","column1","column1"};
 javax.swing.table.DefaultTableModel  model = new javax.swing.table.DefaultTableModel();
 public Frame1()  
 {
   try  
   {
     jbInit();
     model.setColumnIdentifiers(tableheader);
     table1.setModel(model);
   }
   catch(Exception ex) {
     ex.printStackTrace();
   }
 }

 void jbInit() throws Exception  
 {
   this.getContentPane().setLayout(gridBagLayout1);
   this.setLocale(java.util.Locale.getDefault());
   this.getContentPane().add(jScrollPane1,  new GridBagConstraints(0, 0, 1, 1, 1.0, 1.0
           ,GridBagConstraints.CENTER, GridBagConstraints.BOTH, new Insets(35, 57, 138, 79), -67, -264));
   jScrollPane1.getViewport().add(table1, null);
 }
 public static void main(String arg[])
 {
    Frame1 frame = new Frame1();
    frame.setSize(100,100);
    frame.show();
 }
}