Java 中以DataGrid形式显示数据库查询结果和相关JTable操作程序

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.sql.*;
import java.util.*;
import javax.swing.table.*;
class QuerySystem extends JFrame{
 Vector vect=new Vector();
 String title[]={"num","name","birth","school"};
 // 继承AbstractTableModel
 AbstractTableModel tm=new AbstractTableModel(){
   public int getColumnCount(){
    return title.length;
   }
   public int getRowCount(){
    return vect.size();
   }
   public Object getValueAt(int row,int column){
    if(!vect.isEmpty())
     return ((Vector)vect.get(row)).get(column);
    else
     return null;
   }
   public String getColumnName(int column){
    return title[column];
   }
   public void setValueAt(Object value,int row,int column){}
   public boolean isCellEditable(int row,int column){
    return false;
   }
   };
 JTable jt=new JTable(tm);
 JScrollPane jsp=new JScrollPane(jt);
 public QuerySystem()throws SQLException,ClassNotFoundException{
  
   Connection c=connect();
   Statement s=c.createStatement();
   String sql="select * from student";
   ResultSet r=s.executeQuery(sql);
   showResult(r);
  
   //设置table内的单行选定（JTable利用的是ListSelectionModel)
   jt.getSelectionModel().setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
  
   //添加表格（选定行）的双击左键事件
   jt.addMouseListener(new MouseAdapter(){
    public void mouseClicked(MouseEvent e){
     if(e.getClickCount()==2){  //鼠标双击  
      //以下三句为：双击删除选定行
      int row=jt.getSelectedRow();
      vect.removeElementAt(row);
      tm.fireTableStructureChanged();
      
     }
    }
   });
   this.getContentPane().add(jsp,BorderLayout.CENTER);
 }
 //连接数据库方法 返回类型为 Connection
 public Connection connect()throws SQLException,ClassNotFoundException{
  String dburl="jdbc:odbc:driver={Microsoft Access Driver (*.mdb)};DBQ=da/student.mdb"; //数据库字段为：文本，文本，日期，文本
  String user="";
  String password="";
  Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
  Connection c=DriverManager.getConnection(dburl,user,password);
  return c;
 }
 //以DataGrid 样式显示数据库中的查询结果
 public void showResult(ResultSet rs)throws SQLException{
  vect.removeAllElements();
  tm.fireTableStructureChanged();
  while(rs.next()){
   Vector rec_vector=new Vector();
   rec_vector.addElement(rs.getString(1));
   rec_vector.addElement(rs.getString(2));
   rec_vector.addElement(rs.getDate(3));
   rec_vector.addElement(rs.getString(4));
   vect.addElement(rec_vector);
  }
 tm.fireTableStructureChanged();
 }
 
 
 public s
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tatic void main(String[]args)throws SQLException,ClassNotFoundException{
  QuerySystem fm=new QuerySystem();
  fm.setSize(600,400);
  fm.setTitle("");
 }
}