java访问sql数据库问题。。
import java.awt.*;import java.awt.event.*;
import java.sql.*;
public class DBApplication extends Frame implements ActionListener
{
Connection con;
Statement stmt;
ResultSet rs;
Button Query,Update,Delete,increase,show,exit;
TextField T1,T2;
Label L1,L2;
String bookname,booknum;
String str1,str2;
Panel p1,p2;
public DBApplication() {
super("简单数据库应用程序");
Query=new Button("查询");
Update=new Button("更新");
Delete=new Button("删除");
increase=new Button("添加");
show=new Button("显示");
exit=new Button("退出");
T1=new TextField();
T2=new TextField();
T1.setBackground(Color.GREEN);
T2.setBackground(Color.GREEN);
L1=new Label("图书号");
L2=new Label("书名");
p1=new Panel();
p2=new Panel();
p1.setLayout(new GridLayout(2,2,40,10));
p2.setLayout(new GridLayout(2,3,40,10));
this.setLayout(new GridLayout(2,1));
p1.add(L1);
p1.add(T1);
p1.add(L2);
p1.add(T2);
p2.add(show);
p2.add(Query);
p2.add(Update);
p2.add(Delete);
p2.add(increase);
p2.add(exit);
this.add(p1);
this.add(p2);
Query.addActionListener(this);
Update.addActionListener(this);
increase.addActionListener(this);
Delete.addActionListener(this);
show.addActionListener(this);
exit.addActionListener(this);
pack();
this.setBackground(Color.BLUE);
this.setVisible(true);
try
{
Class.forName("com.microsoft.jdbc.sqlserver.SQLServerDriver").newInstance();
con=DriverManager.getConnection("jdbc:sqlserver://lyb-PC:1433;DatabaseName=LIB_M","","");
stmt=con.createStatement();
}
catch(Exception e){}
}
public void actionPerformed(ActionEvent e)
{
if(e.getSource()==show)
{
try
{
rs=stmt.executeQuery("select 图书号,书名 from bookdata");
while(rs.next())
{
bookname=rs.getString("书名");
booknum =rs.getString("图书号");
T1.setText(booknum);
T2.setText(bookname);
}
System.out.println("已访问完");
rs.close();
}
catch(Exception e1){}
}
if(e.getSource()==Query)
{
try{
int flag;
rs=stmt.executeQuery("select 图书号,书名 from bookdata");
while(rs.next())
{
bookname=rs.getString("书名");
booknum =rs.getString("图书号");
T1.setText(booknum);
T2.setText(bookname);
}
}
catch(Exception e2){}
}
if(e.getSource()==Update)
{
try{
str1=T1.getText().trim();
str2=T2.getText().trim();
String strupd="update bookdata set 图书号='"+str1+" 'where 书名='"+str2+"'";
stmt.executeUpdate(strupd);
}
catch(Exception e3){}
}
if(e.getSource()==increase)
{
try{
str1=T1.getText();
str2=T2.getText();
String strinc="insert into bookdata(图书号,书名) values(str1,str2)";
stmt.executeUpdate(strinc);
}
catch(Exception e4){}
}
if(e.getSource()==Delete)
{
try
{
str1=T1.getText();
String strdel="delete * from bookdata where 图书号=str1";
stmt.executeUpdate(strdel);
}
catch(Exception e5){}
}
if(e.getSource()==exit)
{
try
{
rs.close();
stmt.close();
con.close();
}
catch(Exception e6){}
System.exit(0);
}
}
public static void main(String[] args)
{
new DBApplication();
}
}