大家帮我看看这段代码为什么加载驱动失败
import java.awt.*; //导入java.awt包的所有类
import java.awt.event.*; //导入java.awt.event包的所有类
import javax.swing.*; //导入javax.swing包的所有类
import java.util.Random;
import java.sql.*;
public class shuxue extends JFrame {
JFrame fs;
JLabel
xTiMuLb,xXuanXiangLb;
JButton jiaojuanBT;
MenuBar kemuxuanzheJB;
Menu kemuxuanzheJM;
MenuItem
shuxueJI,yuwenJI;
CheckboxGroup[] xGroup=new CheckboxGroup[100];
Checkbox[] choiceA=new Checkbox[100];
Checkbox[] choiceB=new Checkbox[100];
Checkbox[] choiceC=new Checkbox[100];
Checkbox[] choiceD=new Checkbox[100];
String[] xDA=new String[100];
String[] xz=new String[100];
int[] xChouTi=new int[100];
public shuxue(){
fs=new JFrame("数学考试界面");
fs.setSize(400,400);
fs.setLocation(200,150);
fs.setLayout(null);
fs.setVisible(true);
jiaojuanBT=new JButton("交卷");
jiaojuanBT.setBounds(200,0,100,30);
fs.add(jiaojuanBT);
Random rx=new Random();
String driver="com.mysql.jdbc.Driver";
String connStr="jdbc:mysql://localhost:3306/xuesheng?user=root&password=01083686859";
Connection conn=null;
try
{
Class cl=Class.forName(driver);
conn = DriverManager.getConnection(connStr);
Statement stm=conn.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE,ResultSet.CONCUR_READ_ONLY);
ResultSet rst=stm.executeQuery("SELECT * from math");
int xRowNumber=0;
for(int i=0;i<5;i++)
{
xChouTi[i]=rx.nextInt(xRowNumber)+1;
rst.absolute(xChouTi[i]);
String tihao=rst.getString(1);
String timu=rst.getString(2);
String a=rst.getString(3);
String b=rst.getString(4);
String c=rst.getString(5);
String d=rst.getString(6);
xDA[i]=rst.getString(7).trim();
xTiMuLb=new JLabel();
xTiMuLb.setAlignmentX(Label.LEFT);
xTiMuLb.setText((i+1)+"、"+timu);
xTiMuLb.setBounds(20,60+i*40,500,20);
fs.add(xTiMuLb);
xXuanXiangLb=new JLabel();
xXuanXiangLb.setAlignmentX(Label.LEFT);
xXuanXiangLb.setText("A."+a+" B."+b+" C."+c+" D."+d);
xXuanXiangLb.setBounds(20,80+i*40,700,20);
fs.add(xXuanXiangLb);
xGroup[i]=new CheckboxGroup();
choiceA[i]=new Checkbox("A",xGroup[i],false);
choiceB[i]=new Checkbox("B",xGroup[i],false);
choiceC[i]=new Checkbox("C",xGroup[i],false);
choiceD[i]=new Checkbox("D",xGroup[i],false);
choiceA[i].setBounds(550,60+i*40,40,20);
choiceB[i].setBounds(600,60+i*40,40,20);
choiceC[i].setBounds(650,60+i*40,40,20);
choiceD[i].setBounds(700,60+i*40,40,20);
fs.add(choiceA[i]);
fs.add(choiceB[i]);
fs.add(choiceC[i]);
fs.add(choiceD[i]);
}
for(int j=0;j<5;j++)
{
if(xGroup[j].getSelectedCheckbox()==choiceA[j])
{
xz[j]="A";
}
if(xGroup[j].getSelectedCheckbox()==choiceB[j])
{
xz[j]="B";
}
if(xGroup[j].getSelectedCheckbox()==choiceC[j])
{
xz[j]="C";
}
if(xGroup[j].getSelectedCheckbox()==choiceD[j])
{
xz[j]="D";
}
if(xGroup[j].getSelectedCheckbox()==null)
{
xz[j]="E";
}
}
conn.close();
}
catch(SQLException ee)
{
System.out.println("数据库加载失败");
ee.printStackTrace();
}
catch(Exception ee)
{
System.out.println("驱动程序加载失败:"+driver);
ee.printStackTrace();
}
}
public static void main(String args[])
{
new shuxue();
}
}