java。学生休息管理系统。Mysql

(删除);
ph.add(显示);
file=new File("学生信息.txt");
学生散列表=new Hashtable();
if(!file.exists()){
try{
FileOutputStream out=new FileOutputStream(file);
ObjectOutputStream objectOut=new ObjectOutputStream(out);
objectOut.writeObject(学生散列表);
objectOut.close();
out.close();
}
catch(IOException e){}
}
Container con=getContentPane();
con.setLayout(new BorderLayout());
con.add(lb, BorderLayout.NORTH);
con.add(pv, BorderLayout.CENTER);
con.add(ph, BorderLayout.SOUTH);
setDefaultCloseOperation(EXIT_ON_CLOSE);
setBounds(100,100,600,300);
setVisible(true);
Statement stmt;
ResultSet rs;
}
public static void main(String[] args) {StudentManager ff=new StudentManager();}


public class InputAct implements ActionListener{
public void actionPerformed(ActionEvent e){
修改.setEnabled(false);
String number="";
number=学号.getText();
if(number.length()>0){

if(学生散列表.containsKey(number)){
String warning="该生信息已存在，请到修改页面修改！";
JOptionPane.showMessageDialog(null,warning,"警告",
JOptionPane.WARNING_MESSAGE);
}//end if1
else{

String m="该生信息将被录入！";
int ok=JOptionPane.showConfirmDialog(null,m,"确认",
JOptionPane.YES_NO_OPTION,JOptionPane.INFORMATION_MESSAGE);
if(ok==JOptionPane.YES_OPTION)
{
try
{
Class.forName("org.gjt.mm.mysql.Driver");
}
catch(java.lang.ClassNotFoundException e11)
{
System.out.println("Class not found exception occir.Message is:");
System.out.println(e11.getMessage());
}
try
{
PreparedStatement prepstmt1;
Statement stmt;
ResultSet rs;
String url = "jdbc:mysql://localhost/test?user=root&password=0&useUnicode=true&&characterEncoding=8859_1";
String user="root";
String password="0";
Connection conn=null;
try
{
conn=DriverManager.getConnection(u

rl,user,password);
}
catch(Exception ex)
{
ex.printStackTrace();
}
//对制定的数据库添加信息
String sql1="INSERT INTO students(student_id,name,s