JSP Chinese garbage problem

<% request.setCharacterEncoding ("gb2312");%>

add student information

enter Student ID :

enter your name :

enter gender : male
female

<%

String stuno = request.getParameter ("stuno");
/ / stuno = new String (stuno.getBytes ("ISO-8859-1"), " gb2312 ");
String stuname = request.getParameter ("stuname");
/ / stuname = new String (stuname.getBytes ("ISO-8859-1"), " gb2312 ");
String stusex = request.getParameter ("sex");
/ / stusex = new String (stusex.getBytes ("ISO-8859-1"), " gb2312 ");


if (stuno! = null) {
Class.forName ("com.mysql.jdbc.Driver" ) ;
Connection conn = DriverManager.getConnection ("jdbc : mysql :/ / localhost: 3306/school "," root "," mysqladmin ");
PreparedStatement ps = null;
ResultSet rs = null;
String sql = "select stuno from t_student where stuno =? ";
ps = conn.prepareStatement (sql);
ps.setString (1, stuno);
rs = ps.executeQuery ();
if (rs.next ()) {
out.println ( "I'm sorry , student number exists ! " ) ;
}
else {
sql = "insert into t_student (stuno, stuname, stusex) values ​​(?,?,?) ";
ps = conn.prepareStatement (sql);
ps.setString (1, stuno);
ps.setString (2, stuname);
ps.setString (3, stusex);
ps.executeUpdate ();
out.println (" Successfully added ! " ) ;
}
ps.close ();
conn.close ();
}

%>