更正下,上面的程序有问题。应该是这样的(真是抱歉哦)
Connection conn=null;
Statement st=null;   try{
        Class.forName("org.gjt.mm.mysql.Driver");
conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/test","root","");                            
st   = conn.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE,
                                      ResultSet.CONCUR_UPDATABLE);  //改了这里ResultSet rs=st.executeQuery("select * from userinfo");
if(rs.next()){
    rs.moveToInsertRow();
    rs.updateString(1, "d");         
    rs.updateString(2,"m");
    rs.updateString(3,"m"); 
    rs.insertRow();
    rs.moveToCurrentRow();
}
}catch(Exception e){
   e.printStackTrace();
}