java 数据库stmt.executeUpdate(sql);发生异常

[u010668116]

代码如下：
<%
request.setCharacterEncoding("GBK");
String geming=request.getParameter("歌名");
String geshou=request.getParameter("歌手");
String djl=request.getParameter("单击率");
Class.forName("com.mysql.jdbc.Driver");
Connection con=DriverManager.getConnection("jdbc:mysql://localhost:3306/music","root","root");
Statement stmt=con.createStatement();
String sql="insert into musicinfo(musicname,singer,hint) values('"+geming+"','"+geshou+"',"+djl+")";
int i=stmt.executeUpdate(sql);
if(i==1){
out.println("<script language='javaScript'> alert('添加成功，单击确定跳转到主页!');</script>");
response.setHeader("refresh","1;url=index.jsp");
}else{
out.println("<script language='javaScript'>alert('添加失败，单击确定返回添加页面!');</script>");
response.setHeader("refresh","1;url=add.jsp");
}
stmt.close();
con.close();
%>