ajax+mysql

public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {

response.setContentType("text/html；charset=utf-8");
response.setCharacterEncoding("utf-8");

PrintWriter out = response.getWriter();
request.setCharacterEncoding("utf-8");
String id=request.getParameter("username");
String password=request.getParameter("password");

out.println("id = " +id);

//Servlet操作数据库和普通java类一样

Connection ct= null;
PreparedStatement ps =null;
ResultSet rs = null;
try {
//1.加载驱动
Class.forName("com.mysql.jdbc.Driver");
//2.得到连接
ct = DriverManager.getConnection("jdbc:mysql://localhost:3306/work", "root", "1");
//3.创建PreparedStatment 用于传送sql查询语句
ps=(PreparedStatement) ct.prepareStatement("select * from users where id =? and password=?");
//给？赋值
ps.setObject(1, id);
ps.setObject(2, password);

//4.执行操作
rs= ps.executeQuery();
//5.根据结果做处理
if(rs.next())
{//合法
request.getRequestDispatcher("/MainFrame").forward(request, response);
}else
{
request.setAttribute("error", "用户名 或者 密码错误！");
request.getRequestDispatcher("/LoginServlet").forward(request, response);
}

} catch (Exception e) {
e.printStackTrace();
// TODO: handle exception
}finally
{
//关闭资源
if(rs!=null)
{
try {
rs.close();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
rs=null;
}
if(ps!=null)
{
try {
ps.close();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
ps=null;
}
if(ct!=null)
{
try {
ct.close();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
ct=null;
}
}

//out.println("username"+username);

}

public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {

this.doGet(request, response);

}