ajax应用

ajax应用

一、异步校验用户名是否存在

1.需求：

用户名是否存在.png

2.代码：

JQ代码：

HTML代码：

用户名

    
    

服务端代码：

public class CheckUsernameServlet extends HttpServlet {

    protected void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        
        //获得要校验的用户名
        String username = request.getParameter("username");
        
        //传递username到service
        UserService service = new UserService();
        boolean isExist = false;
        try {
            isExist = service.checkUsername(username);
        } catch (SQLException e) {
            e.printStackTrace();
        }
        
        response.getWriter().write("{\"isExist\":"+isExist+"}");
        
    }

    protected void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        doGet(request, response);
    }
}

二、站内搜索

JS代码：

HTML代码：

    

        
        

            
        
    
    Submit

服务端代码：

public class SearchWordServlet extends HttpServlet {

    protected void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        
        //获得关键字
        String word = request.getParameter("word");
        
        //查询该关键字的所有商品
        ProductService service = new ProductService();
        List