《黑马旅游网》综合案例六 BaseServlet 抽取

BaseServlet抽取

减少Servlet的数量，现在是一个功能一个Servlet，将其优化为一个模块一个Servlet，

相当于在数据库中一张表对应一个Servlet,在Servlet中提供不同的方法，完成用户的请求。

BaseServlet：

public class BaseServlet extends HttpServlet {
    @Override
    protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        //完成方法分发
        //1.获取请求路径
        String uri = req.getRequestURI();
        System.out.println("请求uri:"+uri);
        //获取方法名称
        String methodName = uri.substring(uri.lastIndexOf('/') + 1);
        System.out.println("方法名称:"+methodName);
        //获取方法对象Method
        //this:谁调用我？我代表谁
        try {
            //获取方法
            Method method=this.getClass().getMethod(methodName,HttpServletRequest.class,HttpServletResponse.class);
            //执行方法
            method.invoke(this,req,resp);
        } catch (NoSuchMethodException e) {
            e.printStackTrace();
        } catch (IllegalAccessException e) {
            e.printStackTrace();
        } catch (InvocationTargetException e) {
            e.printStackTrace();
        }
    }
}

UserServlet：测试

@WebServlet("/user/*")
public class UserServlet extends BaseServlet {
    public void add(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        System.out.println("add...");
    }

    public void find(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        System.out.println("find...");
    }
}

访问：

控制台：

 UserServlet：把上面写的Servlet全部写到UserServlet这个方法中，复制过来就行

@WebServlet("/user/*")
public class UserServlet extends BaseServlet {
    //声明一个UserService业务对象
    private UserServiceImpl service = new UserServiceImpl();
    /**
     * 注册功能
     * @param request
     * @param response
     * @throws ServletException
     * @throws IOException
     */
    public void rehist(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        //验证码的校验
        String check = request.getParameter("check");
        //从session中获取验证码
        HttpSession session = request.getSession();
        String checkcode_server = (String) session.getAttribute("CHECKCODE_SERVER");
        session.removeAttribute("CHECKCODE_SERVER");//保证验证码只使用一次
        //比较
        if (checkcode_server==null || !checkcode_server.equalsIgnoreCase(check)){
            //验证码错误
            ResultInfo info = new ResultInfo();
            //注册失败
            info.setFlag(false);
            info.setErrorMsg("验证码错误!");
            //将info对象序列化json并且写回客户端
            ObjectMapper mapper = new ObjectMapper();
            String json = mapper.writeValueAsString(info);
            //将json数据写回客户端
            //设置content-type
            response.setContentType("application/json;charset=utf-8");
            response.getWriter().write(json);
            return;
        }

        //获取数据
        Map<String, String[]> map = request.getParameterMap();
        //封装对象
        User user = new User();
        try {
            BeanUtils.populate(user,map);
        } catch (IllegalAccessException e) {
            e.printStackTrace();
        } catch (InvocationTargetException e) {
            e.printStackTrace();
        }
        //调用service完成注册
        //UserServiceImpl service = new UserServiceImpl();
        boolean flag = service.regist(user);
        ResultInfo info = new ResultInfo();
        //响应结果
        if (flag){
            //注册成功
            info.setFlag(true);
        }else {
            //注册失败
            info.setFlag(false);
            info.setErrorMsg("注册失败!");
        }
        //将info对象序列化json并且写回客户端
        ObjectMapper mapper = new ObjectMapper();
        String json = mapper.writeValueAsString(info);
        //将json数据写回客户端
        //设置content-type
        response.setContentType("application/json;charset=utf-8");
        response.getWriter().write(json);
    }

    /**
     * 登录功能
     * @param request
     * @param response
     * @throws ServletException
     * @throws IOException
     */
    public void login(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        //验证码的校验
        String check = request.getParameter("check");
        //从session中获取验证码
        HttpSession session = request.getSession();
        String checkcode_server = (String) session.getAttribute("CHECKCODE_SERVER");
        session.removeAttribute("CHECKCODE_SERVER");//保证验证码只使用一次
        //比较
        if (checkcode_server==null || !checkcode_server.equalsIgnoreCase(check)){
            //验证码错误
            ResultInfo info = new ResultInfo();
            //注册失败
            info.setFlag(false);
            info.setErrorMsg("验证码错误!");
            //将info对象序列化json并且写回客户端
            ObjectMapper mapper = new ObjectMapper();
            String json = mapper.writeValueAsString(info);
            //将json数据写回客户端
            //设置content-type
            response.setContentType("application/json;charset=utf-8");
            response.getWriter().write(json);
            return;
        }

        //获取用户名和密码数据
        Map<String, String[]> map = request.getParameterMap();
        //封装user对象
        User user = new User();
        try {
            BeanUtils.populate(user,map);
        } catch (IllegalAccessException e) {
            e.printStackTrace();
        } catch (InvocationTargetException e) {
            e.printStackTrace();
        }
        //调用Service查询
        //UserServiceImpl service = new UserServiceImpl();
        User u = service.login(user);
        request.getSession().setAttribute("user",u);
        ResultInfo info = new ResultInfo();
        //判断用户对象是否为null
        if (u==null){
            //用户名或密码错误
            info.setFlag(false);
            info.setErrorMsg("用户名或密码错误");
        }
        //判断用户是否激活
        if (u!=null && !"Y".equals(u.getStatus())){
            //用户尚未激活
            info.setFlag(false);
            info.setErrorMsg("您尚未激活，请激活");
        }
        //判断登录成功
        if (u!=null && "Y".equals(u.getStatus())){
            //登录成功
            info.setFlag(true);
        }
        //响应数据
        ObjectMapper mapper = new ObjectMapper();
        response.setContentType("application/json;charset=utf-8");
        mapper.writeValue(response.getOutputStream(),info);
    }

    /**
     * 查询单个对象
     * @param request
     * @param response
     * @throws ServletException
     * @throws IOException
     */
    public void findOne(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        //从session中获取登录用户
        Object user = request.getSession().getAttribute("user");
        //将user写回客户端
        ObjectMapper mapper = new ObjectMapper();
        response.setContentType("application/json;charset=utf-8");
        mapper.writeValue(response.getOutputStream(),user);
    }

    /**
     * 退出功能
     * @param request
     * @param response
     * @throws ServletException
     * @throws IOException
     */
    public void exit(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        //销毁session
        request.getSession().invalidate();
        //跳转登录页面
        response.sendRedirect(request.getContextPath()+"/login.html");
    }

    /**
     * 激活功能
     * @param request
     * @param response
     * @throws ServletException
     * @throws IOException
     */
    public void active(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        //判断激活码
        String code = request.getParameter("code");
        if (code!=null){
            //调用service完成激活
            //UserServiceImpl service = new UserServiceImpl();
            boolean flag = service.active(code);
            //判断标记
            String msg = null;
            if (flag){
                //激活成功
                msg = "激活成功，请<a href='/travel/login.html'>登录</a>";
            }else {
                //激活失败
                msg = "激活失败，请联系管理员！";
            }
            response.setContentType("text/html;charset=utf-8");
            response.getWriter().write(msg);
        }
    }
}

login.html：该路径

 header.html：

register.html：

 UserServiceImpl：regist方法中的路径

优化完成