抽取Servlet

package cn.travel.web.servlet;

import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;


public class BaseServlet extends HttpServlet {
    @Override
    protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        //完成方法的分发
        //获取请求路径
        String uri = req.getRequestURI();
        System.out.println("请求uri:"+uri);
        //获取方法对象
        String methodName = uri.substring(uri.lastIndexOf("/")+1);
        System.out.println("方法名称："+methodName);

        //获取方法对象Method
        try {
            Method method = this.getClass().getDeclaredMethod(methodName,HttpServletRequest.class,HttpServletResponse.class);
            //暴力反射
            //method.setAccessible(true);
            //执行方法
            method.invoke(this,req,resp);
        } catch (NoSuchMethodException e) {
            e.printStackTrace();
        } catch (IllegalAccessException e) {
            e.printStackTrace();
        } catch (InvocationTargetException e) {
            e.printStackTrace();
        }
    }
}

package cn.travel.web.servlet;

import cn.travel.damain.ResultInfo;
import cn.travel.damain.User;
import cn.travel.service.UserService;
import cn.travel.service.impl.UserServiceImpl;
import com.fasterxml.jackson.databind.ObjectMapper;
import org.apache.commons.beanutils.BeanUtils;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.lang.reflect.InvocationTargetException;
import java.util.Map;

@WebServlet("/user/*")
public class UserServlet extends BaseServlet {
    /**
     * 注册功能
     * @param request
     * @param response
     * @throws ServletException
     * @throws IOException
     */
    public void regist(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        //验证码校验
        String checkcode = request.getParameter("checkcode");
        String checkcode_session = (String) request.getSession().getAttribute("checkcode_session");

        //防止验证码复用 保证验证码只能使用一次
        request.getSession().removeAttribute("checkcode_session");

        //比较
        if (checkcode_session == null || !checkcode_session.equalsIgnoreCase(checkcode)) {
            ResultInfo info = new ResultInfo();
            info.setFlag(false);
            info.setErrorMsg("验证码错误");
            //将info对象序列化为json
            ObjectMapper mapper = new ObjectMapper();
            String json = mapper.writeValueAsString(info);
            response.setContentType("application/json;charset=utf-8");
            response.getWriter().write(json);
            return;
        }

        //获取数据
        String username = request.getParameter("username");
        String password = request.getParameter("password");
        String name = request.getParameter("name");
        String birthday = request.getParameter("birthday");
        String email = request.getParameter("email");
        //封装对象
        User user = new User();
        user.setUsername(username);
        user.setPassword(password);
        user.setName(name);
        user.setBirthday(birthday);
        user.setEmail(email);


        //调用service完成注册
        UserService service = new UserServiceImpl();
        boolean flag = service.regist(user);
        //响应结果
        ResultInfo resultInfo = new ResultInfo();
        if (flag) {
            //注册成功
            resultInfo.setFlag(true);
        } else {
            //注册失败
            resultInfo.setFlag(false);
            resultInfo.setErrorMsg("注册失败！");
        }

        //将resultInfo对象序列化为JSON，并写回客户端
        ObjectMapper mapper = new ObjectMapper();
        String json = mapper.writeValueAsString(resultInfo);
        //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 {
        //获取用户名和密码数据
        Map<String, String[]> map = request.getParameterMap();
        //分装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
        UserService service = new UserServiceImpl();
        User u = service.login(user);

        //判断
        ResultInfo resultInfo = new ResultInfo();
        if (u == null) {
            //用户名密码错误
            resultInfo.setFlag(false);
            resultInfo.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
            resultInfo.setFlag(false);
            resultInfo.setErrorMsg("您尚未激活，请前往邮箱激活!");
        }

        //登录成功的判断
        if (u != null && "Y".equals(u.getStatus())) {
            //登录成功
            resultInfo.setFlag(true);
        }

        request.getSession().setAttribute("user", u);
        //响应数据
        ObjectMapper mapper = new ObjectMapper();
        String json = mapper.writeValueAsString(resultInfo);
        response.setContentType("application/json;charset=utf-8");
        response.getWriter().write(json);
    }

    /**
     * 查找单个对象
     * @param request
     * @param response
     * @throws ServletException
     * @throws IOException
     */
    public void findOne(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        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
     * @param request
     * @param response
     * @throws ServletException
     * @throws IOException
     */
    public void exit(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        //销毁session
        request.getSession().invalidate();

        //跳转页面  重定向
        response.sendRedirect(request.getContextPath() + "/login.html");
    }

    /**
     * 激活
     * @param request
     * @param response
     * @throws ServletException
     * @throws IOException
     */
    public void active(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        //获取激活码
        String code = request.getParameter("code");
        if (code != null) {
            //调用service完成激活
            UserService 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='login.html'>登录</a>";
            } else {
                //激活失败
                msg = "激活失败，联系管理员";
            }
            response.setContentType("text/html;charset=utf-8");
            response.getWriter().write(msg);
        }
    }
}