自定义httpSession

一个http请求，会在tomcat中创建一个request对象，一个request对象中会有一个session对象，及会话对象，标识是某个客户端的请求，并可以存储客户端的一些身份信息

自定义session

package com.fen.dou.controller;

import javax.servlet.ServletContext;
import javax.servlet.http.HttpSession;
import javax.servlet.http.HttpSessionContext;
import java.util.Enumeration;

public class CustomHttpSession implements HttpSession {
    private String id;

    CustomHttpSession(String id){
        this.id = id;
    }

    @Override
    public long getCreationTime() {
        return 0;
    }

    @Override
    public String getId() {
        return id;
    }

    @Override
    public long getLastAccessedTime() {
        return 0;
    }

    @Override
    public ServletContext getServletContext() {
        return null;
    }

    @Override
    public void setMaxInactiveInterval(int i) {

    }

    @Override
    public int getMaxInactiveInterval() {
        return 0;
    }

    @Override
    public HttpSessionContext getSessionContext() {
        return null;
    }

    @Override
    public Object getAttribute(String s) {
        return null;
    }

    @Override
    public Object getValue(String s) {
        return null;
    }

    @Override
    public Enumeration<String> getAttributeNames() {
        return null;
    }

    @Override
    public String[] getValueNames() {
        return new String[0];
    }

    @Override
    public void setAttribute(String s, Object o) {

    }

    @Override
    public void putValue(String s, Object o) {

    }

    @Override
    public void removeAttribute(String s) {

    }

    @Override
    public void removeValue(String s) {

    }

    @Override
    public void invalidate() {

    }

    @Override
    public boolean isNew() {
        return false;
    }
}

import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.bind.annotation.RestController;

import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

@RestController
public class SpringSessionController {

    @GetMapping("query")
    @ResponseBody
    public String query(HttpServletRequest request, HttpServletResponse response) {
        HttpSession session = request.getSession();
        session.setAttribute("hello","123123123");
        System.out.println("----------sessionId-----------"+session.getId());
        Cookie[] cookies = request.getCookies();
        if(cookies != null && cookies.length > 0){
            for (Cookie cookie : cookies){
                System.out.println(cookie.getName() + " " + cookie.getValue());
            }
        }
        return String.valueOf(session.getAttribute("hello"));

    }
}

import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.util.UUID;

@WebFilter(urlPatterns = {"/*"},filterName = "ycUpdateSessionFilter")
public class UpdateSessionFilter implements Filter {
    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        HttpServletRequest request =  ((HttpServletRequest) servletRequest);
        HttpServletResponse response =  ((HttpServletResponse) servletResponse);
        Cookie[] cookies = request.getCookies();
        UpdateSessionRequestWrapper updateSessionRequestWrapper = null;
        if(cookies != null && cookies.length > 0){
            for(Cookie cookie : cookies){
                if(cookie.getName().equals("ycSessionId")){
                    CustomHttpSession httpSession = new CustomHttpSession(cookie.getValue()) ;
                    updateSessionRequestWrapper = new UpdateSessionRequestWrapper(request,httpSession);
                }
            }
        }
        if(updateSessionRequestWrapper == null){
            CustomHttpSession httpSession = new CustomHttpSession(UUID.randomUUID().toString()) ;
            Cookie cookie = new Cookie("ycSessionId",httpSession.getId());
            response.addCookie(cookie);
            updateSessionRequestWrapper = new UpdateSessionRequestWrapper(request,httpSession);
        }

        filterChain.doFilter(updateSessionRequestWrapper,servletResponse);
    }
}

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletRequestWrapper;
import javax.servlet.http.HttpSession;

public class UpdateSessionRequestWrapper   extends HttpServletRequestWrapper {
    private HttpSession httpSession;
    public UpdateSessionRequestWrapper(HttpServletRequest request,HttpSession httpSession) {
        super(request);
        this.httpSession = httpSession;
    }
    @Override
    public HttpSession getSession() {
        return httpSession;
    }
}