spring security实现下次自动登录功能过程解析

<security:http auto-config="true" use-expressions="false">
  <!-- 配置链接地址，表示任意路径都需要ROLE_USER权限,这里可以配置
   一个逗号隔开的角色列表-->
  <security:intercept-url pattern="/**" access="ROLE_USER"/>

  <!--自定义登录页面-->
  <security:form-login login-page="/login.html" login-processing-url="/login"
        username-parameter="username" password-parameter="password"
        authentication-failure-forward-url="/failed.html"
        default-target-url="/index.html"

  />
  <!--关闭csrf,默认是开启的-->
  <security:csrf disabled="true"/>

  <security:remember-me remember-me-parameter="remembermeParamater" />
  <!-- 退出 -->
  <security:logout invalidate-session="true" logout-url="/logout.do" logout-success-url="/login.html"/>
 </security:http>

<form action="/login" method="post">
  用户名:<input type="text" name="username" placeholder="请输入用户名"><br>
  密 码:<input type="password" name="password" placeholder="请输入密码"><br>
  记住我:<input id="_spring_security_remember_me" type="checkbox" name="remembermeParamater" value="true">
  <input type="submit" value="登录">
 </form>

CREATE TABLE persistent_logins
(
 username VARCHAR(64),
 series VARCHAR(64),
 token  VARCHAR(64),
 last_used DATE 
 );

<security:remember-me remember-me-parameter="remembermeParamater" data-source-ref="dataSource"
        token-validity-seconds="86400"/>

@GetMapping("/isRemembermeUser")
public boolean isRemembermeUser(){
 Authentication authentication = SecurityContextHolder.getContext().getAuthentication();
 if(authentication==null){
  return false;
 }
 //判断当前用户是否是通过rememberme登录，是返回true,否返回false
 return RememberMeAuthenticationToken.class.isAssignableFrom(authentication.getClass());
}