什么是 Remember Me？
Spring Security 5 已经默认启动了 Remember Me 功能，Spring Security 4 需要按照下面进行配置。给 Spring Security 添加 Remember Me 功能，只需要 2 步:
<input type="checkbox" name="remember-me"/> Remember Me<br>
- 在 Spring Security 配置文件的 http 元素下添加(2592000 为 30 天: 24 * 3600 * 30)
<remember-me key="uniqueAndSecret" token-validity-seconds="2592000"/>
Login.html
<html>
<head>
<title>Login Page</title>
</head>
<body>
<span th:text="${error}" th:if="${error} != null"></span>
<span th:text="${logout}" th:if="${logout} != null"></span>
<form name="loginForm" action="/login" method="POST">
Username: <input type="text" name="username"/><br>
Password: <input type="password" name="password"/><br>
<input type="checkbox" name="remember-me"/> Remember Me<br>
<input name="submit" type="submit" value="登陆"/>
</form>
</body>
</html>
spring-security.xml
<?xml version="1.0" encoding="UTF-8"?>
<beans:beans
xmlns="http://www.springframework.org/schema/security"
xmlns:beans="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/security
http://www.springframework.org/schema/security/spring-security.xsd">
<http auto-config="true">
<intercept-url pattern="/admin" access="hasRole('ADMIN')"/>
<intercept-url pattern="/login" access="permitAll"/>
<form-login login-page="/login"
login-processing-url="/login"
default-target-url ="/hello"
authentication-failure-url="/login?error=1"
username-parameter="username"
password-parameter="password"/>
<access-denied-handler error-page="/deny"/>
<logout logout-url="/logout" logout-success-url="/login?logout=1"/>
<csrf disabled="true"/>
<remember-me key="uniqueAndSecret" token-validity-seconds="2592000"/>
</http>
<beans:bean id="userDetailsService" class="com.xtuer.service.MyUserDetailsService"/>
<authentication-manager>
<authentication-provider user-service-ref="userDetailsService">
<password-encoder hash="bcrypt"/>
</authentication-provider>
</authentication-manager>
</beans:beans>
测试
访问 http://localhost:8080/admin
登录成功
重启浏览器
再次访问 http://localhost:8080/admin
不需要重新登录
