流程图:
1.接上一篇博客https://mp.csdn.net/console/editor/html/104576494，准备好环境。
2.spring-security.xml中的配置：
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:security="http://www.springframework.org/schema/security"
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">
<!-- 配置不拦截的资源 -->
<security:http pattern="/login.jsp" security="none"/>
<security:http pattern="/failer.jsp" security="none"/>
<security:http pattern="/css/**" security="none"/>
<security:http pattern="/img/**" security="none"/>
<security:http pattern="/plugins/**" security="none"/>
<!--
配置具体的规则
auto-config="true" 不用自己编写登录的页面，框架提供默认登录页面
use-expressions="false" 是否使用SPEL表达式（没学习过）
-->
<security:http auto-config="true" use-expressions="false">
<!-- 配置具体的拦截的规则 pattern="请求路径的规则" access="访问系统的人，必须有ROLE_USER或者ROLE_ADMIN的角色" -->
<security:intercept-url pattern="/**" access="ROLE_USER,ROLE_ADMIN"/>
<!-- 定义跳转的具体的页面 -->
<security:form-login
login-page="/login.jsp"
login-processing-url="/login.do"//请求路径
default-target-url="/index.jsp"
authentication-failure-url="/failer.jsp"
authentication-success-forward-url="/pages/main.jsp"
/>
<!-- 关闭跨域请求 -->
<security:csrf disabled="true"/>
<!-- 只要访问到/logout.do就退出，自动跳转到/login.jsp页面 -->
<security:logout invalidate-session="true" logout-url="/logout.do" logout-success-url="/login.jsp" />
</security:http>
<!-- 切换成数据库中的用户名和密码 -->
<security:authentication-manager>
<security:authentication-provider user-service-ref="userService">//userService是认证器需要定义出来
<!-- 配置加密的方式，用户登录的时候可以知道 -->
<security:password-encoder ref="passwordEncoder"/>
</security:authentication-provider>
</security:authentication-manager>
<!-- 配置加密类，当添加用户的时候，对用户密码进行加密 -->
<bean id="passwordEncoder" class="org.springframework.security.crypto.bcrypt.BCryptPasswordEncoder"/>
<!-- 提供了入门的方式，在内存中存入用户名和密码
<security:authentication-manager>
<security:authentication-provider>
<security:user-service>
<security:user name="admin" password="{noop}admin" authorities="ROLE_USER"/>
</security:user-service>
</security:authentication-provider>
</security:authentication-manager>
-->
</beans>
