Spring Security从后台数据库查询实现登陆控制

Spring Security框架是一个控制登陆的框架，通过配置文件获取后台的用户名及密码，进行比较进行登陆判断

使用步骤

　　1、导入依赖

<!-- 身份验证 -->
            <dependency>
                <groupId>org.springframework.security</groupId>
                <artifactId>spring-security-web</artifactId>
                <version>4.1.0.RELEASE</version>
            </dependency>
            <dependency>
                <groupId>org.springframework.security</groupId>
                <artifactId>spring-security-config</artifactId>
                <version>4.1.0.RELEASE</version>
            </dependency>

　　2、web.xml文件中加载spring-security.xml文件

 <context-param>
      <param-name>contextConfigLocation</param-name>
      <param-value>classpath:spring/spring-security.xml</param-value>
      </context-param>
    <listener>
      <listener-class>
        org.springframework.web.context.ContextLoaderListener
      </listener-class>
    </listener>

    <filter>
      <filter-name>springSecurityFilterChain</filter-name>
      <filter-class>org.springframework.web.filter.DelegatingFilterProxy</filter-class>
    </filter>
      <filter-mapping>
        <filter-name>springSecurityFilterChain</filter-name>
        <url-pattern>/*</url-pattern>
      </filter-mapping>

　　3、前端页面

　　　

　　4、后台代码中创建一个实体类实现 UserDetailsService接口，实现其中的方法

//用户登录的认证类
public class UserDetailsServiceImpl  implements UserDetailsService {
　　//service层是获取后台数据库中的用户名信息
    private SellerService sellerService;
    //set方法注入一个
    public void setSellerService(SellerService sellerService) {
        this.sellerService = sellerService;
    }
    //通过用户名去拿数据库中对象，
    @Override
    public UserDetails loadUserByUsername(String username) throws UsernameNotFoundException {
        System.out.println("经过了imp方法");
//        username是得到前端表单的用户名
        //哪些用户有登陆权限，
        List<GrantedAuthority> grant = new ArrayList<>();
        //添加用户的角色信息,能够去使用
        grant.add(new SimpleGrantedAuthority("ROLE_SELLER"));
        //username是控制框架规定的，其实就是实体类的seller_id
        Seller seller = sellerService.findOne(username);
//        若果不存在此用户
        if (seller !=null && "1".equals(seller.getStatus())){
            //只有当审核通过的商家才能登陆,返回的user是你输入的用户名，密码，角色，
                return new User(username,seller.getPassword(),grant);
        }else {
            return null;
        }
    }

　　5、spring-security
　　里面的细则，我上一篇博客有细说，大家可以回顾一下

<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"
    xmlns:dubbo="http://code.alibabatech.com/schema/dubbo" 

    xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
                        http://code.alibabatech.com/schema/dubbo http://code.alibabatech.com/schema/dubbo/dubbo.xsd
                        http://www.springframework.org/schema/security http://www.springframework.org/schema/security/spring-security.xsd">
    <!-- 以下页面不被拦截 -->
    <http pattern="/*.html" security="none"></http>
    <http pattern="/css/**" security="none"></http>
    <http pattern="/img/**" security="none"></http>
    <http pattern="/js/**" security="none"></http>
    <http pattern="/plugins/**" security="none"></http>
    <!--<http pattern="/seller/add.do" security="none"></http>-->
   <!-- 页面拦截规则 -->
    <http use-expressions="false">
        <intercept-url pattern="/**" access="ROLE_SELLER" />
        <form-login login-page="/shoplogin.html"  default-target-url="/admin/index.html" authentication-failure-url="/shoplogin.html" always-use-default-target="true"/>
        <csrf disabled="true"/>
        <headers>
            <frame-options policy="SAMEORIGIN"/> //角色信息
        </headers>
        <logout/>
    </http>
    <!-- 认证管理器 -->
    <authentication-manager>
        <authentication-provider user-service-ref="userDetailService">
        </authentication-provider>
    </authentication-manager>
    <!-- 应用dubbo-->
    <dubbo:application name="youlexuan-shop" />
    <dubbo:registry address="zookeeper://192.168.200.128:2181"/>
    <dubbo:reference id="sellerService"  interface="com.ghh.core.service.SellerService" >
    </dubbo:reference>
　

<!--自定义的配置类-->

　　<beans:bean id="userDetailService" class="com.ghh.shop.service.UserDetailsServiceImpl"> 
　　　　<beans:property name="sellerService" ref="sellerService"/> //ref引用dubbo中的sellerService
　　</beans:bean> 
</beans:beans>

　自定义配置类中指向自定义的UserDetailsServiceImpl类中，将后台返回的用户名，密码，角色信息，进行控制判断