Spring-Security-入门（一）：登录与退出

前言

Spring Security 比较复杂，愿与各位一起研究使用，有歧义的地方，欢迎指出，谢谢！

Github 地址

https://github.com/ChinaSilence/any-spring-security.git 本文示例地址：https://github.com/ChinaSilence/any-spring-security/tree/master/security-login-no-db

启动应用

1、clone 代码之后，进入目录，启动应用

mvn spring-boot:run

2、demo 演示，地址：http://localhost:8080 账号 anoy 密码 pwd

相关解释说明

注解 @EnableWebSecurity

在 Spring boot 应用中使用 Spring Security，用到了 @EnableWebSecurity注解，官方说明如下：

/**
 * Add this annotation to an {@code @Configuration} class to have the Spring Security
 * configuration defined in any {@link WebSecurityConfigurer} or more likely by extending
 * the {@link WebSecurityConfigurerAdapter} base class and overriding individual methods:
 */

意思是说，该注解和 @Configuration 注解一起使用, 注解 WebSecurityConfigurer 类型的类，或者利用 @EnableWebSecurity 注解继承 WebSecurityConfigurerAdapter的类，这样就构成了 Spring Security 的配置。

抽象类 WebSecurityConfigurerAdapter

一般情况，会选择继承 WebSecurityConfigurerAdapter 类，其官方说明如下：

/**
 * Provides a convenient base class for creating a {@link WebSecurityConfigurer}
 * instance. The implementation allows customization by overriding methods.
 *
 * <p>
 * Will automatically apply the result of looking up
 * {@link AbstractHttpConfigurer} from {@link SpringFactoriesLoader} to allow
 * developers to extend the defaults.
 * To do this, you must create a class that extends AbstractHttpConfigurer and then create a file in the classpath at "META-INF/spring.factories" that looks something like:
 * </p>
 * <pre>
 * org.springframework.security.config.annotation.web.configurers.AbstractHttpConfigurer = sample.MyClassThatExtendsAbstractHttpConfigurer
 * </pre>
 * If you have multiple classes that should be added you can use "," to separate the values. For example:
 *
 * <pre>
 * org.springframework.security.config.annotation.web.configurers.AbstractHttpConfigurer = sample.MyClassThatExtendsAbstractHttpConfigurer, sample.OtherThatExtendsAbstractHttpConfigurer
 * </pre>
 *
 */

意思是说 WebSecurityConfigurerAdapter 提供了一种便利的方式去创建 WebSecurityConfigurer的实例，只需要重写 WebSecurityConfigurerAdapter 的方法，即可配置拦截什么URL、设置什么权限等安全控制。

方法 configure(AuthenticationManagerBuilder auth) 和 configure(HttpSecurity http)

Demo 中重写了 WebSecurityConfigurerAdapter 的两个方法：

/**
     * 通过 {@link #authenticationManager()} 方法的默认实现尝试获取一个 {@link AuthenticationManager}.
     * 如果被复写, 应该使用{@link AuthenticationManagerBuilder} 来指定 {@link AuthenticationManager}.
     *
     * 例如, 可以使用以下配置在内存中进行注册公开内存的身份验证{@link UserDetailsService}:
     *
     * // 在内存中添加 user 和 admin 用户
     * @Override
     * protected void configure(AuthenticationManagerBuilder auth) {
     *  auth
     *      .inMemoryAuthentication().withUser("user").password("password").roles("USER").and()
     *      .withUser("admin").password("password").roles("USER", "ADMIN");
     * }
     *
     * // 将 UserDetailsService 显示为 Bean
     * @Bean
     * @Override
     * public UserDetailsService userDetailsServiceBean() throws Exception {
     *  return super.userDetailsServiceBean();
     * }
     *
     */
    protected void configure(AuthenticationManagerBuilder auth) throws Exception {
        this.disableLocalConfigureAuthenticationBldr = true;
    }

/**
     * 复写这个方法来配置 {@link HttpSecurity}. 
     * 通常，子类不能通过调用 super 来调用此方法，因为它可能会覆盖其配置。 默认配置为：
     * 
     * http.authorizeRequests().anyRequest().authenticated().and().formLogin().and().httpBasic();
     *
     */
    protected void configure(HttpSecurity http) throws Exception {
        logger.debug("Using default configure(HttpSecurity). If subclassed this will potentially override subclass configure(HttpSecurity).");

        http
            .authorizeRequests()
                .anyRequest().authenticated()
                .and()
            .formLogin().and()
            .httpBasic();
    }

final 类 HttpSecurity

表1 HttpSecurity 常用方法及说明

用于基于 OpenId 的验证

类 AuthenticationManagerBuilder

/**
 * {@link SecurityBuilder} used to create an {@link AuthenticationManager}. Allows for
 * easily building in memory authentication, LDAP authentication, JDBC based
 * authentication, adding {@link UserDetailsService}, and adding
 * {@link AuthenticationProvider}'s.
 */

意思是， AuthenticationManagerBuilder 用于创建一个 AuthenticationManager，让我能够轻松的实现内存验证、LADP验证、基于JDBC的验证、添加 UserDetailsService、添加 AuthenticationProvider。