Spring Security : 概念模型 AuthenticationProvider 认证提供者-优快云博客

本文链接：https://blog.youkuaiyun.com/andy_zhang2007/article/details/90201594

Spring Security中AuthenticationProvider接口抽象建模了认证提供者这一概念，某个认证提供者能认证符合某种特征的认证令牌Authentication。

Spring Security针对常见的一些场景提供了AuthenticationProvider实现，比如RemoteAuthenticationProvider,DaoAuthenticationProvider,JaasAuthenticationProvider等等。

在Spring Security中，AuthenticationProvider通常的用法是交由ProviderManager统一管理和应用。ProviderManager是一个AuthenticationManager实现，它会被广泛应用于认证认证令牌对象Authentication,但实际上具体的认证工作是委托给了ProviderManager所管理的一组AuthenticationProvider上。

源代码

源代码版本 : Spring Security 5.1.4.RELEASE

package org.springframework.security.authentication;

import org.springframework.security.core.Authentication;
import org.springframework.security.core.AuthenticationException;

/**
 * Indicates a class can process a specific
 * {@link org.springframework.security.core.Authentication} implementation.
 *
 * @author Ben Alex
 */
public interface AuthenticationProvider {
	/**
	 * Performs authentication with the same contract as
	 * org.springframework.security.authentication.AuthenticationManager#authenticate(Authentication)
	 * 
	 *
	 * 对提供的认证令牌对象 authentication 执行认证逻辑。如果认证成功，返回信息填充完整的
	 * 的认证令牌对象 authentication。 无法完成认证的话返回 null。此时调用者，通常是 ProviderManager
	 * 使用其他的认证提供者继续尝试认证该认证令牌对象。
	 * 
	 * @param authentication the authentication request object.
	 *
	 * @return a fully authenticated object including credentials. May return
	 * null if the AuthenticationProvider is unable to support
	 * authentication of the passed Authentication object. In such a case,
	 * the next AuthenticationProvider that supports the presented
	 * Authentication class will be tried.
	 *
	 * @throws AuthenticationException if authentication fails.
	 */
	Authentication authenticate(Authentication authentication)
			throws AuthenticationException;

	/**
	 * Returns true if this AuthenticationProvider supports the
	 * indicated Authentication object.
	 * 
	 * 返回 true 表示当前 AuthenticationProvider 能够支持对该 Authentication 对象的
	 * 认证。 不过返回 true 并不表示当前 AuthenticationProvider 能成功认证该 Authentication
	 * 对象。
	 * 
	 * 该方法通常被 ProviderManager 用作判断当前 AuthenticationProvider
	 * 是否可以用于对某个 Authentication 执行认证的逻辑
	 * 
	 * Returning true does not guarantee an
	 * AuthenticationProvider will be able to authenticate the presented
	 * instance of the Authentication class. It simply indicates it can
	 * support closer evaluation of it. An AuthenticationProvider can still
	 * return null from the #authenticate(Authentication) method to
	 * indicate another AuthenticationProvider should be tried.
	 * 
	 * 
	 * Selection of an AuthenticationProvider capable of performing
	 * authentication is conducted at runtime the ProviderManager.
	 * 
	 *
	 * @param authentication
	 *
	 * @return true if the implementation can more closely evaluate the
	 * Authentication class presented
	 */
	boolean supports(Class<?> authentication);
}