Spring Security 认证流程分析及多方式登录认证实践

import org.springframework.security.core.Authentication;
import org.springframework.security.core.AuthenticationException;
import org.springframework.security.web.authentication.UsernamePasswordAuthenticationFilter;
 
import javax.servlet.FilterChain;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
 
public class CustomAuthenticationFilter extends UsernamePasswordAuthenticationFilter {
 
    @Override
    public Authentication attemptAuthentication(HttpServletRequest request,
                                                HttpServletResponse response) throws AuthenticationException {
        // 从请求中获取用户名和密码
        String username = obtainUsername(request);
        String password = obtainPassword(request);
 
        // 构建一个认证令牌
        Authentication authentication = new UsernamePasswordAuthenticationToken(username, password);
 
        // 设置认证令牌并返回
        return authenticationManager.authenticate(authentication);
    }
 
    @Override
    protected void successfulAuthentication(HttpServletRequest request,
                                            HttpServletResponse response,
                                            FilterChain chain,
                                            Authentication authentication) throws IOException, ServletException {
        // 成功认证后的逻辑
        super.successfulAuthentication(request, response, chain, authentication);
        // 例如保存认证信息到response中或者写入cookie等
    }
 
    @Override
    protected void unsuccessfulAuthentication(HttpServletRequest request,
                                              HttpServletResponse response,
                                              AuthenticationException failed) throws IOException, ServletException {
        // 失败认证后的逻辑
        super.unsuccessfulAuthentication(request, response, failed);
        // 例如返回401错误或者重定向到登录页面等
    }
}

这个代码示例展示了如何扩展Spring Security提供的UsernamePasswordAuthenticationFilter类来创建一个自定义的认证过滤器。它重写了attemptAuthentication方法来获取用户名和密码，然后使用这些信息构建一个认证令牌，并通过认证管理器进行认证。同时，它展示了如何重写successfulAuthentication和unsuccessfulAuthentication方法来处理认证成功和失败的情况。这是一个实际的例子，展示了如何在Spring Security框架中实现自定义登录逻辑。