用户登录权限验证链接跳转处理关键代码

package com.tszr.security;

import org.springframework.security.core.Authentication;
import org.springframework.security.core.GrantedAuthority;
import org.springframework.security.web.DefaultRedirectStrategy;
import org.springframework.security.web.RedirectStrategy;
import org.springframework.security.web.authentication.SimpleUrlAuthenticationSuccessHandler;
import org.springframework.stereotype.Component;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Collection;
import java.util.List;

@Component
public class MyAuthenticationSuccessHandler extends SimpleUrlAuthenticationSuccessHandler {
    //Spring Security的重定向策略
    private RedirectStrategy redirectStrategy = new DefaultRedirectStrategy();
    /**
     * 重写handle方法，通过RedirectStrategy重定向到指定的URL
     */
    @Override
    protected void handle(HttpServletRequest request, HttpServletResponse response, Authentication authentication)
            throws IOException, ServletException {
        //根据当前认证用户的角色返回适当的URL
        String tagetURL = getTargetURL(authentication);
        //重定向到指定的URL
        redirectStrategy.sendRedirect(request, response, tagetURL);
    }

    /**
     * 从Authentication对象中提取当前登录用户的角色，并根据其角色返回适当的URL
     */
    protected String getTargetURL(Authentication authentication) {
        String url = "";
        //获得当前登录用户的权限（角色）集合
        Collection<? extends GrantedAuthority> authorities =  authentication.getAuthorities();
        List<String> roles = new ArrayList<String>();
        //将权限（角色）名称添加到List集合
        for (GrantedAuthority au : authorities) {
            roles.add(au.getAuthority());
        }
        //判断不同角色的用户跳转到不同的URL
        //这里的URL是控制器的请求匹配路径
        if(roles.contains("ROLE_USER")) {
            url = "/user/loginSuccess";
        }else if(roles.contains("ROLE_ADMIN")) {
            url = "/admin/main";
        }else {
            url = "/deniedAccess";
        }
        return url;
    }
}