SpringBoot项目中shiro过滤器的重写以及配置

问题

遇到问题：在前后端分离跨域访问的项目中shiro进行权限拦截失效 (即使有正确权限的访问也会被拦截) 时造成302重定向错误等问题
报错：Response for preflight is invalid (redirect)
1.302原因：使用ajax访问后端项目时无法识别重定向操作
2.shiro拦截失效原因：跨域访问时有一种带预检访问的跨域，即访问时先发出一条methods为OPTIONS的的访问，这种访问不带cookie等信息。造成shiro误判断为无权限访问。
3.一般使用的访问methods都是：get,post,put,delete

解决方案

1.让shiro不对预检访问拦截
2. 改变shiro中无权限，未登录拦截的重定向，这就需要重写几个过滤器
4. 将重写的过滤器进行配置

1.重写shiro 登录 过滤器

过滤器运行机制：
（1）shiro是否拦截访问 以 isAccessAllowed返回值为准
（2）如果isAccessAllowed 方法返回false会进入onAccessDenied方法重定向至 登录 or 无权限 页面

package com.yaoxx.base.shiro;

import java.io.PrintWriter;

import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.commons.lang3.StringUtils;
import org.apache.shiro.web.filter.authc.FormAuthenticationFilter;
import org.apache.shiro.web.util.WebUtils;
import org.springframework.http.HttpStatus;

/**
*  
* @version: 1.0
* @since: JDK 1.8.0_91
* @Description:
* 		未登录过滤器，重写方法为【跨域的预检访问】放行

*/

public class MyAuthenticationFilter extends FormAuthenticationFilter {
   
   @Override
   protected boolean isAccessAllowed(ServletRequest request, ServletResponse response, Object mappedValue) {
   	boolean allowed = super.isAccessAllowed(request, response, mappedValue);
   	if (!allowed) {
   		// 判断请求是否是options请求
   		String method = WebUtils.toHttp(request).getMethod();
   		if (StringUtils.equalsIgnoreCase("OPTIONS", method)) {
   			return true;
   		}
   	}
   	return allowed;
   }

   @Override
   protected boolean onAccessDenied(ServletRequest request, ServletResponse response) throws Exception {
   	if (isLoginRequest(request, response)) { // 判断是否登录
   		if (isLoginSubmission(request, response)) { // 判断是否为post访问
   			return executeLogin(request, response);
   		} else {
   			// sessionID已经注册,但是并没有使用post方式提交
   			return true;
   		}
   	} else {
   		HttpServletRequest req = (HttpServletRequest) request;
   		HttpServletResponse resp = (HttpServletResponse) response;
   		/*
   		 * 跨域访问有时会先发起一条不带token，不带cookie的访问。
   		 * 这就需要我们抓取这条访问，然后给他通过，否则只要是跨域的访问都会因为未登录或缺少权限而被拦截
   		 * （如果重写了isAccessAllowed，就无需下面的判断）
   		 */
//			if (req.getMethod().equals(RequestMethod.OPTIONS.name())) {
//				resp.setStatus(HttpStatus.OK.value());
//				return true;
//			}
   		/*
   		 * 跨域的第二次请求就是普通情况的request了，在这对他进行拦截
   		 */
   		String ajaxHeader = req.getHeader(CustomSessionManager.AUTHORIZATION);
   		if (StringUtils.isNotBlank(ajaxHeader)) {
   			// 前端Ajax请求，则不会重定向
   			resp.setHeader("Access-Control-Allow-Origin", req.getHeader("Origin"));
   			resp.setHeader("Access-Control-Allow-Credentials", "true");
   			resp.setContentType("application/json; charset=utf-8");
   			resp.setCharacterEncoding("UTF-8");
   			resp.setStatus(HttpStatus.UNAUTHORIZED.value());//设置未登录状态码
   			PrintWriter out = resp.getWriter();
//				Map<String, String> result = new HashMap<>();
//				result.put("MESSAGE", "未登录用户");
   			String result = "{\"MESSAGE\":\"未登录用户\"}";
   			out.println(result);
   			out.flush();
   			out.close();
   		} else {
   			// == 如果是普通访问重定向至shiro配置的登录页面 == //
   			saveRequestAndRedirectToLogin(request, response);
   		}
   	}
   	return false;
   }
}

2.重写role权限 过滤器

package com.yaoxx.base.shiro;

import java.io.IOException;
import java.io.PrintWriter;

import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.commons.lang3.StringUtils;
import org.apache.shiro.web.filter.authz.RolesAuthorizationFilter;
import org.apache.shiro.web.util.WebUtils;
import org.springframework.http.HttpStatus;
import org.springframework.web.bind.annotation.RequestMethod;

/**
* 
* @author: yao_x_x
* @since: JDK 1.8.0_91
* @Description: role的过滤器
*/

public class MyAuthorizationFilter extends RolesAuthorizationFilter {

   @Override
   public boolean isAccessAllowed(ServletRequest request, ServletResponse response, Object mappedValue)
   		throws IOException {
   	boolean allowed =super.isAccessAllowed(request, response, mappedValue);
   	if (!allowed) {
   		String method = WebUtils.toHttp(request).getMethod();
   		if (StringUtils.equalsIgnoreCase("OPTIONS", method)) {
   			return true;
   		}
   	}
   	return allowed;
   }

   @Override
   protected boolean onAccessDenied(ServletRequest request, ServletResponse response) throws IOException {
   	HttpServletRequest req = (HttpServletRequest) request;
   	HttpServletResponse resp = (HttpServletResponse) response;
   	if (req.getMethod().equals(RequestMethod.OPTIONS.name())) {
   		resp.setStatus(HttpStatus.OK.value());
   		return true;
   	}
   	// 前端Ajax请求时requestHeader里面带一些参数，用于判断是否是前端的请求
   	String ajaxHeader = req.getHeader(CustomSessionManager.AUTHORIZATION);
   	if (StringUtils.isNotBlank(ajaxHeader)) {
   		// 前端Ajax请求，则不会重定向
   		resp.setHeader("Access-Control-Allow-Origin", req.getHeader("Origin"));
   		resp.setHeader("Access-Control-Allow-Credentials", "true");
   		resp.setContentType("application/json; charset=utf-8");
   		resp.setCharacterEncoding("UTF-8");
   		PrintWriter out = resp.getWriter();
   		String result = "{\"MESSAGE\":\"角色，权限不足\"}";
   		out.println(result);
   		out.flush();
   		out.close();
   		return false;
   	}
   	return super.onAccessDenied(request, response);
   }
}

3.配置过滤器

@Configuration
public class ShiroConfiguration {
	
	@Autowired
	private RoleService roleService;
	@Autowired
	private PermissionService permissionService;
	
	
	
	
	@Bean("shiroFilter")
	public ShiroFilterFactoryBean shiroFilter(@Qualifier("securityManager")SecurityManager manager) {
		ShiroFilterFactoryBean bean = new ShiroFilterFactoryBean();
		bean.setSecurityManager(manager);
		/* 自定义filter注册 */
		Map<String, Filter> filters = bean.getFilters(); 
		filters.put("authc", new MyAuthenticationFilter());
		filters.put("roles", new MyAuthorizationFilter());

		
		Map<String, String> filterChainDefinitionMap =new LinkedHashMap<>();
		filterChainDefinitionMap.put("/login", "anon");
//		filterChainDefinitionMap.put("/*", "authc");
//		filterChainDefinitionMap.put("/admin", "authc,roles[ADMIN]");
		bean.setFilterChainDefinitionMap(filterChainDefinitionMap);
		
		return bean;
	}