作者：fzsyw
1，概述
前后端分离之后，因为HTTP本身是无状态的，Session就没法用了。项目采用jwt的方案后，请求的主要流程如下：用户登录成功之后，服务端会创建一个jwt的token（jwt的这个token中记录了当前的操作账号），并将这个token返回给前端，前端每次请求服务端的数据时，都会将令牌放入Header或者Parameter中，服务端接收到请求后，会先被拦截器拦截，token检验的拦截器会获取请求中的token，然后会检验token的有效性，拦截器都检验成功后，请求会成功到达实际的业务流程中，执行业务逻辑返回给前端数据。在这个过程中，主要涉及到Shiro的拦截器链，Jwt的token管理，多Realm配置等。
2，Shiro的Filter链
Shiro的认证和授权都离不开Filter，因此需要对Shiro的Filter的运行流程很清楚，才能自定义Filter来满足企业的实际需要。另外Shiro的Filter虽然原理都和Servlet的Filter相似，甚至都最终继承相同的接口，但是实际还是有些差别。Shiro中的Filter主要是在ShiroFilter内，对指定匹配的URL进行拦截处理，它有自己的Filter链；而Servlet的Filter和ShiroFilter是同一个级别的，即先走Shiro自己的Filter体系，然后才会委托给Servlet容器的FilterChain进行Servlet容器级别的Filter链执行
2.1 分析Shiro的默认Filter
在Shiro和Spring Boot整合过程中，需要配置ShiroFilterFactoryBean，该类是ShiroFilter的工厂类，并继承了FactoryBean接口。可以从该接口的方法来分析。该接口getObject获取一个实例，按照逻辑，发现调用createFilterChainManager，并创建默认的Filter(按照命名猜测Map<String, Filter> defaultFilters = manager.getFilters())。
public class ShiroFilterFactoryBean implements FactoryBean, BeanPostProcessor { private Map<String, Filter> filters;
private Map<String, String> filterChainDefinitionMap;
/** * * 该工厂类生产的产品类 */ public Object getObject() throws Exception { if (instance == null) { instance = createInstance(); } return instance; }
protected FilterChainManager createFilterChainManager() { //创建默认Filter DefaultFilterChainManager manager = new DefaultFilterChainManager(); Map<String, Filter> defaultFilters = manager.getFilters(); for (Filter filter : defaultFilters.values()) { applyGlobalPropertiesIfNecessary(filter); }
Map<String, Filter> filters = getFilters(); if (!CollectionUtils.isEmpty(filters)) { for (Map.Entry<String, Filter> entry : filters.entrySet()) { String name = entry.getKey(); Filter filter = entry.getValue(); applyGlobalPropertiesIfNecessary(filter); if (filter instanceof Nameable) { ((Nameable) filter).setName(name); } manager.addFilter(name, filter, false); } }
Map<String, String> chains = getFilterChainDefinitionMap(); if (!CollectionUtils.isEmpty(chains)) { for (Map.Entry<String, String> entry : chains.entrySet()) { String url = entry.getKey(); String chainDefinition = entry.getValue(); manager.createChain(url, chainDefinition); } }
return manager; }
protected AbstractShiroFilter createInstance() throws Exception {
log.debug("Creating Shiro Filter instance.");
SecurityManager securityManager = getSecurityManager(); if (securityManager == null) { String msg = "SecurityManager property must be set."; throw new BeanInitializationException(msg); }
if (!(securityManager instanceof WebSecurityManager)) { String msg = "The security manager does not implement the WebSecurityManager interface."; throw new BeanInitializationException(msg); } //创建FilterChainManager FilterChainManager manager = createFilterChainManager();
PathMatchingFilterChainResolver chainResolver = new PathMatchingFilterChainResolver(); chainResolver.setFilterChainManager(manager);
return new SpringShiroFilter((WebSecurityManager) securityManager, chainResolver); } ...}
在DefaultFilterChainManager中addDefaultFilters来添加默认的Filter，DefaultFilter为一系列默认Filter的枚举类。
public class DefaultFilterChainManager implements FilterChainManager { public Map<String, Filter> getFilters() { return filters; }
protected void addFilter(String name, Filter filter, boolean init, boolean overwrite) { Filter existing = getFilter(name); if (existing == null || overwrite) { if (filter instanceof Nameable) { ((Nameable) filter).setName(name); } if (init) { initFilter(filter); } this.filters.put(name, filter); } }
/** * * 创建默认的Filter */ protected void addDefaultFilters(boolean init) { for (DefaultFilter defaultFilter : DefaultFilter.values()) { addFilter(defaultFilter.name(), defaultFilter.newInstance(), init, false); } } ...}
从这个枚举类中可以看到之前添加的共有11个默认Filter，它们的名字分别是anon,authc,authcBaisc等。
public enum DefaultFilter {
anon(AnonymousFilter.class), authc(FormAuthenticationFilter.class), authcBasic(BasicHttpAuthenticationFilter.class), logout(LogoutFilter.class), noSessionCreation(NoSessionCreationFilter.class), perms(PermissionsAuthorizationFilter.class), port(PortFilter.class), rest(HttpMethodPermissionFilter.class), roles(RolesAuthorizationFilter.class), ssl(SslFilter.class), user(UserFilter.class);
private final Class<? extends Filter> filterClass;
private DefaultFilter(Class<? extends Filter> filterClass) { this.filterClass = filterClass; }
public Filter newInstance() { return (Filter) ClassUtils.newInstance(this.filterClass); }
public Class<? extends Filter> getFilterClass() { return this.filterClass; } ...}
2.2 Filter的继承体系分析
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NameableFilter给Filter起个名字，如果没有设置，默认名字就是FilterName。
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OncePerRequestFilter用于防止多次执行Filter；也就是说一次请求只会走一次拦截器链；另外提供 enabled 属性，表示是否开启该拦截器实例，默认 enabled=true 表示开启，如果不想让某个拦截器工作，可以设置为 false 即可。
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AdviceFilter提供了AOP风格的支持。preHandler：在拦截器链执行之前执行，如果返回true则继续拦截器链；否则中断后续的拦截器链的执行直接返回；可以进行预处理（如身份验证、授权等行为）。postHandle：在拦截器链执行完成后执行，后置处理（如记录执行时间之类的）。afterCompletion：类似于AOP中的后置最终增强；即不管有没有异常都会执行，可以进行清理资源（如接触 Subject 与线程的绑定之类的）。
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PathMatchingFilter内置了pathMatcher的实例，方便对请求路径匹配功能及拦截器参数解析的功能，如下所示，对匹配的路径执行isFilterChainContinued的逻辑，如果都没配到，则直接交给拦截器链。
protected boolean preHandle(ServletRequest request, ServletResponse response) throws Exception {
if (this.appliedPaths == null || this.appliedPaths.isEmpty()) { if (log.isTraceEnabled()) { log.trace("appliedPaths property is null or empty. This Filter will passthrough immediately."); } return true; }
for (String path : this.appliedPaths.keySet()) { //对匹配路径进行处理 if (pathsMatch(path, request)) { log.trace("Current requestURI matches pattern '{}'. Determining filter chain execution...", path); Object config = this.appliedPaths.get(path); return isFilterChainContinued(request, response, path, config); } }
return true;} -
AccessControlFilter提供了访问控制的基础功能，isAccessAllowed访问通过，则交给拦截器链，不通过则执行onAccessDenied来确定交给拦截器还是自己处理
public boolean onPreHandle(ServletRequest request, ServletResponse response, Object mappedValue) throws Exception { return isAccessAllowed(request, response, mappedValue) || onAccessDenied(request, response, mappedValue); } -
AuthenticationFilter认证Filter的基类，一般在isAccessAllowed中执行认证逻辑，另外该Filter提供登录成功后跳转的功能
protected boolean isAccessAllowed(ServletRequest request, ServletResponse response, Object mappedValue) { Subject subject = getSubject(request, response); return subject.isAuthenticated();}
protected void issueSuccessRedirect(ServletRequest request, ServletResponse response) throws Exception { WebUtils.redirectToSavedRequest(request, response, getSuccessUrl());} -
AuthenticatingFilter是AuthenticationFilter的子类，提供了executeLogin通用逻辑，通常由子类来实现protected abstract AuthenticationToken createToken(ServletRequest request, ServletResponse response)该方法，然后执行subject.login(token)
public abstract class AuthenticatingFilter extends AuthenticationFilter { public static final String PERMISSIVE = "permissive";
protected boolean executeLogin(ServletRequest request, ServletResponse response) throws Exception { AuthenticationToken token = createToken(request, response); if (token == null) { String msg = "createToken method implementation returned null. A valid non-null AuthenticationToken " + "must be created in order to execute a login attempt."; throw new IllegalStateException(msg); } try { Subject subject = getSubject(request, response); subject.login(token); return onLoginSuccess(token, subject, request, response); } catch (AuthenticationException e) { return onLoginFailure(token, e, request, response); } }
protected abstract AuthenticationToken createToken(ServletRequest request, ServletResponse response) throws Exception;
protected AuthenticationToken createToken(String username, String password, ServletRequest request, ServletResponse response) { boolean rememberMe = isRememberMe(request); String host = getHost(request); return createToken(username, password, rememberMe, host); }
protected AuthenticationToken createToken(String username, String password, boolean rememberMe, String host) { return new UsernamePasswordToken(username, password, rememberMe, host); }
protected boolean onLoginSuccess(AuthenticationToken token, Subject subject, ServletRequest request, ServletResponse response) throws Exception { return true; }
protected boolean onLoginFailure(AuthenticationToken token, AuthenticationException e, ServletRequest request, ServletResponse response) { return false; }
@Override protected boolean isAccessAllowed(ServletRequest request, ServletResponse response, Object mappedValue) { return super.isAccessAllowed(request, response, mappedValue) || (!isLoginRequest(request, response) && isPermissive(mappedValue)); } ...}
2.3 在Shiro中添加自定义的Filter
从上面源码分析，知道了Shiro会提供11个默认的Filter，也是按照拦截器模式交由FilterChainManager来管理Filter，并最终返回SpringShiroFilter。所以添加自定义的Filter，主要有三步。
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实现自己的Filter
如下实现了自己的JwtFilter，主要逻辑可以参考FormAuthenticationFilter。JwtFilter主要是对前端的Api进行校验，检验失败，则抛出异常信息，不给拦截器链处理。
@Slf4jpublic class JwtFilter extends AuthenticatingFilter { private static final String TOKEN_NAME = "token"; /** * 创建令牌 */ @Override protected AuthenticationToken createToken(ServletRequest servletRequest, ServletResponse servletResponse) throws Exception { final String token = getToken((HttpServletRequest) servletRequest); if(StringUtils.isEmpty(token)) { return null; } return new JwtToken(token); } /** * 获取令牌 * @param httpServletRequest * @return */ private String getToken(HttpServletRequest httpServletRequest) { String token = httpServletRequest.getHeader(TOKEN_NAME); if(StringUtils.isEmpty(token)) { token = httpServletRequest.getParameter(TOKEN_NAME); }; if(StringUtils.isEmpty(token)) { Cookie[] cookies = httpServletRequest.getCookies(); if(ArrayUtils.isNotEmpty(cookies)) { for(Cookie cookie :cookies) { if(TOKEN_NAME.equals(cookie.getName())) { token = cookie.getValue(); break; } } } }; return token; } /** * 未通过处理 * @param servletRequest * @param servletResponse * @return * @throws Exception */ @Override protected boolean onAccessDenied(ServletRequest servletRequest, ServletResponse servletResponse) throws Exception { return executeLogin(servletRequest, servletResponse); }
/** * 登录失败执行方法 * @param token * @param e * @param request * @param response * @return */ protected boolean onLoginFailure(AuthenticationToken token, AuthenticationException e, ServletRequest request, ServletResponse response) { response.setContentType("text/html;charset=UTF-8"); try(OutputStream outputStream = response.getOutputStream()){ outputStream.write(e.getMessage().getBytes(SystemConsts.CHARSET)); outputStream.flush(); } catch (IOException e1) { e1.printStackTrace(); } return false; } ...}
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将Filter添加到Shiro中
将自定义的Filter添加到Shiro，并要指定的匹配路径。
public ShiroFilterFactoryBean getShiroFilterFactoryBean(@Autowired org.apache.shiro.mgt.SecurityManager securityManager, @Autowired JwtFilter jwtFilter) { ShiroFilterFactoryBean shiroFilterFactoryBean = new ShiroFilterFactoryBean();
Map<String, Filter> filterMap = new LinkedHashMap<>(); filterMap.put("jwt", jwtFilter); shiroFilterFactoryBean.setFilters(filterMap); Map<String, String> filterChainDefinitionMap = new LinkedHashMap<>(); filterChainDefinitionMap.put("/**", "jwt"); shiroFilterFactoryBean.setFilterChainDefinitionMap(filterChainDefinitionMap); ... return shiroFilterFactoryBean; }
注意：SpringBoot自动帮我们注册了我们的Filter(Filter是注册到整个Filter链，而不是Shiro的Filter链)，但是在Shiro中，我们需要自己实现注册，但是又需要Filter实例存在于Spring容器中，以便能使用其他众多服务(自动注入其他组件……)。所以需要取消Spring Boot的自动注入Filter。可以采用如下方式：
@Beanpublic FilterRegistrationBean registration(@Qualifier("devCryptoFilter") DevCryptoFilter filter）{ FilterRegistrationBean registration = new FilterRegistrationBean(filter); registration.setEnabled(false); return registration;}
3，Jwt整合
使用Jwt需要我们提供对token的创建，校验和获取token中信息的方法。网上有很多，可以借鉴，而且token中也可以存一些其他数据。
public class JwtUtil {
/** * 检验token * @return boolean */ public static boolean verify(String token, String username) { ... }
/** * 获得token中的属性 * @return token中包含的属性 */ public static String getValue(String token, String key) { ... }
/** * 生成token签名EXPIRE_TIME 分钟后过期 * * @param username * 用户名 * @return 加密的token */ public static String createJWT(String userId) { ... }}
4，多Realm配置
用户密码认证和Jwt的认证需要不同的两个Realm，多Realm需要处理不同的Realm，获取到指定Realm的AuthenticationToken的数据模型。
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实现ModularRealmAuthenticator的方法
public class MultiRealmAuthenticator extends ModularRealmAuthenticator {
@Override protected AuthenticationInfo doAuthenticate(AuthenticationToken authenticationToken) throws AuthenticationException { assertRealmsConfigured(); List<Realm> realms = this.getRealms() .stream() .filter(realm -> { return realm.supports(authenticationToken); }) .collect(Collectors.toList()); return realms.size() == 1 ? this.doSingleRealmAuthentication(realms.get(0), authenticationToken) : this.doMultiRealmAuthentication(realms, authenticationToken); }} -
AuthenticatingRealm中实现getAuthenticationTokenClass方法
public Class getAuthenticationTokenClass() { return JwtToken.class;} -
在SecurityManager中配置
@Bean(name = "securityManager")public org.apache.shiro.mgt.SecurityManager defaultWebSecurityManager(@Autowired UserRealm userRealm, @Autowired TokenRealm tokenValidateRealm) { securityManager.setAuthenticator(multiRealmAuthenticator()); securityManager.setRealms(Arrays.asList(userRealm, tokenValidateRealm)); ... return securityManager;}
5，整合Swagger
5.1 添加Swagger依赖
<dependency> <groupId>io.springfox</groupId> <artifactId>springfox-swagger2</artifactId> <version>2.9.2</version></dependency>
<dependency> <groupId>io.springfox</groupId> <artifactId>springfox-swagger-ui</artifactId> <version>2.9.2</version></dependency>
5.2 添加Swagger的配置
@Configurationpublic class Swagger2Config {
@Bean public Docket createRestApi() { return new Docket(DocumentationType.SWAGGER_2) .apiInfo(apiInfo()) .select() .apis(RequestHandlerSelectors.basePackage("XXX")) .paths(PathSelectors.any()) .build(); }
private ApiInfo apiInfo() { return new ApiInfoBuilder() .title("XXX") .description("经供参考") .version("1.0") .build(); }}
6，总结
在整个过程中，遇到的坑就是在Spring boot中Filter的自动注入，中间考虑有不使用注入的方式解决，即直接使用new JwtFilter()的方式，虽然也能解决问题，但是不是很完美，最终还是在网上找到解决方案。对Shiro的Filter链的执行过程加强了理解，能够使用自定的Filter解决实际问题。还有一个后续的问题，退出登录时的Jwt的token处理，它本身不能像Session一样，退出就清除，理论上只要没过期，就一直存在。可以考虑使用缓存，退出时清除即可，然后在校验时，先从缓存获取进行判断。
