在线演示
演示地址：http://139.196.87.48:9002/kitty
用户名：admin 密码：admin
Spring Security
Spring Security 是 Spring 社区的一个顶级项目，也是 Spring Boot 官方推荐使用的安全框架。除了常规的认证（Authentication）和授权（Authorization）之外，Spring Security还提供了诸如ACLs，LDAP，JAAS，CAS等高级特性以满足复杂场景下的安全需求。
Spring Security 应用级别的安全主要包含两个主要部分，即登录认证（Authentication）和访问授权（Authorization），首先用户登录的时候传入登录信息，登录验证器完成登录认证并将登录认证好的信息存储到请求上下文，然后在进行其他操作，如接口访问、方法调用时，权限认证器从上下文中获取登录认证信息，然后根据认证信息获取权限信息，通过权限信息和特定的授权策略决定是否授权。
接下来，本教程将分别对登录认证和访问授权的执行流程进行剖析，并在最后给出完整的案例实现，如果觉得先读前面原理比较难懂，可以先学习后面的实现案例，再结合案例理解登录认证和访问授权的执行原理。
登录认证
登录认证过滤器
如果在继承 WebSecurityConfigurerAdapter 的配置类中的 configure(HttpSecurity http) 方法中有配置 HttpSecurity 的 formLogin，则会返回一个 FormLoginConfigurer 对象。如下是一个 Spring Security 的配置样例， formLogin().x.x 就是配置使用内置的登录验证过滤器，默认实现为 UsernamePasswordAuthenticationFilter。
WebSecurityConfig.java
@Configuration @EnableWebSecurity @EnableGlobalMethodSecurity(prePostEnabled = true) public class WebSecurityConfig extends WebSecurityConfigurerAdapter {@Autowiredprivate UserDetailsService userDetailsService;@Overridepublic void configure(AuthenticationManagerBuilder auth) throws Exception {// 使用自定义身份验证组件auth.authenticationProvider(new JwtAuthenticationProvider(userDetailsService));}@Overrideprotected void configure(HttpSecurity http) throws Exception {http.cors().and().csrf().disable().authorizeRequests()// 首页和登录页面.antMatchers("/").permitAll()// 其他所有请求需要身份认证 .anyRequest().authenticated()// 配置登录认证.and().formLogin().loginProcessingUrl("/login");} }
查看 HttpSecurity , formLogion 方法返回一个 FormLoginConfigurer 对象。
HttpSecurity.java
public FormLoginConfigurer<HttpSecurity> formLogin() throws Exception {return getOrApply(new FormLoginConfigurer<>());}
而 FormLoginConfigurer 的构造函数内绑定了一个 UsernamePasswordAuthenticationFilter 过滤器。
FormLoginConfigurer.java
public FormLoginConfigurer() {super(new UsernamePasswordAuthenticationFilter(), null);usernameParameter("username");passwordParameter("password");}
再看 UsernamePasswordAuthenticationFilter 过滤器的构造函数内绑定了 POST 类型的 /login 请求，也就是说，如果配置了 formLogin 的相关信息，那么在使用 POST 类型的 /login URL进行登录的时候就会被这个过滤器拦截，并进行登录验证，登录验证过程我们下面继续分析。
UsernamePasswordAuthenticationFilter.java
public UsernamePasswordAuthenticationFilter() {super(new AntPathRequestMatcher("/login", "POST"));}
查看 UsernamePasswordAuthenticationFilter，发现它继承了 AbstractAuthenticationProcessingFilter，AbstractAuthenticationProcessingFilter 中的 doFilter 包含了触发登录认证执行流程的相关逻辑。
AbstractAuthenticationProcessingFilter.java
public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain)throws IOException, ServletException {...
Authentication authResult;try {authResult = attemptAuthentication(request, response);if (authResult == null) {// return immediately as subclass has indicated that it hasn't completed// authenticationreturn;}sessionStrategy.onAuthentication(authResult, request, response);}
...
successfulAuthentication(request, response, chain, authResult);}
上面的登录逻辑主要步骤有两个：
1. attemptAuthentication(request, response)
这是 AbstractAuthenticationProcessingFilter 中的一个抽象方法，包含登录主逻辑，由其子类实现具体的登录验证，如 UsernamePasswordAuthenticationFilter 是使用表单方式登录的具体实现。如果是非表单登录的方式，如JNDI等其他方式登录的可以通过继承 AbstractAuthenticationProcessingFilter 自定义登录实现。UsernamePasswordAuthenticationFilter 的登录实现逻辑如下。
UsernamePasswordAuthenticationFilter.java
public Authentication attemptAuthentication(HttpServletRequest request, HttpServletResponse response) throws AuthenticationException {if (postOnly && !request.getMethod().equals("POST")) {throw new AuthenticationServiceException("Authentication method not supported: " + request.getMethod());}// 获取用户名和密码String username = obtainUsername(request);String password = obtainPassword(request);if (username == null) {username = "";}if (password == null) {password = "";}username = username.trim();UsernamePasswordAuthenticationToken authRequest = new UsernamePasswordAuthenticationToken(username, password);// Allow subclasses to set the "details" propertysetDetails(request, authRequest);return this.getAuthenticationManager().authenticate(authRequest);}
2. successfulAuthentication(HttpServletRequest request, HttpServletResponse response, FilterChain chain, Authentication authResult)
登录成功之后，将认证后的 Authentication 对象存储到请求线程上下文，这样在授权阶段就可以获取到 Authentication 认证信息，并利用 Authentication 内的权限信息进行访问控制判断。
AbstractAuthenticationProcessingFilter.java
protected void successfulAuthentication(HttpServletRequest request,HttpServletResponse response, FilterChain chain, Authentication authResult)throws IOException, ServletException {if (logger.isDebugEnabled()) {logger.debug("Authentication success. Updating SecurityContextHolder to contain: " + authResult);}// 登录成功之后，把认证后的 Authentication 对象存储到请求线程上下文，这样在授权阶段就可以获取到此认证信息进行访问控制判断SecurityContextHolder.getContext().setAuthentication(authResult);rememberMeServices.loginSuccess(request, response, authResult);// Fire eventif (this.eventPublisher != null) {eventPublisher.publishEvent(new InteractiveAuthenticationSuccessEvent(authResult, this.getClass()));}successHandler.onAuthenticationSuccess(request, response, authResult);}
从上面的登录逻辑我们可以看到，Spring Security的登录认证过程是委托给 AuthenticationManager 完成的，它先是解析出用户名和密码，然后把用户名和密码封装到一个UsernamePasswordAuthenticationToken 中，传递给 AuthenticationManager，交由 AuthenticationManager 完成实际的登录认证过程。
AuthenticationManager.java
package org.springframework.security.authentication;
import org.springframework.security.core.Authentication;
import org.springframework.security.core.AuthenticationException;
/**
* Processes an {@link Authentication} request.
* @author Ben Alex
*/
public interface AuthenticationManager {
Authentication authenticate(Authentication authentication) throws AuthenticationException;
}
AuthenticationManager 提供了一个默认的 实现 ProviderManager，而 ProviderManager 又将验证委托给了 AuthenticationProvider。
ProviderManager.java
public Authentication authenticate(Authentication authentication)throws AuthenticationException {...
for (AuthenticationProvider provider : getProviders()) {if (!provider.supports(toTest)) {continue;}try {result = provider.authenticate(authentication);if (result != null) {copyDetails(authentication, result);break;}}
...
}
根据验证方式的多样化，AuthenticationProvider 衍生出多种类型的实现，AbstractUserDetailsAuthenticationProvider 是 AuthenticationProvider 的抽象实现，定义了较为统一的验证逻辑，各种验证方式可以选择直接继承 AbstractUserDetailsAuthenticationProvider 完成登录认证，如 DaoAuthenticationProvider 就是继承了此抽象类，完成了从DAO方式获取验证需要的用户信息的。
AbstractUserDetailsAuthenticationProvider.java
public Authentication authenticate(Authentication authentication) throws AuthenticationException {// Determine usernameString username = (authentication.getPrincipal() == null) ? "NONE_PROVIDED" : authentication.getName();boolean cacheWasUsed = true;UserDetails user = this.userCache.getUserFromCache(username);if (user == null) {cacheWasUsed = false;try {
// 子类根据自身情况从指定的地方加载认证需要的用户信息user = retrieveUser(username, (UsernamePasswordAuthenticationToken) authentication);}...try {
// 前置检查，一般是检查账号状态，如是否锁定之类preAuthenticationChecks.check(user);
// 进行一般逻辑认证，如 DaoAuthenticationProvider 实现中的密码验证就是在这里完成的additionalAuthenticationChecks(user, (UsernamePasswordAuthenticationToken) authentication);}...
// 后置检查，如可以检查密码是否过期之类postAuthenticationChecks.check(user); ...
// 验证成功之后返回包含完整认证信息的 Authentication 对象return createSuccessAuthentication(principalToReturn, authentication, user);}
如上面所述， AuthenticationProvider 通过 retrieveUser(String username, UsernamePasswordAuthenticationToken authentication) 获取验证信息，对于我们一般所用的 DaoAuthenticationProvider 是由 UserDetailsService 专门负责获取验证信息的。
DaoAuthenticationProvider.java
protected final UserDetails retrieveUser(String username, UsernamePasswordAuthenticationToken authentication) throws AuthenticationException {try {UserDetails loadedUser = this.getUserDetailsService().loadUserByUsername(username);if (loadedUser == null) {throw new InternalAuthenticationServiceException("UserDetailsService returned null, which is an interface contract violation");}return loadedUser;}}
UserDetailsService 接口只有一个方法，loadUserByUsername(String username)，一般需要我们实现此接口方法，根据用户名加载登录认证和访问授权所需要的信息，并返回一个 UserDetails的实现类，后面登录认证和访问授权都需要用到此中的信息。
public interface UserDetailsService {/*** Locates the user based on the username. In the actual implementation, the search* may possibly be case sensitive, or case insensitive depending on how the* implementation instance is configured. In this case, the <code>UserDetails</code>* object that comes back may have a username that is of a different case than what* was actually requested..** @param username the username identifying the user whose data is required.** @return a fully populated user record (never <code>null</code>)** @throws UsernameNotFoundException if the user could not be found or the user has no* GrantedAuthority*/UserDetails loadUserByUsername(String username) throws UsernameNotFoundException; }
UserDetails 提供了一个默认实现 User，主要包含用户名（username）、密码(password)、权限（authorities）和一些账号或密码状态的标识。
如果默认实现满足不了你的需求，可以根据需求定制自己的 UserDetails，然后在 UserDetailsService 的 loadUserByUsername 中返回即可。
public class User implements UserDetails, CredentialsContainer {// ~ Instance fields// ================================================================================================private String password;private final String username;private final Set<GrantedAuthority> authorities;private final boolean accountNonExpired;private final boolean accountNonLocked;private final boolean credentialsNonExpired;private final boolean enabled;// ~ Constructors// ===================================================================================================public User(String username, String password,Collection<? extends GrantedAuthority> authorities) {this(username, password, true, true, true, true, authorities);}
... }
退出登录
Spring Security 提供了一个默认的登出过滤器 LogoutFilter，默认拦截路径是 /logout，当访问 /logout 路径的时候，LogoutFilter 会进行退出处理。
LogoutFilter.java
package org.springframework.security.web.authentication.logout; public class LogoutFilter extends GenericFilterBean {// ~ Instance fields// ================================================================================================private RequestMatcher logoutRequestMatcher;private final LogoutHandler handler;private final LogoutSuccessHandler logoutSuccessHandler;// ~ Constructors// ===================================================================================================public LogoutFilter(LogoutSuccessHandler logoutSuccessHandler,LogoutHandler... handlers) {this.handler = new CompositeLogoutHandler(handlers);Assert.notNull(logoutSuccessHandler, "logoutSuccessHandler cannot be null");this.logoutSuccessHandler = logoutSuccessHandler;setFilterProcessesUrl("/logout"); // 绑定 /logout}// ~ Methods// ========================================================================================================public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain)throws IOException, ServletException {HttpServletRequest request = (HttpServletRequest) req;HttpServletResponse response = (HttpServletResponse) res;if (requiresLogout(request, response)) {Authentication auth = SecurityContextHolder.getContext().getAuthentication();this.handler.logout(request, response, auth); // 登出处理，可能包含session、cookie、认证信息的清理工作logoutSuccessHandler.onLogoutSuccess(request, response, auth); // 退出后的操作，可能是跳转、返回成功状态等return;}chain.doFilter(request, response);}... }
如下是 SecurityContextLogoutHandler 中的登出处理实现。
SecurityContextLogoutHandler.java
public void logout(HttpServletRequest request, HttpServletResponse response,Authentication authentication) {// 让 session 失效 if (invalidateHttpSession) {HttpSession session = request.getSession(false);if (session != null) {logger.debug("Invalidating session: " + session.getId());session.invalidate();}}// 清理 Security 上下文，其中包含登录认证信息if (clearAuthentication) {SecurityContext context = SecurityContextHolder.getContext();context.setAuthentication(null);}SecurityContextHolder.clearContext();}
访问授权
访问授权主要分为两种：通过URL方式的接口访问控制和方法调用的权限控制。
接口访问权限
在通过比如浏览器使用URL访问后台接口时，是否允许访问此URL，就是接口访问权限。
在进行接口访问时，会由 FilterSecurityInterceptor 进行拦截并进行授权。
FilterSecurityInterceptor 继承了 AbstractSecurityInterceptor 并实现了 javax.servlet.Filter 接口， 所以在URL访问的时候都会被过滤器拦截，doFilter 实现如下。
FilterSecurityInterceptor.java
public void doFilter(ServletRequest request, ServletResponse response,FilterChain chain) throws IOException, ServletException {FilterInvocation fi = new FilterInvocation(request, response, chain);invoke(fi);}
doFilter 方法又调用了自身的 invoke 方法， invoke 方法又调用了父类 AbstractSecurityInterceptor 的 beforeInvocation 方法。
FilterSecurityInterceptor.java
public void invoke(FilterInvocation fi) throws IOException, ServletException {if ((fi.getRequest() != null)&& (fi.getRequest().getAttribute(FILTER_APPLIED) != null)&& observeOncePerRequest) {// filter already applied to this request and user wants us to observe// once-per-request handling, so don't re-do security checking fi.getChain().doFilter(fi.getRequest(), fi.getResponse());}else {// first time this request being called, so perform security checkingif (fi.getRequest() != null && observeOncePerRequest) {fi.getRequest().setAttribute(FILTER_APPLIED, Boolean.TRUE);}InterceptorStatusToken token = super.beforeInvocation(fi);try {fi.getChain().doFilter(fi.getRequest(), fi.getResponse());}finally {super.finallyInvocation(token);}super.afterInvocation(token, null);}}
方法调用权限
在进行后台方法调用时，是否允许该方法调用，就是方法调用权限。比如在方法上添加了此类注解 @PreAuthorize("hasRole('ROLE_ADMIN')") ，Security 方法注解的支持需要在任何配置类中（如 WebSecurityConfigurerAdapter ）添加 @EnableGlobalMethodSecurity(prePostEnabled = true) 开启，才能够使用。
@Configuration @EnableWebSecurity @EnableGlobalMethodSecurity(prePostEnabled = true) public class WebSecurityConfig extends WebSecurityConfigurerAdapter {}
在进行方法调用时，会由 MethodSecurityInterceptor 进行拦截并进行授权。
MethodSecurityInterceptor 继承了 AbstractSecurityInterceptor 并实现了AOP 的 org.aopalliance.intercept.MethodInterceptor 接口， 所以可以在方法调用时进行拦截。
MethodSecurityInterceptor .java
public Object invoke(MethodInvocation mi) throws Throwable {InterceptorStatusToken token = super.beforeInvocation(mi);Object result;try {result = mi.proceed();}finally {super.finallyInvocation(token);}return super.afterInvocation(token, result);}
我们看到，MethodSecurityInterceptor 跟 FilterSecurityInterceptor 一样， 都是通过调用父类 AbstractSecurityInterceptor 的相关方法完成授权，其中 beforeInvocation 是完成权限认证的关键。
AbstractSecurityInterceptor.java
protected InterceptorStatusToken beforeInvocation(Object object) {...// 通过 SecurityMetadataSource 获取权限配置信息，可以定制实现自己的权限信息获取逻辑Collection<ConfigAttribute> attributes = this.obtainSecurityMetadataSource().getAttributes(object); ...
// 确认是否经过登录认证 Authentication authenticated = authenticateIfRequired();// Attempt authorizationtry {
// 通过 AccessDecisionManager 完成授权认证，默认实现是 AffirmativeBasedthis.accessDecisionManager.decide(authenticated, object, attributes);}...}
上面代码显示 AbstractSecurityInterceptor 又是委托授权认证器 AccessDecisionManager 完成授权认证，默认实现是 AffirmativeBased， decide 方法实现如下。
AffirmativeBased.java
public void decide(Authentication authentication, Object object,Collection<ConfigAttribute> configAttributes) throws AccessDeniedException {int deny = 0;
for (AccessDecisionVoter voter : getDecisionVoters()) {
// 通过各种投票策略，最终决定是否授权 int result = voter.vote(authentication, object, configAttributes); switch (result) {
case AccessDecisionVoter.ACCESS_GRANTED:return;
case AccessDecisionVoter.ACCESS_DENIED:deny++;break;
default:break;}...}
而 AccessDecisionManager 决定授权又是通过一个授权策略集合（AccessDecisionVoter ）决定的，授权决定的原则是：
1. 遍历所有授权策略， 如果有其中一个返回 ACCESS_GRANTED，则同意授权。
2. 否则，等待遍历结束，统计 ACCESS_DENIED 个数，只要拒绝数大于1，则不同意授权。
对于接口访问授权，也就是 FilterSecurityInterceptor 管理的URL授权，默认对应的授权策略只有一个，就是 WebExpressionVoter，它的授权策略主要是根据 WebSecurityConfigurerAdapter 内配置的路径访问策略进行匹配，然后决定是否授权。
WebExpressionVoter.java
/*** Voter which handles web authorisation decisions.* @author Luke Taylor* @since 3.0*/ public class WebExpressionVoter implements AccessDecisionVoter<FilterInvocation> {private SecurityExpressionHandler<FilterInvocation> expressionHandler = new DefaultWebSecurityExpressionHandler();public int vote(Authentication authentication, FilterInvocation fi,Collection<ConfigAttribute> attributes) {assert authentication != null;assert fi != null;assert attributes != null;WebExpressionConfigAttribute weca = findConfigAttribute(attributes);if (weca == null) {return ACCESS_ABSTAIN;}EvaluationContext ctx = expressionHandler.createEvaluationContext(authentication, fi);
ctx = weca.postProcess(ctx, fi);return ExpressionUtils.evaluateAsBoolean(weca.getAuthorizeExpression(), ctx) ? ACCESS_GRANTED : ACCESS_DENIED;}... }
对于方法调用授权，在全局方法安全配置类里，可以看到给 MethodSecurityInterceptor 默认配置的有 RoleVoter、AuthenticatedVoter、Jsr250Voter、和 PreInvocationAuthorizationAdviceVoter，其中 Jsr250Voter、PreInvocationAuthorizationAdviceVoter 都需要打开指定的开关，才会添加支持。
GlobalMethodSecurityConfiguration.java
@Configuration public class GlobalMethodSecurityConfiguration implements ImportAware, SmartInitializingSingleton {
...
private MethodSecurityInterceptor methodSecurityInterceptor;
@Beanpublic MethodInterceptor methodSecurityInterceptor() throws Exception {this.methodSecurityInterceptor = isAspectJ()? new AspectJMethodSecurityInterceptor(): new MethodSecurityInterceptor();methodSecurityInterceptor.setAccessDecisionManager(accessDecisionManager());methodSecurityInterceptor.setAfterInvocationManager(afterInvocationManager());methodSecurityInterceptor.setSecurityMetadataSource(methodSecurityMetadataSource());RunAsManager runAsManager = runAsManager();if (runAsManager != null) {methodSecurityInterceptor.setRunAsManager(runAsManager);}return this.methodSecurityInterceptor;}protected AccessDecisionManager accessDecisionManager() {List<AccessDecisionVoter<? extends Object>> decisionVoters = new ArrayList<AccessDecisionVoter<? extends Object>>();ExpressionBasedPreInvocationAdvice expressionAdvice = new ExpressionBasedPreInvocationAdvice();expressionAdvice.setExpressionHandler(getExpressionHandler());if (prePostEnabled()) {decisionVoters.add(new PreInvocationAuthorizationAdviceVoter(expressionAdvice));}if (jsr250Enabled()) {decisionVoters.add(new Jsr250Voter());}decisionVoters.add(new RoleVoter());decisionVoters.add(new AuthenticatedVoter());return new AffirmativeBased(decisionVoters);}
...
}
RoleVoter 是根据角色进行匹配授权的策略。
RoleVoter.java
public class RoleVoter implements AccessDecisionVoter<Object> {
// RoleVoter 默认角色名以 "ROLE_" 为前缀。private String rolePrefix = "ROLE_";public boolean supports(ConfigAttribute attribute) {if ((attribute.getAttribute() != null)&& attribute.getAttribute().startsWith(getRolePrefix())) {return true;}else {return false;}}public int vote(Authentication authentication, Object object,Collection<ConfigAttribute> attributes) {if(authentication == null) {return ACCESS_DENIED;}int result = ACCESS_ABSTAIN;Collection<? extends GrantedAuthority> authorities = extractAuthorities(authentication);// 逐个角色进行匹配，入股有一个匹配得上，则进行授权for (ConfigAttribute attribute : attributes) {if (this.supports(attribute)) {result = ACCESS_DENIED;// Attempt to find a matching granted authorityfor (GrantedAuthority authority : authorities) {if (attribute.getAttribute().equals(authority.getAuthority())) {return ACCESS_GRANTED;}}}}return result;}Collection<? extends GrantedAuthority> extractAuthorities(Authentication authentication) {return authentication.getAuthorities();} }
AuthenticatedVoter 主要是针对有配置以下几个属性来决定授权的策略。
IS_AUTHENTICATED_REMEMBERED：记住我登录状态
IS_AUTHENTICATED_ANONYMOUSLY：匿名认证状态
IS_AUTHENTICATED_FULLY： 完全登录状态，即非上面两种类型
AuthenticatedVoter.java
public int vote(Authentication authentication, Object object,Collection<ConfigAttribute> attributes) {int result = ACCESS_ABSTAIN;for (ConfigAttribute attribute : attributes) {if (this.supports(attribute)) {result = ACCESS_DENIED;// 完全登录状态if (IS_AUTHENTICATED_FULLY.equals(attribute.getAttribute())) {if (isFullyAuthenticated(authentication)) {return ACCESS_GRANTED;}}// 记住我登录状态if (IS_AUTHENTICATED_REMEMBERED.equals(attribute.getAttribute())) {if (authenticationTrustResolver.isRememberMe(authentication)|| isFullyAuthenticated(authentication)) {return ACCESS_GRANTED;}}// 匿名登录状态if (IS_AUTHENTICATED_ANONYMOUSLY.equals(attribute.getAttribute())) {if (authenticationTrustResolver.isAnonymous(authentication)|| isFullyAuthenticated(authentication)|| authenticationTrustResolver.isRememberMe(authentication)) {return ACCESS_GRANTED;}}}}return result;}
PreInvocationAuthorizationAdviceVoter 是针对类似 @PreAuthorize("hasRole('ROLE_ADMIN')") 注解解析并进行授权的策略。
PreInvocationAuthorizationAdviceVoter.java
public class PreInvocationAuthorizationAdviceVoter implements AccessDecisionVoter<MethodInvocation> {private final PreInvocationAuthorizationAdvice preAdvice; public int vote(Authentication authentication, MethodInvocation method,Collection<ConfigAttribute> attributes) { PreInvocationAttribute preAttr = findPreInvocationAttribute(attributes);if (preAttr == null) {// No expression based metadata, so abstainreturn ACCESS_ABSTAIN;}boolean allowed = preAdvice.before(authentication, method, preAttr);return allowed ? ACCESS_GRANTED : ACCESS_DENIED;}private PreInvocationAttribute findPreInvocationAttribute(Collection<ConfigAttribute> config) {for (ConfigAttribute attribute : config) {if (attribute instanceof PreInvocationAttribute) {return (PreInvocationAttribute) attribute;}}return null;} }
PreInvocationAuthorizationAdviceVoter 解析出注解属性配置， 然后通过调用 PreInvocationAuthorizationAdvice 的前置通知方法进行授权认证，默认实现类似 ExpressionBasedPreInvocationAdvice，通知内主要进行了内容的过滤和权限表达式的匹配。
ExpressionBasedPreInvocationAdvice.java
public class ExpressionBasedPreInvocationAdvice implements PreInvocationAuthorizationAdvice {private MethodSecurityExpressionHandler expressionHandler = new DefaultMethodSecurityExpressionHandler();public boolean before(Authentication authentication, MethodInvocation mi, PreInvocationAttribute attr) {PreInvocationExpressionAttribute preAttr = (PreInvocationExpressionAttribute) attr;EvaluationContext ctx = expressionHandler.createEvaluationContext(authentication, mi);Expression preFilter = preAttr.getFilterExpression();Expression preAuthorize = preAttr.getAuthorizeExpression();if (preFilter != null) {Object filterTarget = findFilterTarget(preAttr.getFilterTarget(), ctx, mi);expressionHandler.filter(filterTarget, preFilter, ctx);}if (preAuthorize == null) {return true;}return ExpressionUtils.evaluateAsBoolean(preAuthorize, ctx);}... }
案例实现
接下来，我们以一个实现案例来进行说明讲解。
新建工程
新建一个 Spring Boot 项目 springboot-spring-security。
添加依赖
添加项目依赖，主要是 Spring Security 和 JWT，另外添加 Swagger 和 fastjson 作为辅助工具。
pom.xml
<?xml version="1.0" encoding="UTF-8"?> <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"><modelVersion>4.0.0</modelVersion><groupId>top.ivan.demo</groupId><artifactId>springboot-spring-security</artifactId><version>0.0.1-SNAPSHOT</version><packaging>jar</packaging><name>springboot-spring-security</name><description>Demo project for Spring Boot</description><parent><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-parent</artifactId><version>2.0.4.RELEASE</version><relativePath/> <!-- lookup parent from repository --></parent><properties><project.build.sourceEncoding>UTF-8</project.build.sourceEncoding><project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding><java.version>1.8</java.version><mybatis.spring.version>1.3.2</mybatis.spring.version><swagger.version>2.8.0</swagger.version><jwt.version>0.9.1</jwt.version><fastjson.version>1.2.48</fastjson.version></properties><dependencies><!-- spring boot --><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-web</artifactId></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-test</artifactId><scope>test</scope></dependency><!-- swagger --><dependency><groupId>io.springfox</groupId><artifactId>springfox-swagger2</artifactId><version>${swagger.version}</version></dependency><dependency><groupId>io.springfox</groupId><artifactId>springfox-swagger-ui</artifactId><version>${swagger.version}</version></dependency><!-- spring security --><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-security</artifactId></dependency><!-- jwt --><dependency><groupId>io.jsonwebtoken</groupId><artifactId>jjwt</artifactId><version>${jwt.version}</version></dependency><!-- fastjson --><dependency><groupId>com.alibaba</groupId><artifactId>fastjson</artifactId><version>${fastjson.version}</version></dependency></dependencies><build><plugins><plugin><groupId>org.springframework.boot</groupId><artifactId>spring-boot-maven-plugin</artifactId></plugin></plugins></build></project>
启动类
启动类没什么，主要开启以下包扫描。
SpringSecurityApplication.java
package com.louis.springboot.spring.security;import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.SpringBootApplication; import org.springframework.context.annotation.ComponentScan;/*** 启动器* @author Louis* @date Nov 28, 2018*/ @SpringBootApplication @ComponentScan(basePackages = "com.louis.springboot") public class SpringSecurityApplication {public static void main(String[] args) {SpringApplication.run(SpringSecurityApplication.class, args);} }
跨域配置类
跨域配置类，不多说，都懂得。
CorsConfig.java
package com.louis.springboot.spring.security.config;import org.springframework.context.annotation.Configuration; import org.springframework.web.servlet.config.annotation.CorsRegistry; import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;/*** 跨域配置* @author Louis* @date Nov 28, 2018*/ @Configuration public class CorsConfig implements WebMvcConfigurer {@Overridepublic void addCorsMappings(CorsRegistry registry) {registry.addMapping("/**") // 允许跨域访问的路径.allowedOrigins("*") // 允许跨域访问的源.allowedMethods("POST", "GET", "PUT", "OPTIONS", "DELETE") // 允许请求方法.maxAge(168000) // 预检间隔时间.allowedHeaders("*") // 允许头部设置.allowCredentials(true); // 是否发送cookie } }
Swagger配置类
Swagger配置类，除了常规配置外，加了一个令牌属性，可以在接口调用的时候传递令牌。
SwaggerConfig.java
package com.louis.springboot.spring.security.config; import java.util.ArrayList; import java.util.List;import org.springframework.context.annotation.Bean; import org.springframework.context.annotation.Configuration;import springfox.documentation.builders.ApiInfoBuilder; import springfox.documentation.builders.ParameterBuilder; import springfox.documentation.builders.PathSelectors; import springfox.documentation.builders.RequestHandlerSelectors; import springfox.documentation.schema.ModelRef; import springfox.documentation.service.ApiInfo; import springfox.documentation.service.Parameter; import springfox.documentation.spi.DocumentationType; import springfox.documentation.spring.web.plugins.Docket; import springfox.documentation.swagger2.annotations.EnableSwagger2;/*** Swagger配置* @author Louis* @date Nov 28, 2018*/ @Configuration @EnableSwagger2 public class SwaggerConfig {@Beanpublic Docket createRestApi(){// 添加请求参数，我们这里把token作为请求头部参数传入后端ParameterBuilder parameterBuilder = new ParameterBuilder();List<Parameter> parameters = new ArrayList<Parameter>();parameterBuilder.name("Authorization").description("令牌").modelRef(new ModelRef("string")).parameterType("header").required(false).build();parameters.add(parameterBuilder.build());return new Docket(DocumentationType.SWAGGER_2).apiInfo(apiInfo()).select().apis(RequestHandlerSelectors.any()).paths(PathSelectors.any()).build().globalOperationParameters(parameters);}private ApiInfo apiInfo(){return new ApiInfoBuilder().build();}}
加了令牌属性后的 Swagger 接口调用界面。
安全配置类
下面这个配置类是Spring Security的关键配置。
在这个配置类中，我们主要做了以下几个配置：
1. 访问路径URL的授权策略，如登录、Swagger访问免登录认证等
2. 指定了登录认证流程过滤器 JwtLoginFilter，由它来触发登录认证
3. 指定了自定义身份认证组件 JwtAuthenticationProvider，并注入 UserDetailsService
4. 指定了访问控制过滤器 JwtAuthenticationFilter，在授权时解析令牌和设置登录状态
5. 指定了退出登录处理器，因为是前后端分离，防止内置的登录处理器在后台进行跳转
WebSecurityConfig.java
package com.louis.springboot.spring.security.config;import org.springframework.beans.factory.annotation.Autowired; import org.springframework.context.annotation.Bean; import org.springframework.context.annotation.Configuration; import org.springframework.http.HttpMethod; import org.springframework.security.authentication.AuthenticationManager; import org.springframework.security.config.annotation.authentication.builders.AuthenticationManagerBuilder; import org.springframework.security.config.annotation.method.configuration.EnableGlobalMethodSecurity; import org.springframework.security.config.annotation.web.builders.HttpSecurity; import org.springframework.security.config.annotation.web.configuration.EnableWebSecurity; import org.springframework.security.config.annotation.web.configuration.WebSecurityConfigurerAdapter; import org.springframework.security.core.userdetails.UserDetailsService; import org.springframework.security.web.authentication.UsernamePasswordAuthenticationFilter; import org.springframework.security.web.authentication.logout.HttpStatusReturningLogoutSuccessHandler;import com.louis.springboot.spring.security.security.JwtAuthenticationFilter; import com.louis.springboot.spring.security.security.JwtAuthenticationProvider; import com.louis.springboot.spring.security.security.JwtLoginFilter;/*** Security Config* @author Louis* @date Nov 28, 2018*/ @Configuration @EnableWebSecurity @EnableGlobalMethodSecurity(prePostEnabled = true) public class WebSecurityConfig extends WebSecurityConfigurerAdapter {@Autowiredprivate UserDetailsService userDetailsService;@Overridepublic void configure(AuthenticationManagerBuilder auth) throws Exception {// 使用自定义登录身份认证组件auth.authenticationProvider(new JwtAuthenticationProvider(userDetailsService));}@Overrideprotected void configure(HttpSecurity http) throws Exception {// 禁用 csrf, 由于使用的是JWT，我们这里不需要csrf http.cors().and().csrf().disable().authorizeRequests()// 跨域预检请求.antMatchers(HttpMethod.OPTIONS, "/**").permitAll()// 登录URL.antMatchers("/login").permitAll()// swagger.antMatchers("/swagger-ui.html").permitAll().antMatchers("/swagger-resources").permitAll().antMatchers("/v2/api-docs").permitAll().antMatchers("/webjars/springfox-swagger-ui/**").permitAll()// 其他所有请求需要身份认证 .anyRequest().authenticated();// 退出登录处理器http.logout().logoutSuccessHandler(new HttpStatusReturningLogoutSuccessHandler());// 开启登录认证流程过滤器http.addFilterBefore(new JwtLoginFilter(authenticationManager()), UsernamePasswordAuthenticationFilter.class);// 访问控制时登录状态检查过滤器http.addFilterBefore(new JwtAuthenticationFilter(authenticationManager()), UsernamePasswordAuthenticationFilter.class);}@Bean@Overridepublic AuthenticationManager authenticationManager() throws Exception {return super.authenticationManager();}}
登录认证触发过滤器
JwtLoginFilter 是在通过访问 /login 的POST请求是被首先被触发的过滤器，默认实现是 UsernamePasswordAuthenticationFilter，它继承了 AbstractAuthenticationProcessingFilter，抽象父类的 doFilter 定义了登录认证的大致操作流程，这里我们的 JwtLoginFilter 继承了 UsernamePasswordAuthenticationFilter，并进行了两个主要内容的定制。
1. 覆写认证方法，修改用户名、密码的获取方式，具体原因看代码注释
2. 覆写认证成功后的操作，移除后台跳转，添加生成令牌并返回给客户端
JwtLoginFilter.java
package com.louis.springboot.spring.security.security;import java.io.BufferedReader; import java.io.IOException; import java.io.InputStream; import java.io.InputStreamReader; import java.nio.charset.Charset;import javax.servlet.FilterChain; import javax.servlet.ServletException; import javax.servlet.ServletRequest; import javax.servlet.ServletResponse; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse;import org.springframework.security.authentication.AuthenticationManager; import org.springframework.security.authentication.event.InteractiveAuthenticationSuccessEvent; import org.springframework.security.core.Authentication; import org.springframework.security.core.AuthenticationException; import org.springframework.security.core.context.SecurityContextHolder; import org.springframework.security.web.authentication.UsernamePasswordAuthenticationFilter;import com.alibaba.fastjson.JSON; import com.alibaba.fastjson.JSONObject; import com.louis.springboot.spring.security.utils.HttpUtils; import com.louis.springboot.spring.security.utils.JwtTokenUtils;/*** 启动登录认证流程过滤器* @author Louis* @date Nov 28, 2018*/ public class JwtLoginFilter extends UsernamePasswordAuthenticationFilter {public JwtLoginFilter(AuthenticationManager authManager) {setAuthenticationManager(authManager);}@Overridepublic void doFilter(ServletRequest req, ServletResponse res, FilterChain chain)throws IOException, ServletException {// POST 请求 /login 登录时拦截， 由此方法触发执行登录认证流程，可以在此覆写整个登录认证逻辑super.doFilter(req, res, chain); }@Overridepublic Authentication attemptAuthentication(HttpServletRequest request, HttpServletResponse response) throws AuthenticationException {// 可以在此覆写尝试进行登录认证的逻辑，登录成功之后等操作不再此方法内// 如果使用此过滤器来触发登录认证流程，注意登录请求数据格式的问题// 此过滤器的用户名密码默认从request.getParameter()获取，但是这种// 读取方式不能读取到如 application/json 等 post 请求数据，需要把// 用户名密码的读取逻辑修改为到流中读取request.getInputStream() String body = getBody(request);JSONObject jsonObject = JSON.parseObject(body);String username = jsonObject.getString("username");String password = jsonObject.getString("password");if (username == null) {username = "";}if (password == null) {password = "";}username = username.trim();JwtAuthenticatioToken authRequest = new JwtAuthenticatioToken(username, password);// Allow subclasses to set the "details" property setDetails(request, authRequest);return this.getAuthenticationManager().authenticate(authRequest);}@Overrideprotected void successfulAuthentication(HttpServletRequest request, HttpServletResponse response, FilterChain chain,Authentication authResult) throws IOException, ServletException {// 存储登录认证信息到上下文 SecurityContextHolder.getContext().setAuthentication(authResult);// 记住我服务 getRememberMeServices().loginSuccess(request, response, authResult);// 触发事件监听器if (this.eventPublisher != null) {eventPublisher.publishEvent(new InteractiveAuthenticationSuccessEvent(authResult, this.getClass()));}// 生成并返回token给客户端，后续访问携带此tokenJwtAuthenticatioToken token = new JwtAuthenticatioToken(null, null, JwtTokenUtils.generateToken(authResult));HttpUtils.write(response, token);}/** * 获取请求Body* @param request* @return*/public String getBody(HttpServletRequest request) {StringBuilder sb = new StringBuilder();InputStream inputStream = null;BufferedReader reader = null;try {inputStream = request.getInputStream();reader = new BufferedReader(new InputStreamReader(inputStream, Charset.forName("UTF-8")));String line = "";while ((line = reader.readLine()) != null) {sb.append(line);}} catch (IOException e) {e.printStackTrace();} finally {if (inputStream != null) {try {inputStream.close();} catch (IOException e) {e.printStackTrace();}}if (reader != null) {try {reader.close();} catch (IOException e) {e.printStackTrace();}}}return sb.toString();} }
登录控制器
除了使用上面的登录认证过滤器拦截 /login Post请求之外，我们也可以不使用上面的过滤器，通过自定义登录接口实现，只要在登录接口手动触发登录流程并生产令牌即可。
其实 Spring Security 的登录认证过程只需 调用 AuthenticationManager 的 authenticate(Authentication authentication) 方法，最终返回认证成功的 Authentication 实现类并存储到SpringContexHolder 上下文即可，这样后面授权的时候就可以从 SpringContexHolder 中获取登录认证信息，并根据其中的用户信息和权限信息决定是否进行授权。
LoginController.java
package com.louis.springboot.spring.security.controller;import java.io.IOException;import javax.servlet.http.HttpServletRequest;import org.springframework.beans.factory.annotation.Autowired; import org.springframework.security.authentication.AuthenticationManager; import org.springframework.web.bind.annotation.PostMapping; import org.springframework.web.bind.annotation.RequestBody; import org.springframework.web.bind.annotation.RestController;import com.louis.springboot.spring.security.security.JwtAuthenticatioToken; import com.louis.springboot.spring.security.utils.SecurityUtils; import com.louis.springboot.spring.security.vo.HttpResult; import com.louis.springboot.spring.security.vo.LoginBean;/*** 登录控制器* @author Louis* @date Nov 28, 2018*/ @RestController public class LoginController {@Autowiredprivate AuthenticationManager authenticationManager;/*** 登录接口*/@PostMapping(value = "/login")public HttpResult login(@RequestBody LoginBean loginBean, HttpServletRequest request) throws IOException {String username = loginBean.getUsername();String password = loginBean.getPassword();// 系统登录认证JwtAuthenticatioToken token = SecurityUtils.login(request, username, password, authenticationManager);return HttpResult.ok(token);}}
注意：如果使用此登录控制器触发登录认证，需要禁用登录认证过滤器，即将 WebSecurityConfig 中的以下配置项注释即可，否则访问登录接口会被过滤拦截，执行不会再进入此登录接口，大家根据使用习惯二选一即可。
// 开启登录认证流程过滤器，如果使用LoginController的login接口, 需要注释掉此过滤器，根据使用习惯二选一即可 http.addFilterBefore(new JwtLoginFilter(authenticationManager()), UsernamePasswordAuthenticationFilter.class);
如下是登录认证的逻辑， 可以看到部分逻辑跟上面的登录认证过滤器差不多。
1. 执行登录认证过程，通过调用 AuthenticationManager 的 authenticate(token) 方法实现
2. 将认证成功的认证信息存储到上下文，供后续访问授权的时候获取使用
3. 通过JWT生成令牌并返回给客户端，后续访问和操作都需要携带此令牌
SecurityUtils.java
/*** Security相关操作* @author Louis* @date Nov 28, 2018*/ public class SecurityUtils {/*** 系统登录认证* @param request* @param username* @param password* @param authenticationManager* @return*/public static JwtAuthenticatioToken login(HttpServletRequest request, String username, String password, AuthenticationManager authenticationManager) {JwtAuthenticatioToken token = new JwtAuthenticatioToken(username, password);token.setDetails(new WebAuthenticationDetailsSource().buildDetails(request));// 执行登录认证过程Authentication authentication = authenticationManager.authenticate(token);// 认证成功存储认证信息到上下文 SecurityContextHolder.getContext().setAuthentication(authentication);// 生成令牌并返回给客户端 token.setToken(JwtTokenUtils.generateToken(authentication));return token;}
...
}
令牌生成器
我们令牌是使用JWT生成的，下面是令牌生成的简要逻辑，详细参见源码。
JwtTokenUtils.java
/*** JWT工具类* @author Louis* @date Nov 28, 2018*/ public class JwtTokenUtils implements Serializable {.../*** 生成令牌** @param userDetails 用户* @return 令牌*/public static String generateToken(Authentication authentication) {Map<String, Object> claims = new HashMap<>(3);claims.put(USERNAME, SecurityUtils.getUsername(authentication));claims.put(CREATED, new Date());claims.put(AUTHORITIES, authentication.getAuthorities());return generateToken(claims);}/*** 从数据声明生成令牌** @param claims 数据声明* @return 令牌*/private static String generateToken(Map<String, Object> claims) {Date expirationDate = new Date(System.currentTimeMillis() + EXPIRE_TIME);return Jwts.builder().setClaims(claims).setExpiration(expirationDate).signWith(SignatureAlgorithm.HS512, SECRET).compact();}...}
登录身份认证组件
上面说到登录认证是通过调用 AuthenticationManager 的 authenticate(token) 方法实现的，而 AuthenticationManager 又是通过调用 AuthenticationProvider 的 authenticate(Authentication authentication) 来完成认证的，所以通过定制 AuthenticationProvider 也可以完成各种自定义的需求，我们这里只是简单的继承 DaoAuthenticationProvider 展示如何自定义，具体的大家可以根据各自的需求按需定制。
JwtAuthenticationProvider.java
package com.louis.springboot.spring.security.security;import org.springframework.security.authentication.UsernamePasswordAuthenticationToken; import org.springframework.security.authentication.dao.DaoAuthenticationProvider; import org.springframework.security.core.Authentication; import org.springframework.security.core.AuthenticationException; import org.springframework.security.core.userdetails.UserDetails; import org.springframework.security.core.userdetails.UserDetailsService; import org.springframework.security.crypto.bcrypt.BCryptPasswordEncoder;/*** 身份验证提供者* @author Louis* @date Nov 20, 2018*/ public class JwtAuthenticationProvider extends DaoAuthenticationProvider {public JwtAuthenticationProvider(UserDetailsService userDetailsService) {setUserDetailsService(userDetailsService);setPasswordEncoder(new BCryptPasswordEncoder());}@Overridepublic Authentication authenticate(Authentication authentication) throws AuthenticationException {// 可以在此处覆写整个登录认证逻辑return super.authenticate(authentication);}@Overrideprotected void additionalAuthenticationChecks(UserDetails userDetails, UsernamePasswordAuthenticationToken authentication)throws AuthenticationException {// 可以在此处覆写密码验证逻辑super.additionalAuthenticationChecks(userDetails, authentication);}}
认证信息获取服务
通过跟踪代码运行，我们发现像默认使用的 DaoAuthenticationProvider，在认证的使用都是通过一个叫 UserDetailsService 的来获取用户认证所需信息的。
AbstractUserDetailsAuthenticationProvider 定义了在 authenticate 方法中通过 retrieveUser 方法获取用户信息，子类 DaoAuthenticationProvider 通过 UserDetailsService 来进行获取， 一般情况，这个 UserDetailsService 需要我们自定义，实现从用户服务获取用户和权限信息封装到 UserDetails 的实现类。
AbstractUserDetailsAuthenticationProvider.java
public Authentication authenticate(Authentication authentication) throws AuthenticationException {...
if (user == null) {cacheWasUsed = false;try {user = retrieveUser(username, (UsernamePasswordAuthenticationToken) authentication);}...return createSuccessAuthentication(principalToReturn, authentication, user);}
DaoAuthenticationProvider.java
protected final UserDetails retrieveUser(String username, UsernamePasswordAuthenticationToken authentication)throws AuthenticationException {try {
UserDetails loadedUser = this.getUserDetailsService().loadUserByUsername(username);return loadedUser;}...}
我们自定义的 UserDetailsService，从我们的用户服务 UserService 中获取用户和权限信息。
UserDetailsServiceImpl.java
package com.louis.springboot.spring.security.security; import java.util.List; import java.util.Set; import java.util.stream.Collectors;import org.springframework.beans.factory.annotation.Autowired; import org.springframework.security.core.GrantedAuthority; import org.springframework.security.core.userdetails.UserDetails; import org.springframework.security.core.userdetails.UserDetailsService; import org.springframework.security.core.userdetails.UsernameNotFoundException; import org.springframework.stereotype.Service;import com.louis.springboot.spring.security.model.User; import com.louis.springboot.spring.security.service.UserService;/*** 用户登录认证信息查询* @author Louis* @date Nov 20, 2018*/ @Service public class UserDetailsServiceImpl implements UserDetailsService {@Autowiredprivate UserService userService;@Overridepublic UserDetails loadUserByUsername(String username) throws UsernameNotFoundException {User user = userService.findByUsername(username);if (user == null) {throw new UsernameNotFoundException("该用户不存在");}// 用户权限列表，根据用户拥有的权限标识与如 @PreAuthorize("hasAuthority('sys:menu:view')") 标注的接口对比，决定是否可以调用接口Set<String> permissions = userService.findPermissions(username);List<GrantedAuthority> grantedAuthorities = permissions.stream().map(GrantedAuthorityImpl::new).collect(Collectors.toList());return new JwtUserDetails(username, user.getPassword(), grantedAuthorities);} }
一般而言，定制 UserDetailsService 就可以满足大部分需求了，在 UserDetailsService 满足不了我们的需求的时候考虑定制 AuthenticationProvider。
如果直接定制UserDetailsService ，而不自定义 AuthenticationProvider，可以直接在配置文件 WebSecurityConfig 中这样配置。
WebSecurityConfig.java
@Overridepublic void configure(AuthenticationManagerBuilder auth) throws Exception {// 指定自定义的获取信息获取服务 auth.userDetailsService(userDetailsService)}
用户认证信息
上面 UserDetailsService 加载好用户认证信息后会封装认证信息到一个 UserDetails 的实现类。
默认实现是 User 类，我们这里没有特殊需要，简单继承即可，复杂需求可以在此基础上进行拓展。
JwtUserDetails.java
package com.louis.springboot.spring.security.security; import java.util.Collection;import org.springframework.security.core.GrantedAuthority; import org.springframework.security.core.userdetails.User;/*** 安全用户模型* @author Louis* @date Nov 28, 2018*/ public class JwtUserDetails extends User {private static final long serialVersionUID = 1L;public JwtUserDetails(String username, String password, Collection<? extends GrantedAuthority> authorities) {this(username, password, true, true, true, true, authorities);}public JwtUserDetails(String username, String password, boolean enabled, boolean accountNonExpired,boolean credentialsNonExpired, boolean accountNonLocked, Collection<? extends GrantedAuthority> authorities) {super(username, password, enabled, accountNonExpired, credentialsNonExpired, accountNonLocked, authorities);}}
用户操作代码
简单的用户模型，包含用户名密码。
User.java
package com.louis.springboot.spring.security.model;/*** 用户模型* @author Louis* @date Nov 28, 2018*/ public class User {private Long id;private String username;private String password;...}
用户服务接口，只提供简单的用户查询和权限查询接口用于模拟。
UserService.java
/*** 用户管理* @author Louis* @date Nov 28, 2018*/ public interface UserService {/*** 根据用户名查找用户* @param username* @return*/User findByUsername(String username);/*** 查找用户的菜单权限标识集合* @param userName* @return*/Set<String> findPermissions(String username);}
用户服务实现，只简单获取返回模拟数据，实际场景根据情况从DAO获取即可。
SysUserServiceImpl.java
@Service public class SysUserServiceImpl implements UserService {@Overridepublic User findByUsername(String username) {User user = new User();user.setId(1L);user.setUsername(username);String password = new BCryptPasswordEncoder().encode("123");user.setPassword(password);return user;}@Overridepublic Set<String> findPermissions(String username) {Set<String> permissions = new HashSet<>();permissions.add("sys:user:view");permissions.add("sys:user:add");permissions.add("sys:user:edit");return permissions;}}
用户控制器，提供三个测试接口，其中权限列表中未包含删除接口定义的权限（'sys:user:delete'），登录之后也将无权限调用。
UserController.java
/*** 用户控制器* @author Louis * @date Oct 31, 2018*/ @RestController @RequestMapping("user") public class UserController {@PreAuthorize("hasAuthority('sys:user:view')")@GetMapping(value="/findAll")public HttpResult findAll() {return HttpResult.ok("the findAll service is called success.");}@PreAuthorize("hasAuthority('sys:user:edit')")@GetMapping(value="/edit")public HttpResult edit() {return HttpResult.ok("the edit service is called success.");}@PreAuthorize("hasAuthority('sys:user:delete')")@GetMapping(value="/delete")public HttpResult delete() {return HttpResult.ok("the delete service is called success.");}}
登录认证检查过滤器
访问接口的时候，登录认证检查过滤器 JwtAuthenticationFilter 会拦截请求校验令牌和登录状态，并根据情况设置登录状态。
JwtAuthenticationFilter.java
/*** 登录认证检查过滤器* @author Louis* @date Nov 20, 2018*/ public class JwtAuthenticationFilter extends BasicAuthenticationFilter {@Autowiredpublic JwtAuthenticationFilter(AuthenticationManager authenticationManager) {super(authenticationManager);}@Overrideprotected void doFilterInternal(HttpServletRequest request, HttpServletResponse response, FilterChain chain) throws IOException, ServletException {// 获取token, 并检查登录状态 SecurityUtils.checkAuthentication(request);chain.doFilter(request, response);}}
SecurityUtils.java
/*** 获取令牌进行认证* @param request*/public static void checkAuthentication(HttpServletRequest request) {// 获取令牌并根据令牌获取登录认证信息Authentication authentication = JwtTokenUtils.getAuthenticationeFromToken(request);// 设置登录认证信息到上下文 SecurityContextHolder.getContext().setAuthentication(authentication);}
JwtTokenUtils.java
/*** 根据请求令牌获取登录认证信息* @param token 令牌* @return 用户名*/public static Authentication getAuthenticationeFromToken(HttpServletRequest request) {Authentication authentication = null;// 获取请求携带的令牌String token = JwtTokenUtils.getToken(request);if(token != null) {// 请求令牌不能为空if(SecurityUtils.getAuthentication() == null) {// 上下文中Authentication为空Claims claims = getClaimsFromToken(token);if(claims == null) {return null;}String username = claims.getSubject();if(username == null) {return null;}if(isTokenExpired(token)) {return null;}Object authors = claims.get(AUTHORITIES);List<GrantedAuthority> authorities = new ArrayList<GrantedAuthority>();if (authors != null && authors instanceof List) {for (Object object : (List) authors) {authorities.add(new GrantedAuthorityImpl((String) ((Map) object).get("authority")));}}authentication = new JwtAuthenticatioToken(username, null, authorities, token);} else {if(validateToken(token, SecurityUtils.getUsername())) {// 如果上下文中Authentication非空，且请求令牌合法，直接返回当前登录认证信息authentication = SecurityUtils.getAuthentication();}}}return authentication;}
接口测试
找到 SpringSecurityApplication， 启动程序， 访问 http://localhost:8080/swagger-ui.html，进入Swagger。
我们先再未登录没有令牌的时候直接访问接口，发现都返回无权限，禁止访问的结果。
返回拒绝访问结果。
打开 LoginController，输入我们用户名和密码（username:amdin, password:123）
登录成功之后，成功返回令牌，如下图所示。
拷贝返回的令牌，粘贴到令牌参数输入框，再次访问 /user/edit 接口。
这个时候，成功的返回了结果： the edit service is called success.
同样的，拷贝返回的令牌，粘贴到令牌参数输入框，访问 /user/delete 接口。
发现还是返回拒绝访问的结果，那是因为访问这个接口需要 'sys:user:delete' 权限，而我们之前返回的权限列表中并没有包含，所以授权访问失败。
我们修改一下 SysUserServiceImpl，添加上‘sys:user:delete’ 权限，重新登录，再次访问一遍。
发现删除接口也可以访问了，记住务必要重新调用登录接口，获取令牌后拷贝到删除接口，再次访问删除接口。
到此，Spring Security 的讲解就结束了，本人知识有限，有不正确的地方，烦请指正，不尽感激。
源码下载
码云：https://gitee.com/liuge1988/spring-boot-demo.git
作者：朝雨忆轻尘
出处：https://www.cnblogs.com/xifengxiaoma/
版权所有，欢迎转载，转载请注明原文作者及出处。
