Spring @CrossOrigin 通配符解决跨域问题

@CrossOrigin 通配符解决跨域问题

痛点:

对很多api接口需要开放H5 Ajax跨域请求支持由于环境多套域名不同,而CrossOrigin 原生只支持* 或者具体域名的跨域支持所以想让CrossOrigin 支持下通配 *.abc.com 支持所有origin 为 abc.com域(包括各种子域名)名来的Ajax 请求支持跨域.

解决思路:

支持通配

@CrossOrigin(origins = {"*.abc.com"}) 通配主域+任意子域 www.abc.com order.api.abc.com dev.order.abc.com 等
@CrossOrigin(origins = {"*.order.abc.com"}) 通配order子域子域名 dev.order.abc.com test.order.abc.com uat.order.abc.com 等

Spring 默认支持cors 拓展下 Spring 对跨域的处理类

解决方案:

获取 RequestMappingHandlerMapping 设置自定义 MyCorsProcessor 代替DefaultCorsProcessor

/*** 给requestMappingHandlerMapping 对象注入自定义 MyCorsProcessor* @author tomas* @create 2019/8/12**/
@Configuration
@EnableWebMvc
public class MyWebMvcConfig extends DelegatingWebMvcConfiguration {@Beanpublic RequestMappingHandlerMapping requestMappingHandlerMapping() {RequestMappingHandlerMapping handlerMapping = super.requestMappingHandlerMapping();handlerMapping.setCorsProcessor(new MyCorsProcessor());return handlerMapping;}
}

/*** MyCorsProcessor 描述* 自定义 如果xxx.com域下的请求允许跨域** @author tomas* @create 2019/8/12**/
public class MyCorsProcessor extends DefaultCorsProcessor {/*** Check the origin of the request against the configured allowed origins.* @param requestOrigin the origin to check* @return the origin to use for the response, or {@code null} which* means the request origin is not allowed*/@Nullablepublic String checkOrigin(CorsConfiguration config, @Nullable String requestOrigin) {if (!StringUtils.hasText(requestOrigin)) {return null;}if (ObjectUtils.isEmpty(config.getAllowedOrigins())) {return null;}if (config.getAllowedOrigins().contains(CorsConfiguration.ALL)) {if (config.getAllowCredentials() != Boolean.TRUE) {return CorsConfiguration.ALL;}else {return requestOrigin;}}AntPathMatcher pathMatcher = new AntPathMatcher("|");      for (String allowedOrigin :config.getAllowedOrigins()) {if (requestOrigin.equalsIgnoreCase(allowedOrigin)) {return requestOrigin;}//推荐方式:正则  注意(CrossOrigin(origins = {"*.abc.com"}) ) 主域会匹配主域+子域   origins = {"*.pay.abc.com"} 子域名只会匹配子域if(pathMatcher.isPattern(allowedOrigin)&&pathMatcher.match(allowedOrigin,requestOrigin)){return requestOrigin;}//不推荐方式:写死if(allowedOrigin.contains("*.abc.com")&& requestOrigin.contains("abc.com")){return requestOrigin;}}return null;}
}

原理分析:

Spring mvc cors

Spring MVC 的文档这样说：
Spring MVC 的 HandlerMapping 实现内置支持 CORS, 在成功映射一个请求到一个 handler 之后， HandlerMapping 会检查 CORS 配置以采取下一步动作。
https://docs.spring.io/spring/docs/current/spring-framework-reference/web.html#mvc-cors-processing
Spring MVC 会在找到 handler 后通过添加一个拦截器来检查 CORS 配置。

下面来看一下 Spring MVC 中的 CORS 的实现。
DispatcherServlet 调用 AbstractHandlerMapping 中的 getHandler() 方法：

  /*** Look up a handler for the given request, falling back to the default* handler if no specific one is found.* @param request current HTTP request* @return the corresponding handler instance, or the default handler* @see #getHandlerInternal*/
@Override
@Nullable
public final HandlerExecutionChain getHandler(HttpServletRequest request) throws Exception {Object handler = getHandlerInternal(request);if (handler == null) {handler = getDefaultHandler();}if (handler == null) {return null;}// Bean name or resolved handler?if (handler instanceof String) {String handlerName = (String) handler;handler = obtainApplicationContext().getBean(handlerName);}HandlerExecutionChain executionChain = getHandlerExecutionChain(handler, request);if (CorsUtils.isCorsRequest(request)) {CorsConfiguration globalConfig = this.globalCorsConfigSource.getCorsConfiguration(request);CorsConfiguration handlerConfig = getCorsConfiguration(handler, request);CorsConfiguration config = (globalConfig != null ? globalConfig.combine(handlerConfig) : handlerConfig);executionChain = getCorsHandlerExecutionChain(request, executionChain, config);}return executionChain;}

对于 Ajax 请求 getCorsHandlerExecutionChain 自动加上一个 CorsInterceptor 的拦截器：

 /*** Update the HandlerExecutionChain for CORS-related handling.* <p>For pre-flight requests, the default implementation replaces the selected* handler with a simple HttpRequestHandler that invokes the configured* {@link #setCorsProcessor}.* <p>For actual requests, the default implementation inserts a* HandlerInterceptor that makes CORS-related checks and adds CORS headers.* @param request the current request* @param chain the handler chain* @param config the applicable CORS configuration (possibly {@code null})* @since 4.2*/
protected HandlerExecutionChain getCorsHandlerExecutionChain(HttpServletRequest request,HandlerExecutionChain chain, @Nullable CorsConfiguration config) {if (CorsUtils.isPreFlightRequest(request)) {HandlerInterceptor[] interceptors = chain.getInterceptors();chain = new HandlerExecutionChain(new PreFlightHandler(config), interceptors);}else {chain.addInterceptor(new CorsInterceptor(config));}return chain;}

AbstractHandlerMapping中私有class CorsInterceptor


private class CorsInterceptor extends HandlerInterceptorAdapter implements CorsConfigurationSource {@Nullableprivate final CorsConfiguration config;public CorsInterceptor(@Nullable CorsConfiguration config) {this.config = config;}@Overridepublic boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler)throws Exception {return corsProcessor.processRequest(this.config, request, response);}@Override@Nullablepublic CorsConfiguration getCorsConfiguration(HttpServletRequest request) {return this.config;}}

CorsInterceptor中preHandle方法实际处理 processRequest的是AbstractHandlerMapping.this.corsProcessor

这个corsProcessor =new DefaultCorsProcessor() 是一个默认的跨域处理类

我们的重点就是重写DefaultCorsProcessor的checkOrigin 方法

 @Override@SuppressWarnings("resource")public boolean processRequest(@Nullable CorsConfiguration config, HttpServletRequest request,HttpServletResponse response) throws IOException {if (!CorsUtils.isCorsRequest(request)) {return true;}......return handleInternal(serverRequest, serverResponse, config, preFlightRequest);}/*** Handle the given request.*/protected boolean handleInternal(ServerHttpRequest request, ServerHttpResponse response,CorsConfiguration config, boolean preFlightRequest) throws IOException {String requestOrigin = request.getHeaders().getOrigin();String allowOrigin = checkOrigin(config, requestOrigin);HttpHeaders responseHeaders = response.getHeaders();responseHeaders.addAll(HttpHeaders.VARY, Arrays.asList(HttpHeaders.ORIGIN,HttpHeaders.ACCESS_CONTROL_REQUEST_METHOD, HttpHeaders.ACCESS_CONTROL_REQUEST_HEADERS));if (allowOrigin == null) {logger.debug("Rejecting CORS request because '" + requestOrigin + "' origin is not allowed");rejectRequest(response);return false;}..........response.flush();return true;}/*** Check the origin and determine the origin for the response. The default* implementation simply delegates to* {@link org.springframework.web.cors.CorsConfiguration#checkOrigin(String)}.*/// 重写此方法 支持通配符 或者支持正则表达式 写法见开头解决方案@Nullableprotected String checkOrigin(CorsConfiguration config, @Nullable String requestOrigin) {return config.checkOrigin(requestOrigin);}
}

dispatcherServlet 中在真正 invoke handler 之前会先调用拦截器：从而通过加的 cors 拦截器阻止请求。
doDispatch 方法：

 // Determine handler adapter for the current request.HandlerAdapter ha = getHandlerAdapter(mappedHandler.getHandler());// Process last-modified header, if supported by the handler.String method = request.getMethod();boolean isGet = "GET".equals(method);if (isGet || "HEAD".equals(method)) {long lastModified = ha.getLastModified(request, mappedHandler.getHandler());if (logger.isDebugEnabled()) {logger.debug("Last-Modified value for [" + getRequestUri(request) + "] is: " + lastModified);}if (new ServletWebRequest(request, response).checkNotModified(lastModified) && isGet) {return;}}if (!mappedHandler.applyPreHandle(processedRequest, response)) {return;}// Actually invoke the handler.mv = ha.handle(processedRequest, response, mappedHandler.getHandler());if (asyncManager.isConcurrentHandlingStarted()) {return;}applyDefaultViewName(processedRequest, mv);mappedHandler.applyPostHandle(processedRequest, response, mv);

注意问题:

如果您正在使用 Spring Security，请确保在 Spring 安全级别启用 CORS，并允许它利用 Spring MVC 级别定义的配置。在 Spring 安全级别启用 CORS：


@EnableWebSecuritypublic class WebSecurityConfig extends WebSecurityConfigurerAdapter {    @Override    protected void configure(HttpSecurity http) throws Exception {        http.cors().and()...    }}

全局 CORS 配置

　　除了细粒度、基于注释的配置之外，您还可能需要定义一些全局 CORS 配置。这类似于使用筛选器，但可以声明为 Spring MVC 并结合细粒度 @CrossOrigin 配置。默认情况下，所有 origins and GET, HEAD and POST methods 是允许的。

使整个应用程序的 CORS 简化为：


@Configuration@EnableWebMvcpublic class WebConfig extends WebMvcConfigurer {    @Override    public void addCorsMappings(CorsRegistry registry) {        registry.addMapping("/**");    }}

基于过滤器的 CORS 支持

　　作为上述其他方法的替代，Spring 框架还提供了 CorsFilter。在这种情况下，不用使用@CrossOrigin或``WebMvcConfigurer#addCorsMappings(CorsRegistry),，例如，可以在 Spring Boot 应用程序中声明如下的过滤器：


@Configurationpublic class MyConfiguration {    @Bean    public FilterRegistrationBean corsFilter() {        UrlBasedCorsConfigurationSource source = new UrlBasedCorsConfigurationSource();        CorsConfiguration config = new CorsConfiguration();        config.setAllowCredentials(true);        config.addAllowedOrigin("http://domain1.com");        config.addAllowedHeader("*");        config.addAllowedMethod("*");        source.registerCorsConfiguration("/**", config);        FilterRegistrationBean bean = new FilterRegistrationBean(new CorsFilter(source));        bean.setOrder(0);        return bean;    }}

感谢 @大神张林峰老师 @王昆老师 @中睿老师给出的宝贵意见

1、官方文档 https://spring.io/blog/2015/06/08/cors-support-in-spring-framework

2、https://blog.csdn.net/weixin_33713503/article/details/88039675

https://www.jianshu.com/p/d05303d34222

https://www.cnblogs.com/helloz/p/10961039.html

2、https://blog.csdn.net/taiyangnimeide/article/details/78305131

3、https://blog.csdn.net/snowin1994/article/details/53035433

* * *

转载于:https://www.cnblogs.com/wangdaijun/p/11348463.html