作者:codecraft
原文链接:https://segmentfault.com/a/1190000015282327
序
本文主要研究下spring cloud gateway的RedirectToGatewayFilter
GatewayAutoConfiguration
spring-cloud-gateway-core-2.0.0.RC2-sources.jar!/org/springframework/cloud/gateway/config/GatewayAutoConfiguration.java
@Configuration@ConditionalOnProperty(name = "spring.cloud.gateway.enabled", matchIfMissing = true)@EnableConfigurationProperties@AutoConfigureBefore(HttpHandlerAutoConfiguration.class)@AutoConfigureAfter({GatewayLoadBalancerClientAutoConfiguration.class, GatewayClassPathWarningAutoConfiguration.class})@ConditionalOnClass(DispatcherHandler.class)
public class GatewayAutoConfiguration { //......
@Bean
public RedirectToGatewayFilterFactory redirectToGatewayFilterFactory() { return new RedirectToGatewayFilterFactory();
} //......}RedirectToGatewayFilterFactory
spring-cloud-gateway-core-2.0.0.RC2-sources.jar!/org/springframework/cloud/gateway/filter/factory/RedirectToGatewayFilterFactory.java
public class RedirectToGatewayFilterFactory extends AbstractGatewayFilterFactory<RedirectToGatewayFilterFactory.Config> { public static final String STATUS_KEY = "status"; public static final String URL_KEY = "url"; public RedirectToGatewayFilterFactory() { super(Config.class);
} @Override
public List<String> shortcutFieldOrder() { return Arrays.asList(STATUS_KEY, URL_KEY);
} @Override
public GatewayFilter apply(Config config) { return apply(config.status, config.url);
} public GatewayFilter apply(String statusString, String urlString) { final HttpStatus httpStatus = parse(statusString);
Assert.isTrue(httpStatus.is3xxRedirection(), "status must be a 3xx code, but was " + statusString); final URL url; try {
url = URI.create(urlString).toURL();
} catch (MalformedURLException e) { throw new IllegalArgumentException("Invalid url " + urlString, e);
} return apply(httpStatus, url);
} public GatewayFilter apply(HttpStatus httpStatus, URL url) { return (exchange, chain) ->
chain.filter(exchange).then(Mono.defer(() -> { if (!exchange.getResponse().isCommitted()) {
setResponseStatus(exchange, httpStatus); final ServerHttpResponse response = exchange.getResponse();
response.getHeaders().set(HttpHeaders.LOCATION, url.toString()); return response.setComplete();
} return Mono.empty();
}));
} public static class Config {
String status;
String url; public String getStatus() { return status;
} public void setStatus(String status) { this.status = status;
} public String getUrl() { return url;
} public void setUrl(String url) { this.url = url;
}
}
}可以看到配置文件有两个参数，一个是status，一个是url
这里对status进行了校验，必须是3xx
然后设置response status code，同时在header的location写入要跳转的url
实例
spring: cloud: gateway: routes: - id: prefixpath_route uri: http://example.org filters: - RedirectTo=302, http://acme.org
小结
spring cloud gateway提供了RedirectToGatewayFilter，可以直接在配置文件对指定的路由进行3xx跳转。