(1). 概述
在前面(第六节),分析了:RoutePredicateHandlerMapping,它主要获取用户配置:Route中的断言(Predicate)对象.调用apply(Exchange).获取符合断言的Route对象.并把这个Route设置到:Exchange中.所以:Gateway是首先执行断言(Predicate).
这一节,主要讲解:Filter的执行.
(2). FilteringWebHandler类图
- 所有的:GlobalFilter都会进行适配成:GatewayFilterAdapter(典型的适配模式),而GatewayFilterAdapter,又会被:OrderedGatewayFilter对象包裹.
(2). FilteringWebHandler
public class FilteringWebHandler
// ***********************************************
// SimpleHandlerAdapter会回调handler方法.
// ***********************************************
implements WebHandler {
private final List<GatewayFilter> globalFilters;
public FilteringWebHandler(List<GlobalFilter> globalFilters) {
// 2.1 对globalFilters进行加工处理
this.globalFilters = loadFilters(globalFilters);
}
private static List<GatewayFilter> loadFilters(List<GlobalFilter> filters) {
// 2.2 适配并加工
return filters.stream()
.map(filter -> {
// **********************************************
// 适配模式,把GlobalFilter适配成:GatewayFilter
// **********************************************
GatewayFilterAdapter gatewayFilter = new GatewayFilterAdapter(filter);
// 判断是否为:Ordered排序的子类
if (filter instanceof Ordered) {
int order = ((Ordered) filter).getOrder();
// Wrapper模式
return new OrderedGatewayFilter(gatewayFilter, order);
}
return gatewayFilter;
}).collect(Collectors.toList());
} // end loadFilters
// reactor-netty解析后,最终会调用:handler.
public Mono<Void> handle(ServerWebExchange exchange) {
// 获取用户级别的:GatewayFilter
// GATEWAY_ROUTE_ATTR是在:
// RoutePredicateHandlerMapping.getHandlerInternal
// 进行设置的.
Route route = exchange.getRequiredAttribute(GATEWAY_ROUTE_ATTR);
List<GatewayFilter> gatewayFilters = route.getFilters();
// 获取全局级别的:GatewayFilter(GlobalFilter已经被适配成:GatewayFilter)
List<GatewayFilter> combined = new ArrayList<>(this.globalFilters);
combined.addAll(gatewayFilters);
//TODO: needed or cached?
// 排序
AnnotationAwareOrderComparator.sort(combined);
if (logger.isDebugEnabled()) {
logger.debug("Sorted gatewayFilterFactories: "+ combined);
}
// **************************************************************************
// RouteToRequestUrlFilter负责把网关:URL进行转换成target uri.
// org.springframework.cloud.gateway.filter.RouteToRequestUrlFilter
// NettyRoutingFilter负责把请求转发到:target uri
// org.springframework.cloud.gateway.filter.NettyRoutingFilter
// **************************************************************************
// combined =
// [
OrderedGatewayFilter{delegate=GatewayFilterAdapter{delegate=AdaptCachedBodyGlobalFilter}, order=-2147482648},
OrderedGatewayFilter{delegate=GatewayFilterAdapter{delegate=NettyWriteResponseFilter}, order=-1},
OrderedGatewayFilter{delegate=GatewayFilterAdapter{delegate=ForwardPathFilter}, order=0},
OrderedGatewayFilter{delegate=RewritePathGatewayFilterFactory$$Lambda$570/369895363, order=1},
OrderedGatewayFilter{delegate=SetStatusGatewayFilterFactory$$Lambda$572/14733990, order=2},
OrderedGatewayFilter{delegate=GatewayFilterAdapter{delegate=RouteToRequestUrlFilter}, order=10000},
OrderedGatewayFilter{delegate=GatewayFilterAdapter{delegate=WebsocketRoutingFilter}, order=2147483646},
OrderedGatewayFilter{delegate=GatewayFilterAdapter{NettyRoutingFilter}, order=2147483647},
OrderedGatewayFilter{delegate=GatewayFilterAdapter{delegate=ForwardRoutingFilter}, order=2147483647}
// ]
// 挨个调用相应的:filter方法
return new DefaultGatewayFilterChain(combined).filter(exchange);
}// end handle
}
(3). NettyRoutingFilter初始化
NettyRoutingFilter负责proxy请求到目标服务器.
public class GatewayAutoConfiguration {
@Configuration
@ConditionalOnClass(HttpClient.class)
protected static class NettyConfiguration {
@Bean
@ConditionalOnMissingBean
public HttpClient httpClient(HttpClientProperties properties) {
// configure pool resources
HttpClientProperties.Pool pool = properties.getPool();
ConnectionProvider connectionProvider;
if (pool.getType() == DISABLED) {
connectionProvider = ConnectionProvider.newConnection();
} else if (pool.getType() == FIXED) {
connectionProvider = ConnectionProvider.fixed(pool.getName(),
pool.getMaxConnections(), pool.getAcquireTimeout());
} else {
connectionProvider = ConnectionProvider.elastic(pool.getName());
}
HttpClient httpClient = HttpClient.create(connectionProvider)
.tcpConfiguration(tcpClient -> {
if (properties.getConnectTimeout() != null) {
tcpClient = tcpClient.option(ChannelOption.CONNECT_TIMEOUT_MILLIS, properties.getConnectTimeout());
}
// configure proxy if proxy host is set.
HttpClientProperties.Proxy proxy = properties.getProxy();
if (StringUtils.hasText(proxy.getHost())) {
tcpClient = tcpClient.proxy(proxySpec -> {
ProxyProvider.Builder builder = proxySpec
.type(ProxyProvider.Proxy.HTTP)
.host(proxy.getHost());
PropertyMapper map = PropertyMapper.get();
map.from(proxy::getPort)
.whenNonNull()
.to(builder::port);
map.from(proxy::getUsername)
.whenHasText()
.to(builder::username);
map.from(proxy::getPassword)
.whenHasText()
.to(password -> builder.password(s -> password));
map.from(proxy::getNonProxyHostsPattern)
.whenHasText()
.to(builder::nonProxyHosts);
});
}
return tcpClient;
});
HttpClientProperties.Ssl ssl = properties.getSsl();
if (ssl.getTrustedX509CertificatesForTrustManager().length > 0
|| ssl.isUseInsecureTrustManager()) {
httpClient = httpClient.secure(sslContextSpec -> {
// configure ssl
SslContextBuilder sslContextBuilder = SslContextBuilder.forClient();
X509Certificate[] trustedX509Certificates = ssl
.getTrustedX509CertificatesForTrustManager();
if (trustedX509Certificates.length > 0) {
sslContextBuilder.trustManager(trustedX509Certificates);
} else if (ssl.isUseInsecureTrustManager()) {
sslContextBuilder.trustManager(InsecureTrustManagerFactory.INSTANCE);
}
sslContextSpec.sslContext(sslContextBuilder)
.defaultConfiguration(ssl.getDefaultConfigurationType())
.handshakeTimeout(ssl.getHandshakeTimeout())
.closeNotifyFlushTimeout(ssl.getCloseNotifyFlushTimeout())
.closeNotifyReadTimeout(ssl.getCloseNotifyReadTimeout());
});
}
return httpClient;
}
@Bean
public HttpClientProperties httpClientProperties() {
return new HttpClientProperties();
}
// ***************************************************************
// NettyRoutingFilter
// ***************************************************************
@Bean
public NettyRoutingFilter routingFilter(HttpClient httpClient,
ObjectProvider<List<HttpHeadersFilter>> headersFilters,
HttpClientProperties properties) {
return new NettyRoutingFilter(httpClient, headersFilters, properties);
}
@Bean
public NettyWriteResponseFilter nettyWriteResponseFilter(GatewayProperties properties) {
return new NettyWriteResponseFilter(properties.getStreamingMediaTypes());
}
@Bean
public ReactorNettyWebSocketClient reactorNettyWebSocketClient(HttpClient httpClient) {
return new ReactorNettyWebSocketClient(httpClient);
}
} //end NettyConfiguration
}
(4). 总结
- FilteringWebHandler是WebHandler的实现类,它负责把GlobalFilter转换成:GatewayFilter.
- handler在执行时,获得配置的:GatewayFilter和全局GatewayFilterAdapter.调用相应的:filter方法.
