SpringCloudGateway开发过程解析

2023-08-05 03:46:04 309

路由简介：

1.SpringCloudGateWay是用于替代zuul作为API网关，在gateway中有三个重要的名词：过滤器，断言，路由

过滤器与断言是路由的一部分，路由便是将请求进行一系列的处理后分发到各个服务的一个过程。

路由的过程：首先会加载断言以及路由，在接受到请求后根据断言加载的顺序会匹配到先加载的断言，只有与断言匹配了的请求才会进入路由，没有匹配到的服务会将请求当成普通的访问请求。

2：路由加载断言的方式：

断言加载的方式有四种，分别是配置文件，java编码，数据库以及注册中心

第一种配置文件：

在官方文档中主要介绍的就是配置文件的加载方式

官方地址：https://cloud.spring.io/spring-cloud-gateway/reference/html/#gateway-starter

一般的断言有三种要素：id,uri,predicate.

id是断言的标识，uri是ip+端口，predicate则是断言匹配的规则

3：示例：

新建一个springboot项目，并且引入springcloudgateway的依赖



org.springframework.boot
spring-boot-starter-test
test


org.springframework.cloud
spring-cloud-starter-gateway

在启动类注册三个全局过滤器

@SpringBootApplication
publicclassGateWayApplication{

publicstaticvoidmain(String[]args){
SpringApplication.run(GateWayApplication.class,args);
}

@Bean
@Order(-1)
publicGlobalFiltera(){
return(exchange,chain)->{

returnchain.filter(exchange).then(Mono.fromRunnable(()->{
System.out.println(-1);
}));
};
}

@Bean
@Order(0)
publicGlobalFilterb(){
return(exchange,chain)->{

returnchain.filter(exchange).then(Mono.fromRunnable(()->{
System.out.println(0);
}));
};
}

@Bean
@Order(1)
publicGlobalFilterc(){
return(exchange,chain)->{

returnchain.filter(exchange).then(Mono.fromRunnable(()->{
System.out.println(1);
}));
};
}
}

在配置文件类配置两条路由

server.port:7777
spring:
application:
name:gateway
cloud:
gateway:
discovery:
locator:
enabled:true
lower-case-service-id:true
routes:
-id:method_route
uri:http://127.0.0.1:9999
predicates:
-Method=GET
-id:method_route
uri:http://127.0.0.1:8006
predicates:
-Method=GET

发送请求，请求到达后匹配的是第一条路由，由此可以知道路由匹配的顺序会根据加载的顺序来

4：SpringCloudGateWay从注册中心获得路由

在官方文档中，我们可以看到有这样的一段话

ConfiguringPredicatesandFiltersForDiscoveryClientRoutes

BydefaulttheGatewaydefinesasinglepredicateandfilterforroutescreatedviaaDiscoveryClient.

Thedefaultpredicateisapathpredicatedefinedwiththepattern/serviceId/**,whereserviceIdistheidoftheservicefromtheDiscoveryClient.

Thedefaultfilterisrewritepathfilterwiththeregex/serviceId/(?.*)andthereplacement/${remaining}.Thisjuststripstheserviceidfromthepathbeforetherequestissentdownstream.

Ifyouwouldliketocustomizethepredicatesand/orfiltersusedbytheDiscoveryClientroutesyoucandosobysettingspring.cloud.gateway.discovery.locator.predicates[x]andspring.cloud.gateway.discovery.locator.filters[y].Whendoingsoyouneedtomakesuretoincludethedefaultpredicateandfilterabove,ifyouwanttoretainthatfunctionality.Belowisanexampleofwhatthislookslike.

地址：https://cloud.spring.io/spring-cloud-gateway/reference/html/#_global_filters

spring.cloud.gateway.discovery.locator.predicates[0].name:Path
spring.cloud.gateway.discovery.locator.predicates[0].args[pattern]:"'/'+serviceId+'/**'"
spring.cloud.gateway.discovery.locator.predicates[1].name:Host
spring.cloud.gateway.discovery.locator.predicates[1].args[pattern]:"'**.foo.com'"
spring.cloud.gateway.discovery.locator.filters[0].name:Hystrix
spring.cloud.gateway.discovery.locator.filters[0].args[name]:serviceId
spring.cloud.gateway.discovery.locator.filters[1].name:RewritePath
spring.cloud.gateway.discovery.locator.filters[1].args[regexp]:"'/'+serviceId+'/(?.*)'"
spring.cloud.gateway.discovery.locator.filters[1].args[replacement]:"'/${remaining}'"

根据文档介绍，依照这种方式，可以从注册中心获得断言与过滤器的配置

5：SpringGateWay从数据库配置路由

publicclassDBRouteDefinitionRepositoryimplementsRouteDefinitionRepository

项目中实现了RouteDefinitionRepository后，springgateway会采用你实现的这个类去加载路由，如果不实现则采用他默认的方式加载路由

publicclassDBRouteDefinitionRepositoryimplementsRouteDefinitionRepository{
//保存路由
privatefinalMaproutes=synchronizedMap(newLinkedHashMap());

privateLoggerlog=LoggerFactory.getLogger(DBRouteDefinitionRepository.class);
//初始標準
privatebooleaninit_flag=true;
//
privatefinalGatewayPropertiesproperties;
privateDynamicRouteServiceImplservice;


publicDBRouteDefinitionRepository(GatewayPropertiesproperties){
this.properties=properties;
this.service=newDynamicRouteServiceImpl();

}

@Override
publicFluxgetRouteDefinitions(){
if(init_flag){
ListrouteDefinitions=newArrayList<>();
Listrs=newArrayList<>();
try{
routeDefinitions=service.quertAllRoutes();//从数据库中加载route
rs=this.properties.getRoutes();//获得配置文件的route
for(RouteDefinitionrse:rs){
routeDefinitions.add(rse);
}
routes.clear();
routeDefinitions.forEach(x->routes.put(x.getId(),x));
init_flag=false;
}catch(Exceptione){
//TODOAuto-generatedcatchblock
e.printStackTrace();
log.error("InitRouteFail,Can'tgetRoutes.",e);
}
returnFlux.fromIterable(routeDefinitions);
}else{
returnFlux.fromIterable(routes.values());
}

}

@Override
publicMonodelete(MonorouteId){
returnrouteId.flatMap(id->{
if(routes.containsKey(id)){
routes.remove(id);
returnMono.empty();
}
returnMono.defer(()->Mono.error(newNotFoundException("RouteDefinitionnotfound:"+routeId)));
});
}

@Override
publicMonosave(Monoroute){
returnroute.flatMap(r->{
routes.put(r.getId(),r);
returnMono.empty();
});
}
}

这个是我自己实现的类，这个类可以从数据库与配置文件中获得路由配置，从数据库中获得路由配置可以根据个人的要求来

@Validated
publicclassRouteDefinition{

@NotEmpty
privateStringid=UUID.randomUUID().toString();

@NotEmpty
@Valid
privateListpredicates=newArrayList<>();

@Valid
privateListfilters=newArrayList<>();

@NotNull
privateURIuri;

privateintorder=0;

publicRouteDefinition(){
}

publicRouteDefinition(Stringtext){
inteqIdx=text.indexOf('=');
if(eqIdx<=0){
thrownewValidationException("UnabletoparseRouteDefinitiontext'"+text
+"'"+",mustbeoftheformname=value");
}

setId(text.substring(0,eqIdx));

String[]args=tokenizeToStringArray(text.substring(eqIdx+1),",");

setUri(URI.create(args[0]));

for(inti=1;igetPredicates(){
returnpredicates;
}

publicvoidsetPredicates(Listpredicates){
this.predicates=predicates;
}

publicListgetFilters(){
returnfilters;
}

publicvoidsetFilters(Listfilters){
this.filters=filters;
}

publicURIgetUri(){
returnuri;
}

publicvoidsetUri(URIuri){
this.uri=uri;
}

publicintgetOrder(){
returnorder;
}

publicvoidsetOrder(intorder){
this.order=order;
}

@Override
publicbooleanequals(Objecto){
if(this==o){
returntrue;
}
if(o==null||getClass()!=o.getClass()){
returnfalse;
}
RouteDefinitionrouteDefinition=(RouteDefinition)o;
returnObjects.equals(id,routeDefinition.id)
&&Objects.equals(predicates,routeDefinition.predicates)
&&Objects.equals(order,routeDefinition.order)
&&Objects.equals(uri,routeDefinition.uri);
}

@Override
publicinthashCode(){
returnObjects.hash(id,predicates,uri);
}

@Override
publicStringtoString(){
return"RouteDefinition{"+"id='"+id+'\''+",predicates="+predicates
+",filters="+filters+",uri="+uri+",order="+order+'}';
}

}

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持毛票票。

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SpringCloudGateway开发过程解析

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