SpringCloudGateway开发过程解析

SpringCloudGateway开发过程解析

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

public class GateWayApplication {

public static void main(String[] args) {

SpringApplication.run(GateWayApplication.class, args);

}

@Bean

@Order(-1)

public GlobalFilter a() {

return (exchange, chain) -> {

return chain.filter(exchange).then(Mono.fromRunnable(() -> {

System.out.println(-1);

}));

};

}

@Bean

@Order(0)

public GlobalFilter b() {

return (exchange, chain) -> {

return chain.filter(exchange).then(Mono.fromRunnable(() -> {

System.out.println(0);

}));

};

}

@Bean

@Order(1)

public GlobalFilter c() {

return (exchange, chain) -> {

return chain.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

Configuring Predicates and Filters For DiscogqvCZveryClient Routes

By default the Gateway defines a single predicate and filter for routes created via a DiscoveryClient.

The default predicate is a path predicate defined with the pattern /serviceId/**, where serviceId is the id of the service from the DiscoveryClient.

The default filter is rewrite path filter with the regex /serviceId/(?.*) and the replacement /${remaining}. This just strips the service id from the path before the request is sent downstream.

If you would like to customize the predicates and/or filters used by the DiscoveryClient routes you can do so by setting spring.cloud.gateway.discovery.locator.predicates[x] and spring.cloud.gateway.discovery.locator.filters[y]. When doing so you need to make sure to include the default predicate and filter above, if you want to retain that functionality. Below is an example of what this looks like.

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

http://

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

public class DBRouteDefinitionRepository implements RouteDefinitionRepository

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

public class DBRouteDefinitionRepository implements RouteDefinitionRepository {

//保存路由

private final Map routes = synchronizedMap(new LinkedHashMap());

private Logger log = LoggerFactory.getLogger(DBRouteDefinitionRepository.class);

//初始標準

private boolean init_flag = true;

//

private final GatewayProperties properties;

private DynamicRouteServiceImpl service;

public DBRouteDefinitionRepository(GatewayProperties properties) {

this.properties = properties;

this.service = new DynamicRouteServiceImpl();

}

@Override

public Flux getRouteDefinitions() {

if(init_flag) {

List routeDefinitions = new ArrayList<>();

List rs = new ArrayList<>();

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 (RouteDefinition rse : rs) {

routeDefinitions.add(rse);

}

routes.clear();

routeDefinitions.forEach(x->routes.put(x.getId(), x));

init_flag=false;

} catch (Exception e) {

// TODO Auto-generated catch block

e.printStackTrace();

log.error("Init Route Fail,Can't get Routes.",e);

}

return Flux.fromIterable(routeDefinitions);

}else {

return Flux.fromIterable(routes.values());

}

}

@Override

public Mono delete(Mono routeId) {

return routeId.flatMap(id -> {

if (routes.containsKey(id)) {

routes.remove(id);

return Mono.empty();

}

return Mono.defer(() -> Mono.error(new NotFoundException("RouteDefinition not found: "+routeId)));

});

}

@Override

public Mono save(Mono route) {

return route.flatMap( r -> {

routes.put(r.getId(), r);

return Mono.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

public class RouteDefinition {

@NotEmpty

private String id = UUID.randomUUID().toString();

@NotEmpty

@Valid

private List predicates = new ArrayList<>();

@Valid

private List filters = new ArrayList<>();

@NotNull

private URI uri;

private int order = 0;

public RouteDefinition() {

}

public RouteDefinition(String text) {

int eqIdx = text.indexOf('=');

if (eqIdx <= 0) {

throw new ValidationException("Unable to parse RouteDefinition text '" + text

+ "'" + ", must be of the form name=value");

}

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

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

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

for (int i = 1; i < args.length; i++) {

this.predicates.add(new PredicateDefinition(args[i]));

}

}

public String getId() {

return id;

}

public void setId(String id) {

this.id = id;

}

public List getPredicates() {

return predicates;

}

public void setPredicates(List predicates) {

this.predicates = predicates;

}

public List getFilters() {

return filters;

}

public void setFilters(List filters) {

this.filters = filters;

}

public URI getUri() {

return uri;

}

public void setUri(URI uri) {

this.uri = uri;

}

public int getOrder() {

return order;

}

public void setOrder(int order) {

this.order = order;

}

@Override

public boolean equals(Object o) {

if (this == o) {

return true;

}

if (o == null || getClass() != o.getClass()) {

return false;

}

RouteDefinition routeDefinition = (RouteDefinition) o;

return Objects.equals(id, routeDefinition.id)

&& Objects.equals(predicates, routeDefinition.predicates)

&& Objects.equals(order, routeDefinition.order)

&& Objects.equals(uri, routeDefinition.uri);

}

@Override

public int hashCode() {

return Objects.hash(id, predicates, uri);

}

@Override

public String toString() {

return "RouteDefinition{" + "id='" + id + '\'' + ", predicates=" + predigqvCZcates

+ ", filters=" + filters + ", uri=" + uri + ", order=" + order + '}';

}

}

版权声明：本文内容由网络用户投稿，版权归原作者所有，本站不拥有其著作权，亦不承担相应法律责任。如果您发现本站中有涉嫌抄袭或描述失实的内容，请联系我们jiasou666@gmail.com 处理，核实后本网站将在24小时内删除侵权内容。