Spring cloud gateway工作流程原理解析

Z时代
2024-01-10
分类：综合

spring cloud gateway的包结构(在Idea 2019.3中展示)

这个包是spring-cloud-gateway-core.这里是真正的spring-gateway的实现的地方.

为了证明,我们打开spring-cloud-starter-gateway的pom文件


  <dependencies>
    <dependency>
      <groupId>org.springframework.cloud</groupId>
      <artifactId>spring-cloud-starter</artifactId>
    </dependency>
    <dependency>
      <groupId>org.springframework.cloud</groupId>
      <artifactId>spring-cloud-gateway-core</artifactId>
    </dependency>
    <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-webflux</artifactId>
    </dependency>
  </dependencies>

除了cloud-start,starter-webflux就是cloud-gateway-core.所以后面我们就分析

cloud-gateway-core这个jar包.

其中actuate中定义了GatewayControllerEndpoint,它提供了对外访问的接口.


  // TODO: Flush out routes without a definition
  @GetMapping("/routes")
  public Flux<Map<String, Object>> routes() {
    return this.routeLocator.getRoutes().map(this::serialize);
  }
  @GetMapping("/routes/{id}")
  public Mono<ResponseEntity<Map<String, Object>>> route(@PathVariable String id) {
    //......
  }
//以下方法是继承于父类,抽象类AbstractGatewayControllerEndpoint
  @PostMapping("/refresh")
  public Mono<Void> refresh() {
    this.publisher.publishEvent(new RefreshRoutesEvent(this));
    return Mono.empty();
  }
  @GetMapping("/globalfilters")
  public Mono<HashMap<String, Object>> globalfilters() {
    return getNamesToOrders(this.globalFilters);
  }
  @GetMapping("/routefilters")
  public Mono<HashMap<String, Object>> routefilers() {
    return getNamesToOrders(this.GatewayFilters);
  }
  @GetMapping("/routepredicates")
  public Mono<HashMap<String, Object>> routepredicates() {
    return getNamesToOrders(this.routePredicates);
  }
  @PostMapping("/routes/{id}")
  @SuppressWarnings("unchecked")
  public Mono<ResponseEntity<Object>> save(@PathVariable String id,
      @RequestBody RouteDefinition route) {}
  @DeleteMapping("/routes/{id}")
  public Mono<ResponseEntity<Object>> delete(@PathVariable String id) {
    return this.routeDefinitionWriter.delete(Mono.just(id))
        .then(Mono.defer(() -> Mono.just(ResponseEntity.ok().build())))
        .onErrorResume(t -> t instanceof NotFoundException,
            t -> Mono.just(ResponseEntity.notFound().build()));
  }
  @GetMapping("/routes/{id}/combinedfilters")
  public Mono<HashMap<String, Object>> combinedfilters(@PathVariable String id) {
    // TODO: missing global filters
  }

config包里定义了一些Autoconfiguration和一些properties.读取配置文件就在这里完成.

我们这里看一下GatewayProperties.java


@ConfigurationProperties("spring.cloud.gateway")
@Validated
public class GatewayProperties {
  /**
   * List of Routes.
   */
  @NotNull
  @Valid
  private List<RouteDefinition> routes = new ArrayList<>();
  /**
   * List of filter definitions that are applied to every route.
   */
  private List<FilterDefinition> defaultFilters = new ArrayList<>();
  private List<MediaType> streamingMediaTypes = Arrays
      .asList(MediaType.TEXT_EVENT_STREAM, MediaType.APPLICATION_STREAM_JSON);
  #该类包括三个属性,路由列表,默认过滤器列表和MediaType列表.路由列表中的路由定义RouteDefinition.
    过滤器中定义的FilterDefinition.