Spring Gateway 网关

1.网关与动态路由的依赖

        <!-- 网关 配置 -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
        </dependency>
        <!-- 负载均衡 网关依赖 -->
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-loadbalancer</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-gateway</artifactId>
        </dependency>
        <!--聚合网关 knife4j-->
        <dependency>
            <groupId>com.github.xiaoymin</groupId>
            <artifactId>knife4j-spring-boot-starter</artifactId>
        </dependency>

2.配置动态路由

server:
  port: 11100
spring:
  application:
    name: gateway
  cloud:
    nacos:
      discovery:
        server-addr: localhost:8848    # 注册中心
    gateway:
      discovery:
        locator:
          enabled: true  # 开启动态路由
  main:
    web-application-type: reactive    # 选择启动服务器



#      routes:
#        - id: gateway-beijing # 这个配置指定这个路劲的名称,其他的没有关系
#          uri: lb://beijing   # 路由的目标  lb 是loadBalamce 负载均衡,注册到nacos
#          predicates:
#            # predicates 为断言,下面的路径是否为满足
#            - Path=/bj/**

3.API 中需要的配置类

1. config 类

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.cloud.gateway.route.RouteLocator;
import org.springframework.stereotype.Component;
import springfox.documentation.swagger.web.SwaggerResource;
import springfox.documentation.swagger.web.SwaggerResourcesProvider;

import java.util.ArrayList;
import java.util.HashSet;
import java.util.List;
import java.util.Set;

@Component
public class SwaggerProvider implements SwaggerResourcesProvider {
    /**
     * 接口地址
     */
    public static final String API_URI = "/v2/api-docs";
    /**
     * 路由加载器
     */
    @Autowired
    private RouteLocator routeLocator;
    /**
     * 网关应用名称
     */
    @Value("${spring.application.name}")
    private String applicationName;

    @Override
    public List<SwaggerResource> get() {
        //接口资源列表
        List<SwaggerResource> resources = new ArrayList<>();
        //服务名称列表
        List<String> routeHosts = new ArrayList<>();
        // 获取所有可用的应用名称
        routeLocator.getRoutes().filter(route -> route.getUri().getHost() != null)
                .filter(route -> !applicationName.equals(route.getUri().getHost()))
                .subscribe(route -> routeHosts.add(route.getUri().getHost()));
        // 去重，多负载服务只添加一次
        Set<String> existsServer = new HashSet<>();
        routeHosts.forEach(host -> {
            // 拼接url
            String url = "/" + host + API_URI;
            //不存在则添加
            if (!existsServer.contains(url)) {
                existsServer.add(url);
                SwaggerResource swaggerResource = new SwaggerResource();
                swaggerResource.setUrl(url);
                swaggerResource.setName(host);
                resources.add(swaggerResource);
            }
        });
        return resources;
    }
}

2.controllrt 

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import reactor.core.publisher.Mono;
import springfox.documentation.swagger.web.*;

import java.util.Optional;

@RestController
@RequestMapping("/swagger-resources")
public class SwaggerController {
    @Autowired(required = false)
    private SecurityConfiguration securityConfiguration;
    @Autowired(required = false)
    private UiConfiguration uiConfiguration;
    private final SwaggerResourcesProvider swaggerResources;
    @Autowired
    public SwaggerController(SwaggerResourcesProvider swaggerResources) {
        this.swaggerResources = swaggerResources;
    }
    @GetMapping("/configuration/security")
    public Mono<ResponseEntity<SecurityConfiguration>> securityConfiguration() {
        return Mono.just(new ResponseEntity<>(
                Optional.ofNullable(securityConfiguration).orElse(SecurityConfigurationBuilder.builder().build()), HttpStatus.OK));
    }
    @GetMapping("/configuration/ui")
    public Mono<ResponseEntity<UiConfiguration>> uiConfiguration() {
        return Mono.just(new ResponseEntity<>(
                Optional.ofNullable(uiConfiguration).orElse(UiConfigurationBuilder.builder().build()), HttpStatus.OK));
    }
    @GetMapping("")
    public Mono<ResponseEntity> swaggerResources() {
        return Mono.just((new ResponseEntity<>(swaggerResources.get(), HttpStatus.OK)));
    }
}

3.filter 类

import org.springframework.cloud.gateway.filter.GatewayFilter;
import org.springframework.cloud.gateway.filter.factory.AbstractGatewayFilterFactory;
import org.springframework.http.server.reactive.ServerHttpRequest;
import org.springframework.stereotype.Component;
import org.springframework.util.StringUtils;
import org.springframework.web.server.ServerWebExchange;

@Component
public class SwaggerHeaderFilter extends AbstractGatewayFilterFactory {
    private static final String HEADER_NAME = "X-Forwarded-Prefix";

    private static final String URI = "/v2/api-docs";

    @Override
    public GatewayFilter apply(Object config) {
        return (exchange, chain) -> {
            ServerHttpRequest request = exchange.getRequest();
            String path = request.getURI().getPath();
            if (!StringUtils.endsWithIgnoreCase(path,URI )) {
                return chain.filter(exchange);
            }
            String basePath = path.substring(0, path.lastIndexOf(URI));
            ServerHttpRequest newRequest = request.mutate().header(HEADER_NAME, basePath).build();
            ServerWebExchange newExchange = exchange.mutate().request(newRequest).build();
            return chain.filter(newExchange);
        };
    }
}