spring cloud gateway 3.1.7版本 自定义负载均衡 具体代码 java

好的，下面是一个简单的自定义负载均衡器的代码示例：

1. 创建自定义负载均衡器类

import java.util.List;
import org.springframework.cloud.client.ServiceInstance;
import org.springframework.cloud.client.discovery.DiscoveryClient;
import org.springframework.cloud.gateway.config.LoadBalancerProperties;
import org.springframework.cloud.gateway.filter.GatewayFilterChain;
import org.springframework.cloud.gateway.filter.LoadBalancerClientFilter;
import org.springframework.cloud.gateway.filter.factory.AbstractGatewayFilterFactory;
import org.springframework.cloud.loadbalancer.core.ServiceInstanceListSupplier;
import org.springframework.cloud.loadbalancer.support.LoadBalancerClientFactory;
import org.springframework.cloud.loadbalancer.support.LoadBalancerClientFactoryWrapper;
import org.springframework.stereotype.Component;
import org.springframework.web.server.ServerWebExchange;
import reactor.core.publisher.Mono;

@Component
public class CustomLoadBalancerClientFilter extends LoadBalancerClientFilter {

    public CustomLoadBalancerClientFilter(LoadBalancerClientFactory clientFactory, LoadBalancerProperties properties) {
        super(clientFactory, properties);
    }

    @Override
    public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {
        // 自定义负载均衡逻辑
        System.out.println("Custom Load Balancer executed!");
        return super.filter(exchange, chain);
    }
}

2. 创建自定义负载均衡器工厂类

import org.springframework.cloud.gateway.filter.GatewayFilter;
import org.springframework.cloud.gateway.filter.factory.AbstractGatewayFilterFactory;
import org.springframework.cloud.loadbalancer.core.ServiceInstanceListSupplier;
import org.springframework.cloud.loadbalancer.support.LoadBalancerClientFactory;
import org.springframework.context.ApplicationContext;
import org.springframework.stereotype.Component;

@Component
public class CustomLoadBalancerClientFilterFactory extends AbstractGatewayFilterFactory<CustomLoadBalancerClientFilterFactory.Config> {

    private final LoadBalancerClientFactory clientFactory;

    public CustomLoadBalancerClientFilterFactory(ApplicationContext context, LoadBalancerClientFactory clientFactory) {
        super(Config.class);
        this.clientFactory = new LoadBalancerClientFactoryWrapper(clientFactory, context);
    }

    @Override
    public GatewayFilter apply(Config config) {
        return new CustomLoadBalancerClientFilter(clientFactory, getLoadBalancerProperties());
    }

    public static class Config {
        // 可以在这里添加自定义配置项
    }
}

3. 配置自定义负载均衡器

在Spring Boot应用程序中的配置文件（如application.yml）中添加以下配置：

spring:
  cloud:
    gateway:
      routes:
        - id: my_route
          uri: lb://my_service
          predicates:
            - Path=/foo/**
          filters:
            - CustomLoadBalancerClient

或者在Java代码中使用以下方式配置：

@Bean
public RouteLocator customRouteLocator(RouteLocatorBuilder builder) {
    return builder.routes()
        .route("my_route", r -> r.path("/foo/**")
            .filters(f -> f.filter(new CustomLoadBalancerClientFilterFactory().apply(new CustomLoadBalancerClientFilterFactory.Config())))
            .uri("lb://my_service"))
        .build();
}

以上代码示例中，我们创建了一个名为“CustomLoadBalancerClientFilter”的自定义负载均衡器，该负载均衡器在执行时会打印一条日志。我们还创建了一个名为“CustomLoadBalancerClientFilterFactory”的自定义负载均衡器工厂类，这个工厂类会返回一个自定义负载均衡器实例。最后，我们在Spring Cloud Gateway的配置中使用了这个自定义负载均衡器。

希望这个示例对你有所帮助。