没有从NameResolver调用GRPC Java负载平衡-启动方法

import io.grpc.NameResolver;
import io.grpc.NameResolverProvider;
import io.grpc.Attributes;
import io.grpc.EquivalentAddressGroup;
import java.net.InetSocketAddress;
import java.net.URI;
import java.util.Arrays;
import java.util.List;

public class CustomNameResolverFactory extends NameResolver.Factory {
    @Override
    public NameResolver newNameResolver(URI targetUri, Attributes params) {
        // 解析服务名称，获取服务地址列表
        List<EquivalentAddressGroup> servers = Arrays.asList(
            new EquivalentAddressGroup(new InetSocketAddress("server1.example.com", 8080)),
            new EquivalentAddressGroup(new InetSocketAddress("server2.example.com", 8080))
        );
        
        return new CustomNameResolver(servers);
    }

    @Override
    public String getDefaultScheme() {
        return "custom";
    }
}

public class CustomNameResolver extends NameResolver {
    private final List<EquivalentAddressGroup> servers;

    public CustomNameResolver(List<EquivalentAddressGroup> servers) {
        this.servers = servers;
    }

    @Override
    public String getServiceAuthority() {
        return "custom-service";
    }

    @Override
    public void start(Listener2 listener) {
        // 将服务地址列表通知给gRPC
        listener.onResult(ResolutionResult.newBuilder().setAddresses(servers).build());
    }

    @Override
    public void shutdown() {
        // 关闭资源
    }
}

// 创建gRPC Channel时设置NameResolver工厂类
ManagedChannel channel = ManagedChannelBuilder.forTarget("custom://custom-service")
    .nameResolverFactory(new CustomNameResolverFactory())
    .build();