2018-08-08 非SpringCloud项目接入Eurek

非SpringCloud项目，有时会需要调用新SpringCloud项目，通过Eureka获取动态服务地址进行远程调用，很方便。
也可以删除Eureka的部分，直接使用Ribbon调用。

EurekaClient 初始化类

/**
 * @author slankka
 */
@Configuration
public class EurekaClientConfiguration {

    Logger log = LoggerFactory.getLogger(getClass());

    private static ApplicationInfoManager applicationInfoManager;
    private static EurekaClient eurekaClient;

    private static synchronized ApplicationInfoManager initializeApplicationInfoManager(
        EurekaInstanceConfig instanceConfig) {
        if (applicationInfoManager == null) {
            InstanceInfo instanceInfo = new EurekaConfigBasedInstanceInfoProvider(instanceConfig)
                .get();
            applicationInfoManager = new ApplicationInfoManager(instanceConfig, instanceInfo);
        }

        return applicationInfoManager;
    }

    private static synchronized EurekaClient initializeEurekaClient(
        ApplicationInfoManager applicationInfoManager, EurekaClientConfig clientConfig) {
        if (eurekaClient == null) {
            eurekaClient = new DiscoveryClient(applicationInfoManager, clientConfig);
        }

        return eurekaClient;
    }

    @Bean(destroyMethod = "shutdown")
    public EurekaClient eurekaClient() {
        //初始化应用信息管理器，设置其状态为STARTING
        applicationInfoManager = initializeApplicationInfoManager(new MyDataCenterInstanceConfig());
        applicationInfoManager.setInstanceStatus(InstanceInfo.InstanceStatus.STARTING);
        log.info("Registering service to eureka with status STARTING");

        //读取配置文件(classpath:eureka-client.properties)，初始化eurekaClient，并设置应用信息管理器的状态为UP
        eurekaClient = initializeEurekaClient(applicationInfoManager,
            new DefaultEurekaClientConfig());
        DiscoveryManager.getInstance().setDiscoveryClient((DiscoveryClient) eurekaClient);
        try {
            Thread.sleep(2000);
        } catch (InterruptedException e) {
        }
        applicationInfoManager.setInstanceStatus(InstanceInfo.InstanceStatus.UP);
        log.info("Initialization finished, now changing eureka client status to UP");

        long startTime = System.currentTimeMillis();

        //开启一个线程验证注册结果
        return eurekaClient;
    }


}

服务配置类，目前是手动创建有点Low，后续可以改进为注解，使用Spring ImportBean进行改进自动创建Bean。

/**
 * @author slankka
 */
@Configuration
public class RemoteServiceConfiguration {

    Logger log = LoggerFactory.getLogger(RemoteServiceConfiguration.class);

    public RemoteServiceConfiguration() {
        try {
            //这里读取其他配置
            ConfigurationManager.loadPropertiesFromResources("config.properties");
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    @Autowired
    private EurekaClient eurekaClient;

    class EurekaClientProvider implements Provider<EurekaClient> {
        @Override
        public EurekaClient get() {
            return eurekaClient;
        }
    }

    /**
     * 自动创建Ribbon
     * @return
     */
    @Bean
    public RibbonClientRemote remoteService() {

        InstanceInfo nextServerFromEureka = eurekaClient
            .getNextServerFromEureka("APOLLO-CONFIGSERVICE", false);
        log.error("------------------------,APOLLO-CONFIGSERVICE= {}:{}",
            nextServerFromEureka.getIPAddr(), nextServerFromEureka.getPort());

        RibbonClientRemote service = Feign.builder().client(RibbonClient.create())
            .logger(new Slf4jLogger()).logLevel(Level.FULL).encoder(new JacksonEncoder())
            .decoder(new JacksonDecoder())
            .target(RibbonClientRemote.class, "http://APOLLO-CONFIGSERVICE");

        return service;
    }

    /**
     * 手动创建Ribbon
     */
    public RibbonClientRemote remoteServiceManuallyMade() {
                IRule rule = new AvailabilityFilteringRule();
        ServerList<DiscoveryEnabledServer> list = new DiscoveryEnabledNIWSServerList("APOLLO-CONFIGSERVICE", new EurekaClientProvider());
        ServerListFilter<DiscoveryEnabledServer> filter = new ZoneAffinityServerListFilter<DiscoveryEnabledServer>();

        ZoneAwareLoadBalancer<DiscoveryEnabledServer> lb = LoadBalancerBuilder.<DiscoveryEnabledServer>newBuilder()
            .withDynamicServerList(list)
            .withRule(rule)
            .withServerListFilter(filter)
            .buildDynamicServerListLoadBalancer();

        RibbonClient client = RibbonClient.builder().lbClientFactory(new LBClientFactory() {
            @Override
            public LBClient create(String clientName) {
                return LBClient.create(lb, ClientFactory.getNamedConfig(clientName));
            }
        }).build();
                RibbonClientRemote service = Feign.builder().client(client).logger(new Slf4jLogger()).logLevel(Level.FULL).encoder(new JacksonEncoder())
            .decoder(new JacksonDecoder()).target(RibbonClientRemote.class, "http://APOLLO-CONFIGSERVICE");
        return service;
    }


    /**
     * * Ribbon负载均衡策略实现 * 使用ZoneAvoidancePredicate和AvailabilityPredicate来判断是否选择某个server，前一个判断判定一个zone的运行性能是否可用，
     * * 剔除不可用的zone（的所有server），AvailabilityPredicate用于过滤掉连接数过多的Server。 *
     */
    private IRule zoneAvoidanceRule() {
        return new ZoneAvoidanceRule();
    }

    /**
     * Ribbon负载均衡策略实现 * 随机选择一个server。 *
     */
    private IRule randomRule() {
        return new RandomRule();
    }


}

Feign接口

/**
 * @Author: slankka
 * @Date: 2018/08/08 10:24.
 */
public interface RibbonClientRemote {

    @Headers({"Content-Type: application/json", "Accept: application/json"})
    @RequestLine("GET /info")
    InfoBean info();

}

这里直接调用 APOLLO-CONFIGSERVICE/info

Controller类

/**
 * @Author: slankka
 * @Date: 2018/08/04 22:25.
 */
@RequestMapping("/core")
@Controller
public class CoreController {

    private Logger logger = LoggerFactory.getLogger(getClass());

    @Autowired
    private RibbonClientRemote ribbonClientRemote;

    @RequestMapping("/raw")
    @ResponseBody
    public String respone() {
        return "{\"code\":200,\"msg\":\"你好中文\",\"data\":null}";
    }

    @RequestMapping("/ribbon")
    @ResponseBody
    public InfoBean ribbon() {
        return ribbonClientRemote.info();
    }

}