普通Java(Spring)項目直接使用Eureka

引用jar包

<dependency>
    <groupId>com.netflix.archaius</groupId>
    <artifactId>archaius-core</artifactId>
    <version>0.7.5</version>
</dependency>
<dependency>
    <groupId>com.netflix.eureka</groupId>
    <artifactId>eureka-client</artifactId>
    <version>1.7.0</version>
</dependency>
<dependency>
    <groupId>com.netflix.eureka</groupId>
    <artifactId>eureka-core</artifactId>
    <version>1.7.0</version>
</dependency>
<dependency>
    <groupId>org.apache.httpcomponents</groupId>
    <artifactId>httpcore</artifactId>
    <version>4.4</version>
</dependency>

基礎配置文件config.properties

eureka.region=default
eureka.name=my_project
eureka.vipAddress=service.io
eureka.port=8001

eureka.preferSameZone=true
eureka.shouldUseDns=false
eureka.serviceUrl.default=http://localhost:5111/eureka/

 

基礎代碼類 

ExampleServiceBase

代碼:

import com.netflix.appinfo.ApplicationInfoManager;
import com.netflix.appinfo.InstanceInfo;
import com.netflix.config.DynamicPropertyFactory;
import com.netflix.discovery.EurekaClient;

import javax.annotation.PostConstruct;
import javax.annotation.PreDestroy;
import javax.inject.Inject;
import javax.inject.Singleton;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintStream;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.Date;

/**
 * An example service (that can be initialized in a variety of ways) that registers with eureka
 * and listens for REST calls on port 8001.
 */
@Singleton
public class ExampleServiceBase {

    private final ApplicationInfoManager applicationInfoManager;
    private final EurekaClient eurekaClient;
    private final DynamicPropertyFactory configInstance;

    @Inject
    public ExampleServiceBase(ApplicationInfoManager applicationInfoManager,
                              EurekaClient eurekaClient,
                              DynamicPropertyFactory configInstance) {
        this.applicationInfoManager = applicationInfoManager;
        this.eurekaClient = eurekaClient;
        this.configInstance = configInstance;
    }

    @PostConstruct
    public void start() {
        // A good practice is to register as STARTING and only change status to UP
        // after the service is ready to receive traffic
        System.out.println("Registering service to eureka with STARTING status");
        applicationInfoManager.setInstanceStatus(InstanceInfo.InstanceStatus.STARTING);

        System.out.println("Simulating service initialization by sleeping for 2 seconds...");
        try {
            Thread.sleep(2000);
        } catch (InterruptedException e) {
            // Nothing
        }

        // Now we change our status to UP
        System.out.println("Done sleeping, now changing status to UP");
        applicationInfoManager.setInstanceStatus(InstanceInfo.InstanceStatus.UP);
        waitForRegistrationWithEureka(eurekaClient);
        System.out.println("Service started and ready to process requests..");

        try {
            int myServingPort = applicationInfoManager.getInfo().getPort();  // read from my registered info
            ServerSocket serverSocket = new ServerSocket(myServingPort);
            final Socket s = serverSocket.accept();
            System.out.println("Client got connected... processing request from the client");
            processRequest(s);

        } catch (IOException e) {
            e.printStackTrace();
        }

        System.out.println("Simulating service doing work by sleeping for " + 5 + " seconds...");
        try {
            Thread.sleep(5 * 1000);
        } catch (InterruptedException e) {
            // Nothing
        }
    }

    @PreDestroy
    public void stop() {
        if (eurekaClient != null) {
            System.out.println("Shutting down server. Demo over.");
            eurekaClient.shutdown();
        }
    }

    private void waitForRegistrationWithEureka(EurekaClient eurekaClient) {
        // my vip address to listen on
        String vipAddress = configInstance.getStringProperty("eureka.vipAddress", "sampleservice.mydomain.net").get();
        InstanceInfo nextServerInfo = null;
        while (nextServerInfo == null) {
            try {
                nextServerInfo = eurekaClient.getNextServerFromEureka(vipAddress, false);
            } catch (Throwable e) {
                System.out.println("Waiting ... verifying service registration with eureka ...");

                try {
                    Thread.sleep(10000);
                } catch (InterruptedException e1) {
                    e1.printStackTrace();
                }
            }
        }
    }

    private void processRequest(final Socket s) {
        try {
            BufferedReader rd = new BufferedReader(new InputStreamReader(s.getInputStream()));
            String line = rd.readLine();
            if (line != null) {
                System.out.println("Received a request from the example client: " + line);
            }
            String response = "BAR " + new Date();
            System.out.println("Sending the response to the client: " + response);

            PrintStream out = new PrintStream(s.getOutputStream());
            out.println(response);

        } catch (Throwable e) {
            System.err.println("Error processing requests");
        } finally {
            if (s != null) {
                try {
                    s.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
    }
}

 

註冊服務代碼

ExampleEurekaService

* Copyright 2012 Netflix, Inc.
 *
 *    Licensed under the Apache License, Version 2.0 (the "License");
 *    you may not use this file except in compliance with the License.
 *    You may obtain a copy of the License at
 *
 *        http://www.apache.org/licenses/LICENSE-2.0
 *
 *    Unless required by applicable law or agreed to in writing, software
 *    distributed under the License is distributed on an "AS IS" BASIS,
 *    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *    See the License for the specific language governing permissions and
 *    limitations under the License.
 */

import com.netflix.appinfo.EurekaInstanceConfig;
import com.netflix.appinfo.InstanceInfo;
import com.netflix.appinfo.providers.EurekaConfigBasedInstanceInfoProvider;
import com.netflix.discovery.DiscoveryClient;
import com.netflix.discovery.EurekaClient;

import com.netflix.appinfo.ApplicationInfoManager;
import com.netflix.appinfo.MyDataCenterInstanceConfig;
import com.netflix.config.DynamicPropertyFactory;
import com.netflix.discovery.DefaultEurekaClientConfig;
import com.netflix.discovery.EurekaClientConfig;

/**
 * Sample Eureka service that registers with Eureka to receive and process requests.
 * This example just receives one request and exits once it receives the request after processing it.
 *
 */
public class ExampleEurekaService {

    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;
    }


    public static void main(String[] args) {

        DynamicPropertyFactory configInstance = com.netflix.config.DynamicPropertyFactory.getInstance();
        ApplicationInfoManager applicationInfoManager = initializeApplicationInfoManager(new MyDataCenterInstanceConfig());
        EurekaClient eurekaClient = initializeEurekaClient(applicationInfoManager, new DefaultEurekaClientConfig());

        ExampleServiceBase exampleServiceBase = new ExampleServiceBase(applicationInfoManager, eurekaClient, configInstance);
        try {
            exampleServiceBase.start();
        } finally {
            // the stop calls shutdown on eurekaClient
            exampleServiceBase.stop();
        }
    }
}

 

以上信息參考項目:

https://github.com/Netflix/eureka/tree/master/eureka-examples