spring cloud eureka服务发现注册（二）

海涛

发布于 2019-09-12 11:24:10

3660

发布于 2019-09-12 11:24:10

环境说明:spring boot2.0 + jdk1.8

第一步：搭建eureka server,创建一个maven项目，也可以直接idea或者 https://start.spring.io/ 快速创建 pom.xml文件

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.1.4.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.hht</groupId>
    <artifactId>eureka-server</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>eureka-server</name>
    <description>Demo project for Spring Boot</description>

    <properties>
        <java.version>1.8</java.version>
        <spring-cloud.version>Greenwich.SR1</spring-cloud.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-eureka-server</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>

    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>${spring-cloud.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

</project>

启动类

package com.hht.eurekaserver;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.netflix.eureka.server.EnableEurekaServer;

@SpringBootApplication
@EnableEurekaServer
public class EurekaServerApplication {

    public static void main(String[] args) {
        SpringApplication.run(EurekaServerApplication.class, args);
    }

}

配置文件

spring.application.name=spring-cloud-eureka-server
server.port=12345

eureka.client.register-with-eureka=false
eureka.client.fetch-registry=false
eureka.client.service-url.defaultZone=\
  http://localhost:${server.port}/eureka

注意单节点情况：

eureka.client.register-with-eureka=false

eureka.client.fetch-registry=false

启动成功后访问 http://localhost:12345/

第二步，搭建eureka client端部分，包括服务注册、发现和使用，整体结构如下图

user-api模块用来定义接口

package com.hht.user.domain;

/**
 * @author hht
 * @ClassName User
 * @Description TODO
 * @Date 2019/4/30 15:50
 * @VERSION 1.0
 */
public class User {
    private Long id;
    private String name;

    public Long getId() {
        return id;
    }

    public void setId(Long id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }
}

package com.hht.user.service;

import com.hht.user.domain.User;
import org.springframework.stereotype.Service;

import java.util.Collection;

public interface UserService {
    /**
     * 保存用户
     *
     * @param user
     * @return 如果保存成功的话，返回<code>true</code>，
     * 否则返回<code>false</code>
     */
    boolean save(User user);

    /**
     * 查询所有的用户对象
     *
     * @return 不会返回<code>null</code>
     */
    Collection<User> findAll();
}

user-service-consumer模块用来模拟服务发现和使用

pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <parent>
        <artifactId>eureka-client</artifactId>
        <groupId>com.hht</groupId>
        <version>0.0.1-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>user-service-consumer</artifactId>

    <dependencies>
        <dependency>
            <groupId>com.hht</groupId>
            <artifactId>user-api</artifactId>
            <version>${project.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
        </dependency>
    </dependencies>

</project>

# 应用名称
spring.application.name=user-service-client
server.port=8080

# Eureka 服务器地址
eureka.client.serviceUrl.defaultZone= http://localhost:12345/eureka
eureka.instance.prefer-ip-address=true
eureka.instance.ip-address=192.168.1.160

@SpringBootApplication
@EnableDiscoveryClient
public class UserConsumerApplication {
    public static void main(String[] args) {
        SpringApplication.run(UserConsumerApplication.class,args);
    }
}

实现接口类，通过restTemplate（实验，一般生产环境有替代方案）

package com.hht.service;

import com.hht.user.domain.User;
import com.hht.user.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.web.client.RestTemplate;

import java.util.Collection;

/**
 * @author hht
 * @ClassName com.hht.service.UserServiceProxy
 * @Description TODO
 * @Date 2019/4/30 16:16
 * @VERSION 1.0
 */
@Service
public class UserServiceProxy implements UserService {
    private static final String PROVIDER_SERVER_URL_PREFIX = "http://user-service-provider";

    /**
     * 通过 REST API 代理到服务器提供者
     */
    @Autowired
    private RestTemplate restTemplate;

    @Override
    public boolean save(User user) {
        User returnValue =
                restTemplate.postForObject(PROVIDER_SERVER_URL_PREFIX + "/user/save", user, User.class);
        return returnValue != null;
    }

    @Override
    public Collection<User> findAll() {
        return restTemplate.getForObject(PROVIDER_SERVER_URL_PREFIX + "/user/list", Collection.class);
    }
}

user-service-provider模块用来模拟服务提供方

pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <parent>
        <artifactId>eureka-client</artifactId>
        <groupId>com.hht</groupId>
        <version>0.0.1-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>user-provider</artifactId>

    <dependencies>
        <dependency>
            <groupId>com.hht</groupId>
            <artifactId>user-api</artifactId>
            <version>${project.version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-web</artifactId>
            <version>5.1.9.RELEASE</version>
            <scope>compile</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-web</artifactId>
            <version>5.1.9.RELEASE</version>
            <scope>compile</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
        </dependency>
    </dependencies>
</project>

# 应用名称
spring.application.name=user-service-provider
# Eureka Client 端口
server.port=8081
# Eureka 服务器地址
eureka.client.serviceUrl.defaultZone= http://localhost:12345/eureka
eureka.instance.prefer-ip-address=true
eureka.instance.ip-address=192.168.1.160

接口实现类，业务的真实逻辑

package com.hht.service;

import com.hht.respository.UserRespository;
import com.hht.user.domain.User;
import com.hht.user.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.Collection;


@Service
public class UserServiceImpl implements UserService {


    @Autowired
    private UserRespository respository;

    @Override
    public boolean save(User user) {
        return respository.save(user);
    }

    @Override
    public Collection<User> findAll() {
        return respository.findAll();
    }
}

到此结束：整体逻辑为，两个client 都注册到了 server端，通过访问服务名字+方法调用另一个服务附加：一般生产环境需要高可用只要修改eureka server的配置文件，启动多个即可

eureka.client.register-with-eureka=false  #去掉
eureka.client.fetch-registry=false        #去掉
eureka.client.service-url.defaultZone=\   #填写除自己外的，其它server节点地址
  http://localhost:${server.port}/eureka

测试代码地址：https://gitee.com/huhaitao/spring_cloud_test/tree/master/eureka

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