高可用服务注册中心、服务提供者、服务消费者|微服务配置内容

前言：

高可用服务注册中心：首先要知道什么是一个高可用的服务注册中心，基于spring boot建成的服务注册中心是一个单节点的服务注册中心，这样一旦发生了故障，那么整个服务就会瘫痪，所以我们需要一个高可用的服务注册中心，那么在Eureka中，我们通过集群来解决这个问题。啥叫集群呢？就是多配几个，一个服务注册中心挂了，还有另一个。

服务提供者：被其他微服务调用的微服务

服务消费者：调用的其他微服务的微服务

另外要注意jdk的版本需要1.8或1.8以上，否则无法执行。

1 但这里我遇到了一个奇怪的问题：本来我的jdk版本是1.6的，我需要更换。但是怎么配置环境
2 变量，在命令行输入java -version仍然是1.6，这里并不是配错了，而是在安装JDK1.6时，
3 自动将java.exe、javaw.exe、javaws.exe三个可执行文件复制到了C:Windows
4 System32目录，我们所执行的java命令正是这个java.exe所以我们先需要将这3个可执行
5 文件删除，然后再配置jdk1.8

另附java环境搭建方法

https://jingyan.baidu.com/article/c85b7a6414f2ee003bac95d5.html

那开始项目吧！

1、首先创建一个高可用的服务注册中心吧，取名为erueka-server

2、pom.xml内容配置

 1 <?xml version="1.0" encoding="UTF-8"?>
 2 <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 3     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
 4     <modelVersion>4.0.0</modelVersion>
 5 
 6     <groupId>wfw.wlovet</groupId>
 7     <artifactId>eureka-server</artifactId>
 8     <version>0.0.1-SNAPSHOT</version>
 9     <packaging>jar</packaging>
10 　　
11     <name>eureka-server</name>
12     <description>Demo project for Spring Boot</description>
13 
14     <parent>
15         <groupId>org.springframework.boot</groupId>
16         <artifactId>spring-boot-starter-parent</artifactId>
17         <version>1.5.6.RELEASE</version>
18         <relativePath/> <!-- lookup parent from repository -->
19     </parent>
20 
21     <properties>
22         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
23         <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
24         <java.version>1.8</java.version>
25     </properties>
26 
27     <dependencies>
28         <dependency>
29             <groupId>org.springframework.boot</groupId>
30             <artifactId>spring-boot-starter</artifactId>
31         </dependency>
32 
33         <dependency>
34             <groupId>org.springframework.cloud</groupId>
35             <artifactId>spring-cloud-starter-eureka-server</artifactId>
36         </dependency>
37 
38         <dependency>
39             <groupId>org.springframework.boot</groupId>
40             <artifactId>spring-boot-starter-test</artifactId>
41             <scope>test</scope>
42         </dependency>
43     </dependencies>
44 
45     <dependencyManagement>
46         <dependencies>
47             <dependency>
48                 <groupId>org.springframework.cloud</groupId>
49                 <artifactId>spring-cloud-dependencies</artifactId>
50                 <version>Dalston.SR3</version>
51                 <type>pom</type>
52                 <scope>import</scope>
53             </dependency>
54         </dependencies>
55     </dependencyManagement>
56     <build>
57         <plugins>
58             <plugin>
59                 <groupId>org.springframework.boot</groupId>
60                 <artifactId>spring-boot-maven-plugin</artifactId>
61             </plugin>
62         </plugins>
63     </build>
64 </project>

3、两个配置文件之peer1的内容

1 server.port=1111
2 eureka.instance.hostname=peer1
3 eureka.client.register-with-eureka=false
4 eureka.client.fetch-registry=false
5 eureka.client.service-url.defaultZone=http://peer2:1112/eureka/

4、两个配置文件之peer2的内容

1 server.port=1112
2 eureka.instance.hostname=peer2
3 eureka.client.register-with-eureka=false
4 eureka.client.fetch-registry=false
5 eureka.client.service-url.defaultZone=http://peer1:1111/eureka/

关于这两个配置文件需要知道如下几点：

1.在peer1的配置文件中，让它的service-url指向peer2，在peer2的配置文件中让它的service-url指向peer1
2.为了让peer1和peer2能够被正确的访问到，我们需要在C:WindowsSystem32driversetc目录下的hosts文件总添加两行配置，如下:
127.0.0.1 peer1
127.0.0.1 peer2
3.由于peer1和peer2互相指向对方，实际上我们构建了一个双节点的服务注册中心集群

5、java程序启动代码

 1 import org.springframework.boot.SpringApplication;
 2 import org.springframework.boot.autoconfigure.SpringBootApplication;
 3 import org.springframework.cloud.netflix.eureka.server.EnableEurekaServer;
 4 
 5 @EnableEurekaServer
 6 @SpringBootApplication
 7 public class Application {
 8     public static void main(String[] args) {
 9         SpringApplication.run(Application.class, args);
10     }
11 }

　　最后包的结构：

6、将该maven项目打包成可执行的.jar文件

选中pom.xml文件，右击鼠标点击run，选择Maven install，等待即可

7、生成jar文件之后，我们在命令行通过java命令来启动项目，在启动的时候我们可以设置采用不同的配置文件来启动项目，命令如下：

1 java -jar eureka-server-0.0.1-SNAPSHOT.jar --spring.profiles.active=peer1  
2 java -jar eureka-server-0.0.1-SNAPSHOT.jar --spring.profiles.active=peer2

8、在浏览器中进行验证

输入localhost:1111与localhost:1112

9、接下来创建一个服务提供者，取名为server-provider

10、pom.xml配置为

<?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>
    <groupId>wfw.wlovet</groupId>
    <artifactId>provider</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>jar</packaging>
    <name>provider</name>
    <description>Demo project for Spring Boot</description>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>1.5.6.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <java.version>1.8</java.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-eureka</artifactId>
        </dependency>
    </dependencies>
    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>Dalston.SR3</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>

11、application.properties的配置为

spring.application.name=hello-service
eureka.client.serviceUrl.defaultZone=http://peer1:1111/eureka/,http://peer2:1112/eureka/

12、控制类HelloController代码为

package com.wlovet.controller;

import java.util.List;

import org.apache.log4j.Logger;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.cloud.client.ServiceInstance;
import org.springframework.cloud.client.discovery.DiscoveryClient;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class HelloController {
    private final Logger logger = Logger.getLogger(getClass());
    @Autowired
    private DiscoveryClient client;

    @RequestMapping(value = "/hello", method = RequestMethod.GET)
    public String index() {
        List<ServiceInstance> instances = client.getInstances("hello-service");
        for (int i = 0; i < instances.size(); i++) {
            logger.info("/hello,host:" + instances.get(i).getHost() + ",service_id:" + instances.get(i).getServiceId());
        }
        return "Hello World";
    }
}

13、启动类ServerApplication代码为

package com.wlovet;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;

@SpringBootApplication
@EnableDiscoveryClient//此处注解必须
public class ServerApplication {

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

14、打包成可执行的jar文件|打包教程请看上文

　　最后包的结构：

15、在命令行中输入

java -jar provider-0.0.1-SNAPSHOT.jar --server.port=8081
java -jar provider-0.0.1-SNAPSHOT.jar --server.port=8082

16、最后创建一个服务消费者，取名为ribbon-consumer

17、pom.xml配置为,此处增加了spring-cloud-starter-ribbon

<?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>

    <groupId>wfw.wlovet</groupId>
    <artifactId>ribbon-consumer</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>jar</packaging>

    <name>ribbon-consumer</name>
    <description>Demo project for Spring Boot</description>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>1.5.6.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <java.version>1.8</java.version>
        <spring-cloud.version>Dalston.SR3</spring-cloud.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-eureka</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-ribbon</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.apache.xbean</groupId>
            <artifactId>xbean-spring</artifactId>
            <version>4.2</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>
                spring-boot-starter-data-elasticsearch
            </artifactId>
        </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>

18、application.propertes配置内容为（作为测试我只打开一个服务注册中心）

spring.application.name=ribbon-consumer
server.port=9000
eureka.client.service-url.defaultZone=http://peer1:1111/eureka

19、启动类ConsumerApplication的内容为

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
import org.springframework.cloud.client.loadbalancer.LoadBalanced;
import org.springframework.context.annotation.Bean;
import org.springframework.web.client.RestTemplate;
@SpringBootApplication
@EnableDiscoveryClient
public class ConsumerApplication {

    public static void main(String[] args) {
        SpringApplication.run(ConsumerApplication.class, args);
    }
    
    //LoadBalanced负责加载负载均衡
    @LoadBalanced
    @Bean
    RestTemplate restTemplate() {
        //RestTemplate为负载均衡
        return new RestTemplate();
    }
}

20、控制转发类ConsumerController的内容为

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.client.RestTemplate;

@RestController
public class ConsumerController {
    @Autowired
    RestTemplate restTemplate;

    @RequestMapping(value = "/ribbon-consumer", method = RequestMethod.GET)
    public String helloController() {
        return restTemplate.getForEntity("http://hello-service/hello", String.class).getBody();
    }
}

　　　最后包的结构：

21、测试项目

　　启动服务注册中心---->启动服务提供项目---->启动服务消费项目---->在浏览器内输入localhost:9000/ribbon-consumer

　　结果为：

至此，简单的微服务就搭好了！

em。。。。但我在运行ribbon-consumer的时候又遇到一个奇怪的问题，感觉我好像说过相同的话。。。

　　啊？有点莫名奇妙-.-!，然后自己手动导包解决的，em。。。。不知所以然