Eureka 注册中心和服务提供者

什么是Eureka组件

spring cloud Eureka ，提供服务注册和服务发现的功能。

一：spring cloud Eureka

Eureka Server 服务端

Eureka Client 客户端

服务注册

代码实现：

1.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">
    <modelVersion>4.0.0</modelVersion>

    <groupId>org.example</groupId>
    <artifactId>springCloud01</artifactId>
    <packaging>pom</packaging>
    <version>1.0-SNAPSHOT</version>
    <modules>
        <module>EurekaServer</module>
    </modules>
    <!--    父工程-->
    <parent>
        <artifactId>spring-boot-starter-parent</artifactId>
        <groupId>org.springframework.boot</groupId>
        <version>2.0.7.RELEASE</version>
    </parent>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <!--        JDk9-->
        <dependency>
            <groupId>javax.xml.bind</groupId>
            <artifactId>jaxb-api</artifactId>
            <version>2.3.0</version>
        </dependency>
        <dependency>
            <groupId>com.sun.xml.bind</groupId>
            <artifactId>jaxb-impl</artifactId>
            <version>2.3.0</version>
        </dependency>
        <dependency>
            <groupId>org.glassfish.jaxb</groupId>
            <artifactId>jaxb-runtime</artifactId>
            <version>2.3.0</version>
        </dependency>
        <dependency>
            <groupId>javax.activation</groupId>
            <artifactId>activation</artifactId>
            <version>1.1.1</version>
        </dependency>

    </dependencies>

    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>Finchley.SR2</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>
</project>

2.父工程下实现一个子模块Module实现Eureka Server

<?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>springCloud01</artifactId>
        <groupId>org.example</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>EurekaServer</artifactId>

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

</project>

3.配置文件

server:
  port: 8761
eureka:
  client:
    register-with-eureka: false
    fetch-registry: false
    service-url:
      defaultZone: http://localhost:8761/eureka/

4.创建启动类：

package com.southwind;

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

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

5.检查打开

http://localhost:8761

注册第一个微服务

服务提供者

服务消费者和服务提供者都是通过Eureka Client 连接到Eureka Server完成注册。

1.创建一个模块，实现Eureka Client

<?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>springCloud01</artifactId>
        <groupId>org.example</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>provider</artifactId>

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

</project>

2.配置文件：

server:
  port: 8010
spring:
  application:
    name: provider
eureka:
  client:
    service-url:
      defaultZone: http://localhost:8761/eureka/
  instance:
    prefer-ip-address: true

3.创建启动类：

package com.southwind;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

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

4.数据持久化：

接口：

package com.southwind.repository;

import com.southwind.entity.Student;

import java.util.Collection;

public interface StudentRepository {
    public Collection<Student> findAll();
    public Student findById(Integer id);
    public  void saveOrUpdate(Student student);
    public void deleteById(Integer id);
}

实现类：

package com.southwind.repository.impl;

import com.southwind.entity.Student;
import com.southwind.repository.StudentRepository;

import java.util.Collection;
import java.util.HashMap;
import java.util.Map;

public class StudentRepositoryImpl implements StudentRepository {
    private static Map<Integer,Student> map;
    static {
        map=new HashMap<>();
        map.put(1,new Student(1,"张三"));
        map.put(1,new Student(2,"李四"));
        map.put(1,new Student(3,"王五"));
    }
    @Override
    public Collection<Student> findAll() {
        return map.values();
    }

    @Override
    public Student findById(Integer id) {
        return map.get(id);
    }

    @Override
    public void saveOrUpdate(Student student) {
        map.put(student.getId(),student);
    }

    @Override
    public void deleteById(Integer id) {
        map.remove(id);
    }
}

Handler：

package com.southwind.Handler;

import com.southwind.entity.Student;
import com.southwind.repository.StudentRepository;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.*;

import java.util.Collection;

@RestController
@RequestMapping("/provider")
public class StudentHandler {
    @Autowired
    private StudentRepository studentRepository;
    @GetMapping("/findall")
    public Collection<Student> findall(){
        return studentRepository.findAll();
    }
    @GetMapping("/findbyid/{id}")
    public Student findById(@PathVariable("id") Integer id){
        return studentRepository.findById(id);
    }
    @PostMapping("/save")
    public void save(@RequestBody Student student){
        studentRepository.saveOrUpdate(student);
    }
    @DeleteMapping("/delete")
    public void deletebyid(Integer id){
        studentRepository.deleteById(id);
    }

}