简单实践 java spring cloud 负载均衡

1 概要

1.1 实现一个最简单的微服务。远程调用+负载均衡，基本上完成了最核心的微服务框架。

远程调用：RestTemplate

注册中心：eureka

负载均衡：Ribbon

1.2 要点

1.2.1 依赖

1.2.1.1 主框架依赖

• spring boot 依赖

            org.springframework.cloud
            spring-cloud-starter
        

•  spring cloud 依赖

        
            
                org.springframework.cloud
                spring-cloud-dependencies
                ${spring-cloud.version}
                pom
                import
            
        
    

 1.2.1.2  eureka依赖

• 服务端依赖

org.springframework.cloud
            spring-cloud-starter-netflix-eureka-server

• 客户端依赖 

org.springframework.cloud
            spring-cloud-starter-netflix-eureka-client

 1.2.2 配置文件

• 服务设置

server:
  port: 10086
spring:
  application:
    name: eureka server

•  服务注册

eureka:
  client:
    service-url:
      defaultZone: http://127.0.0.1:10086/eureka/

1.2 技术关键词

• spring-cloud-starter
  

• spring-cloud-dependencies

• spring-cloud-starter-netflix-eureka-server

• spring-cloud-starter-netflix-eureka-client

• spring-boot-starter-web

• spring:
    application:
      name: eureka server

• eureka:
    client:
      service-url:
        defaultZone: http://127.0.0.1:10086/eureka/

• @SpringBootApplication
  @EnableEurekaServer

• @Bean
  @LoadBalanced
  public RestTemplate

• @Autowired
  RestTemplate restTemplate;

• @RestController

• return "函数2"+restTemplate.getForObject(url,String.class);

• SpringApplication.run(Main.class);

 

2 代码

2.1 父工程

 

    4.0.0
    
        com.xjc.springcloundtest
        demo8
        0.0.1-SNAPSHOT
    
    untitled

    
        21
        21
        UTF-8
    
    
        
            org.springframework.cloud
            spring-cloud-starter-netflix-eureka-server
        
    

2.2 注册中 eureka

2.2.1 工程文件

 

    4.0.0
    
        com.xjc.springcloundtest
        demo8
        0.0.1-SNAPSHOT
    
    untitled

    
        21
        21
        UTF-8
    
    
        
            org.springframework.cloud
            spring-cloud-starter-netflix-eureka-server
        
    

2.2.2 配置文件

server:
  port: 10086
spring:
  application:
    name: eureka server
eureka:
  client:
    service-url:
      defaultZone: http://127.0.0.1:10086/eureka/

2.2.3 主函数

package com.xjc.springcloundtest;

import com.netflix.discovery.shared.Application;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.netflix.eureka.server.EnableEurekaServer;

@SpringBootApplication
@EnableEurekaServer
public class Main {
    public static void main(String[] args) {
        SpringApplication.run(Main.class);
        System.out.println("Hello world!");
    }
}

2.2.4 运行效果

2.3 服务工程

2.2.1 工程文件

    4.0.0
    
        com.xjc.springcloundtest
        demo8
        0.0.1-SNAPSHOT
    

    untitled1

    
        21
        21
        UTF-8
    
    
        
            org.springframework.cloud
            spring-cloud-starter-netflix-eureka-client
        
        
            org.springframework.boot
            spring-boot-starter-web
        
    

2.3.2 配置文件

spring:
  application:
    name: server1
eureka:
  client:
    service-url:
      defaultZone: http://127.0.0.1:10086/eureka/

2.3.3 主函数

package com.xjc.springcloundtest;

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

@SpringBootApplication
public class Main {
    public static void main(String[] args) {
        SpringApplication.run(Main.class);
        System.out.println("Hello world!");
    }
}

2.3.4 控制器

package com.xjc.springcloundtest;

import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class TestController {
    @RequestMapping("/fun")
    public String fun(){
        return "函数1";
    }
}

2.3.5 运行效果

 

2.4 消费者

2.4.1 工程文件

    4.0.0
    
        com.xjc.springcloundtest
        demo8
        0.0.1-SNAPSHOT
    

    untitled2

    
        21
        21
        UTF-8
    
    
        
            org.springframework.cloud
            spring-cloud-starter-netflix-eureka-client
        
        
            org.springframework.boot
            spring-boot-starter-web
        
    

2.4.2 配置文件

server:
  port: 8081
spring:
  application:
    name: server2
eureka:
  client:
    service-url:
      defaultZone: http://127.0.0.1:10086/eureka/

2.4.3 主函数

package com.xjc.springcloundtest;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.web.client.RestTemplateBuilder;
import org.springframework.cloud.client.loadbalancer.LoadBalanced;
import org.springframework.context.annotation.Bean;
import org.springframework.web.client.RestTemplate;

@SpringBootApplication
public class Main {
    public static void main(String[] args) {
        SpringApplication.run(Main.class);
        System.out.println("Hello world!");
    }
    @Bean
    @LoadBalanced
    public RestTemplate restTemplate(RestTemplateBuilder builder ){
        return builder.build();
    }
}

2.4.4 消费者

package com.xjc.springcloundtest;

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

@RestController
public class TestController {

    @Autowired
    RestTemplate restTemplate;

    @RequestMapping("/fun")
    public String fun(){
        //String url = "http://localhost:8080/fun";
        String url = "http://server1/fun";
        return "函数2"+restTemplate.getForObject(url,String.class);
    }
}

2.4.5 运行效果