restTemplate實現跨服務API調用

同時使用ribbon，實現接口調用的負載均衡。

1 註冊中心

略…

2 消費端

2.1 pom

        <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>
    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>Brixton.SR5</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>

2.2 application.properties

spring.application.name=ribbon-consumer
server.port=9000
# 本地啓動註冊中心
eureka.client.service-url.defaultZone=http://localhost:1111/eureka/

2.3 啓動類

package com.example.lei;

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;

@EnableDiscoveryClient
@SpringBootApplication
public class RibbonConsumerApplication {

    @Bean
    @LoadBalanced
    RestTemplate restTemplate(){
        return new RestTemplate();
    }
    public static void main(String[] args) {
        SpringApplication.run(RibbonConsumerApplication.class, args);
    }

}

2.4 消費

package com.example.lei.controller;

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;

/**
 * @Author: leimin
 * @Description: new class
 * @Date: 2020/6/8 16:04
 * @Version: 1.0
 */
@RestController
public class ConsumerController {

    /**
     * xx
     */
    @Autowired
    RestTemplate restTemplate;

    /**
     * yyy
     * @return rr
     */
    @RequestMapping(value = "/ribbon-consumer", method = RequestMethod.GET)
    private String helloConsumer(){

        return restTemplate.getForEntity("http://HELLO-SERVICE/hello",String.class).getBody();
    }
}

3 服務端

3.1 pom

        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-eureka-server</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-ribbon</artifactId>
            <version>2.2.0.RELEASE</version>
        </dependency>
    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>Brixton.SR5</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>

3.2 application.properties

spring.application.name=hello-service
# 服務註冊到兩臺註冊中心
eureka.client.service-url.defaultZone=http://peer1:1111/eureka/,http://peer2:1112/eureka

3.3 啓動類

package com.didispace.springboothello;

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

/**
 * 能夠被發現爲客戶端
 */
@EnableDiscoveryClient
@SpringBootApplication
public class SpringBootHelloApplication {

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

}

3.4 服務

package com.didispace.springboothello.controller;

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;

import java.util.logging.Logger;

/**
 * @Author: leimin
 * @Description: new class
 * @Date: 2020/6/8 9:08
 * @Version: 1.0
 */
@RestController
public class HelloController {

    /**
     * xx
     */
    private final Logger logger = Logger.getLogger(String.valueOf(getClass()));

    /**
     * xx
     */
    @Autowired
    private DiscoveryClient client;

    /**
     * xx
     * @return xx
     */
    @RequestMapping(value = "/hello",method = RequestMethod.GET)
    public String index(){

        ServiceInstance instance = client.getLocalServiceInstance();
        logger.info("/hello,host:" + instance.getHost()+", service_id:" +instance.getServiceId());

        return "hello World !";
    }
}