Spring cloud服务的注册和发现

可参考：http://blog.csdn.net/liaomin416100569/article/details/78059174

服务（service）发送邮件

服务的概念：

服务注册和发现

地址:https://cloud.spring.io/spring-cloud-netflix/

配置注册中心:

在eurekaserver中加入依赖

<parent>

    <groupId>org.springframework.boot</groupId>

    <artifactId>spring-boot-starter-parent</artifactId>

    <version>1.5.9.RELEASE</version>

</parent>

<dependencyManagement>

    <dependencies>

        <dependency>

            <groupId>org.springframework.cloud</groupId>

            <artifactId>spring-cloud-dependencies</artifactId>

            <version>Dalston.SR4</version>

            <type>pom</type>

            <scope>import</scope>

        </dependency>

    </dependencies>

</dependencyManagement>

<dependencies>

    <dependency>

        <groupId>org.springframework.cloud</groupId>

        <artifactId>spring-cloud-starter-eureka-server</artifactId>

    </dependency>

   

</dependencies>

注册中心的资源文件application.yml

server:

port: 8761#eureka默认端口

eureka:

instance:

hostname: localhost#主机名

client:

registerWithEureka: false

fetchRegistry: false

serviceUrl:

defaultZone: http://${eureka.instance.hostname}:${server.port}/eureka/

网址：

http://cloud.spring.io/spring-cloud-static/Dalston.SR5/single/spring-cloud.html#spring-cloud-eureka-server

注册中心的启动类(EnableEurekaServer)

package cn.et;

 

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, args);

}

}

eurekaServer的访问地址：localhost:8761 出现界面

eureka client 的配置（客户端）

spring.mail.host=smtp.163.com

Spring.mail.password=123456

spring.mail.port=25

spring.mail.protocol=smtp

[email protected]

eureka.client.serviceUrl.defaultZone=http://localhost:8761/eureka/

spring.application.name=email

server.port=8081

 

在注册中的main方法上加@EnableEurekaClient启动自动注册

Eureka客户端启动类

package cn.et;

 

import org.springframework.boot.SpringApplication;

import org.springframework.boot.autoconfigure.SpringBootApplication;

import org.springframework.cloud.netflix.eureka.EnableEurekaClient;

@EnableEurekaClient

@SpringBootApplication

public class Main {

public static void main(String[] args) {

SpringApplication.run(Main.class, args);

}

}

Ribbon

<dependency>

    	<groupId>org.springframework.cloud</groupId>

    	<artifactId>spring-cloud-starter-ribbon</artifactId>

</dependency>

@EnableEurekaClient和@EnableDiscoveryClient是一样的

Ribbon的main方法

@SpringBootApplication

@EnableEurekaClient

@RibbonClient(value="EMAIL")

/**

 * 表示当前这个服务需要调用其他的服务的名称

 * @author Administrator

 *

 */

@Configuration

public class Main {

  @LoadBalanced

    @Bean

    RestTemplate restTemplate() {

        return new RestTemplate();

    }

public static void main(String[] args) {

SpringApplication.run(Main.class, args);

}

Ribbon用get发送和post发送

package cn.et;

 

import java.util.HashMap;

import java.util.Map;

 

import org.springframework.beans.factory.annotation.Autowired;

import org.springframework.cloud.client.ServiceInstance;

import org.springframework.cloud.client.loadbalancer.LoadBalancerClient;

import org.springframework.http.HttpEntity;

import org.springframework.http.HttpHeaders;

import org.springframework.stereotype.Controller;

import org.springframework.web.bind.annotation.GetMapping;

import org.springframework.web.bind.annotation.PostMapping;

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

import org.springframework.web.bind.annotation.ResponseBody;

import org.springframework.web.client.RestClientException;

import org.springframework.web.client.RestTemplate;

 

 

@Controller

public class SendController {

@Autowired

private RestTemplate restTemplate;//通过restTemplate来调用ribbon

@Autowired  

    private LoadBalancerClient loadBalancer;

/**  

     * 启动多个发布者 端口不一致 程序名相同   

     * 使用  

     * @LoadBalanced必须添加  

     * @return  

     */  

@ResponseBody

    @RequestMapping("/choosePub")  

    public String choosePub() {  

        StringBuffer sb=new StringBuffer();  

        for(int i=0;i<=10;i++) {  

            ServiceInstance ss=loadBalancer.choose("EMAILSERVER");//从两个idserver中选择一个 这里涉及到选择算法  

            sb.append(ss.getUri().toString()+"<br/>");

        }  

        return sb.toString();  

    }    

@GetMapping("/sendClient")

public String send(String email_to,String email_subject ,String email_content){

//调用email服务

String controller="/send";

//通过注册中心客户端负载均衡  获取一台主机来调用

try {

controller += "?email_to="+email_to+"&email_subject="+email_subject+"&email_content="+email_content;

String result=restTemplate.getForObject("http://EMAILSERVER"+controller, String.class);

} catch (RestClientException e) {

// TODO Auto-generated catch block

e.printStackTrace();

return "redirect:/error.html";

}

 

//通过redirect返回string类型跳转,不允许spring控制器用@ResponseBody

return "redirect:/suc.html";

}

/**

 * 演示post

 * @param email_to

 * @param email_subject

 * @param email_content

 * @return

 */

@PostMapping("/sendClientpost")

public String postsend(String email_to,String email_subject ,String email_content){

try {

//

HttpHeaders headers=new HttpHeaders();

Map<String,Object> map=new HashMap<String,Object>();

map.put("email_to",email_to );

map.put("email_subject", email_subject);

map.put("email_content", email_content);

HttpEntity<Map> request=new HttpEntity<Map>(map, headers);

String result=restTemplate.postForObject("http://EMAILSERVER/send",request, String.class);

} catch (RestClientException e) {

// TODO Auto-generated catch block

e.printStackTrace();

return "redirect:/error.html";

}

return "redirect:/suc.html";

}

/**

 * 演示调用sendmail的/user/这个请求

 * @return

 */

@ResponseBody

@GetMapping("/invokeUser")

public String invokeUser(String id){

String resul=restTemplate.getForObject("http://EMAILSERVER/user/{id}",String.class,id);

return resul;

}

}

发送邮件的控制类

package cn.et;

 

import java.util.HashMap;

import java.util.Map;

 

import org.springframework.beans.factory.annotation.Autowired;

import org.springframework.mail.SimpleMailMessage;

import org.springframework.mail.javamail.JavaMailSender;

import org.springframework.web.bind.annotation.GetMapping;

import org.springframework.web.bind.annotation.PathVariable;

import org.springframework.web.bind.annotation.PostMapping;

import org.springframework.web.bind.annotation.RequestBody;

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

 

@RestController

public class MailController {

@Autowired

private JavaMailSender jms;

@PostMapping("/send")

public String send(@RequestBody Map<String,Object> map){

SimpleMailMessage mailMessage=new SimpleMailMessage();

mailMessage.setFrom("[email protected]");

mailMessage.setTo(map.get("email_to").toString());

mailMessage.setSubject(map.get("email_subject").toString());

mailMessage.setText(map.get("email_content").toString());

jms.send(mailMessage);

return "1";

}

@GetMapping("/a")

public String a(){

return "2";

}

@GetMapping("/user/{userId}")

public Map getUser(@PathVariable String userId){

Map map=new HashMap();

map.put("id", userId);

map.put("name", "zs_"+userId);

return map;

}

}

启动MailController

package cn.et;

 

import org.springframework.boot.SpringApplication;

import org.springframework.boot.autoconfigure.SpringBootApplication;

import org.springframework.cloud.client.loadbalancer.LoadBalanced;

import org.springframework.cloud.netflix.eureka.EnableEurekaClient;

import org.springframework.cloud.netflix.ribbon.RibbonClient;

import org.springframework.context.annotation.Bean;

import org.springframework.context.annotation.Configuration;

import org.springframework.web.client.RestTemplate;

 

@SpringBootApplication

@EnableEurekaClient

@RibbonClient(value = "EMAILSERVER")

/**

 * 表示当前这个服务需要调用其他的服务的名称

 *

 * @author Administrator

 *

 */

@Configuration

public class Main {

@LoadBalanced//启动负载均衡

@Bean

RestTemplate restTemplate() {

return new RestTemplate();

}

 

public static void main(String[] args) {

SpringApplication.run(Main.class, args);

}

 

}

定义LoadBalancerClient 可以用于测试选择的服务器的算法负载的算法的类需要实现 IRule 接口以下列表摘自网络

策略名	策略描述
BestAvailableRule	选择一个最小的并发请求的server
AvailabilityFilteringRule	过滤掉那些因为一直连接失败的被标记为circuit tripped的后端server，并过滤掉那些高并发的的后端server（active connections 超过配置的阈值）
WeightedResponseTimeRule	根据相应时间分配一个weight，相应时间越长，weight越小，被选中的可能性越低。
RetryRule	对选定的负载均衡策略机上重试机制。
RoundRobinRule	roundRobin方式轮询选择server
RandomRule	随机选择一个server
ZoneAvoidanceRule	复合判断server所在区域的性能和server的可用性选择server

ribbon默认的配置类为 RibbonClientConfiguration 其中配置IRule的bean为

负载均衡的规则配置:

EMAILSERVER:用户名

EMAILSERVER.ribbon.NFLoadBalancerRuleClassName=com.netflix.loadbalancer.RandomRule

Feign(面向接口式)

加入依赖:

<dependency>

    	<groupId>org.springframework.cloud</groupId>

    	<artifactId>spring-cloud-starter-feign</artifactId>

</dependency>

配置文件:

spring.application.name=EMAIL

server.port=8888

eureka.client.serviceUrl.defaultZone=http://localhost:8761/eureka/

#服务器的算法(随机)

EMAILSERVER.ribbon.NFLoadBalancerRuleClassName=com.netflix.loadbalancer.RandomRule

接口

package cn.et;

 

import java.util.Map;

 

import org.springframework.cloud.netflix.feign.FeignClient;

import org.springframework.web.bind.annotation.GetMapping;

import org.springframework.web.bind.annotation.PathVariable;

import org.springframework.web.bind.annotation.PostMapping;

import org.springframework.web.bind.annotation.RequestBody;

 

@FeignClient("EMAILSERVER")

public interface IsendMail {

@GetMapping("/user/{userId}")

public Map getUser(@PathVariable("userId") String userId);

@PostMapping("/send")

public String send(@RequestBody Map<String,Object> map);

}

控制类

package cn.et;



import java.util.HashMap;

import java.util.Map;

 

import org.springframework.beans.factory.annotation.Autowired;

import org.springframework.http.HttpEntity;

import org.springframework.http.HttpHeaders;

import org.springframework.stereotype.Controller;

import org.springframework.web.bind.annotation.GetMapping;

import org.springframework.web.bind.annotation.PostMapping;

import org.springframework.web.bind.annotation.ResponseBody;

import org.springframework.web.client.RestClientException;

 

 

@Controller

public class SendController {

 

@Autowired

private IsendMail sendMail;

@GetMapping("/sendClient")

public String send(String email_to,String email_subject ,String email_content){

//调用email服务

String controller="/send";

//通过注册中心客户端负载均衡  获取一台主机来调用

try {

controller += "?email_to="+email_to+"&email_subject="+email_subject+"&email_content="+email_content;

//String result=restTemplate.getForObject("http://EMAILSERVER"+controller, String.class);

} catch (RestClientException e) {

// TODO Auto-generated catch block

e.printStackTrace();

return "redirect:/error.html";

}

return "redirect:/suc.html";

}

/**

 * 演示post

 * @param email_to

 * @param email_subject

 * @param email_content

 * @return

 */

@PostMapping("/sendClientpost")

public String postsend(String email_to,String email_subject ,String email_content){

try {

Map<String,Object> map=new HashMap<String,Object>();

map.put("email_to",email_to );

map.put("email_subject", email_subject);

map.put("email_content", email_content);

sendMail.send(map);

} catch (RestClientException e) {

// TODO Auto-generated catch block

e.printStackTrace();

return "redirect:/error.html";

}

return "redirect:/suc.html";

}

/**

 * 演示调用sendmail的/user/这个请求

 * @return

 */

@ResponseBody

@GetMapping("/invokeUser")

public String invokeUser(String id){

Map map=sendMail.getUser(id);

return map.get("name").toString();

}

}

启动类

package cn.et;

 

import java.util.Map;

 

import org.springframework.cloud.netflix.feign.FeignClient;

import org.springframework.web.bind.annotation.GetMapping;

import org.springframework.web.bind.annotation.PathVariable;

import org.springframework.web.bind.annotation.PostMapping;

import org.springframework.web.bind.annotation.RequestBody;

 

@FeignClient("EMAILSERVER")

public interface IsendMail {

@GetMapping("/user/{userId}")

public Map getUser(@PathVariable("userId") String userId);

@PostMapping("/send")

public String send(@RequestBody Map<String,Object> map);

}