SpringCloud介紹及入門(二)

接口的實現

在user_service_interface中添加一個User的類。 增長私有屬性 id,name , 並利用快捷鍵Alt+Insert 實現get,set的快速生成。

實體類User

要注意要有一個無參的構造函數，不然消費者調用的時候會報錯

package com.project.microservice.domain;

public class User {
    private Long Id;
    private String Name;


    public Long getId() {
        return Id;
    }

    public void setId(Long id) {
        Id = id;
    }

    public String getName() {
        return Name;
    }

    public void setName(String name) {
        Name = name;
    }

    public User(Long id, String name) {
        Id = id;
        Name = name;
    }
    public User(){

    }

    @Override
    public String toString() {
        return "User{" +
                "Id=" + Id +
                ", Name='" + Name + '\'' +
                '}';
    }


}

接口定義

package com.project.microservice.service;

import com.project.microservice.domain.User;

public interface IUserService {
    User getUserInfo(Long id,String name);
}

SANPSHOP是什麼

一個快照版本。這樣能夠不用頻繁更新。

在Maven依賴管理中，惟一標識一個依賴項是由該依賴項的三個屬性構成的，分別是groupId、artifactId以及version。這三個屬性能夠惟一肯定一個組件（Jar包或者War包）

一個倉庫通常分爲public(Release)倉和SNAPSHOT倉，前者存放正式版本，後者存放快照版本。若是在項目配置文件中（不管是build.gradle仍是pom.xml）指定的版本號帶有’-SNAPSHOT’後綴，好比版本號爲’Junit-4.10-SNAPSHOT’，那麼打出的包就是一個快照版本。

參考：http://www.javashuo.com/article/p-zldqfhkk-ke.html

User_service_provider_8001生產者的實現。

思路：該項目主要是提供服務，而後在Eureka註冊中心中去註冊，業務邏輯主要是主要是實現接口層的方法 。作爲eureserver的客戶端，導入client的包，導入接口的包。

provider中pom.xml的主要配置

<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-netflix-eureka-client</artifactId>
</dependency>

provider中的啓動類

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

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

yml的配置

server:
  port: 8001
spring:
  application:
    name: microservice-provider-user
eureka:
  register-with-eureka: true #
  fetch-registry: true #
  client:
    service-url:
      defaultZone: http://127.0.0.1:7001/eureka/
  instance:
    prefer-ip-address: true

實現接口

import com.project.microservice.domain.User;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
@RequestMapping("/provider")
public class UserController {
    @RequestMapping("/user/{id}")
    public User getUserInfo(@PathVariable(value = "id")Long id, String name) {
        return new User(id,name);
    }
}

注意

register-with-eureka: true #
  fetch-registry: true #

這兩項配置在服務中心中要設置爲false,表示不發現自身服務，可是在客戶端，必定要設置爲true，不然發現不了。

測試生產者調用結果：

註冊中心會自動顯示出生產者

生產者直接調用結果

消費者代碼的實現

消費者項目pom.xml中引用接口和相應的依賴，web,test,cloud

<?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>microservice_paent</artifactId>
        <groupId>com.project</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>User_service_consume_9001</artifactId>

    <dependencies>
        <dependency>
            <groupId>com.project</groupId>
            <artifactId>User_service_interface</artifactId>
            <version>1.0-SNAPSHOT</version>
        </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.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
        </dependency>
    </dependencies>
</project>

Resource的yml中進行相應的配置

server:
  port: 9001
eureka:
  register-with-eureka: false #
  fetch-registry: false #
  client:
    service-url:
      defaultZone: http://127.0.0.1:7001/eureka/
  instance:
    prefer-ip-address: true

消費者啓動類的配置

引用SpringBootApplication和EnableEurekaClient兩個註解。

package com.project;

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

@SpringBootApplication
@EnableEurekaClient
public class UserConsumeApplication {
    public static void main(String[] args) {

        SpringApplication.run(UserConsumeApplication.class,args);
    }
}

建立webcontroller實現調用生產者的代碼

要注意不能直接用生產者的ip地址，由於生產纔在註冊中心註冊之後，會變，用ip找不到。

package com.project.web.controller;

import com.project.microservice.domain.User;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.cloud.client.loadbalancer.LoadBalancerClient;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.client.RestTemplate;


@RestController
@RequestMapping("/consumer/user")
public class UserController {
    private static final String URL_PREFIX="http://MICROSERVICE-PROVIDER-USER";

    @Autowired
    private LoadBalancerClient loadBalancerClient;

    @Autowired
    private RestTemplate restTemplate;

    @RequestMapping("/{id}")
    public User get(@PathVariable("id") Long id, String name) {
        return restTemplate.getForObject(URL_PREFIX+"/provider/user/"+id+"?name="+name,User.class);
    }


}

關於RestTemplate的配置

package com.project.config;

import org.springframework.cloud.client.loadbalancer.LoadBalanced;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.client.RestTemplate;
@Configuration
public class ConfigBean {
    @Bean
    @LoadBalanced
    public RestTemplate getRestTemplate(){
        return new RestTemplate();
    }
}

啓動消費者進行測試