SpringCloud介绍及入门(二)

接口的实现

在user_service_interface中添加一个User的类。 增加私有属性 id,name , 并利用快捷键Alt+Insert 实现get,set的快速生成。

实体类User

要注意要有一个无参的构造函数，否则消费者调用的时候会报错

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 + '\'' +
                '}';
    }

}

接口定义

package com.project.microservice.service;

import com.project.microservice.domain.User;

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

SANPSHOP是什么

一个快照版本。这样可以不用频繁更新。

在Maven依赖管理中，唯一标识一个依赖项是由该依赖项的三个属性构成的，分别是groupId、artifactId以及version。这三个属性可以唯一确定一个组件（Jar包或者War包）

一个仓库一般分为public(Release)仓和SNAPSHOT仓，前者存放正式版本，后者存放快照版本。如果在项目配置文件中（无论是build.gradle还是pom.xml）指定的版本号带有’-SNAPSHOT’后缀，比如版本号为’Junit-4.10-SNAPSHOT’，那么打出的包就是一个快照版本。

参考：https://www.cnblogs.com/huang0925/p/5169624.html

User_service_provider_8001生产者的实现。

思路：该项目主要是提供服务，然后在Eureka注册中心中去注册，业务逻辑主要是主要是实现接口层的方法 。做为eureserver的客户端，导入client的包，导入接口的包。

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中的启动类

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

实现接口

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 #

这两项配置在服务中心中要设置为false,表示不发现自身服务，但是在客户端，一定要设置为true，否则发现不了。

测试生产者调用结果：

注册中心会自动显示出生产者

生产者直接调用结果

消费者代码的实现

消费者项目pom.xml中引用接口和相应的依赖，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中进行相应的配置

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

消费者启动类的配置

引用SpringBootApplication和EnableEurekaClient两个注解。

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);
    }
}

创建webcontroller实现调用生产者的代码

要注意不能直接用生产者的ip地址，因为生产才在注册中心注册以后，会变，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);
    }

}

关于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();
    }
}

启动消费者进行测试