springcloud入门案例

springcloud入门案例

首先搭建好eureka服务，教程：https://www.cnblogs.com/Y-wee/p/14129138.html

1、公共模块

新建一个普通项目作为公共模块项目，编写一些公共代码，实现代码复用，案例项目名为：common

• 编写实体类，作为公共代码

package com.yl.bean;

import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;

import java.io.Serializable;

@Data
@NoArgsConstructor
@AllArgsConstructor
public class User implements Serializable {
    private String username;
    private String password;
}

2、服务提供者

新建项目继承父工程，作为服务提供者，案例项目名：server

2.1、修改pom文件

• 继承父工程

 <parent>
     <groupId>com.yl</groupId>
     <artifactId>springcloue_parent_02</artifactId>
     <version>0.0.1-SNAPSHOT</version>
     <relativePath/> <!-- lookup parent from repository -->
 </parent>

• 导入依赖

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter</artifactId>
</dependency>

<!--公共模块-->
<dependency>
    <groupId>com.yl</groupId>
    <artifactId>common</artifactId>
    <version>1.0-SNAPSHOT</version>
</dependency>

<!--配置eureka的客户端-->
<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
</dependency>

<!--配置web的starter-->
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-web</artifactId>
</dependency>

2.2、控制器

package com.yl.controller;

import com.yl.bean.User;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class ServerController {

    @RequestMapping("/getUser")
    public User getUser(){
        User user=new User("yl01","1111");

        return user;
    }

}

2.3、全局配置文件

spring:
  application:
    name: server
server:
  port: 8801
  #eureka的基本信息
eureka:
  instance:
    hostname: 127.0.0.1
  client:
    service-url:
      defaultZone: http://127.0.0.1:7001/eureka/
    #它本身是一个普通的服务，需要在eureka-server注册
    register-with-eureka: true
    #需要获取注册信息
    fetch-registry: true

2.4、启动类添加@EnableEurekaClient注解

package com.yl;

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

@SpringBootApplication
@EnableEurekaClient
public class ServerApplication {

    public static void main(String[] args) {
//        SpringApplication.run(ServerApplication.class, args);
        SpringApplication springApplication=new SpringApplication(ServerApplication.class);
        springApplication.setBannerMode(Banner.Mode.OFF);
        springApplication.run(args);
    }

}

2.5、测试服务提供者是否搭建成功

• 启动eureka服务
• 启动服务提供者
• 浏览器访问http://localhost:7001
• 查看是否有SERVER服务

3、服务消费者

新建项目继承父工程，作为服务消费者，案例项目名：client

3.1、修改pom文件

• 继承父工程

 <parent>
     <groupId>com.yl</groupId>
     <artifactId>springcloue_parent_02</artifactId>
     <version>0.0.1-SNAPSHOT</version>
     <relativePath/> <!-- lookup parent from repository -->
 </parent>

• 导入依赖

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-web</artifactId>
</dependency>

<!--公共模块-->
<dependency>
    <groupId>com.yl</groupId>
    <artifactId>common</artifactId>
    <version>1.0-SNAPSHOT</version>
</dependency>

<!--配置eureka的客户端-->
<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
</dependency>

<!--配置ribbon-->
<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-starter-netflix-ribbon</artifactId>
</dependency>

<!--支持feign-->
<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-starter-openfeign</artifactId>
</dependency>

<!--支持hystrix组件-->
<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-starter-netflix-hystrix</artifactId>
</dependency>

3.2、业务层接口，使用feign实现

package com.yl.service;

import com.yl.bean.User;
import org.springframework.cloud.openfeign.FeignClient;
import org.springframework.web.bind.annotation.RequestMapping;

@FeignClient(value = "SERVER")//调用的服务名
public interface IUserService {

    @RequestMapping("/getUser")//调用的服务地址
    User getUser();

}

3.3、控制器

package com.yl.controller;

import com.yl.bean.User;
import com.yl.service.IUserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class UserController {
    @Autowired
    private IUserService userService;

    @RequestMapping("/getUser")
    public User getUser(){
        return userService.getUser();
    }

}

3.4、全局配置文件

spring:
  application:
    name: client
server:
  port: 8080
  #eureka的基本信息
eureka:
  instance:
    hostname: 127.0.0.1
  client:
    service-url:
      defaultZone: http://127.0.0.1:7001/eureka/
    #它本身是一个普通的服务，需要在eureka-server注册
    register-with-eureka: true
    #需要获取注册信息
    fetch-registry: true

3.5、启动类添加@EnableEurekaClient注解和@EnableFeignClients注解

package com.yl;

import org.springframework.boot.Banner;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.netflix.eureka.EnableEurekaClient;
import org.springframework.cloud.netflix.hystrix.EnableHystrix;
import org.springframework.cloud.openfeign.EnableFeignClients;

@SpringBootApplication
@EnableEurekaClient
@EnableFeignClients
public class ClientApplication {

    public static void main(String[] args) {
//        SpringApplication.run(ClientApplication.class, args);
        SpringApplication springApplication=new SpringApplication(ClientApplication.class);
        springApplication.setBannerMode(Banner.Mode.OFF);
        springApplication.run(args);
    }

}

3.6、测试服务消费者是否搭建成功

• 启动eureka服务
• 启动服务提供者
• 启动服务消费者
• 浏览器访问：http://localhost:8080/getUser

4、业务层使用RestTemplate实现

如果不使用feign，使用RestTemplate实现，则需要编写一个配置类

@Configuration
public class RestTemplateConfig {

    //配置RestTempleate成为bean
    @Bean
    @LoadBalanced
    RestTemplate restTemplate(){
        return new RestTemplate();
    }
}

业务层接口不使用注解实现，使用实现类去实现

@Service
public class IUserServiceImpl implements IUserService {
    @Autowired
    RestTemplate restTemplate;

    @Override
    public User getUser() {
        String url="http://SERVICE/getUser";//通过http restful api实现远程调用服务
        
        User user=restTemplate.getForObject(url,User.class);

        return user;
    }
}