SpringCloud框架讲解，以及如何在idea上搭建一个简单的SpringCloud框架并使用Ribbon技术

    一：springCloud框架
    是springboot的升级框架，其中包含很多子项目
    eureka注册中心， feign消费者，Hystrix熔断器，Zuul路由，
    Config全局配置中心，Bus消息总线，负载均衡策略
    
    底层基于httpClient实现，发布一个controller类
    
    spring家族：
    spring Framework5.0 --》 springboot2.0 --》springcloud Finchley.SR2
    
    springboot（微服务）相对于spring 约定优于配置

 

  二：搭建springCloud框架

   1.创建maven多模块儿项目

删除src文件夹

2.在springcloud项目上创建springboot项目勾选cloud discovery --》Eureka Server

 

3.在配置类配置Eureka注册服务 Eureka Server

server:
  port: 8761


eureka:
  instance:
    hostname: localhost
  client:
    register-with-eureka: false
    fetch-registry: false
    service-url:
      defaultZone: http://${eureka.instance.hostname}:${server.port}/eureka
  server:
    enable-self-preservation: false

3.在启动类上加@EnableEurekaServer 启用eureka服务端  

package com.jk.app;

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

@SpringBootApplication
@EnableEurekaServer
public class SpringCloudEurekaApplication {

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

}

4.启动项目访问路径地址，访问Eureka注册中心，出现如下图表示访问成功

5.创建一个生产者springcloud-provider

记得勾选Eureka Discover选项

6.配置生产者的配置文件

server:
  port: 8765

spring:
  application:
    name: springcloud-user-reg

eureka:
  client:
    service-url:
      defaultZone: http://localhost:8761/eureka

7.在生产者启动类上加上@EnableEurekaClient注解，并写一个方法进行测试框架是否搭建成功

package com.jk.app;

import org.springframework.beans.factory.annotation.Value;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.netflix.eureka.EnableEurekaClient;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;

@SpringBootApplication
@EnableEurekaClient
@RestController
@ComponentScan("com.jk.*")
public class SpringcloudProviderApplication {

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

    }

    /**
     * 测试方法
     */

    //动态取端口号,${server.port}和配置文件的值对应
    @Value("${server.port}")
    String post;
    @GetMapping("test")
    public String test(){
        //返回一句话
        return "I post port is :" +post;
    }

}

8.浏览器访问路径

访问成功

9.我们回到Eureka注册中心看一下，发现注册中心已经注册上了！

   idea启动多个实例的方法：
    Edit Configurations--> single instance only 只能启动单个实力 将勾去掉
    Edit Configurations--> Allow running in parallel 允许并行启动 将勾选上

 

 

10.接着创建消费者的项目，创建项目选择 Web  Eureka Discover   Ribbon

11.配置消费者的配置类

server:
  port: 8672

spring:
  application:
    name: springcloud-ribbon

eureka:
  client:
    service-url:
      defaultZone: http://localhost:8761/eureka

12.同样在在启动类上加@EnableEurekaClient 注解

13.在启动类中将RestRestTemplate注入spring中

package com.jk.app;

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.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.web.client.RestTemplate;

@SpringBootApplication
@EnableEurekaClient
@ComponentScan("com.jk.*")
public class SpringcloudRibbonApplication {

    public static void main(String[] args) {
        SpringApplication.run(SpringcloudRibbonApplication.class, args);
    }
    // 将RestTemplate注入到spring容器中
    // LoadBalanced负载均衡默认为轮询
    // 通过注入在controller中就可以使用调用生产者实例
    @Bean
    @LoadBalanced
    RestTemplate restTemplate(){
        return new RestTemplate();
    }


}

14.在消费者项目的controller中注入RestTemplate
        @Autowired
        private RestTemplate restTemplate;

package com.jk.controller;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.client.RestTemplate;

@RestController
public class UserController {

    @Autowired
    private RestTemplate restTemplate;
}

15.消费者调用生产者
    restTemplate.getForObject("http://生产者实例名/请求生产者的Controller方法", 返回值类型.class);

在生产者项目创建Controller，并写一个测试方法测试

package com.jk.controller;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.ResponseBody;

@Controller
public class UserController {

    /**
     * 测试
     * @return
     */
    @GetMapping("testPro")
    @ResponseBody
    public String test(){
        System.out.println("ribbon调用生产者成功");
        return "success";
    }
}

16.回到消费者controller调用方法

package com.jk.controller;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.client.RestTemplate;

@RestController
public class UserController {

    @Autowired
    private RestTemplate restTemplate;

    /**
     * 调用生产者
     */

    //调用请求
    //get  查
    //Post  增
    //delete 删
    //put 改
    @GetMapping("select")
    public String select(){
        String result = restTemplate.getForObject("",String.class);
        return result;
    }
}

17.启动项目访问路径

调用方法成功！

18.接着创建common项目接入实体Bean

package com.jk.model;

public class User {
    private Integer userId;
    private String userName;



    public Integer getUserId() {
        return userId;
    }

    public void setUserId(Integer userId) {
        this.userId = userId;
    }

    public String getUserName() {
        return userName;
    }

    public void setUserName(String userName) {
        this.userName = userName;
    }

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

13.在provider生产者项目和ribbon消费者的pom.xml文件中引入和common项目的依赖关系

        <dependency>
            <groupId>com.jk</groupId>
            <artifactId>common</artifactId>
            <version>1.0-SNAPSHOT</version>
        </dependency>

14.在生产者的controller中写一个新增的方法

package com.jk.controller;

import com.jk.model.User;
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.RequestBody;
import org.springframework.web.bind.annotation.ResponseBody;

@Controller
public class UserController {

    /**
     * 测试
     * @return
     */
    @GetMapping("testPro")
    @ResponseBody
    public String test(){
        System.out.println("ribbon调用生产者成功");
        return "success";
    }

    /**
     * 新增的方法
     */
    @PostMapping("save")
    @ResponseBody
    public User save(@RequestBody User user){
        user.setUserId(11);
        return user;
    }

}

15.在消费者的controller中调用生产者发布的新增接口

@PostMapping("save")
    public User save(){
        User user = new User();
        user.setUserName("路明非");
        User user1 = restTemplate.postForObject("http://SPRINGCLOUD-USER-REG/save", user, User.class);
        return user1;
    }

16.启动项目访问地址

调用成功，搭建完毕。开始连接数据库

17.我在common项目中写入一个实体类

18.生产者项目中的pom.xml文件中引入数据库核心jar包

        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.4</version>
        </dependency>
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>1.3.2</version>
        </dependency>

19.生产者项目配置类配置

server:
  port: 8765



spring:
  application:
    name: springcloud-user-reg
  datasource:
    driver-class-name: com.mysql.jdbc.Driver
    url: jdbc:mysql://localhost:3306/math?serverTimezone=Hongkong&useUnicode=true&characterEncoding=utf-8
    username: root
    password: root

eureka:
  client:
    service-url:
      defaultZone: http://localhost:8761/eureka
mybatis:
  mapper-locations: classpath:mapper/*.xml

20.创建包结构

controller层记得加controller注解，Autowired注解注入service层

 /**
     * 数据库查询order列表
     *
     */
    @GetMapping("queryOrder")
    @ResponseBody
    public List<OrderBean> queryOrder(){
        return userService.queryOrder();
    }

service层

/**
     * 查询
     * @return
     */
    List<OrderBean> queryOrder();

serviceImpl层记得加Service注解，Autowired注解注入Mapper层

    @Override
    public List<OrderBean> queryOrder() {
        return userMapper.queryOrder();
    }

mapper层

    @Select("select * from t_order")
    List<OrderBean> queryOrder();

20.在生产者启动类加上@MapperScan("com.jk.mapper")扫描Mapper层

21.消费者Controller层调用查询方法

 /**
     * 调用生产者查询方法
     */
    @GetMapping("queryOrder")
    public List<OrderBean> queryOrder(){
        List forObject = restTemplate.getForObject("http://SPRINGCLOUD-USER-REG/queryOrder", List.class);
        return forObject;
    }

22.启动项目访问

查询成功

我的mysql数据库

连接数据库成功！