springCloud核心教程_IDEA版本

傷城~ 2022-12-19 00:40 123阅读 0赞

[码云项目地址][Link 1]

# 父工程创建 #

## 创建普通maven项目 ##

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L0JMVUVTS1lIT1NU_size_16_color_FFFFFF_t_70_pic_center]

1.  删除src
2.  配置核心xml

<?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">
        <modelVersion>4.0.0</modelVersion>
    
        <groupId>com.llt</groupId>
        <artifactId>springcloud</artifactId>
        <version>1.0-SNAPSHOT</version>
        <modules>
            <module>springcloudapi</module>
        </modules>
        
        <packaging>pom</packaging>
        
        <properties>
            <junit.version>4.13.1</junit.version>
            <log4j.version>1.2.17</log4j.version>
            <logback.core.version>1.3.0-alpha5</logback.core.version>
            <mysql.connector.java>8.0.12</mysql.connector.java>
            <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
            <maven.compiler.source>1.8</maven.compiler.source>
            <maven.compiler.target>1.8</maven.compiler.target>
        </properties>
        
        
        <dependencyManagement>
            <dependencies>
                <dependency>
                    <groupId>org.springframework.cloud</groupId>
                    <artifactId>spring-cloud-dependencies</artifactId>
                    <version>Hoxton.SR8</version>
                    <type>pom</type>
                    <scope>import</scope>
                </dependency>
                
                <dependency>
                    <groupId>org.springframework.boot</groupId>
                    <artifactId>spring-boot-dependencies</artifactId>
                    <version>2.3.5.RELEASE</version>
                    <type>pom</type>
                    
                    <scope>import</scope>
                </dependency>
            
                
                <dependency>
                    <groupId>mysql</groupId>
                    <artifactId>mysql-connector-java</artifactId>
                    <version>${mysql.connector.java}</version>
                </dependency>
                <dependency>
                    <groupId>com.alibaba</groupId>
                    <artifactId>druid</artifactId>
                    <version>1.2.2</version>
                </dependency>
                
                
                <dependency>
                    <groupId>org.mybatis.spring.boot</groupId>
                    <artifactId>mybatis-spring-boot-starter</artifactId>
                    <version>2.1.3</version>
                </dependency>
                
                <dependency>
                    <groupId>junit</groupId>
                    <artifactId>junit</artifactId>
                    <version>${junit.version}</version>
                </dependency>
                <dependency>
                    <groupId>log4j</groupId>
                    <artifactId>log4j</artifactId>
                    <version>${log4j.version}</version>
                </dependency>
                
                <dependency>
                    <groupId>ch.qos.logback</groupId>
                    <artifactId>logback-core</artifactId>
                    <version>${logback.core.version}</version>
                </dependency>
            </dependencies>
        </dependencyManagement>
    </project>

## 创建子工程一样是maven ##

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L0JMVUVTS1lIT1NU_size_16_color_FFFFFF_t_70_pic_center 1]

## 创建数据库 ##

命名以及字符集排序  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L0JMVUVTS1lIT1NU_size_16_color_FFFFFF_t_70_pic_center 2]

## 调用远程服务注意事项 ##

1.  如果是post请求需要在方法括号添加@RequestBody

@PostMapping("/dept/add")
        public   boolean addDept(@RequestBody Dept dept){ 
            System.out.println(dept.getDname());
            return deptService.addDept(dept);
        }

## Eureka服务注册发现 ##

#### 服务段 ####

*  xml

<dependency>
               <groupId>org.springframework.cloud</groupId>
               <artifactId>spring-cloud-starter-netflix-eureka-server</artifactId>
               <version>2.2.5.RELEASE</version>
           </dependency>

*  yaml  
    service-url: \# 监控页面  
    defaultZone 新版本不用配置 默认ip地址+端口号

server:
     port: 7001
    #Eureka
    eureka:
     instance:
       hostname: localhost
     client:
    # register-with-eureka 是否在注册中心注册自己 false 不注册
       register-with-eureka: false
    # fetch-registry 如果是false 说明自己是注册中心
       fetch-registry: false
       service-url: # 监控页面
         defaultZone: http://${ eureka.instance.hostname}:${ server.port}/eureka/

#### 客户端 ####

*  xml  
    添加监控信息

<dependency>
               <groupId>org.springframework.boot</groupId>
               <artifactId>spring-boot-starter-actuator</artifactId>
               <version>2.3.5.RELEASE</version>
           </dependency>
    <dependency>
       <groupId>org.springframework.cloud</groupId>
       <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
       <version>2.2.5.RELEASE</version>
    </dependency>

*  yaml

server:
      port: 8001
    #mybatis 配置
    mybatis:
      type-aliases-package: com.llt.springcloud.pojo
      config-location: classpath:mybatis/mybatis-config.xml
      mapper-locations: classpath:mybatis/mapper/*.xml
    spring:
      application:
        name: springcloud-provider-dept8001
      datasource:
        type: com.alibaba.druid.pool.DruidDataSource
        username: root
        password: root
        driver-class-name: com.mysql.cj.jdbc.Driver
        url: jdbc:mysql://localhost:3306/db01?serverTimezone=UTC&useUnicode=true&characterEncoding=utf8&useSSL=false
    eureka:
      client:
        service-url:
          defaultZone: http://localhost:7001/eureka/
      instance:
        instance-id: springcloud-provider-dept8001
     # spring-boot-starter-actuator 配置
    info:
      app.name: llt
      company.name: mingwen

# Ribbon 消费者负载均衡 #

*  默认的轮询

package com.llt.springcloud.config;
    
    import com.netflix.loadbalancer.IRule;
    import com.netflix.loadbalancer.RandomRule;
    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 { 
    // Configuration spring applicationContext.xml
        @Bean
        //负责均衡 RestTemplate
        @LoadBalanced
        public RestTemplate getRestTemplate(){ 
            return new RestTemplate();
        }
    
    
    }

*  自定义  
    ![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L0JMVUVTS1lIT1NU_size_16_color_FFFFFF_t_70_pic_center 3]\* 启动类

package com.llt.springcloud;
    
    import com.llt.myrule.LltRule;
    import org.springframework.boot.SpringApplication;
    import org.springframework.boot.autoconfigure.SpringBootApplication;
    import org.springframework.cloud.netflix.eureka.EnableEurekaClient;
    import org.springframework.cloud.netflix.ribbon.RibbonClient;
    
    @SpringBootApplication
    @EnableEurekaClient
    //微服务启动就可以加载自定义的
    @RibbonClient(name = "SPRINGCLOUD-PROVIDER-DEPT",configuration = LltRule.class)
    // eureka 于 ribbom 整合以后 客户端可以直接调用方法 不用关心ip地址
    public class DeptConsumer_80 { 
        public static void main(String[] args) { 
            SpringApplication.run(DeptConsumer_80.class,args);
        }
    }

*  LlRule

package com.llt.myrule;
    
    import com.netflix.loadbalancer.IRule;
    import org.springframework.context.annotation.Bean;
    import org.springframework.context.annotation.Configuration;
    
    @Configuration
    public class LltRule { 
        @Bean
        public IRule myIRule(){ 
            //返回值可以改成自己写的
            return new LltRandomRule();
        }
    }

*  LltRandomRule

package com.llt.myrule;
    
    import com.netflix.client.config.IClientConfig;
    import com.netflix.loadbalancer.AbstractLoadBalancerRule;
    import com.netflix.loadbalancer.ILoadBalancer;
    import com.netflix.loadbalancer.Server;
    
    import java.util.List;
    import java.util.concurrent.ThreadLocalRandom;
    
    /** * 1. 每个服务 访问2次换下一个服务 * total = 0 total==2 指向下一节点 * index = 0 默认节点选择1 * */
    public class LltRandomRule extends AbstractLoadBalancerRule { 
        private int total=0;//被调用的次数
        private int currentIndex=0;//当前谁在提供服务
        public LltRandomRule() { 
        }
    
        @SuppressWarnings({ "RCN_REDUNDANT_NULLCHECK_OF_NULL_VALUE"})
        public Server choose(ILoadBalancer lb, Object key) { 
            if (lb == null) { 
                return null;
            } else { 
                Server server = null;
    
                while(server == null) { 
                    if (Thread.interrupted()) { 
                        return null;
                    }
    
                    List<Server> upList = lb.getReachableServers();
                    List<Server> allList = lb.getAllServers();
                    int serverCount = allList.size();
                    if (serverCount == 0) { 
                        return null;
                    }
    
    // int index = this.chooseRandomInt(serverCount);
    // server = (Server)upList.get(index);
                    //=================自定义======================
    // int currentindex = this.chooseRandomInt(serverCount);
    
                    if (total<1){ 
                        server = upList.get(total);
                        total++;
                    }else { 
                     total = 0;
    // currentIndex=currentIndex+1;
    // if(currentIndex>=upList.size());{ 
    // currentIndex = 0;
    // }
                        server = upList.get(total);
                    }
                    System.out.println("total:==="+total);
                    System.out.println("upList.size():==="+upList.size());
                    //=================自定义======================
                    if (server == null) { 
                        Thread.yield();
                    } else { 
                        if (server.isAlive()) { 
                            return server;
                        }
    
                        server = null;
                        Thread.yield();
                    }
                }
    
                return server;
            }
        }
    
        protected int chooseRandomInt(int serverCount) { 
    
            return ThreadLocalRandom.current().nextInt(serverCount);
        }
    
        public Server choose(Object key) { 
            return this.choose(this.getLoadBalancer(), key);
        }
    
        public void initWithNiwsConfig(IClientConfig clientConfig) { 
        }
    }

## Feign 负载均衡 ##

feign是声明式的web service客户端，它让微服务之间的调用变得更简单了，类似controllr调用service。SpringCloud集成了Ribbon和Eureka,可在使用Feign时提供负载均衡的http客户端。  
feign,主要是社区，大家都习惯面向接口编程。这个是很多开发人员的规范。调用微服务访问两种方法  
1.微服务名字\[ribbon\]  
2.接口和注解\[feign \]  
Feign 不建议用get请求传参 很麻烦  
启动项目用80 别用feign  
![在这里插入图片描述][20201106162952849.png_pic_center]

*  这样子可以用

package com.llt.springcloud.service;
    
    import com.llt.springcloud.pojo.Dept;
    import org.springframework.cloud.openfeign.FeignClient;
    import org.springframework.stereotype.Controller;
    import org.springframework.web.bind.annotation.*;
    
    import java.util.List;
    @FeignClient(value = "SPRINGCLOUD-PROVIDER-DEPT")
    @Controller
    public interface DeptClientSerevice { 
         @GetMapping("/dept/getById/{id}")
         Dept queryById(@PathVariable("id") Long id);
         @GetMapping("/dept/list")
         List<Dept> queryAll();
         @PostMapping("/dept/add")
         boolean addDept(Dept dept);
    }

[Link 1]: https://gitee.com/blueskyliu/demo-of-spring-cloud-demo.git
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[20201106162952849.png_pic_center]: /images/20221120/89bb1e064f8b432ab34e0e0b3b301a29.png