初识SpringCloud微服务

HUC思梦

发布于 2020-09-03 16:57:33

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发布于 2020-09-03 16:57:33

文章被收录于专栏：HUC思梦的java专栏HUC思梦的java专栏

本文使用生产端与消费端两个工程来展示微服务之间的调用方式

具体内容详见代码注释

生产端工程：

pom.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.cloud.demo</groupId>
    <artifactId>micro-provider</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>jar</packaging>

    <name>micro-provider</name>
    <description>Demo project for Spring Boot</description>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.0.6.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <java.version>1.8</java.version>
    </properties>

    <!--spring cloud依赖管理-->
    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>Finchley.SR2</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>1.3.2</version>
        </dependency>

        <!--引入zookeeper 测试时使用，只能连接本地的zookeeper-->
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-zookeeper-all</artifactId>
            <exclusions>
                <exclusion>
                    <groupId>org.apache.zookeeper</groupId>
                    <artifactId>zookeeper</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
        <dependency>
            <groupId>org.apache.zookeeper</groupId>
            <artifactId>zookeeper</artifactId>
            <version>3.4.12</version>
            <exclusions>
                <exclusion>
                    <groupId>org.slf4j</groupId>
                    <artifactId>slf4j-log4j12</artifactId>
                </exclusion>
            </exclusions>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <configuration>
                    <fork>true</fork>
                </configuration>
            </plugin>
        </plugins>
    </build>


</project>

application.yml配置

spring:
  datasource:
    driver-class-name: com.mysql.jdbc.Driver
    url: jdbc:mysql:///testdb?useSSL=true
    username: root
    password: 123
  application:
    name: provider   #配置服务名
  cloud:
    zookeeper:
      connect-string: localhost:2181  #注册zookeeper地址

mybatis:
  configuration:
    map-underscore-to-camel-case: true # 配置mybatis字段与实体类属性映射


# 配置打印SQL的日志
logging:
  level:
    com.cloud.demo.microprovider.mapper:  debug

UserInfo实体类

package com.cloud.demo.microprovider.domain;

import lombok.Getter;
import lombok.Setter;

import java.util.Date;

@Getter    //lombok插件生成get方法
@Setter    //lombok插件生成set方法
public class UserInfo {
    private Integer userId;
    private String userName;
    private int userAge;
    private Date userBirth;
}

service接口

package com.cloud.demo.microprovider.service;

import com.cloud.demo.microprovider.domain.UserInfo;

public interface UserService {
    UserInfo getUserById(Integer userId);
}

service实现类

package com.cloud.demo.microprovider.service;

import com.cloud.demo.microprovider.domain.UserInfo;
import com.cloud.demo.microprovider.mapper.UserInfoMapper;
import org.springframework.stereotype.Service;

import javax.annotation.Resource;

@Service
public class UserServiceImpl implements UserService {
    @Resource
    private UserInfoMapper userMapper;

    @Override
    public UserInfo getUserById(Integer userId) {
        return userMapper.getUser(userId);
    }
}

Mapper

package com.cloud.demo.microprovider.mapper;

import com.cloud.demo.microprovider.domain.UserInfo;
import org.apache.ibatis.annotations.Param;
import org.apache.ibatis.annotations.Select;

public interface UserInfoMapper {

    @Select("SELECT USER_ID, " +
            "USER_NAME, USER_AGE, " +
            "USER_BIRTH FROM T_USER WHERE USER_ID=#{userId}")
    UserInfo getUser(@Param("userId") Integer userId);
}

Controller

package com.cloud.demo.microprovider.controller;

import com.cloud.demo.microprovider.domain.UserInfo;
import com.cloud.demo.microprovider.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class UserController {

    @Autowired
    private UserService userService;

    @GetMapping("user/{id}")
    public UserInfo getUser(@PathVariable("id") Integer userId) {
        return userService.getUserById(userId);
    }
}

服务启动类：

package com.cloud.demo.microprovider;

import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;

@SpringBootApplication
@MapperScan("com.cloud.demo.microprovider.mapper")//扫描Mapper到Spring容器中
@EnableDiscoveryClient //将服务注册到Zookeeper中管理
public class MicroProviderApplication {

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

消费端工程：

pom.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.gerry.cloud.demo</groupId>
    <artifactId>micro-consumer</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>jar</packaging>

    <name>micro-consumer</name>
    <description>Demo project for Spring Boot</description>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.0.6.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <java.version>1.8</java.version>
    </properties>

    <!--spring cloud依赖管理-->
    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>Finchley.SR2</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>

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

        <!--引入zookeeper 测试时使用，只能连接本地zookeeper-->
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-zookeeper-all</artifactId>
            <exclusions>
                <exclusion>
                    <groupId>org.apache.zookeeper</groupId>
                    <artifactId>zookeeper</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
        <dependency>
            <groupId>org.apache.zookeeper</groupId>
            <artifactId>zookeeper</artifactId>
            <version>3.4.12</version>
            <exclusions>
                <exclusion>
                    <groupId>org.slf4j</groupId>
                    <artifactId>slf4j-log4j12</artifactId>
                </exclusion>
            </exclusions>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <configuration>
                    <fork>true</fork>
                </configuration>
            </plugin>
        </plugins>
    </build>


</project>

application.yml配置

server:
  port: 8888  #为了与生成端端口不同，设置端口号

spring:
  cloud:
    zookeeper:
      connect-string: localhost:2181  #注册zookeeper地址
      discovery:
        register: false  #设置为false代表不会注册进zookeeper

实体类

package com.gerry.cloud.demo.microconsumer.vo;

import com.fasterxml.jackson.annotation.JsonAlias;
import com.fasterxml.jackson.annotation.JsonFormat;
import lombok.Getter;
import lombok.Setter;

import java.util.Date;

@Getter
@Setter
public class UserVo {
    private Integer userId;
    @JsonAlias("userName") // 配置json字段映射
    private String personName;
    private int userAge;
    @JsonFormat(pattern = "yyyy-MM-dd")
    private Date userBirth;
}

package com.gerry.cloud.demo.microconsumer.config;

import org.springframework.boot.SpringBootConfiguration;
import org.springframework.cloud.client.loadbalancer.LoadBalanced;
import org.springframework.context.annotation.Bean;
import org.springframework.web.client.RestTemplate;

/**
 * 把RestTemplate对象装配到spring容器管理
 */
@SpringBootConfiguration
public class RestTemplateConfiguration {
    @Bean
    @LoadBalanced  //负载均衡
    public RestTemplate restTemplate() {
        return new RestTemplate();
    }
}

Controller

package com.gerry.cloud.demo.microconsumer.controller;

import com.gerry.cloud.demo.microconsumer.vo.UserVo;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.cloud.client.loadbalancer.LoadBalancerClient;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.client.RestTemplate;

@RestController
public class UserWarpController {

    @Autowired
    private RestTemplate restTemplate;

    @Autowired
    private LoadBalancerClient loadBalancerClient;

    // 写死访问api方式测试
    /*@GetMapping("warp/user/{version}/{id}")
    public UserVo getUser(@PathVariable("version") double version
            , @PathVariable("id") Integer userId, String name) {
        System.out.println(version);
        System.out.println(name);
        // url必须是rest风格路径
        return restTemplate.getForObject("http://localhost:8080//user/"+userId, UserVo.class);
    }*/

    /*@GetMapping("warp/user/{id}") 
    public UserVo getUser(@PathVariable("id") Integer userId) {  //可以实现负载均衡
        ServiceInstance serviceInstance = loadBalancerClient.choose("provider");
        String host = serviceInstance.getHost(); // 主机名
        int port = serviceInstance.getPort(); // 端口号
        String url = String.format("http://%s:%s/%s/%d",host, port, "user", userId);
        System.out.println(url);
        // url必须是rest风格路径
        return restTemplate.getForObject(url, UserVo.class);
    }*/

    @GetMapping("warp/user/{id}") //可以实现负载均衡
    public UserVo getUser(@PathVariable("id") Integer userId) {
        // url必须是rest风格路径
        return restTemplate.getForObject("http://provider/user/"+userId, UserVo.class);
    }
}

服务启动类

package com.gerry.cloud.demo.microconsumer;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;

@SpringBootApplication
@EnableDiscoveryClient
public class MicroConsumerApplication {

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

注意：此篇文章只是测试时使用，只能连接本地zookeeper，不能连接远程zookeeper，原因是zookeeper依赖不对，应改为：

        <!--Service Discovery with Zookeeper-->
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-zookeeper-discovery</artifactId>
        </dependency>

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原始发表：2018-10-27 ，如有侵权请联系 cloudcommunity@tencent.com 删除

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