乐趣区

关于java:初识SpringCloud

jiezi

初识 SpringCloud

Spring Cloud 是一套残缺的微服务解决方案，基于 Spring Boot 框架，精确的说，它不是一个框架，而是一个大的容器，它将市面上较好的微服务框架集成进来，从而简化了开发者的代码量。

Spring Cloud 是什么？

Spring Cloud 是一系列框架的有序汇合，它利用 Spring Boot 的开发便利性简化了分布式系统的开发，比方服务发现、服务网关、服务路由、链路追踪等。Spring Cloud 并不反复造轮子，而是将市面上开发得比拟好的模块集成进去，进行封装，从而缩小了各模块的开发成本。换句话说：Spring Cloud 提供了构建分布式系统所需的“全家桶”。

Spring Cloud 现状

目前，国内应用 Spring Cloud 技术的公司并不多见，不是因为 Spring Cloud 不好，次要起因有以下几点：

  • Spring Cloud 中文文档较少，呈现问题网上没有太多的解决方案。
  • 国内守业型公司技术老大大多是阿里系员工，而阿里系多采纳 Dubbo 来构建微服务架构。
  • 大型公司根本都有本人的分布式解决方案，而中小型公司的架构很多用不上微服务，所以没有采纳 Spring Cloud 的必要性。

然而，微服务架构是一个趋势，而 Spring Cloud 是微服务解决方案的佼佼者.

Spring Cloud 优缺点

长处

  • 集大成者，Spring Cloud 蕴含了微服务架构的方方面面。
  • 约定优于配置，基于注解，没有配置文件。
  • 轻量级组件，Spring Cloud 整合的组件大多比拟轻量级，且都是各自畛域的佼佼者。
  • 开发简便，Spring Cloud 对各个组件进行了大量的封装，从而简化了开发。
  • 开发灵便，Spring Cloud 的组件都是解耦的，开发人员能够灵便按需抉择组件。

毛病

  • 我的项目结构复杂，每一个组件或者每一个服务都须要创立一个我的项目。
  • 部署门槛高，我的项目部署须要配合 Docker 等容器技术进行集群部署，而要想深刻理解 Docker，学习老本高。

Spring Cloud 的劣势是不言而喻的。学习 Spring Cloud 是一个不错的抉择。

Spring Cloud 和 Dubbo 比照

Dubbo 只是实现了服务治理，而 Spring Cloud 实现了微服务架构的方方面面，服务治理只是其中的一个方面。上面通过一张图对其进行比拟：

能够看出，Spring Cloud 比拟全面，而 Dubbo 因为只实现了服务治理，须要集成其余模块，须要独自引入，减少了学习老本和集成老本。

我的项目构造

父我的项目 pom

<?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>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.1.4.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>cn.com.codingce</groupId>
    <artifactId>springcloud</artifactId>
    <version>1.0-SNAPSHOT</version>
    <modules>
        <module>springcloud-api</module>
        <module>springcloud-provider-dept</module>
        <module>springcloud-consumer-dept</module>
    </modules>

    <!-- 打包形式 -->
    <packaging>pom</packaging>

    <!-- 对立配置 版本号 -->
    <properties>
        <junit.version>4.12</junit.version>
        <lombok.version>1.16.10</lombok.version>
        <mysql.version>8.0.11</mysql.version>
        <druid.version>1.1.10</druid.version>
        <logbackcore.version>1.2.3</logbackcore.version>
    </properties>

    <dependencyManagement>
        <dependencies>

            <!-- springcloud 的依赖 -->
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>Greenwich.SR1</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>

            <!--springboot 依赖 -->
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-dependencies</artifactId>
                <scope>2.1.4.RELEASE</scope>
            </dependency>

            <!-- 连贯数据库 -->
            <dependency>
                <groupId>mysql</groupId>
                <artifactId>mysql-connector-java</artifactId>
                <version>${mysql.version}</version>
            </dependency>

            <!-- https://mvnrepository.com/artifact/com.alibaba/druid -->
            <dependency>
                <groupId>com.alibaba</groupId>
                <artifactId>druid</artifactId>
                <version>${druid.version}</version>
            </dependency>

            <!-- https://mvnrepository.com/artifact/org.mybatis.spring.boot/mybatis-spring-boot-starter -->
            <dependency>
                <groupId>org.mybatis.spring.boot</groupId>
                <artifactId>mybatis-spring-boot-starter</artifactId>
                <version>1.3.2</version>
            </dependency>

            <!-- https://mvnrepository.com/artifact/ch.qos.logback/logback-core -->
            <dependency>
                <groupId>ch.qos.logback</groupId>
                <artifactId>logback-core</artifactId>
                <version>1.2.3</version>
            </dependency>

            <!-- https://mvnrepository.com/artifact/junit/junit -->
            <dependency>
                <groupId>junit</groupId>
                <artifactId>junit</artifactId>
                <version>${junit.version}</version>
            </dependency>

            <dependency>
                <groupId>org.projectlombok</groupId>
                <artifactId>lombok</artifactId>
                <version>${lombok.version}</version>
            </dependency>

            <!-- https://mvnrepository.com/artifact/org.springframework.boot/spring-boot-devtools -->
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-devtools</artifactId>
                <version>2.2.2.RELEASE</version>
            </dependency>

            <!-- https://mvnrepository.com/artifact/org.springframework.boot/spring-boot-starter-jetty -->
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-jetty</artifactId>
                <version>2.0.1.RELEASE</version>
            </dependency>

            <!-- https://mvnrepository.com/artifact/org.springframework.boot/spring-boot-starter-web -->
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-web</artifactId>
                <version>2.0.1.RELEASE</version>
            </dependency>

            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-devtools</artifactId>
                <version>2.1.4.RELEASE</version>
            </dependency>

        </dependencies>
    </dependencyManagement>


</project>

实体类

pom

<?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>springcloud</artifactId>
        <groupId>cn.com.codingce</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>springcloud-api</artifactId>

    <dependencies>
        <!-- 以后 module 本人须要的依赖, 如果父依赖中曾经配置了版本 -->
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
        </dependency>

        <!--junit-->
<!--        <dependency>-->
<!--            <groupId>junit</groupId>-->
<!--            <artifactId>junit</artifactId>-->
<!--        </dependency>-->

        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
        </dependency>

        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid</artifactId>
        </dependency>

    </dependencies>
</project>

Dept

package cn.com.codingce.pojo;

import lombok.experimental.Accessors;

import java.io.Serializable;

/**
 * @author xzMa
 * Dept 实体类 orm  类表关系映射
 */
@Accessors  // 链式写法
public class Dept implements Serializable {
    private Long deptno;
    private String dname;
    private String db_source;

    /**
     * Dept dept = new Dept();
     * dept.setDeptNo("").setDeptyName().....  都行
     */

    public Dept() {}

    public Dept(Long deptno, String dname, String db_source) {
        this.deptno = deptno;
        this.dname = dname;
        this.db_source = db_source;
    }


    public Long getDeptno() {return deptno;}

    public void setDeptno(Long deptno) {this.deptno = deptno;}

    public String getDname() {return dname;}

    public void setDname(String dname) {this.dname = dname;}

    public String getDb_source() {return db_source;}

    public void setDb_source(String db_source) {this.db_source = db_source;}

    @Override
    public String toString() {
        return "Dept{" +
                "deptno=" + deptno +
                ", dname='" + dname + '\'' +
                ", db_source='" + db_source + '\'' +
                '}';
    }
}

服务端

pom

<?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>springcloud</artifactId>
        <groupId>cn.com.codingce</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>springcloud-provider-dept</artifactId>

    <dependencies>
        <!-- 咱们须要拿到实体类, 所以要配置 api -module-->
        <dependency>
            <groupId>cn.com.codingce</groupId>
            <artifactId>springcloud-api</artifactId>
            <version>1.0-SNAPSHOT</version>
        </dependency>

        <!--junit-->
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
        </dependency>

        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
        </dependency>

        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid</artifactId>
        </dependency>

        <!-- https://mvnrepository.com/artifact/ch.qos.logback/logback-core -->
        <dependency>
            <groupId>ch.qos.logback</groupId>
            <artifactId>logback-core</artifactId>
        </dependency>

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

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

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

<!--        &lt;!&ndash;jetty&ndash;&gt;-->
<!--        &lt;!&ndash; https://mvnrepository.com/artifact/org.springframework.boot/spring-boot-starter-jetty &ndash;&gt;-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-jetty</artifactId>
        </dependency>

        <!-- 热部署工具 -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
        </dependency>
    </dependencies>
</project>

Controller

package cn.com.codingce.controller;

import cn.com.codingce.pojo.Dept;
import cn.com.codingce.service.DeptService;
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.PostMapping;
import org.springframework.web.bind.annotation.RestController;

import javax.annotation.Resource;
import java.util.List;

/**
 * @author xzMa
 *
 * 提供 RestFul 服务
 */
@RestController
public class DeptController {

    @Resource
    private DeptService deptService;

    @PostMapping("/dept/add")
    public boolean addDept(Dept dept) {return deptService.addDept(dept);
    }

    @GetMapping("/dept/get/{id}")
    public Dept queryBuId(@PathVariable("id") Long id) {return deptService.queryById(id);
    }

    @GetMapping("/dept/list")
    public List<Dept> queryAll() {return deptService.queryAll();
    }

}

DAO (mapper)

package cn.com.codingce.dao;

import cn.com.codingce.pojo.Dept;
import org.apache.ibatis.annotations.Mapper;
import org.springframework.stereotype.Repository;

import java.util.List;

@Mapper
@Repository
public interface DeptDao {public boolean addDept(Dept dept);

    public Dept queryById(Long id);

    public List<Dept> queryAll();}

Mapper.xml

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
        PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="cn.com.codingce.dao.DeptDao">

    <insert id="addDept" parameterType="Dept">
        insert into dept(dname, db_source) values (#{dname}, DATABASE())
    </insert>
    
    <select id="queryById" parameterType="Long" resultType="Dept">
        select * from dept where deptno = #{deptno}
    </select>

    <select id="queryAll" resultType="Dept">
        select * from dept
    </select>

</mapper>

Service 接口 

package cn.com.codingce.service;

import cn.com.codingce.pojo.Dept;

import java.util.List;

public interface DeptService {public boolean addDept(Dept dept);

    public Dept queryById(Long id);

    public List<Dept> queryAll();}

Service 实现类 

package cn.com.codingce.service;

import cn.com.codingce.dao.DeptDao;
import cn.com.codingce.pojo.Dept;
import org.springframework.stereotype.Service;

import javax.annotation.Resource;
import java.util.List;

@Service
public class DeptServiceImpl implements DeptService {

    @Resource
    private DeptDao deptDao;

    @Override
    public boolean addDept(Dept dept) {return deptDao.addDept(dept);
    }

    @Override
    public Dept queryById(Long id) {return deptDao.queryById(id);
    }

    @Override
    public List<Dept> queryAll() {return deptDao.queryAll();
    }
}

mybatis-config.xml

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE configuration
        PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-config.dtd">
<!-- 外围配置文件 -->
<configuration>
    <!-- 开启二级缓存 -->
    <settings>
        <setting name="cacheEnabled" value="true"/>
        <setting name="logImpl" value="STDOUT_LOGGING"/>
    </settings>
</configuration>

application.yml

server:
  port: 8001

#mybatis 配置
mybatis:
  type-aliases-package: cn.com.codingce.pojo
  config-location: classpath:mybatis/mybatis-config.xml
  mapper-locations: classpath:mybatis/mapper/*.xml
#  configuration:
#    map-underscore-to-camel-case: true

# spring 配置
spring:
  application:
    name: springcloud-provider-dept
  datasource:
    type: com.alibaba.druid.pool.DruidDataSource # 数据源 德鲁伊
    driver-class-name: com.mysql.jdbc.Driver
    url: jdbc:mysql://cdb-q9atzwrq.bj.tencentcdb.com:10167/db01?useSSL=true
    username: root
    password: 123456

客户端

pom

<?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>springcloud</artifactId>
        <groupId>cn.com.codingce</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>springcloud-consumer-dept</artifactId>

    <dependencies>
        <!-- 咱们须要拿到实体类, 所以要配置 api -module-->
        <dependency>
            <groupId>cn.com.codingce</groupId>
            <artifactId>springcloud-api</artifactId>
            <version>1.0-SNAPSHOT</version>
        </dependency>

        <!-- 热部署工具 -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
        </dependency>

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

配置文件 

package cn.com.codingce.config;

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
    public RestTemplate getRestTemplate() {return new RestTemplate();
    }

}

Controller

package cn.com.codingce.controller;

import cn.com.codingce.pojo.Dept;
import org.springframework.beans.factory.annotation.Autowired;
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;

import java.util.List;

@RestController
public class DeptConsumerController {

    // 了解消费者, 不应该有 service 层
    //RestFul 格调
    //(url, 实体: Map classs<T> responseType)

    @Autowired
    private RestTemplate restTemplate;  // 提供多种便捷拜访近程 http 服务的办法

    private static final String REST_URL_PREFIX = "http://localhost:8001";


    @RequestMapping("/consumer/dept/add")
    public boolean add(Dept dept) {return restTemplate.postForObject(REST_URL_PREFIX + "/dept/add", dept, Boolean.class);
    }

    //http://localhost:8001/dept/list
    @RequestMapping("/consumer/dept/get/{id}")
    public Dept get(@PathVariable("id") Long id) {return restTemplate.getForObject(REST_URL_PREFIX + "/dept/get/" + id, Dept.class);
    }

    @RequestMapping("/consumer/dept/list")
    public List<Dept> list() {return restTemplate.getForObject(REST_URL_PREFIX + "/dept/list" , List.class);
    }

}

application.yml

server:
  port: 80
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