创建一个微服务项目

深碍√TFBOYSˉ_ 2023-07-18 09:43 20阅读 0赞

## 微服务的设计原则： ##

1、单一职责原则 一个微服务只干一件事  
2、服务自治原则 每个微服务应该能做到独立开发、测试、部署、维护，不需要其他模块的参与  
3、轻量级通讯原则 最好能够通过http请求在服务之间进行互相的调用  
4、接口明确原则 微服务之间进行访问、调用都是通过接口的方式进行调用，尽量避免在一个微服务  
中包含其他微服务的内容

## **微服务版本对应关系** ##

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L20wXzQ2NTQ5MDg1_size_16_color_FFFFFF_t_70]

## 使用spring cloud做微服务的大体结构 ##

![在这里插入图片描述][2020032616452935.png]

## 开发步骤： ##

创建项目为maven项目，我的jdk版本是jdk1.8，因此需要改动一下maven配置文件，将jdk版本改为jdk1.8，不然建立的项目为jdk1.5版本如图  
![在这里插入图片描述][2020032616520484.png]

## 修改：maven下的setting.xml文件 ##

![在这里插入图片描述][20200326165307426.png]  
在200行左右找到如下位置，改为：![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L20wXzQ2NTQ5MDg1_size_16_color_FFFFFF_t_70 1]  
复制代码块粘贴进去

## 创建项目： ##

## ①创建父工程 ##

![在这里插入图片描述][20200326165631201.png]  
![在这里插入图片描述][20200326165643870.png]  
![在这里插入图片描述][20200326165653194.png]

## ②：在父工程导入依赖 ##

<dependencyManagement>
      	<dependencies>
      		
      		<dependency>
    		    <groupId>org.springframework.cloud</groupId>
    		    <artifactId>spring-cloud-dependencies</artifactId>
    		    <version>Greenwich.SR1</version>
    		    <type>pom</type>
    		    <scope>runtime</scope>
    		</dependency>
    
      		
      		<dependency>
      			<groupId>org.springframework.boot</groupId>
      			<artifactId>spring-boot-dependencies</artifactId>
      			<version>2.1.0.RELEASE</version>
      			<type>pom</type>
      			<scope>import</scope>
      		</dependency>
      		
      		
      		<dependency>
    		    <groupId>mysql</groupId>
    		    <artifactId>mysql-connector-java</artifactId>
    		    <version>5.1.44</version>
    		</dependency>
    		
    		
    		<dependency>
    		    <groupId>com.alibaba</groupId>
    		    <artifactId>druid</artifactId>
    		    <version>1.1.15</version>
    		</dependency>
      		
      		
      		<dependency>
    		    <groupId>org.mybatis.spring.boot</groupId>
    		    <artifactId>mybatis-spring-boot-starter</artifactId>
    		    <version>1.3.2</version>
    		</dependency>
    		
    		
    		<dependency>
    		    <groupId>junit</groupId>
    		    <artifactId>junit</artifactId>
    		    <version>4.12</version>
    		    <scope>test</scope>
    		</dependency>
    		
    		
    		<dependency>
    		    <groupId>log4j</groupId>
    		    <artifactId>log4j</artifactId>
    		    <version>1.2.17</version>
    		</dependency>
    		
      	</dependencies>
      </dependencyManagement>
      
      <build>
      	<finalName>SpringCloud63</finalName>
      	<resources>
      		<resource>
      			<directory>src/main/resources</directory>
      			<filtering>true</filtering>
      		</resource>
      	</resources>
      	<plugins>
      		<plugin>
      			<groupId>org.apache.maven.plugins</groupId>
      			<artifactId>maven-resources-plugin</artifactId>
      			<configuration>
      				<delimiters>
      					<delimiter>$</delimiter>
      				</delimiters>
      			</configuration>
      		</plugin>
      	</plugins>
      </build>

## ③创建公共模块，在父项目名上右键->新建 ##

![在这里插入图片描述][20200326165824325.png]  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L20wXzQ2NTQ5MDg1_size_16_color_FFFFFF_t_70 2]  
![在这里插入图片描述][20200326165942411.png]  
![在这里插入图片描述][20200326170008566.png]

## ④在公共模块（SpringCloud63\_Commons）中添加公共类Product类 ##

需要提前在pom.xml引入lombok

<dependency>
    			<groupId>org.projectlombok</groupId>
    			<artifactId>lombok</artifactId>
    			<optional>true</optional>
    		</dependency>

Product类

package com.woniuxy.commons.entity;
    
    import java.io.Serializable;
    import java.util.List;
    
    import lombok.Data;
    
    @Data
    public class Product implements Serializable{ 
    	private static final long serialVersionUID = 1L;
    	private Integer pid;
    	private String pname;
    	private Double price;
    	private Integer count;
    	private String detial;
    	private List<String> images;	
    	private List<String> productType;	
    }

## ⑤创建user模块 ##

创建方式和上一样，不过类型选为war包：  
点击fish，出现错误是因为项目为war包，需要导入web.xml,点击选择项目，右键，找到 java EE toos,点击Generate Depoyment Descript stub即可  
![在这里插入图片描述][20200326170834680.png]  
![在这里插入图片描述][20200326170844613.png]

## 在user模块的pom中导入commons模块 ##

<dependency>
    			<groupId>com.woniuxy</groupId>
    			<artifactId>SpringCloud63_Commons</artifactId>
    			<version>${ project.version}</version>
    		</dependency>

## ⑥创建商品模块，创建方式与创建用户模块一致 ##

## ⑦在商品模块的pom中引入以下依赖 ##

<dependencies>
    		
    		<dependency>
    			<groupId>com.woniuxy</groupId>
    			<artifactId>SpringCloud63_Commons</artifactId>
    			<version>${ project.version}</version>
    		</dependency>
    		
    		<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>
    		
    		<dependency>
    			<groupId>ch.qos.logback</groupId>
    			<artifactId>logback-core</artifactId>
    		</dependency>
    		
    		
    		<dependency>
    			<groupId>org.springframework.boot</groupId>
    			<artifactId>spring-boot-starter-web</artifactId>
    		</dependency>
    		<dependency>
    			<groupId>org.springframework.boot</groupId>
    			<artifactId>spring-boot-starter-test</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-devtools</artifactId>
    		</dependency>
             
    		<dependency>
    		    <groupId>log4j</groupId>
    		    <artifactId>log4j</artifactId>
    		</dependency>
    	</dependencies>

## ⑧给商品模块添加application.yml文件 ##

![在这里插入图片描述][20200326171056913.png]

server:
      port: 8002
    spring:
      application:
        name: springcloud63-product
      datasource:
        type: com.alibaba.druid.pool.DruidDataSource
        driver-class-name: com.mysql.jdbc.Driver
        url: jdbc:mysql://localhost:3306/car
        username: root
        password: 123456

## ⑨编写mapper、service、handler ##

mapper

package com.woniuxy.product.mapper;
    
    import java.util.List;
    
    import org.apache.ibatis.annotations.Many;
    import org.apache.ibatis.annotations.Mapper;
    import org.apache.ibatis.annotations.Result;
    import org.apache.ibatis.annotations.Results;
    import org.apache.ibatis.annotations.Select;
    import org.apache.ibatis.annotations.Update;
    
    import com.woniuxy.commons.entity.Product;
    
    
    @Mapper
    public interface ProductMapper { 
    	//查询所有的商品
    	@Select("select * from product")
    	@Results({ 
    		//主键映射
    		@Result(id=true,column="pid",property="pid"),
    		//图片
    		@Result(column="pid",property="images",many=@Many(select="findImagesByPid")),
    		//商品类型
    		@Result(column="pid",property="productType",many=@Many(select="findProductTypeByPid"))
    	})
    	public List<Product> all();
    	
    	//以pid作为条件查询对应的图片
    	@Select("select name from images where pid = #{pid}")
    	public List<String> findImagesByPid(int pid);
    	
    	//以pid作为查询条件，查询所有的类型
    	@Select("select productType from producttype where pid = #{pid}")
    	public List<String> findProductTypeByPid(int pid);
    	
    	
    	//以pid查询商品
    	@Select("select * from product where pid = #{pid}")
    	@Results({ 
    		//主键映射
    		@Result(id=true,column="pid",property="pid"),
    		//图片
    		@Result(column="pid",property="images",many=@Many(select="findImagesByPid")),
    		//商品类型
    		@Result(column="pid",property="productType",many=@Many(select="findProductTypeByPid"))
    	})
    	public Product findProductByPid(Integer pid);
    	
    	
    	//加减库存
    	@Update("update set count=count+#{count} where pid=#{pid}")
    	public int changeCount(Product product);
    }

service

package com.woniuxy.product.service;
    
    import java.util.List;
    
    import com.woniuxy.commons.entity.Product;
    
    
    public interface ProductService { 
    	public List<Product> all();
    	public Product findProductByPid(Integer pid);
    }

serviceimpl

package com.woniuxy.product.service.impl;
    
    import java.util.List;
    
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.cache.annotation.Cacheable;
    import org.springframework.stereotype.Service;
    
    import com.woniuxy.commons.entity.Product;
    import com.woniuxy.product.mapper.ProductMapper;
    import com.woniuxy.product.service.ProductService;
    
    
    @Service
    public class ProductServiceImpl implements ProductService{ 
    	@Autowired
    	private ProductMapper productMapper;
    
    	@Cacheable("all")
    	@Override
    	public List<Product> all() { 
    		return productMapper.all();
    	}
    	@Cacheable("findProductByPid")
    	@Override
    	public Product findProductByPid(Integer pid) { 
    		// TODO Auto-generated method stub
    		return productMapper.findProductByPid(pid);
    	}
    }

handler

package com.woniuxy.product.handler;
    
    import java.util.List;
    
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.RestController;
    
    import com.woniuxy.commons.entity.Product;
    import com.woniuxy.product.service.ProductService;
    
    
    @RestController
    @RequestMapping("/product")
    public class ProductHandler { 
    	@Autowired
    	private ProductService productService;
    	
    	//所有商品
    	@RequestMapping("/all")
    	public List<Product> all() { 
    		System.err.println("8002");
    		return productService.all();
    	}
    	
    	@RequestMapping("/findByPid")
    	public Product findByPid(Integer pid) { 
    		return productService.findProductByPid(pid);
    	}
    	
    }

## ⑩编写启动类，启动测试 … ##

结果展示：取得数据  
![在这里插入图片描述][2020032617165595.png]

## ***user与product之间使用RestTemplate进行通信*** ##

## 11、在user模块中添加以下依赖 spring boot ##

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

## 12、在user模块中添加一个配置类，创建restTemplate ##

package com.woniuxy.user.configuration;
    
    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 RestTemplateConfiguration { 
    	@Bean
    	@LoadBalanced//加载负载均衡
    	public RestTemplate cerate() { 
    		return new RestTemplate();
    	}
    }

## 13、创建handler，指定请求方法，通过resttemplate访问product模块 ##

package com.woniuxy.user.handler;
    
    import java.util.List;
    
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.RestController;
    import org.springframework.web.client.RestTemplate;
    
    import com.woniuxy.commons.entity.Product;
    import com.woniuxy.commons.service.FeignProductService;
    
    @RestController
    @RequestMapping("/user")
    public class UserHandler { 
    	@Autowired
    	private RestTemplate restTemplate;
    	
    	
    	@RequestMapping("/all")
    	public List<Product> all() { 
    		//原始地址
    		//String url = "http://localhost:8002/product/all";
    		
    		List<Product> products = restTemplate.getForObject(url, List.class);
    		
    	
    	}
    }

## 14、创建启动类进行测试 ##

package com.woniuxy.user;
    
    import org.springframework.boot.SpringApplication;
    import org.springframework.boot.autoconfigure.SpringBootApplication;
    import org.springframework.cloud.netflix.eureka.EnableEurekaClient;
    import org.springframework.cloud.openfeign.EnableFeignClients;
    
    @SpringBootApplication
    @EnableEurekaClient
    public class UserApplication { 
    	public static void main(String[] args) { 
    		SpringApplication.run(UserApplication.class, args);

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