Spring Cloud Alibaba 之 user服务

项目技术选型

• Spring Boot
• Spring MVC
• MyBatis + 通用Mapper （官网信息https://mapperhelper.github.io/docs/）
• Spring Cloud Alibaba

项目结构

pom 文件

<?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 https://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>2.1.9.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>com.laiya</groupId>
<artifactId>user-center</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>user-center</name>
<description>Demo project for Spring Boot</description> <properties>
<java.version>1.8</java.version>
</properties> <dependencies>
<!--Sporing Boot-->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<!--Nacos-->
<dependency>
<groupId>com.alibaba.cloud</groupId>
<artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
</dependency>
<!--feign-->
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-openfeign</artifactId>
</dependency>
<dependency>
<groupId>io.github.openfeign</groupId>
<artifactId>feign-httpclient</artifactId>
</dependency>
<!-- nacos 动态配置-->
<!-- <dependency>-->
<!-- <groupId>com.alibaba.cloud</groupId>-->
<!-- <artifactId>spring-cloud-starter-alibaba-nacos-config</artifactId>-->
<!-- </dependency>--> <!--Redis-->
<!-- <dependency>-->
<!-- <groupId>org.springframework.boot</groupId>-->
<!-- <artifactId>spring-boot-starter-data-redis-reactive</artifactId>-->
<!-- </dependency>--> <!--Mysql-->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
</dependency>
<!--Mybatis-->
<dependency>
<groupId>org.mybatis.spring.boot</groupId>
<artifactId>mybatis-spring-boot-starter</artifactId>
<version>2.1.2</version>
</dependency> <!--Lombok-->
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<optional>true</optional>
</dependency> <dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-thymeleaf</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-websocket</artifactId>
</dependency>
<!--Test-->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
<exclusions>
<exclusion>
<groupId>org.junit.vintage</groupId>
<artifactId>junit-vintage-engine</artifactId>
</exclusion>
</exclusions>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-websocket</artifactId>
<version>5.2.6.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-zipkin</artifactId>
</dependency> <dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-actuator</artifactId>
</dependency>
<dependency>
<groupId>com.alibaba.cloud</groupId>
<artifactId>spring-cloud-alibaba-sentinel</artifactId>
</dependency>
</dependencies>
<dependencyManagement> <dependencies>
<!--整合Spring Cloud-->
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-dependencies</artifactId>
<version>Greenwich.SR3</version>
<type>pom</type>
<scope>import</scope>
</dependency>
<!--整合Spring Cloud Alibaba-->
<dependency>
<groupId>com.alibaba.cloud</groupId>
<artifactId>spring-cloud-alibaba-dependencies</artifactId>
<version>2.1.0.RELEASE</version>
<type>pom</type>
<scope>import</scope>
</dependency> </dependencies>
</dependencyManagement> <!--分别设置开发，测试，生产环境-->
<profiles>
<!-- 开发环境 -->
<profile>
<id>dev</id>
<activation>
<activeByDefault>true</activeByDefault>
</activation>
<properties>
<environment>dev</environment>
</properties>
</profile>
<!-- 测试环境 -->
<profile>
<id>test</id>
<activation>
<activeByDefault>false</activeByDefault>
</activation>
<properties>
<environment>test</environment>
</properties>
</profile>
<!-- 生产环境 -->
<profile>
<id>pro</id>
<activation>
<activeByDefault>false</activeByDefault>
</activation>
<properties>
<environment>pro</environment>
</properties>
</profile>
</profiles> <build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId> <dependencies>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>8.0.16</version>
</dependency>
</dependencies>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<configuration>
<source>8</source>
<target>8</target>
</configuration>
</plugin> </plugins>
<!-- 打包后文件名称：项目名-环境-版本 -->
<finalName>${project.artifactId}-${environment}-${project.version}</finalName>
<resources>
<resource>
<directory>src/main/resources</directory>
<!-- 开启过滤替换功能-->
<filtering>true</filtering>
<includes>
<!-- 项目打包完成的包中只包含当前环境文件 -->
<include>application.yml</include>
<include>application-${environment}.yml</include>
<include>bootstrap.yml</include>
<include>mybatis/*/*.xml</include>
<include>templates/*.html</include>
<include>static/</include>
</includes>
</resource>
</resources>
</build></project>

pom 里配置了多环境打包，openfeign，zipkin，actuator，sentinel，websocket，lombok 等组件下面对这些组件

• openfeign 是用来为微服务架构下服务之间的调用提供了解决方案，可以理解为被封装的请求模式。
• zipkin 是用来做链路跟踪的工具，是一个开放源代码分布式的跟踪系统，每个服务向zipkin报告计时数据，zipkin会根据调用关系通过Zipkin UI生成依赖关系图（以后的博客里会将）
• actuator 是用来做应用的健康检查，Spring Boot Actuator可以帮助你监控和管理Spring Boot应用，比如健康检查、审计、统计和HTTP追踪等。所有的这些特性可以通过JMX或者HTTP endpoints来获得。
• sentinel 是面向分布式服务架构的高可用流量防护组件，主要以流量为切入点，从限流、流量整形、熔断降级、系统负载保护、热点防护等多个维度来帮助开发者保障微服务的稳定性。
• websocket 全双工通讯协议，可简单理解为服务端可以主动向客户端发送请求

实现多环境打包需要配置多个*.yml 配置文件,配置文件

• application.yml 内容

spring:
profiles:
active: "@environment@"


application-dev内容

#======================================#
#========== Server settings ==========#
#======================================#
server:
port: 8086
# servlet:
# context-path: /user-center
tomcat:
uri-encoding: UTF-8spring:
#server name
application:
name: user-center
#======================================#
#========== Database settings ==========#
#======================================#
datasource:
driver-class-name: com.mysql.cj.jdbc.Driver
username:
password: xxxxx
url: jxxxxx #======================================#
#========== Nacos ==========#
#======================================#
cloud:
nacos:
discovery:
# nacos server address
server-addr: xxxx thymeleaf:
prefix: classpath:/templates/
check-template-location: true
suffix: .html
encoding: utf-8
servlet:
content-type: text/html
mode: HTML5
cache: false
#======================================#
#========== zipkin ==========#
#======================================#
zipkin:
base-url:xxx
discovery-client-enabled: false
sleuth:
sampler:
# 抽样率 10%
probability: 1.0#======================================#
#========== MyBatis settings ==========#
#======================================#mybatis:
mapper-locations: classpath:templates/*/*.xml #======================================#
#========== Redis settings ==========#
#======================================#
# redis:
# enabled: true
# host: xxx
# port: 6379
# ssl: false
# database: 0
# password: x'x'x'x
# jedis:
# pool:
# # 最大空闲连接数
# maxIdle: 3
# # 最大活动连接数
# maxActive: 20feign:
client:
config:
# 想要配置的微服务 名称 全局配置 default
user-center:
loggerLevel: full
# httpclient 连接池
httpclient:
enabled: true
# feign 的最大连接数
max-connections: 200
# feign 的单个路径最大连接数
max-connections-per-route: 50#======================================#
#========== Config sttings ==========#
#======================================##
body:
controllerMethodList:
swaggerResources,
getDocumentation
management:
endpoints:
web:
exposure:
include: '*'

mysql 配置信息说明

datasource:
driver-class-name: com.mysql.cj.jdbc.Driver
username:
password: xxxxx
url: jxxxxx


mysql 版本>= 6.x 需要用 com.mysql.cj.jdbc.Driver

mysql 版本<= 5.x 需要用 com.mysql.jdbc.Driver

** com.mysql.jdbc.Driver 源码 如下**

public class Driver extends com.mysql.cj.jdbc.Driver {
public Driver() throws SQLException {
super();
} static {
System.err.println("Loading class `com.mysql.jdbc.Driver'. This is deprecated. The new driver class is `com.mysql.cj.jdbc.Driver'. "
+ "The driver is automatically registered via the SPI and manual loading of the driver class is generally unnecessary.");
}
}

通过源码我们可以看到 Driver 继承了 com.mysql.cj.jdbc.Driver，如果不加 cj 项目也可以运行但是会打印出一句警告的话，大概意思是说驱动版本需要升级

所以在出现这句话的时候大家不要谎。

另外需要注意的是在为应用起名字的时候尽量不要用_ 和特殊字符，可以用-,否则在启动的时候会打印出警告

针对微服务，我们在新增微服务组件的时候尽量遵循三个步骤

1 pom 文件引入依赖

2 yml 写配置

3 项目加注解

用户微服务引入Nacos 步骤

• 引入依赖

<!--Nacos-->
<dependency>
<groupId>com.alibaba.cloud</groupId>
<artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
</dependency>


• yml写配置

#=========================#
#========== Nacos =========#
#=========================#
spring:
cloud:
nacos:
discovery:
server-addr: (nacos 请求地址,格式为 ip[域名]:port; 例如 xxx.com:8848,注意 地址前面不要加http 后者https)
# namespace: (Nacos 命名空间的uuid 不是名称)
# cluster-name: xxx


• 项目加注解（没有注解，不需要）
  
  ** 启动当前项目后，成功后会先发现Nacos 控制台服务管理里会有一个user-center 的服务**
  
  
  
  至此 微服务注册到Nacos 便成功了，我们发现服务注册很简单，只需要简单的两步，加依赖，写配置
  
  针对不同环境打包的命令为 mvn install -Ppro/-Pdev/-Ptest,需要哪个环境就打哪个环境的包

下一节会为大家讲解服务和服务之间的调用，希望能够帮助大家搭建一个简单的微服务系统。