云原生技术-微服务SpringCloud(1)
❤️作者简介：2022新星计划第三季云原生与云计算赛道Top5、华为云享专家、云原生领域潜力新星
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作者目的：如有错误请指正，将来会不断的完善笔记，帮助更多的Java爱好者入门，共同进步！
文章目录
-
- 云原生技术-微服务SpringCloud(1)
-
- 搭建提供者、消费者模块
- 引入注册中心SpringCloud Eureka
-
-
- Bug：引入Eureka后报错。
-
- 搭建Eureka集群
- 搭建提供者集群(为了负载均衡)
-
-
- Bug：ribbon+restTemplate报错
- 使用actuator功能
-
- Feign/OpenFeign
-
-
- Bug：OpenFeign调用失败报错405
-
云原生技术-微服务SpringCloud(1)
搭建提供者、消费者模块
1：创建一个空Maven项目，删除src目录
2：父POM
<packaging>pompackaging>
<properties>
<spring.cloud-version>Hoxton.RELEASEspring.cloud-version>
<spring.boot-version>2.2.4.RELEASEspring.boot-version>
<project.build.sourceEncoding>UTF-8project.build.sourceEncoding>
<project.reporting.outputEncoding>UTF-8project.reporting.outputEncoding>
<java.version>1.8java.version>
<maven.compiler.source>10maven.compiler.source>
<maven.compiler.target>10maven.compiler.target>
<encoding>UTF-8encoding>
properties>
<dependencyManagement>
<dependencies>
<dependency>
<groupId>org.springframework.cloudgroupId>
<artifactId>spring-cloud-dependenciesartifactId>
<version>${spring.cloud-version}version>
<type>pomtype>
<scope>importscope>
dependency>
<dependency>
<groupId>org.springframework.bootgroupId>
<artifactId>spring-boot-dependenciesartifactId>
<version>${spring.boot-version}version>
<type>pomtype>
<scope>importscope>
dependency>
<dependency>
<groupId>org.mybatis.spring.bootgroupId>
<artifactId>mybatis-spring-boot-starterartifactId>
<version>1.3.1version>
dependency>
<dependency>
<groupId>mysqlgroupId>
<artifactId>mysql-connector-javaartifactId>
<version>5.1.47version>
dependency>
<dependency>
<groupId>com.alibabagroupId>
<artifactId>druidartifactId>
<version>1.0.9version>
dependency>
dependencies>
dependencyManagement>
<build>
<resources>
<resource>
<directory>src/main/javadirectory>
<includes>
<include>**/*.xmlinclude>
includes>
<filtering>truefiltering>
resource>
resources>
build>
3.创建一个子模块，作微服务的提供者，端口号为8001
里面代码如下。。。
deptController
@RestController
public class deptController {
private deptService deptService;
@Autowired
@Qualifier("deptServiceImpl")
public void setDeptService(com.boot.service.deptService deptService) {
this.deptService = deptService;
}
@GetMapping(path = "/queryAllDept")
public List<dept> queryAllDept(){
return deptService.queryAllDept();
}
}
dao层。deptMapper
@Mapper //把这个Mapper接口变成可以注入的Bean,*****一定要。
@Repository //变成组件 ***一定要
public interface deptMapper {
List<dept> queryAllDept();
}
Mapper.xml
DOCTYPE mapper
PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.boot.dao.deptMapper">
<select id="queryAllDept" resultType="com.pojo.dept">
select deptid,deptName from dept;
select>
mapper>
service层省略，和普通springBoot项目构建是一样的
application.yml(8001)
server:
port: 8001
spring:
application:
# 微服务名
name: provider_dept8001/8002
datasource:
url: jdbc:mysql://localhost:3306/ssmrl?serverTimezone=UTC
driver-class-name: com.mysql.jdbc.Driver
username: root
password: 18420163207
type: com.alibaba.druid.pool.DruidDataSource
创建一个子模块(springcloud-02-api)，专门放实体类
public class dept implements Serializable {
private String deptid;
private String deptName;
public dept() {
}
public dept(String deptid, String deptName) {
this.deptid = deptid;
this.deptName = deptName;
}
public String getDeptid() {
return deptid;
}
public void setDeptid(String deptid) {
this.deptid = deptid;
}
public String getDeptName() {
return deptName;
}
public void setDeptName(String deptName) {
this.deptName = deptName;
}
@Override
public String toString() {
return "dept{" +
"deptid='" + deptid + '\'' +
", deptName='" + deptName + '\'' +
'}';
}
}
创建另外一个子模块，springcloud-02-provider-dept8002
把springcloud-02-provider-dept8001代码全部复制上去，修改配置文件application.yml(8002)
server:
port: 8002
spring:
application:
# 微服务名
name: provider_dept8001/8002
datasource:
url: jdbc:mysql://localhost:3306/ssmrl?serverTimezone=UTC
driver-class-name: com.mysql.jdbc.Driver
username: root
password: 18420163207
type: com.alibaba.druid.pool.DruidDataSource
为什么我们要复制多一份微服务提供者代码？
因为考虑到后面我们要使用负载均衡ribbon或者openFeign（不过底层也是ribbon）
4.创建子模块springcloud-02-comsumer-dept80
controller层：
@RestController
public class deptController80 {
@Autowired
private RestTemplate restTemplate;
private final String URL_DEPT="http://localhost:8001/";
@GetMapping("/comsumer/queryAllDept")
public List<dept> queryAllDept80(){
List<dept> res = restTemplate.getForObject(URL_DEPT + "queryAllDept", List.class);
return res;
}
}
因为默认的RestTemplate没有放入IOC容器中（也就是没有Bean），我们需要手动的放入IOC容器
config层
@Configuration
public class restTemplateConfig {
@Bean
public RestTemplate restTemplate(){
return new RestTemplate();
}
}
application.yml(80)
server:
port: 80
#
spring:
application:
name: comsumer_dept80
为什么微服务消费者层的端口是80，因为80端口可以省略不写，就比如我们打开百度，也是不需要写端口号的，因为微服务消费者层是给用户去访问的
消费者层只需要Controller去远程调用提供者的Controller方法即可，所以消费者层—不能—有dao，service层
这样提供者和消费者就搭建好了，接下来我们可以引入SpringCloud组件了。。。。。。。
引入注册中心SpringCloud Eureka
配置如下：
创建子模块springcloud-02-eureka7001(eureka注册中心服务端)
pom.xml
<dependencies>
<dependency>
<groupId>org.springframework.bootgroupId>
<artifactId>spring-boot-starter-webartifactId>
dependency>
<dependency>
<groupId>org.springframework.bootgroupId>
<artifactId>spring-boot-starter-actuatorartifactId>
dependency>
<dependency>
<groupId>org.springframework.cloudgroupId>
<artifactId>spring-cloud-starter-netflix-eureka-serverartifactId>
dependency>
dependencies>
eureka模块主启动类
@SpringBootApplication
@EnableEurekaServer //开启Eureka服务器
public class SpringBootApplication7001 {
public static void main(String[] args) {
SpringApplication.run(SpringBootApplication7001.class,args);
}
}
application.yml(7001)
server:
port: 7001
# 配置eureka
eureka:
instance:
hostname: eureka-server7001.com
client:
register-with-eureka: false
fetchRegistry: false
service-url:
defaultZone: http://${eureka.instance.hostname}:7001/eureka/
给提供者springcloud-02-provider-dept8001和8002修改如下
@SpringBootApplication
@EnableEurekaClient //eureka客户端
public class SpringBootApplication8001 {
public static void main(String[] args) {
SpringApplication.run(SpringBootApplication8001.class,args);
}
}
server:
port: 8001
spring:
application:
# 微服务名
name: provider_dept
datasource:
url: jdbc:mysql://localhost:3306/ssmrl?serverTimezone=UTC
driver-class-name: com.mysql.jdbc.Driver
username: root
password: 18420163207
type: com.alibaba.druid.pool.DruidDataSource
# eureka Client
eureka:
client:
service-url:
defaultZone: http://eureka-server7001.com:7001/eureka/
register-with-eureka: true
fetch-registry: false
instance:
instance-id: eureka-client8001
server:
port: 8002
spring:
application:
# 微服务名
name: provider_dept
datasource:
url: jdbc:mysql://localhost:3306/ssmrl?serverTimezone=UTC
driver-class-name: com.mysql.jdbc.Driver
username: root
password: 18420163207
type: com.alibaba.druid.pool.DruidDataSource
# eureka
eureka:
client:
fetch-registry: false
register-with-eureka: true
service-url:
defaultZone: http://eureka-server7001.com:7001/eureka/
instance:
prefer-ip-address: true
instance-id: eureka-client8002
Bug：引入Eureka后报错。
。。。取名要规范。。。
搭建Eureka集群
创建springcloud-02-eureka7002和7003两个模块
application.yml（7001）
server:
port: 7001
# 配置eureka
eureka:
instance:
hostname: eureka-server7001.com
client:
register-with-eureka: false
fetchRegistry: false
service-url:
defaultZone: http://eureka-server7002.com:7002/eureka/,http://eureka-server7003.com:7003/eureka/ #集群版就修改这个。单机认自己，集群认其他
application.yml（7002）
server:
port: 7002
spring:
application:
name: eureka7002 #这里可有可无，除了微服务提供者。
eureka:
instance:
hostname: eureka-server7002.com
client:
fetch-registry: false
register-with-eureka: false
service-url:
defaultZone: http://eureka-server7001.com:7001/eureka/,http://eureka-server7003.com:7003/eureka/
application.yml（7003）
server:
port: 7003
spring:
application:
name: eureka7003
eureka:
instance:
hostname: eureka-server7003.com
client:
register-with-eureka: false
fetch-registry: false
service-url:
defaultZone: http://eureka-server7001.com:7001/eureka/,http://eureka-server7002.com:7002/eureka/
其实Eureka集群没啥变化，也就是修改了serviceUrl的defaultZone罢了。记住一句话，单机版认自己，集群版认其他
搭建提供者集群(为了负载均衡)
在8001和8002微服务中修改defaultZone。
eureka:
client:
service-url:
defaultZone: http://eureka-server7001.com:7001/eureka/, http://eureka-server7002.com:7002/eureka/, http://eureka-server7003.com:7003/eureka/
还有8001和8002的微服务名要一致（spring.application.name）
spring:
application:
# 微服务名
name: provider-dept #8001和8002要一致
在springcloud-02-comsumer-dept80消费者层
@Configuration
public class restTemplateConfig {
@Bean
@LoadBalanced //开启负载均衡
public RestTemplate restTemplate(){
return new RestTemplate();
}
}
@SpringBootApplication
@EnableEurekaClient
public class SpringBootApplication80 {
public static void main(String[] args) {
SpringApplication.run(SpringBootApplication80.class,args);
}
}
用Ribbon+RestTemplate员工调用提供者的Controller方法
@RestController
public class deptController80 {
@Autowired
private RestTemplate restTemplate;
private final String URL_DEPT="http://PROVIDER-DEPT/"; //实现负载均衡用提供者微服务名代替IP:Port
@GetMapping("/comsumer/queryAllDept")
public List<dept> queryAllDept80(){
List<dept> res = restTemplate.getForObject(URL_DEPT + "queryAllDept", List.class);
return res;
}
}
application.yml(80)
server:
port: 80
#
spring:
application:
name: comsumer-dept80
eureka:
client:
fetch-registry: true
register-with-eureka: false
service-url:
defaultZone: http://eureka-server7001.com:7001/eureka/,http://eureka-server7002.com:7002/eureka/,http://eureka-server7003.com:7003/eureka/
Bug：ribbon+restTemplate报错
ribbon不支持微服务名有下划线（_）,修改过来即可
spring:
application:
# 微服务名
name: provider-dept
使用actuator功能
#暴露端点。使用actuator功能
management:
endpoints:
web:
exposure:
include: "*"
Feign/OpenFeign
创建子模块springcloud-02-comsumer-openFeign-dept80
所需的依赖
<dependency>
<groupId>org.springframework.cloudgroupId>
<artifactId>spring-cloud-starter-openfeignartifactId>
dependency>
点进去看看
我们可以发现，Feign/openFeign的底层就是Ribbon，所以openFeign自带了负载均衡的功能，相较于Ribbon+restTemplate，openFeign无需手动的使用@LoadBalanced注解来开启负载均衡，而Ribbon需要在restTemplate的Bean上加这个注解才有负载均衡的能力
主启动类
@SpringBootApplication
@EnableFeignClients //开启Feign的客户端支持
public class springApplicationFeign80 {
public static void main(String[] args) {
SpringApplication.run(springApplicationFeign80.class,args);
}
}
编写微服务接口
@Service
@FeignClient("PROVIDER-DEPT") //标注这个微服务接口是属于“PROVIDER-DEPT”这个微服务的
public interface deptService {
//下面的代码直接从微服务提供者的controller复制过来即可
@GetMapping(path = "/queryAllDept")
public List<dept> queryAllDept();
}
然后便是使用
@RestController
public class deptController {
@Autowired
private deptService deptService;
@RequestMapping("/feign/queryAllDept")
public List<dept> queryAllDept(){
return deptService.queryAllDept();
}
}
Bug：OpenFeign调用失败报错405
错误类型：
原因是我们没有在提供者加上@PathVariable或者@RequestParam注解
解决方法一：在提供者加上@RequestParam注解（每个提供者传入的参数都要加上这个注解）
@RestController
public class deptController {
private deptService deptService;
@Value("${server.port}")
private String port;
@Autowired
@Qualifier("deptServiceImpl")
public void setDeptService(com.boot.service.deptService deptService) {
this.deptService = deptService;
}
@GetMapping(path = "/queryAllDept")
@HystrixCommand(fallbackMethod = "queryAllDept_Hystrix",commandProperties = {
@HystrixProperty(name = "circuitBreaker.enabled",value = "true"),
@HystrixProperty(name = "circuitBreaker.requestVolumeThreshold",value = "10"),
@HystrixProperty(name = "circuitBreaker.sleepWindowInMilliseconds",value = "20000"),//注意这是毫秒。1秒=1000毫秒
@HystrixProperty(name = "circuitBreaker.errorThresholdPercentage",value = "50")
})
public List<dept> queryAllDept(@RequestParam("id") String id){
List<dept> depts = deptService.queryAllDept();
depts.add(new dept("999",port));
if(Integer.parseInt(id)<0){
throw new RuntimeException();
}
return depts;
}
/**
* 服务熔断
*/
public List<dept> queryAllDept_Hystrix(@RequestParam("id") String id){
List<dept> depts = deptService.queryAllDept();
depts.add(new dept("1066","Break"));
return depts;
}
}
修改openFeign的微服务接口
@Service
@FeignClient("PROVIDER-DEPT")
public interface deptService {
@GetMapping(path = "/queryAllDept")
public List<dept> queryAllDept(@RequestParam("id") String id);
}
没有报错了！！！
解决方法二：在微服务提供者加上@PathVariable注解。。
省略！！！
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