[Java知识库]SpringCloud+eureka

eureka集群

主pom

<!--统一jar包和版本管理-->
  <properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <maven.compiler.source>1.8</maven.compiler.source>
    <maven.compiler.target>1.8</maven.compiler.target>
<!--    <junit.version>4.12</junit.version>-->
<!--    <log4j.version>1.2.17</log4j.version>-->
<!--    <lombox.version></lombox.version>-->
  </properties>
<!--  用于父类管理能让子项目使用一个依赖不需要版本号，版本升级只需要在顶层更改，只是声明不引入jar包-->
  <dependencyManagement>
    <dependencies>
      <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-dependencies</artifactId>
        <version>2.2.2.RELEASE</version>
        <type>pom</type>
        <scope>import</scope>
      </dependency>
      <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-dependencies</artifactId>
        <version>Hoxton.SR1</version>
        <type>pom</type>
        <scope>import</scope>
      </dependency>
      <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>
      <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
        <version>8.0.28</version>
        <type>pom</type>
        <scope>import</scope>
      </dependency>
      <dependency>
        <groupId>com.alibaba</groupId>
        <artifactId>druid</artifactId>
        <version>1.2.4</version>
        <type>pom</type>
        <scope>import</scope>
      </dependency>
      <dependency>
        <groupId>org.mybatis.spring.boot</groupId>
        <artifactId>mybatis-spring-boot-starter</artifactId>
        <version>2.1.3</version>
        <type>pom</type>
        <scope>import</scope>
      </dependency>

    </dependencies>
  </dependencyManagement>
  <build>
    <plugins>
      <plugin>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-maven-plugin</artifactId>
        <version>2.3.4.RELEASE</version>
        <configuration>
          <fork>true</fork>
          <addResources>true</addResources>
        </configuration>
      </plugin>
    </plugins>
  </build>

微服务

提取公共实体

pom

<dependencies>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
        </dependency>
        <dependency>
            <groupId>cn.hutool</groupId>
            <artifactId>hutool-all</artifactId>
            <version>5.5.7</version>
        </dependency>
    </dependencies>

注：实体类直接创建即刻

注入

@Configuration
public class ApplicationContextConfig {
    @Bean
    @LoadBalanced //负载均衡
    public RestTemplate getRestTemplate(){
        return new RestTemplate();
    }
}

使用

@RestController
@Slf4j
public class OrderController {
    @Resource
    RestTemplate restTemplate;

//    public static final String PAYMENT_URL="http://localhost:8001"; //单机
    public static final String PAYMENT_URL="http://CLOUD-PAYMENT-SERVICE"; //集群

    @GetMapping("/consumer/payment/create")
    public CommonResult<Payment> create(Payment payment){
        return  restTemplate.postForObject(PAYMENT_URL+"/payment/create",payment,CommonResult.class);
    }

    @GetMapping("/consumer/payment/get/{id}")
    public CommonResult<Payment> getPayment(@PathVariable("id") long id){
        return restTemplate.getForObject(PAYMENT_URL+"/payment/get/"+id,CommonResult.class);
    }
}

eureka

两注解

@EnableEurekaClient //用于consumer以及provider
@EnableEurekaServer //用于server

consumer——pom

<dependencies>
    <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
    </dependency>

    <dependency>
        <groupId>org.example</groupId>
        <artifactId>cloud-api-commons</artifactId>
        <version>1.0-SNAPSHOT</version>
    </dependency>

    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-actuator</artifactId>
    </dependency>
 <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-devtools</artifactId>
        <scope>runtime</scope>
        <optional>true</optional>
    </dependency>
    <dependency>
        <groupId>org.projectlombok</groupId>
        <artifactId>lombok</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-test</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-devtools</artifactId>
        <scope>runtime</scope>
        <optional>true</optional>
    </dependency>
</dependencies>

consumer——yml

server:
  port: 88
spring:
  application:
    name: cloud-order-service
eureka:
  client:
    register-with-eureka: true
    fetch-registry: true
    service-url:
#      defaultZone: http://localhost:7001/eureka 单机版本
      defaultZone: http://eureka7001.com:7001/eureka,http://eureka7002.com:7002/eureka #集群版本

provider——pom

<dependencies>
    <dependency>
        <groupId>org.example</groupId>
        <artifactId>cloud-api-commons</artifactId>
        <version>1.0-SNAPSHOT</version>
    </dependency>
    <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-starter-netflix-eureka-client</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-actuator</artifactId>
    </dependency>
    <dependency>
        <groupId>org.mybatis.spring.boot</groupId>
        <artifactId>mybatis-spring-boot-starter</artifactId>
    </dependency>
    <dependency>
        <groupId>com.alibaba</groupId>
        <artifactId>druid-spring-boot-starter</artifactId>
        <version>1.2.4</version>
    </dependency>
    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-jdbc</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-devtools</artifactId>
        <scope>runtime</scope>
        <optional>true</optional>
    </dependency>
    <dependency>
        <groupId>org.projectlombok</groupId>
        <artifactId>lombok</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-test</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-devtools</artifactId>
        <scope>runtime</scope>
        <optional>true</optional>
    </dependency>
</dependencies>

provider——yml

server:
  port: 8001
spring:
  application:
    name: cloud-payment-service
  datasource:
    druid:
      db-type: com.alibaba.druid.poor.DruidDataSource
      driver-class-name: com.mysql.cj.jdbc.Driver
      url: jdbc:mysql://localhost:3306/test?useUnicode=true&characterEncoding=UTF-8&serverTimezone=Asia/Shanghai
      username: root
      password: jp3212217

mybatis:
  mapper-locations: classpath:mapper/*.xml
  type-aliases-package: com.pxx.cloud.entities

eureka:
  client:
    register-with-eureka: true
    fetch-registry: true
    service-url:
#      defaultZone: http://localhost:7001/eureka # 单机版本
      defaultZone: http://eureka7001.com:7001/eureka,http://eureka7002.com:7002/eureka  #集群版本
  instance:
    instance-id: payment8001
    prefer-ip-address: true
#自我保护机制对应设置
    lease-renewal-interval-in-seconds: 1 #客户端向服务端发送心跳时间间隔（s，默认30s）
    lease-expiration-duration-in-seconds: 2 #服务端受到最后一次心跳后等待时间上限（s，默认90s，超时将剔除服务）

eureka——server——pom

<dependencies>
    <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-starter-netflix-eureka-server</artifactId>
    </dependency>
    <dependency>
        <groupId>org.example</groupId>
        <artifactId>cloud-api-commons</artifactId>
        <version>1.0-SNAPSHOT</version>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-actuator</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-test</artifactId>
    </dependency>
</dependencies>

eureka——server——yml

server:
  port: 7001
eureka:
  instance:
    hostname: eureka7001.com
  client:
    register-with-eureka: false
    fetch-registry: false
    service-url:
      defaultZone: http://eureka7002.com:7002/eureka/

服务发现

@Resource
    private DiscoveryClient discoveryClient;


@GetMapping("/payment/discovery")
    public Object discovery(){
        List<String> services = discoveryClient.getServices();//得到服务清单列表
        for (String service : services) {
            log.info(service);
        }
        List<ServiceInstance> instances = discoveryClient.getInstances("CLOUD-PAYMENT-SERVICE");
        for (ServiceInstance instance : instances) {
            log.info(instance.getInstanceId()+instance.getHost()+instance.getPort()+instance.getUri());
        }
        return this.discoveryClient;

    }

自我保护机制

默认开启

7001关闭自我保护机制

server:
  enable-self-preservation: false
  eviction-interval-timer-in-ms: 2000

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