Spring Cloud Circuit breaker provides an abstraction across different circuit breaker implementations. It provides a consistent API to use in your applications allowing you the developer to choose the circuit breaker implementation that best fits your needs for your app.
Spring Cloud断路器提供了一个跨不同断路器的抽象实现。它提供了在您的应用程序中使用的一致的API，允许您的开发人员选择最适合您的应用程序需要的断路器实现。
支持断路器实现有以下几种
Netfix Hystrix (Spring Cloud官方已经不予支持)
Resilience4J （支持）
Sentinel
Spring Retry
2、快速开始
pom.xml
maven依赖配置文件，如下：
<?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>2.6.4</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>com.mindasoft</groupId>
<artifactId>spring-cloud-circuitbreaker-consumer</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>spring-cloud-circuitbreaker-consumer</name>
<description>Demo project for Spring Boot</description>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
<java.version>1.8</java.version>
<spring-cloud.version>2021.0.1</spring-cloud.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-circuitbreaker-resilience4j</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>
<scope>test</scope>
</dependency>
</dependencies>
<dependencyManagement>
<dependencies>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-dependencies</artifactId>
<version>${spring-cloud.version}</version>
<type>pom</type>
<scope>import</scope>
</dependency>
</dependencies>
</dependencyManagement>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
<repositories>
<repository>
<id>nexus-aliyun</id>
<name>Nexus aliyun</name>
<url>https://maven.aliyun.com/repository/public</url>
<layout>default</layout>
<snapshots>
<enabled>false</enabled>
</snapshots>
<releases>
<enabled>true</enabled>
</releases>
</repository>
</repositories>
<pluginRepositories>
<pluginRepository>
<id>nexus-aliyun</id>
<name>Nexus aliyun</name>
<url>https://maven.aliyun.com/repository/public</url>
<snapshots>
<enabled>false</enabled>
</snapshots>
<releases>
<enabled>true</enabled>
</releases>
</pluginRepository>
</pluginRepositories>
</project>
比上个项目多了如下配置：
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-circuitbreaker-resilience4j</artifactId>
</dependency>
使用resilience4j 实现断路器。
application.properties
server.port=9004
# 服务注册中心地址
eureka.client.service-url.defaultZone=http://localhost:9000/eureka/
# 服务名称
spring.application.name=circuitbreaker-customer
SpringCloudCircuitBreakerConsumerApplication
package com.mindasoft;
import io.github.resilience4j.circuitbreaker.CircuitBreakerConfig;
import io.github.resilience4j.timelimiter.TimeLimiterConfig;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.circuitbreaker.resilience4j.Resilience4JCircuitBreakerFactory;
import org.springframework.cloud.circuitbreaker.resilience4j.Resilience4JConfigBuilder;
import org.springframework.cloud.client.circuitbreaker.Customizer;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
import org.springframework.cloud.client.loadbalancer.LoadBalanced;
import org.springframework.context.annotation.Bean;
import org.springframework.web.client.RestTemplate;
import java.time.Duration;
@EnableDiscoveryClient // Eureka Discovery Client 标识
@SpringBootApplication
public class
SpringCloudCircuitBreakerConsumerApplication {
// 开启负载均衡的功能
@Bean
@LoadBalanced
RestTemplate restTemplate() {
return new RestTemplate();
}
@Bean
public Customizer<Resilience4JCircuitBreakerFactory> defaultCustomizer() {
return factory -> factory.configureDefault(id -> new Resilience4JConfigBuilder(id)
.timeLimiterConfig(TimeLimiterConfig.custom().timeoutDuration(Duration.ofSeconds(3)).build())
.circuitBreakerConfig(CircuitBreakerConfig.ofDefaults())
.build());
}
public static void main(String[] args) {
SpringApplication.run(SpringCloudCircuitBreakerConsumerApplication.class, args);
}
}
