文章目录

• SpringCloud学习笔记（1）- Spring Cloud Alibaba
• 服务治理
• • Nacos 服务注册
  • Nacos 服务发现与调用
  • Ribbon 负载均衡
  • Sentinel 服务限流降级
  • • 流控规则
    • 流控效果
    • 降级规则
    • 热点规则
    • 授权规则
    • 自定义规则异常返回
  • 整合 RocketMQ
  • • 安装 RocketMQ
    • 安装 RocketMQ 控制台
    • Java 实现消息发送
    • Java 实现消息消费
  • Spring Boot 整合 RocketMQ
  • 服务网关
  • • Gateway 限流
  • 分布式事务
  • • 模拟分布式事务异常
    • Seata 解决（事务回滚）

SpringCloud学习笔记（1）- Spring Cloud Alibaba

创建父工程

Spring Cloud Alibaba 的环境在父工程中创建，微服务的各个组件作为子工程，继承父工程的环境。

Spring Boot —》Spring Cloud —》Spring Cloud Alibaba

pom.xml 中添加。

<dependencyManagement><dependencies><dependency><groupId>org.springframework.cloudgroupId><artifactId>spring-cloud-dependenciesartifactId><version>Hoxton.SR3version><type>pomtype><scope>importscope>dependency><dependency><groupId>com.alibaba.cloudgroupId><artifactId>spring-cloud-alibaba-dependenciesartifactId><version>2.2.1.RELEASEversion><type>pomtype><scope>importscope>dependency>dependencies>
dependencyManagement>

服务治理

服务注册 + 服务发现

Nacos 服务注册

解压，启动服务。

Nacos 搭建成功，接下来注册服务。

在父工程路径下创建子工程，让子工程继承父工程的环境依赖，pom.xml 中添加 nacos 发现组件。

<dependency><groupId>com.alibaba.cloudgroupId><artifactId>spring-cloud-starter-alibaba-nacos-discoveryartifactId>
dependency>

application.yml 中配置

spring:cloud:nacos:discovery:# 指定nacos server地址server-addr: localhost:8848application:name: my-nacos

Nacos 服务发现与调用

pom.xml 添加 discovery，完成服务发现。

<dependency><groupId>com.alibaba.cloudgroupId><artifactId>spring-cloud-starter-alibaba-nacos-discoveryartifactId>
dependency>

通过 discoveryClient 发现注册到 nacos 中的 provider 服务。

@RestController
public class ConsumerController {@Autowiredprivate DiscoveryClient discoveryClient;@GetMapping("/instances")public List<ServiceInstance> instances(){List<ServiceInstance> provider = discoveryClient.getInstances("provider");return provider;}}

@Configuration
public class ConsumerConfig {@Beanpublic RestTemplate restTemplate(){return new RestTemplate();}}

@RestController
public class ConsumerController {@Autowiredprivate DiscoveryClient discoveryClient;@Autowiredprivate RestTemplate restTemplate;@GetMapping("/index")public String index(){List<ServiceInstance> provider = discoveryClient.getInstances("provider");int index = ThreadLocalRandom.current().nextInt(provider.size());String url = provider.get(index).getUri()+"/index";return "consumer随机远程调用provier："+this.restTemplate.getForObject(url, String.class);}}

Ribbon 负载均衡

@Configuration
public class ConsumerConfig {@Bean@LoadBalancedpublic RestTemplate restTemplate(){return new RestTemplate();}}

@RestController
public class ConsumerController {@Autowiredprivate RestTemplate restTemplate;@GetMapping("/index")public String index(){return "consumer远程调用provier："+this.restTemplate.getForObject("http://provider/index", String.class);}}

随机 （随机的算法）

server:port: 8180
provider:ribbon:NFLoadBalancerRuleClassName: com.netflix.loadbalancer.RandomRule

Nacos 权重 （基于权重的算法）

@Slf4j
public class NacosWeightedRule extends AbstractLoadBalancerRule {@Autowiredprivate NacosDiscoveryProperties nacosDiscoveryProperties;@Overridepublic void initWithNiwsConfig(IClientConfig iClientConfig) {//读取配置文件}@Overridepublic Server choose(Object o) {ILoadBalancer loadBalancer = this.getLoadBalancer();BaseLoadBalancer baseLoadBalancer = (BaseLoadBalancer) loadBalancer;//获取要请求的微服务名称String name = baseLoadBalancer.getName();//获取服务发现的相关APINamingService namingService = nacosDiscoveryProperties.namingServiceInstance();try {Instance instance = namingService.selectOneHealthyInstance(name);log.info("选择的实例是port={},instance={}",instance.getPort(),instance);return new NacosServer(instance);} catch (NacosException e) {e.printStackTrace();return null;}}
}

server:port: 8180
provider:ribbon:NFLoadBalancerRuleClassName: com.southwind.configuration.NacosWeightedRule

Sentinel 服务限流降级

雪崩效应

解决方案

1、设置线程超时

2、设置限流

3、熔断器 Sentinel、Hystrix （类比保险丝）

• 降级
• 限流
• 熔断

1、provider模块pom.xml 引入依赖

<dependency><groupId>com.alibaba.cloudgroupId><artifactId>spring-cloud-starter-alibaba-sentinelartifactId>
dependency><dependency><groupId>org.springframework.bootgroupId><artifactId>spring-boot-starter-actuatorartifactId>
dependency>

2、application 配置

management:endpoints:web:exposure:include: '*'
spring:cloud:sentinel:transport:dashboard: localhost:8080

3、下载 Sentinel 控制台，解压，启动。

流控规则

直接限流

关联限流

链路限流

1、pom.xml 添加依赖

<dependency><groupId>com.alibaba.cspgroupId><artifactId>sentinel-coreartifactId><version>1.7.1version>
dependency><dependency><groupId>com.alibaba.cspgroupId><artifactId>sentinel-web-servletartifactId><version>1.7.1version>
dependency>

2、application.yml

spring:cloud:sentinel:filter:enabled: false

3、写配置类（让能关联到Service）

package com.southwind.configuration;import com.alibaba.csp.sentinel.adapter.servlet.CommonFilter;
import org.springframework.boot.web.servlet.FilterRegistrationBean;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;@Configuration
public class FilterConfiguration {@Beanpublic FilterRegistrationBean registrationBean(){FilterRegistrationBean registrationBean = new FilterRegistrationBean();registrationBean.setFilter(new CommonFilter());registrationBean.addUrlPatterns("/*");registrationBean.addInitParameter(CommonFilter.WEB_CONTEXT_UNIFY,"false");  //让所有链路开放出来才能限制registrationBean.setName("sentinelFilter");return registrationBean;}
}

4、Service

@Service
public class HelloService {@SentinelResource("test")public void test(){System.out.println("test");}
}

5、Controller

@GetMapping("/test1")
public String test1(){this.helloService.test();return "test1";
}@GetMapping("/test2")
public String test2(){this.helloService.test();return "test2";
}

流控效果

快速失败

直接抛出异常

Warm UP

给系统一个预热的时间，预热时间段内单机阈值较低，预热时间过后单机阈值增加，预热时间内当前的单机阈值是设置的阈值的三分之一，预热时间过后单机阈值恢复设置的值。

排队等待

当请求调用失败之后，不会立即抛出异常，等待下一次调用，时间范围是超时时间，在时间范围内如果能请求成功则不抛出异常，如果请求则抛出异常。

降级规则

RT

单个请求的响应时间超过阈值，则进入准降级状态，接下来 1 S 内连续 5 个请求响应时间均超过阈值，就进行降级，持续时间为时间窗口的值。

异常比例

每秒异常数量占通过量的比例大于阈值，就进行降级处理，持续时间为时间窗口的值。

异常数

1 分钟内的异常数超过阈值就进行降级处理，时间窗口的值要大于 60S，否则刚结束熔断又进入下一次熔断了。

热点规则

热点规则是流控规则的更细粒度操作，可以具体到对某个热点参数的限流，设置限流之后，如果带着限流参数的请求量超过阈值，则进行限流，时间为统计窗口时长。

必须要添加 @SentinelResource，即对资源进行流控。

@GetMapping("/hot")
@SentinelResource("hot")
public String hot(@RequestParam(value = "num1",required = false) Integer num1,@RequestParam(value = "num2",required = false) Integer num2){return num1+"-"+num2;
}

授权规则

给指定的资源设置流控应用（追加参数），可以对流控应用进行访问权限的设置，具体就是添加白名单和黑名单。

如何给请求指定流控应用，通过实现 RequestOriginParser 接口来完成，代码如下所示。

package com.southwind.configuration;import com.alibaba.csp.sentinel.adapter.servlet.callback.RequestOriginParser;
import org.springframework.util.StringUtils;import javax.servlet.http.HttpServletRequest;public class RequestOriginParserDefinition implements RequestOriginParser {@Overridepublic String parseOrigin(HttpServletRequest httpServletRequest) {String name = httpServletRequest.getParameter("name");if(StringUtils.isEmpty(name)){throw new RuntimeException("name is null");}return name;}
}

要让 RequestOriginParserDefinition 生效，需要在配置类中进行配置。

package com.southwind.configuration;import com.alibaba.csp.sentinel.adapter.servlet.callback.WebCallbackManager;
import org.springframework.context.annotation.Configuration;import javax.annotation.PostConstruct;@Configuration
public class SentinelConfiguration {@PostConstructpublic void init(){WebCallbackManager.setRequestOriginParser(new RequestOriginParserDefinition());}
}

自定义规则异常返回

创建异常处理类

package com.southwind.handler;import com.alibaba.csp.sentinel.adapter.servlet.callback.UrlBlockHandler;
import com.alibaba.csp.sentinel.slots.block.BlockException;
import com.alibaba.csp.sentinel.slots.block.degrade.DegradeException;
import com.alibaba.csp.sentinel.slots.block.flow.FlowException;import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;public class ExceptionHandler implements UrlBlockHandler {@Overridepublic void blocked(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, BlockException e) throws IOException {httpServletResponse.setContentType("text/html;charset=utf-8");String msg = null;if(e instanceof FlowException){msg = "限流";}else if(e instanceof DegradeException){msg = "降级";}httpServletResponse.getWriter().write(msg);}
}

进行配置。

@Configuration
public class SentinelConfiguration {@PostConstructpublic void init(){WebCallbackManager.setUrlBlockHandler(new ExceptionHandler());}
}

整合 RocketMQ

安装 RocketMQ

1、传入 Linux 服务器

2、解压缩

unzip rocketmq-all-4.7.1-bin-release.zip

3、启动 NameServer

nohup ./bin/mqnamesrv &

4、检查是否启动成功

netstat -an | grep 9876

5、启动 Broker

启动之前需要编辑配置文件，修改 JVM 内存设置，默认给的内存 4 GB，超过我们的 JVM 了。

cd bin
vim runserver.sh

vim runbroker.sh

启动 Broker

nohup ./mqbroker -n localhost:9876 &

可以查看日志

tail -f ~/logs/rocketmqlogs/broker.log

启动成功

6、测试 RocketMQ

消息发送

cd bin
export NAMESRV_ADDR=localhost:9876
./tools.sh org.apache.rocketmq.example.quickstart.Producer

消息接收

cd bin
export NAMESRV_ADDR=localhost:9876
./tools.sh org.apache.rocketmq.example.quickstart.Consumer

7、关闭 RocketMQ

cd bin
./mqshutdown broker
./mqshutdown namesrv

安装 RocketMQ 控制台

1、解压缩，修改配置，打包

mvn clean package -Dmaven.test.skip=true

2、进入 target 启动 jar

java -jar rocketmq-console-ng-1.0.0.jar 

打开浏览器访问 localhost:9877，如果报错如下：

这是因为我们的 RocketMQ 安装在 Linux 中，控制台在 windows，Linux 需要开放端口才能访问，开放 10909 和 9876 端口

firewall-cmd --zone=public --add-port=10909/tcp --permanent
firewall-cmd --zone=public --add-port=9876/tcp --permanent
systemctl restart firewalld.service
firewall-cmd --reload

重新启动控制台项目

Java 实现消息发送

1、pom.xml 中引入依赖

<dependency><groupId>org.apache.rocketmqgroupId><artifactId>rocketmq-spring-boot-starterartifactId><version>2.1.0version>
dependency>

2、生产消息

package com.southwind;import org.apache.rocketmq.client.producer.DefaultMQProducer;
import org.apache.rocketmq.client.producer.SendResult;
import org.apache.rocketmq.common.message.Message;public class Test {public static void main(String[] args) throws Exception {//创建消息生产者DefaultMQProducer producer = new DefaultMQProducer("myproducer-group");//设置NameServerproducer.setNamesrvAddr("192.168.248.129:9876");//启动生产者producer.start();//构建消息对象Message message = new Message("myTopic","myTag",("Test MQ").getBytes());//发送消息SendResult result = producer.send(message, 1000);System.out.println(result);//关闭生产者producer.shutdown();}
}

3、直接运行，如果报错 sendDefaultImpl call timeout，可以开放 10911 端口

firewall-cmd --zone=public --add-port=10911/tcp --permanent
systemctl restart firewalld.service
firewall-cmd --reload

打开 RocketMQ 控制台，可查看消息。

Java 实现消息消费

package com.southwind.service;import lombok.extern.slf4j.Slf4j;
import org.apache.rocketmq.client.consumer.DefaultMQPushConsumer;
import org.apache.rocketmq.client.consumer.listener.ConsumeConcurrentlyContext;
import org.apache.rocketmq.client.consumer.listener.ConsumeConcurrentlyStatus;
import org.apache.rocketmq.client.consumer.listener.MessageListenerConcurrently;
import org.apache.rocketmq.client.exception.MQClientException;
import org.apache.rocketmq.common.message.MessageExt;import java.util.List;@Slf4j
public class ConsumerTest {public static void main(String[] args) throws MQClientException {//创建消息消费者DefaultMQPushConsumer consumer = new DefaultMQPushConsumer("myconsumer-group");//设置NameServerconsumer.setNamesrvAddr("192.168.248.129:9876");//指定订阅的主题和标签consumer.subscribe("myTopic","*");//回调函数consumer.registerMessageListener(new MessageListenerConcurrently() {@Overridepublic ConsumeConcurrentlyStatus consumeMessage(List<MessageExt> list, ConsumeConcurrentlyContext consumeConcurrentlyContext) {log.info("Message=>{}",list);return ConsumeConcurrentlyStatus.CONSUME_SUCCESS;}});//启动消费者consumer.start();}
}

Spring Boot 整合 RocketMQ

provider

1、pom.xml

<dependency><groupId>org.apache.rocketmqgroupId><artifactId>rocketmq-spring-boot-starterartifactId><version>2.1.0version>
dependency>
<dependency><groupId>org.apache.rocketmqgroupId><artifactId>rocketmq-clientartifactId><version>4.7.0version>
dependency>

2、application.yml

rocketmq:name-server: 192.168.248.129:9876producer:group: myprovider

3、Order

package com.southwind.entity;import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;import java.util.Date;@Data
@AllArgsConstructor
@NoArgsConstructor
public class Order {private Integer id;private String buyerName;private String buyerTel;private String address;private Date createDate;
}

4、Controller

@Autowired
private RocketMQTemplate rocketMQTemplate;@GetMapping("/create")
public Order create(){Order order = new Order(1,"张三","123123","软件园",new Date());this.rocketMQTemplate.convertAndSend("myTopic",order);return order;
}

consumer

1、pom.xml

<dependency><groupId>org.apache.rocketmqgroupId><artifactId>rocketmq-spring-boot-starterartifactId><version>2.1.0version>
dependency>
<dependency><groupId>org.apache.rocketmqgroupId><artifactId>rocketmq-clientartifactId><version>4.7.0version>
dependency>

2、application.yml

rocketmq:name-server: 192.168.248.129:9876

3、Service

@Slf4j
@Service
@RocketMQMessageListener(consumerGroup = "myConsumer",topic = "myTopic")
public class SmsService implements RocketMQListener<Order> {@Overridepublic void onMessage(Order order) {log.info("新订单{},发短信",order);}
}

服务网关

Spring Cloud Gateway 是基于 Netty，跟 Servlet 不兼容，所以你的工程中不能出现 Servlet 的组件 。

1、pom.xml

注意，一定不能出现 spring web 的依赖，因为 Gateway 与 Servlet 不兼容。

<dependency><groupId>org.springframework.cloudgroupId><artifactId>spring-cloud-starter-gatewayartifactId>
dependency>

2、application.yml

server:port: 8010
spring:application:name: gatewaycloud:gateway:discovery:locator:enabled: trueroutes: - id: provider_route   uri: http://localhost:8081 predicates: - Path=/provider/** filters:- StripPrefix=1

上面这种做法其实没有用到 nacos ，现在我们让 gateway 直接去 nacos 中发现服务，配置更加简单了。

1、pom.xml 引入 nacos

<dependency><groupId>org.springframework.cloudgroupId><artifactId>spring-cloud-starter-gatewayartifactId>
dependency><dependency><groupId>com.alibaba.cloudgroupId><artifactId>spring-cloud-starter-alibaba-nacos-discoveryartifactId>
dependency>

2、application.yml

server:port: 8010
spring:application:name: gatewaycloud:gateway:discovery:locator:enabled: true

Gateway 限流

基于路由限流

1、pom.xml

<dependency><groupId>org.springframework.cloudgroupId><artifactId>spring-cloud-starter-gatewayartifactId>
dependency><dependency><groupId>com.alibaba.cspgroupId><artifactId>sentinel-spring-cloud-gateway-adapterartifactId>
dependency>

2、配置类

package com.southwind.configuration;import com.alibaba.csp.sentinel.adapter.gateway.common.rule.GatewayFlowRule;
import com.alibaba.csp.sentinel.adapter.gateway.common.rule.GatewayRuleManager;
import com.alibaba.csp.sentinel.adapter.gateway.sc.SentinelGatewayFilter;
import com.alibaba.csp.sentinel.adapter.gateway.sc.callback.BlockRequestHandler;
import com.alibaba.csp.sentinel.adapter.gateway.sc.callback.GatewayCallbackManager;
import com.alibaba.csp.sentinel.adapter.gateway.sc.exception.SentinelGatewayBlockExceptionHandler;
import org.springframework.beans.factory.ObjectProvider;
import org.springframework.cloud.gateway.filter.GlobalFilter;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.Ordered;
import org.springframework.core.annotation.Order;
import org.springframework.http.HttpStatus;
import org.springframework.http.MediaType;
import org.springframework.http.codec.ServerCodecConfigurer;
import org.springframework.web.reactive.function.BodyInserters;
import org.springframework.web.reactive.function.server.ServerResponse;
import org.springframework.web.reactive.result.view.ViewResolver;
import org.springframework.web.server.ServerWebExchange;
import reactor.core.publisher.Mono;import javax.annotation.PostConstruct;
import java.util.*;@Configuration
public class GatewayConfiguration {private final List<ViewResolver> viewResolvers;private final ServerCodecConfigurer serverCodecConfigurer;public GatewayConfiguration(ObjectProvider<List<ViewResolver>> viewResolversProvider,ServerCodecConfigurer serverCodecConfigurer) {this.viewResolvers = viewResolversProvider.getIfAvailable(Collections::emptyList);this.serverCodecConfigurer = serverCodecConfigurer;}//配置限流的异常处理@Bean@Order(Ordered.HIGHEST_PRECEDENCE)public SentinelGatewayBlockExceptionHandler sentinelGatewayBlockExceptionHandler() {return new SentinelGatewayBlockExceptionHandler(viewResolvers, serverCodecConfigurer);}//配置初始化的限流参数@PostConstructpublic void initGatewayRules(){Set<GatewayFlowRule> rules = new HashSet<>();rules.add(new GatewayFlowRule("provider_route").setCount(1).setIntervalSec(1));GatewayRuleManager.loadRules(rules);}//初始化限流过滤器@Bean@Order(Ordered.HIGHEST_PRECEDENCE)public GlobalFilter sentinelGatewayFilter() {return new SentinelGatewayFilter();}//自定义限流异常页面@PostConstructpublic void initBlockHandlers(){BlockRequestHandler blockRequestHandler = new BlockRequestHandler() {@Overridepublic Mono<ServerResponse> handleRequest(ServerWebExchange serverWebExchange, Throwable throwable) {Map map = new HashMap();map.put("code",0);map.put("msg","被限流了");return ServerResponse.status(HttpStatus.OK).contentType(MediaType.APPLICATION_JSON).body(BodyInserters.fromObject(map));}};GatewayCallbackManager.setBlockHandler(blockRequestHandler);}
}

3、application.yml

server:port: 8010
spring:application:name: gatewaycloud:gateway:discovery:locator:enabled: trueroutes:- id: provider_routeuri: http://localhost:8081predicates:- Path=/provider/**filters:- StripPrefix=1

基于 API 分组限流

1、修改配置类，添加基于 API 分组限流的方法，修改初始化的限流参数

package com.southwind.configuration;import com.alibaba.csp.sentinel.adapter.gateway.common.SentinelGatewayConstants;
import com.alibaba.csp.sentinel.adapter.gateway.common.api.ApiDefinition;
import com.alibaba.csp.sentinel.adapter.gateway.common.api.ApiPathPredicateItem;
import com.alibaba.csp.sentinel.adapter.gateway.common.api.ApiPredicateItem;
import com.alibaba.csp.sentinel.adapter.gateway.common.api.GatewayApiDefinitionManager;
import com.alibaba.csp.sentinel.adapter.gateway.common.rule.GatewayFlowRule;
import com.alibaba.csp.sentinel.adapter.gateway.common.rule.GatewayRuleManager;
import com.alibaba.csp.sentinel.adapter.gateway.sc.SentinelGatewayFilter;
import com.alibaba.csp.sentinel.adapter.gateway.sc.callback.BlockRequestHandler;
import com.alibaba.csp.sentinel.adapter.gateway.sc.callback.GatewayCallbackManager;
import com.alibaba.csp.sentinel.adapter.gateway.sc.exception.SentinelGatewayBlockExceptionHandler;
import org.springframework.beans.factory.ObjectProvider;
import org.springframework.cloud.gateway.filter.GlobalFilter;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.Ordered;
import org.springframework.core.annotation.Order;
import org.springframework.http.HttpStatus;
import org.springframework.http.MediaType;
import org.springframework.http.codec.ServerCodecConfigurer;
import org.springframework.web.reactive.function.BodyInserters;
import org.springframework.web.reactive.function.server.ServerResponse;
import org.springframework.web.reactive.result.view.ViewResolver;
import org.springframework.web.server.ServerWebExchange;
import reactor.core.publisher.Mono;import javax.annotation.PostConstruct;
import java.util.*;@Configuration
public class GatewayConfiguration {private final List<ViewResolver> viewResolvers;private final ServerCodecConfigurer serverCodecConfigurer;public GatewayConfiguration(ObjectProvider<List<ViewResolver>> viewResolversProvider,ServerCodecConfigurer serverCodecConfigurer) {this.viewResolvers = viewResolversProvider.getIfAvailable(Collections::emptyList);this.serverCodecConfigurer = serverCodecConfigurer;}//配置限流的异常处理@Bean@Order(Ordered.HIGHEST_PRECEDENCE)public SentinelGatewayBlockExceptionHandler sentinelGatewayBlockExceptionHandler() {return new SentinelGatewayBlockExceptionHandler(viewResolvers, serverCodecConfigurer);}//配置初始化的限流参数@PostConstructpublic void initGatewayRules(){Set<GatewayFlowRule> rules = new HashSet<>();rules.add(new GatewayFlowRule("provider_api1").setCount(1).setIntervalSec(1));rules.add(new GatewayFlowRule("provider_api2").setCount(1).setIntervalSec(1));GatewayRuleManager.loadRules(rules);}//初始化限流过滤器@Bean@Order(Ordered.HIGHEST_PRECEDENCE)public GlobalFilter sentinelGatewayFilter() {return new SentinelGatewayFilter();}//自定义限流异常页面@PostConstructpublic void initBlockHandlers(){BlockRequestHandler blockRequestHandler = new BlockRequestHandler() {@Overridepublic Mono<ServerResponse> handleRequest(ServerWebExchange serverWebExchange, Throwable throwable) {Map map = new HashMap();map.put("code",0);map.put("msg","被限流了");return ServerResponse.status(HttpStatus.OK).contentType(MediaType.APPLICATION_JSON).body(BodyInserters.fromObject(map));}};GatewayCallbackManager.setBlockHandler(blockRequestHandler);}//自定义API分组@PostConstructprivate void initCustomizedApis(){Set<ApiDefinition> definitions = new HashSet<>();ApiDefinition api1 = new ApiDefinition("provider_api1").setPredicateItems(new HashSet<ApiPredicateItem>(){{add(new ApiPathPredicateItem().setPattern("/provider/api1/**").setMatchStrategy(SentinelGatewayConstants.URL_MATCH_STRATEGY_PREFIX));}});ApiDefinition api2 = new ApiDefinition("provider_api2").setPredicateItems(new HashSet<ApiPredicateItem>(){{add(new ApiPathPredicateItem().setPattern("/provider/api2/demo1"));}});definitions.add(api1);definitions.add(api2);GatewayApiDefinitionManager.loadApiDefinitions(definitions);}
}

2、Controller 添加方法

@GetMapping("/api1/demo1")
public String demo1(){return "demo";
}@GetMapping("/api1/demo2")
public String demo2(){return "demo";
}@GetMapping("/api2/demo1")
public String demo3(){return "demo";
}@GetMapping("/api2/demo2")
public String demo4(){return "demo";
}

也可以基于 Nacos 服务发现组件进行限流

server:port: 8010
spring:application:name: gatewaycloud:gateway:discovery:locator:enabled: true

API 分组代码修改，改为 discovery 中的服务名。

ApiDefinition api2 = new ApiDefinition("provider_api2").setPredicateItems(new HashSet<ApiPredicateItem>(){{add(new ApiPathPredicateItem().setPattern("/p1/api2/demo1"));}});

分布式事务

模拟分布式事务异常

1、创建两个工程 order、pay，pom.xml

<dependency><groupId>org.springframework.bootgroupId><artifactId>spring-boot-starter-jdbcartifactId>
dependency>
<dependency><groupId>org.springframework.bootgroupId><artifactId>spring-boot-starter-webartifactId>
dependency><dependency><groupId>mysqlgroupId><artifactId>mysql-connector-javaartifactId><scope>runtimescope>
dependency>
<dependency><groupId>org.projectlombokgroupId><artifactId>lombokartifactId><optional>trueoptional>
dependency>

2、建两个数据库 order、pay，两个微服务分别访问。

3、分别写两个服务的 application.yml

server:port: 8010
spring:application:name: orderdatasource:driver-class-name: com.mysql.cj.jdbc.Driverusername: rootpassword: 123456url: jdbc:mysql://localhost:3306/order

server:port: 8020
spring:application:name: paydatasource:driver-class-name: com.mysql.cj.jdbc.Driverusername: rootpassword: 123456url: jdbc:mysql://localhost:3306/pay

4、分别写两个 Service

package com.southwind.service;import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.stereotype.Service;@Service
public class OrderService {@Autowiredprivate JdbcTemplate jdbcTemplate;public void save(){this.jdbcTemplate.update("insert into orders(username) values ('张三')");}
}

package com.southwind.service;import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.stereotype.Service;@Service
public class PayService {@Autowiredprivate JdbcTemplate jdbcTemplate;public void save(){this.jdbcTemplate.update("insert into pay(username) values ('张三')");}
}

5、控制器 Order 通过 RestTemplate 调用 Pay 的服务

package com.southwind.controller;import com.southwind.service.OrderService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.client.RestTemplate;@RestController
public class OrderController {@Autowiredprivate OrderService orderService;@Autowiredprivate RestTemplate restTemplate;@GetMapping("/save")public String save(){//订单this.orderService.save();int i = 10/0;//支付this.restTemplate.getForObject("http://localhost:8020/save",String.class);return "success";}
}

package com.southwind.controller;import com.southwind.service.PayService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;@RestController
public class PayController {@Autowiredprivate PayService payService;@GetMapping("/save")public String save(){this.payService.save();return "success";}
}

6、启动类

package com.southwind;import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.Bean;
import org.springframework.web.client.RestTemplate;@SpringBootApplication
public class OrderApplication {public static void main(String[] args) {SpringApplication.run(OrderApplication.class, args);}@Beanpublic RestTemplate restTemplate(){return new RestTemplate();}
}

package com.southwind;import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;@SpringBootApplication
public class PayApplication {public static void main(String[] args) {SpringApplication.run(PayApplication.class, args);}}

分布式异常模拟结束，Order 存储完成之后，出现异常，会导致 Pay 无法存储，但是 Order 数据库不会进行回滚。

Seata 解决（事务回滚）

1、下载

2、解压，修改两个文件

regisry.conf

registry {type = "nacos"nacos {serverAddr = "localhost"namespace = "public"cluster = "default"}
}config {type = "nacos"nacos {serverAddr = "localhost"namespace = "public"cluster = "default"}
}

nacos-config.txt

3、启动 Nacos，运行 nacos-config.sh 将 Seata 配置导入 Nacos

进入 conf，右键 Git Bash Here

cd conf
sh nacos-config.sh 127.0.0.1

执行成功，刷新 Nacos，配置加入（如下图）

nacos-config.txt 配置已生效

4、启动 Seata Server， JDK 8 以上环境无法启动

cd bin
seata-server.bat -p 8090 -m file

启动成功，Nacos 注册成功。

Seata 服务环境搭建完毕，接下来去应用中添加。

1、初始化数据库，在两个数据库中添加事务日志记录表，SQL Seata 已经提供。

2、直接在两个数据库运行脚本。

CREATE TABLE `undo_log` (`id` bigint(20) NOT NULL AUTO_INCREMENT,`branch_id` bigint(20) NOT NULL,`xid` varchar(100) NOT NULL,`context` varchar(128) NOT NULL,`rollback_info` longblob NOT NULL,`log_status` int(11) NOT NULL,`log_created` datetime NOT NULL,`log_modified` datetime NOT NULL,`ext` varchar(100) DEFAULT NULL,PRIMARY KEY (`id`),UNIQUE KEY `ux_undo_log` (`xid`,`branch_id`)
) ENGINE=InnoDB AUTO_INCREMENT=1 DEFAULT CHARSET=utf8;

3、两个工程的 pom.xml 添加 Seata 组件和 Nacos Config 组件。

<dependency><groupId>com.alibaba.cloudgroupId><artifactId>spring-cloud-starter-alibaba-seataartifactId><version>2.1.1.RELEASEversion>
dependency><dependency><groupId>com.alibaba.cloudgroupId><artifactId>spring-cloud-starter-alibaba-nacos-configartifactId>
dependency>

4、给 JDBCTemplate 添加代理数据源

package com.southwind;import io.seata.rm.datasource.DataSourceProxy;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.Bean;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.web.client.RestTemplate;import javax.sql.DataSource;@SpringBootApplication
public class OrderApplication {public static void main(String[] args) {SpringApplication.run(OrderApplication.class, args);}@Beanpublic RestTemplate restTemplate(){return new RestTemplate();}@Beanpublic JdbcTemplate jdbcTemplate(DataSource dataSource){return new JdbcTemplate(new DataSourceProxy(dataSource));}
}

package com.southwind;import io.seata.rm.datasource.DataSourceProxy;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.Bean;
import org.springframework.jdbc.core.JdbcTemplate;import javax.sql.DataSource;@SpringBootApplication
public class PayApplication {public static void main(String[] args) {SpringApplication.run(PayApplication.class, args);}@Beanpublic JdbcTemplate jdbcTemplate(DataSource dataSource){return new JdbcTemplate(new DataSourceProxy(dataSource));}}

5、将 registry.conf 复制到两个工程的 resources 下。

6、给两个工程添加 bootstrap.yml 读取 Nacos 配置。

spring:application:name: ordercloud:nacos:config:server-addr: localhost:8848namespace: publicgroup: SEATA_GROUPalibaba:seata:tx-service-group: ${spring.application.name}

spring:application:name: paycloud:nacos:config:server-addr: localhost:8848namespace: publicgroup: SEATA_GROUPalibaba:seata:tx-service-group: ${spring.application.name}

tx-service-group 需要和 Nacos 配置中的名称一致。

7、在 Order 调用 Pay 处添加注解 @GlobalTransactional

package com.southwind.controller;import com.southwind.service.OrderService;
import io.seata.spring.annotation.GlobalTransactional;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.client.RestTemplate;@RestController
public class OrderController {@Autowiredprivate OrderService orderService;@Autowiredprivate RestTemplate restTemplate;@GetMapping("/save")@GlobalTransactionalpublic String save(){//订单this.orderService.save();int i = 10/0;//支付this.restTemplate.getForObject("http://localhost:8020/save",String.class);return "success";}
}

【视频参考】https://www.bilibili.com/video/BV1Mt4y1i7JW
【源码参考】https://github.com/monkeyhlj/spring-study

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