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SpringCloud学习笔记（1）- Spring Cloud Alibaba
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SpringCloud学习笔记（1）- Spring Cloud Alibaba
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文章目錄
- SpringCloud學習筆記（1）- Spring Cloud Alibaba
- 服務治理
- Nacos 服務注冊
- Nacos 服務發現與調用
- Ribbon 負載均衡
- Sentinel 服務限流降級
- 流控規則
- 流控效果
- 降級規則
- 熱點規則
- 授權規則
- 自定義規則異常返回
- 整合 RocketMQ
- 安裝 RocketMQ
- 安裝 RocketMQ 控制臺
- Java 實現消息發送
- Java 實現消息消費
- Spring Boot 整合 RocketMQ
- 服務網關
- Gateway 限流
- 分布式事務
- 模擬分布式事務異常
- Seata 解決（事務回滾）
SpringCloud學習筆記（1）- Spring Cloud Alibaba
創建父工程
Spring Cloud Alibaba 的環境在父工程中創建，微服務的各個組件作為子工程，繼承父工程的環境。
Spring Boot —》Spring Cloud —》Spring Cloud Alibaba
pom.xml 中添加。
<dependencyManagement><dependencies><!-- Spring Cloud Hoxton --><dependency><groupId>org.springframework.cloud</groupId><artifactId>spring-cloud-dependencies</artifactId><version>Hoxton.SR3</version><type>pom</type><scope>import</scope></dependency><!-- Spring Cloud Alibaba --><dependency><groupId>com.alibaba.cloud</groupId><artifactId>spring-cloud-alibaba-dependencies</artifactId><version>2.2.1.RELEASE</version><type>pom</type><scope>import</scope></dependency></dependencies> </dependencyManagement>服務治理
服務注冊 + 服務發現
Nacos 服務注冊
解壓，啟動服務。
Nacos 搭建成功，接下來注冊服務。
在父工程路徑下創建子工程，讓子工程繼承父工程的環境依賴，pom.xml 中添加 nacos 發現組件。
<dependency><groupId>com.alibaba.cloud</groupId><artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId> </dependency>application.yml 中配置
spring:cloud:nacos:discovery:# 指定nacos server地址server-addr: localhost:8848application:name: my-nacosNacos 服務發現與調用
pom.xml 添加 discovery，完成服務發現。
<dependency><groupId>com.alibaba.cloud</groupId><artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId> </dependency>通過 discoveryClient 發現注冊到 nacos 中的 provider 服務。
@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隨機遠程調用provier："+this.restTemplate.getForObject(url, String.class);}}Ribbon 負載均衡
@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遠程調用provier："+this.restTemplate.getForObject("http://provider/index", String.class);}}隨機 （隨機的算法）
server:port: 8180 provider:ribbon:NFLoadBalancerRuleClassName: com.netflix.loadbalancer.RandomRuleNacos 權重 （基于權重的算法）
@Slf4j public class NacosWeightedRule extends AbstractLoadBalancerRule {@Autowiredprivate NacosDiscoveryProperties nacosDiscoveryProperties;@Overridepublic void initWithNiwsConfig(IClientConfig iClientConfig) {//讀取配置文件}@Overridepublic Server choose(Object o) {ILoadBalancer loadBalancer = this.getLoadBalancer();BaseLoadBalancer baseLoadBalancer = (BaseLoadBalancer) loadBalancer;//獲取要請求的微服務名稱String name = baseLoadBalancer.getName();//獲取服務發現的相關APINamingService namingService = nacosDiscoveryProperties.namingServiceInstance();try {Instance instance = namingService.selectOneHealthyInstance(name);log.info("選擇的實例是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.NacosWeightedRuleSentinel 服務限流降級
雪崩效應
解決方案
1、設置線程超時
2、設置限流
3、熔斷器 Sentinel、Hystrix （類比保險絲）
- 降級
- 限流
- 熔斷
1、provider模塊pom.xml 引入依賴
2、application 配置
management:endpoints:web:exposure:include: '*' spring:cloud:sentinel:transport:dashboard: localhost:80803、下載 Sentinel 控制臺，解壓，啟動。
流控規則
直接限流
關聯限流
鏈路限流
1、pom.xml 添加依賴
<dependency><groupId>com.alibaba.csp</groupId><artifactId>sentinel-core</artifactId><version>1.7.1</version> </dependency><dependency><groupId>com.alibaba.csp</groupId><artifactId>sentinel-web-servlet</artifactId><version>1.7.1</version> </dependency>2、application.yml
spring:cloud:sentinel:filter:enabled: false3、寫配置類（讓能關聯到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"); //讓所有鏈路開放出來才能限制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
快速失敗
直接拋出異常
Warm UP
給系統一個預熱的時間，預熱時間段內單機閾值較低，預熱時間過后單機閾值增加，預熱時間內當前的單機閾值是設置的閾值的三分之一，預熱時間過后單機閾值恢復設置的值。
排隊等待
當請求調用失敗之后，不會立即拋出異常，等待下一次調用，時間范圍是超時時間，在時間范圍內如果能請求成功則不拋出異常，如果請求則拋出異常。
降級規則
RT
單個請求的響應時間超過閾值，則進入準降級狀態，接下來 1 S 內連續 5 個請求響應時間均超過閾值，就進行降級，持續時間為時間窗口的值。
異常比例
每秒異常數量占通過量的比例大于閾值，就進行降級處理，持續時間為時間窗口的值。
異常數
1 分鐘內的異常數超過閾值就進行降級處理，時間窗口的值要大于 60S，否則剛結束熔斷又進入下一次熔斷了。
熱點規則
熱點規則是流控規則的更細粒度操作，可以具體到對某個熱點參數的限流，設置限流之后，如果帶著限流參數的請求量超過閾值，則進行限流，時間為統計窗口時長。
必須要添加 @SentinelResource，即對資源進行流控。
@GetMapping("/hot") @SentinelResource("hot") public String hot(@RequestParam(value = "num1",required = false) Integer num1,@RequestParam(value = "num2",required = false) Integer num2){return num1+"-"+num2; }授權規則
給指定的資源設置流控應用（追加參數），可以對流控應用進行訪問權限的設置，具體就是添加白名單和黑名單。
如何給請求指定流控應用，通過實現 RequestOriginParser 接口來完成，代碼如下所示。
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;} }要讓 RequestOriginParserDefinition 生效，需要在配置類中進行配置。
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());} }自定義規則異常返回
創建異常處理類
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 = "降級";}httpServletResponse.getWriter().write(msg);} }進行配置。
@Configuration public class SentinelConfiguration {@PostConstructpublic void init(){WebCallbackManager.setUrlBlockHandler(new ExceptionHandler());} }整合 RocketMQ
安裝 RocketMQ
1、傳入 Linux 服務器
2、解壓縮
unzip rocketmq-all-4.7.1-bin-release.zip3、啟動 NameServer
nohup ./bin/mqnamesrv &4、檢查是否啟動成功
netstat -an | grep 9876
5、啟動 Broker
啟動之前需要編輯配置文件，修改 JVM 內存設置，默認給的內存 4 GB，超過我們的 JVM 了。
cd bin vim runserver.sh vim runbroker.sh
啟動 Broker
可以查看日志
tail -f ~/logs/rocketmqlogs/broker.log
啟動成功
6、測試 RocketMQ
消息發送
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.Consumer7、關閉 RocketMQ
cd bin ./mqshutdown broker ./mqshutdown namesrv安裝 RocketMQ 控制臺
1、解壓縮，修改配置，打包
mvn clean package -Dmaven.test.skip=true
2、進入 target 啟動 jar
打開瀏覽器訪問 localhost:9877，如果報錯如下：
這是因為我們的 RocketMQ 安裝在 Linux 中，控制臺在 windows，Linux 需要開放端口才能訪問，開放 10909 和 9876 端口
重新啟動控制臺項目
Java 實現消息發送
1、pom.xml 中引入依賴
<dependency><groupId>org.apache.rocketmq</groupId><artifactId>rocketmq-spring-boot-starter</artifactId><version>2.1.0</version> </dependency>2、生產消息
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 {//創建消息生產者DefaultMQProducer producer = new DefaultMQProducer("myproducer-group");//設置NameServerproducer.setNamesrvAddr("192.168.248.129:9876");//啟動生產者producer.start();//構建消息對象Message message = new Message("myTopic","myTag",("Test MQ").getBytes());//發送消息SendResult result = producer.send(message, 1000);System.out.println(result);//關閉生產者producer.shutdown();} }3、直接運行，如果報錯 sendDefaultImpl call timeout，可以開放 10911 端口
firewall-cmd --zone=public --add-port=10911/tcp --permanent systemctl restart firewalld.service firewall-cmd --reload打開 RocketMQ 控制臺，可查看消息。
Java 實現消息消費
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 {//創建消息消費者DefaultMQPushConsumer consumer = new DefaultMQPushConsumer("myconsumer-group");//設置NameServerconsumer.setNamesrvAddr("192.168.248.129:9876");//指定訂閱的主題和標簽consumer.subscribe("myTopic","*");//回調函數consumer.registerMessageListener(new MessageListenerConcurrently() {@Overridepublic ConsumeConcurrentlyStatus consumeMessage(List<MessageExt> list, ConsumeConcurrentlyContext consumeConcurrentlyContext) {log.info("Message=>{}",list);return ConsumeConcurrentlyStatus.CONSUME_SUCCESS;}});//啟動消費者consumer.start();} }Spring Boot 整合 RocketMQ
provider
1、pom.xml
<dependency><groupId>org.apache.rocketmq</groupId><artifactId>rocketmq-spring-boot-starter</artifactId><version>2.1.0</version> </dependency> <dependency><groupId>org.apache.rocketmq</groupId><artifactId>rocketmq-client</artifactId><version>4.7.0</version> </dependency>2、application.yml
rocketmq:name-server: 192.168.248.129:9876producer:group: myprovider3、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,"張三","123123","軟件園",new Date());this.rocketMQTemplate.convertAndSend("myTopic",order);return order; }consumer
1、pom.xml
<dependency><groupId>org.apache.rocketmq</groupId><artifactId>rocketmq-spring-boot-starter</artifactId><version>2.1.0</version> </dependency> <dependency><groupId>org.apache.rocketmq</groupId><artifactId>rocketmq-client</artifactId><version>4.7.0</version> </dependency>2、application.yml
rocketmq:name-server: 192.168.248.129:98763、Service
@Slf4j @Service @RocketMQMessageListener(consumerGroup = "myConsumer",topic = "myTopic") public class SmsService implements RocketMQListener<Order> {@Overridepublic void onMessage(Order order) {log.info("新訂單{},發短信",order);} }服務網關
Spring Cloud Gateway 是基于 Netty，跟 Servlet 不兼容，所以你的工程中不能出現 Servlet 的組件 。
1、pom.xml
注意，一定不能出現 spring web 的依賴，因為 Gateway 與 Servlet 不兼容。
<dependency><groupId>org.springframework.cloud</groupId><artifactId>spring-cloud-starter-gateway</artifactId> </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上面這種做法其實沒有用到 nacos ，現在我們讓 gateway 直接去 nacos 中發現服務，配置更加簡單了。
1、pom.xml 引入 nacos
<dependency><groupId>org.springframework.cloud</groupId><artifactId>spring-cloud-starter-gateway</artifactId> </dependency><dependency><groupId>com.alibaba.cloud</groupId><artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId> </dependency>2、application.yml
server:port: 8010 spring:application:name: gatewaycloud:gateway:discovery:locator:enabled: trueGateway 限流
基于路由限流
1、pom.xml
<dependency><groupId>org.springframework.cloud</groupId><artifactId>spring-cloud-starter-gateway</artifactId> </dependency><dependency><groupId>com.alibaba.csp</groupId><artifactId>sentinel-spring-cloud-gateway-adapter</artifactId> </dependency>2、配置類
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;}//配置限流的異常處理@Bean@Order(Ordered.HIGHEST_PRECEDENCE)public SentinelGatewayBlockExceptionHandler sentinelGatewayBlockExceptionHandler() {return new SentinelGatewayBlockExceptionHandler(viewResolvers, serverCodecConfigurer);}//配置初始化的限流參數@PostConstructpublic void initGatewayRules(){Set<GatewayFlowRule> rules = new HashSet<>();rules.add(new GatewayFlowRule("provider_route").setCount(1).setIntervalSec(1));GatewayRuleManager.loadRules(rules);}//初始化限流過濾器@Bean@Order(Ordered.HIGHEST_PRECEDENCE)public GlobalFilter sentinelGatewayFilter() {return new SentinelGatewayFilter();}//自定義限流異常頁面@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 分組限流
1、修改配置類，添加基于 API 分組限流的方法，修改初始化的限流參數
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;}//配置限流的異常處理@Bean@Order(Ordered.HIGHEST_PRECEDENCE)public SentinelGatewayBlockExceptionHandler sentinelGatewayBlockExceptionHandler() {return new SentinelGatewayBlockExceptionHandler(viewResolvers, serverCodecConfigurer);}//配置初始化的限流參數@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);}//初始化限流過濾器@Bean@Order(Ordered.HIGHEST_PRECEDENCE)public GlobalFilter sentinelGatewayFilter() {return new SentinelGatewayFilter();}//自定義限流異常頁面@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);}//自定義API分組@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 服務發現組件進行限流
server:port: 8010 spring:application:name: gatewaycloud:gateway:discovery:locator:enabled: trueAPI 分組代碼修改，改為 discovery 中的服務名。
ApiDefinition api2 = new ApiDefinition("provider_api2").setPredicateItems(new HashSet<ApiPredicateItem>(){{add(new ApiPathPredicateItem().setPattern("/p1/api2/demo1"));}});分布式事務
模擬分布式事務異常
1、創建兩個工程 order、pay，pom.xml
<dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-jdbc</artifactId> </dependency> <dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-web</artifactId> </dependency><dependency><groupId>mysql</groupId><artifactId>mysql-connector-java</artifactId><scope>runtime</scope> </dependency> <dependency><groupId>org.projectlombok</groupId><artifactId>lombok</artifactId><optional>true</optional> </dependency>2、建兩個數據庫 order、pay，兩個微服務分別訪問。
3、分別寫兩個服務的 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/pay4、分別寫兩個 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 ('張三')");} } 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 ('張三')");} }5、控制器 Order 通過 RestTemplate 調用 Pay 的服務
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(){//訂單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、啟動類
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);}}分布式異常模擬結束，Order 存儲完成之后，出現異常，會導致 Pay 無法存儲，但是 Order 數據庫不會進行回滾。
Seata 解決（事務回滾）
1、下載
2、解壓，修改兩個文件
regisry.conf
nacos-config.txt
3、啟動 Nacos，運行 nacos-config.sh 將 Seata 配置導入 Nacos
進入 conf，右鍵 Git Bash Here
cd conf sh nacos-config.sh 127.0.0.1執行成功，刷新 Nacos，配置加入（如下圖）
nacos-config.txt 配置已生效
4、啟動 Seata Server， JDK 8 以上環境無法啟動
啟動成功，Nacos 注冊成功。
Seata 服務環境搭建完畢，接下來去應用中添加。
1、初始化數據庫，在兩個數據庫中添加事務日志記錄表，SQL Seata 已經提供。
2、直接在兩個數據庫運行腳本。
3、兩個工程的 pom.xml 添加 Seata 組件和 Nacos Config 組件。
<dependency><groupId>com.alibaba.cloud</groupId><artifactId>spring-cloud-starter-alibaba-seata</artifactId><version>2.1.1.RELEASE</version> </dependency><dependency><groupId>com.alibaba.cloud</groupId><artifactId>spring-cloud-starter-alibaba-nacos-config</artifactId> </dependency>4、給 JDBCTemplate 添加代理數據源
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、將 registry.conf 復制到兩個工程的 resources 下。
6、給兩個工程添加 bootstrap.yml 讀取 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 配置中的名稱一致。
7、在 Order 調用 Pay 處添加注解 @GlobalTransactional
【視頻參考】https://www.bilibili.com/video/BV1Mt4y1i7JW
【源碼參考】https://github.com/monkeyhlj/spring-study
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