springcloudalibaba项目的搭建

第一步：搭建父项目，创建一个Maven项目，父项目不写代码，直接删除src

第二步：父项目需要的包

// 打包方式
<packaging>pom</packaging>

<!--SpringBoot，帮子项目管理依赖的版本号-->
<parent><groupId> org.springframework.boot</groupId><artifactId>spring-boot-starter-parent</artifactId><version>2.2.5.RELEASE</version>
</parent>

<!--SpringCloudalibaba需要的依赖-->
<dependencyManagement><dependencies><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><dependency><groupId>org.springframework.cloud</groupId><artifactId>spring-cloud-dependencies</artifactId><version>Hoxton.SR3</version><type>pom</type><scope>import</scope></dependency></dependencies>
</dependencyManagement>

<!--一些公共的依赖-->
<dependencies><dependency><groupId>junit</groupId><artifactId>junit</artifactId><version>4.12</version></dependency><dependency><groupId>org.projectlombok</groupId><artifactId>lombok</artifactId></dependency><dependency><groupId>com.alibaba</groupId><artifactId>fastjson</artifactId><version>1.2.58</version></dependency>
</dependencies>

第三步：创建子项目springcloudalibaba-user-server

user项目功能1.项目启动时要注册到nacos，启动nacos的方式，到下载的bin目录下，输入命令：startup.cmd -m standalone启动，功能2：限流，熔断，功能4：限流持久化。功能5：nacos的远程配置中心，功能6：三层架构

1.user模块需要导包

<dependencies><dependency><groupId>com.alibaba.cloud </groupId><artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-web</artifactId></dependency><!--        配置中心客户端--><dependency><groupId>com.alibaba.cloud</groupId><artifactId>spring-cloud-starter-alibaba-nacos-config</artifactId></dependency><!--sentinel的包--><dependency><groupId>com.alibaba.cloud</groupId><artifactId>spring-cloud-starter-alibaba-sentinel</artifactId></dependency><!--Sentinel和Nacos做持久的--><dependency><groupId>com.alibaba.csp</groupId><artifactId>sentinel-datasource-nacos</artifactId><version>1.5.2</version></dependency>
<!-- 数据库的jar包 -->
<dependency><groupId>mysql</groupId><artifactId>mysql-connector-java</artifactId><version>5.1.26</version>
</dependency>
<!--mybaties,和spring的集合包-->
<dependency><groupId>org.mybatis.spring.boot</groupId><artifactId>mybatis-spring-boot-starter</artifactId><version>1.1.1</version>
</dependency>
</dependencies>

2.yaml配置

2.1 bootstrap.yml

server:port: 1010
spring:application:name: user-servercloud:sentinel:transport:dashboard: localhost:1111 #senticel服务控制台地址nacos:discovery:server-addr: 127.0.0.1:8848    #注册中心地址config:server-addr: localhost:8848 #配置中心file-extension: yaml #配置文件格式prefix: application-user #配置前缀 ，默认使用sring.application.namegroup: DEFAULT_GROUP #默认分组namespace: 1415d50f-943a-469c-af50-10ca5f8dc91b #命名空间的idprofiles:active: dev

2.2 application.yaml

spring:cloud:sentinel:transport:dashboard: localhost:1111 #senticel服务控制台地址datasource:flow:nacos: #限流持久配置server-addr: localhost:8848    #使用nacos的持久dataId: application-user-dev   #获取限流的数据源的dataIdgroupId: DEFAULT_GROUPrule-type: flow #类型：限流namespace: 1415d50f-943a-469c-af50-10ca5f8dc91b # 因为我们在test里放的这个，持久化限流机制

连接数据库的配置
spring:datasource:password: 364911driver-class-name: com.mysql.jdbc.Driverurl: jdbc:mysql:///movie?useUnicode=true&characterEncoding=utf-8username: root
mybatis:type-aliases-package: cn.zwj.domain

2.启动类

@SpringBootApplication
public class UserStart {public static void main(String[] args) {SpringApplication.run(UserStart.class,args);}
}

3.controller层代码

@RefreshScope  //刷新配置
@RestController
public class UserController {@Value("${testTement}")private String testTement;@GetMapping("/user/{id}") // blockHandler里有许多规则，包括限流等@SentinelResource(value = "这就是取一个名字", blockHandler = "getBlockHandlerUserById", fallback = "getfallback")public User getUserById(@PathVariable Long id) {int i = 1/0; // 设置一个异常return User.builder().name("陈涛").intro("又在打来福了" + testTement).build();}// 限流与阻塞处理 : 参数要和 被降级的方法参数一样 ，注意限流的优先级比熔断要高，比如，同时有限流和熔断，一定会执行限流public User getBlockHandlerUserById(@PathVariable Long id, BlockException ex) {// 来判断究竟是哪个异常if (ex instanceof FlowException) {return User.builder().name("流控异常").build();} else if (ex instanceof DegradeException) {return User.builder().name("熔断异常").build();} else if (ex instanceof ParamFlowException) {return User.builder().name("热点异常").build();} else if (ex instanceof SystemBlockException) {return User.builder().name("系统异常").build();} else if (ex instanceof AuthorityException) {return User.builder().name("授权异常").build();}return User.builder().name("陈涛").intro("把来福咬了,我要限流" + testTement).id(id).build();}public User getfallback(@PathVariable Long id, Throwable ex) {ex.printStackTrace();return User.builder().name("这里是熔断处理").build();}
}

具体步骤：user模块的远程配置中心和持久化限流如何配置

1.要配置远程中心：第一步点击+，如果需要配置命名空间，可以先创建一个命名空间，命名空间id可以不写，可以使用默认的，然后再在这个命名空间添加配置文件如application-user-dev.yaml

2.配置限流持久化

2.1 到安装目录下输入 java -jar -Dserver.port=1111 sentinel-dashboard-1.6.0.jar

2.2 第一步：在配置列表增加配置如下：就点击+号

[

{

"resource": "这就是取一个名字",

"limitApp": "default",

"grade": 1,

"count": 1,

"strategy": 0,

"controlBehavior": 0,

"clusterMode": false

}

]

其中resouce就是要找对那个资源进行限流，

就是@SentinelResource这个注解的value值

第四步：springcloudalibaba-order-server模块

模块功能：1.需要配置远程配置 2.要通过openfeign掉user时做负载均衡和熔断处理

1.导包

<dependencies><dependency><groupId>com.alibaba.cloud </groupId><artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-web</artifactId></dependency><!--        配置中心客户端--><dependency><groupId>com.alibaba.cloud</groupId><artifactId>spring-cloud-starter-alibaba-nacos-config</artifactId></dependency><dependency><groupId>cn.zwj</groupId><artifactId>springcloudalibaba-user-common</artifactId><version>1.0-SNAPSHOT</version></dependency><dependency><groupId>org.springframework.cloud</groupId><artifactId>spring-cloud-starter-openfeign</artifactId></dependency><!--sentinel的包--><dependency><groupId>com.alibaba.cloud</groupId><artifactId>spring-cloud-starter-alibaba-sentinel</artifactId></dependency>
</dependencies>

2.启动类

@SpringBootApplication
@EnableFeignClients
public class OrderStart {public static void main(String[] args) {SpringApplication.run(OrderStart.class,args);}
}

3.controller层

@RestController
@RefreshScope
public class OrderController {@Autowiredprivate UserFeign userFeign;@GetMapping("/order/{id}")public User getUserById(@PathVariable Long id) {return userFeign.getUserById(id);}
}

为了通过openfeign用负载均衡的方式，给user发请求。所有我们要创建一个接口如userfeign

打上@feignclient注解

@FeignClient(value = "user-server", fallbackFactory = FallbackFactoryOrder.class)
public interface UserFeign {@GetMapping("/user/{id}")User getUserById(@PathVariable Long id);
}

value为我们要发请求服务名，GetMapping为对方user要接收的参数@PathVariable Long id，形参也是，我们在conreoller层发请求时，先把这个接收注入，再给他传值。

要实现熔断fallbackFactory，写一个类去继承

FallbackFactory<UserFeign>的泛型，泛型就是你发请求的接口

@Component
public class FallbackFactoryOrder implements FallbackFactory<UserFeign> {@Overridepublic UserFeign create(Throwable throwable) {return new UserFeign() {@Overridepublic User getUserById(Long id) {return User.builder().name("返回兜底数据").build();}};}
}

必须要加@Component注解，这样才能给spring管理