Spring cloud 实现房源查询功能的实例代码
作者:天海奈奈
前言
这个项目的功能很简单只涉及了查询功能,这个项目的的目的是熟悉SpringCloud框架,明白服务与服务之间的调用是通过http请求完成的使用微服务的架构而Feign可以使其像调用本地方法一样,学会在其他模块调用另一模块的服务和内容,完成负载均衡,学会将不同端口注册到eureka ,了解网关并会配置网关和使用断路器。
核心组件
服务注册中心
Spring Cloud Netflix Eureka
服务调用方式
REST API、Feign、 Ribbon
服务网关
Spring Cloud Netflix Zuul
断路器
Spring Cloud Netflix Hystrix
数据库设计
由于本项目只是为了完整的实现SpringCloud项目并明白框架功能故只设计查询功能,所以只设计两张表
表1 house
表2
1 项目搭建
本项目是一个多模块项目,创建一个 Spring Initializr 项目 不自动添加依赖项,完成创建后删除自带的src目录,并在根目录下创建新的maven模块。
1.1添加依赖
<?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> <packaging>pom</packaging> <modules> <module>house-server</module> <module>eureak-server</module> <module>house-zuul</module> </modules> <parent> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-parent</artifactId> <version>2.1.12.RELEASE</version> <relativePath/> <!-- lookup parent from repository --> </parent> <groupId>com.xatu</groupId> <artifactId>spring-cloud-house-test1</artifactId> <version>0.0.1-SNAPSHOT</version> <name>spring-cloud-house-test1</name> <description>spring-cloud-house-test1</description> <properties> <java.version>1.8</java.version> </properties> <dependencies> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter</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>Greenwich.SR5</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> </project>
2 开发房源查询模块:
2.1 house-list 模块
2.1.1模块总览:
端口号 8081 url接口 /house
参数名称 :null
参数类型 : null
说明 : 找到上线房源 打印list
2 .1.2写配置文件
创建application.properties
server.port=8081 spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver spring.datasource.url=jdbc:mysql://localhost:3306/house_test?serverTimezone=UTC&useUnicode=true&characterEncoding=utf-8&useSSL=true spring.datasource.username=root spring.datasource.password=123456 logging.pattern.console=%clr(%d{${LOG_DATEFORMAT_PATTERN:HH:mm:ss.SSS}}){faint} %clr(${LOG_LEVEL_PATTERN:-%5p}) %clr(${PID:- }){magenta} %clr(---){faint} %clr([%15.15t]){faint} %clr(%-40.40logger{39}){cyan} %clr(:){faint} %m%n${LOG_EXCEPTION_CONVERSION_WORD:%wEx} mybatis.configuration.map-underscore-to-camel-case=true spring.application.name=house-list eureka.client.service-url.defaultZone=http://localhost:8000/eureka/
2.1.3 依赖项配置
<?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 http://maven.apache.org/xsd/maven-4.0.0.xsd"> <parent> <artifactId>house-server</artifactId> <groupId>com.xatu</groupId> <version>0.0.1-SNAPSHOT</version> </parent> <modelVersion>4.0.0</modelVersion> <artifactId>houser-list</artifactId> <properties> <maven.compiler.source>8</maven.compiler.source> <maven.compiler.target>8</maven.compiler.target> </properties> <dependencies> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> </dependency> <dependency> <groupId>org.mybatis.spring.boot</groupId> <artifactId>mybatis-spring-boot-starter</artifactId> <version>2.1.1</version> </dependency> <!-- eureka-client--> <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId> </dependency> </dependencies> <build> <plugins> <plugin> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-maven-plugin</artifactId> </plugin> </plugins> </build> </project>
2.1.3 启动类
/** * 描述: 项目启动类 */ @SpringBootApplication @EnableEurekaClient public class HouseListApplication { public static void main(String[] args) { SpringApplication.run(HouseListApplication.class, args); }
2.1.4 controller
/** * 描述: CourseListController课程列表Controller */ @RestController//将返结果是json对象 public class HouseListController { @Autowired HouseListService houseListService; @GetMapping("/house") public List<House> houseList() { return houseListService.getCourseList(); } }
2.1.5 创建entity实体类,实现set /get 方法并用自动生成重写toString方法。
/** * 描述: House实体类 */ public class House implements Serializable { Integer id; Integer houseId; String houseName; Integer valid; @Override public String toString() { return "Course{" + "id=" + id + ", courseId=" + houseId + ", courseName='" + houseName + '\'' + ", valid=" + valid + '}'; } public Integer getId() { return id; } public void setId(Integer id) { this.id = id; } public Integer getHouseId() { return houseId; } public void setHouseId(Integer houseId) { this.houseId = houseId; } public String getHouseName() { return houseName; } public void setHouseName(String houseName) { this.houseName = houseName; } public Integer getValid() { return valid; } public void setValid(Integer valid) { this.valid = valid; } }
2.1.6 service
/** * 描述: 房源列表服务 */ public interface HouseListService { List<House> getCourseList(); }
impl 实现类
@Service public class HouseListServiceImpl implements HouseListService { @Autowired HouseMapper houseMapper; @Override public List<House> getCourseList() { return houseMapper.findValidCourses(); } }
mapper
/** * 描述: 房源的Mapper类 */ @Mapper @Repository public interface HouseMapper { @Select("SELECT * FROM house WHERE valid = 1") List<House> findValidCourses(); }
这里实现的是查询已上线的房源。
2.2 房价模块
2.2.1 总览
端口号 8083
url接口 /price
参数名称 :houseId
参数类型 : int
说明 : 获取到对应房源id的价格
url接口 /HouseInPrice
参数名称 :null
参数类型 : null
说明 : 作用与/list/house类似只是为了测试引入功能
url接口 /houseAndPrice
参数名称 :null
参数类型 : null
说明 : 获取到房子id 价格 id 名字
2.2.2 配置文件与依赖
server.port=8082 spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver spring.datasource.url=jdbc:mysql://localhost:3306/house_test?serverTimezone=UTC&useUnicode=true&characterEncoding=utf-8&useSSL=true spring.datasource.username=root spring.datasource.password=123456 logging.pattern.console=%clr(%d{${LOG_DATEFORMAT_PATTERN:HH:mm:ss.SSS}}){faint} %clr(${LOG_LEVEL_PATTERN:-%5p}) %clr(${PID:- }){magenta} %clr(---){faint} %clr([%15.15t]){faint} %clr(%-40.40logger{39}){cyan} %clr(:){faint} %m%n${LOG_EXCEPTION_CONVERSION_WORD:%wEx} #tuo feng ming ming zhuan huan mybatis.configuration.map-underscore-to-camel-case=true spring.application.name=house-price eureka.client.service-url.defaultZone=http://localhost:8000/eureka/ house-list.ribbon.NFLoadBanlancerRuleClassName=com.netflix.loadbalancer.RoundRobinRule feign.hystrix.enabled=true
<?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 http://maven.apache.org/xsd/maven-4.0.0.xsd"> <parent> <artifactId>house-server</artifactId> <groupId>com.xatu</groupId> <version>0.0.1-SNAPSHOT</version> </parent> <modelVersion>4.0.0</modelVersion> <artifactId>house-price</artifactId> <properties> <maven.compiler.source>8</maven.compiler.source> <maven.compiler.target>8</maven.compiler.target> </properties> <dependencies> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> </dependency> <dependency> <groupId>org.mybatis.spring.boot</groupId> <artifactId>mybatis-spring-boot-starter</artifactId> <version>2.1.1</version> </dependency> <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId> </dependency> <!-- feign--> <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-starter-openfeign</artifactId> </dependency> <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-starter-netflix-hystrix</artifactId> </dependency> <dependency> <groupId>com.xatu</groupId> <artifactId>houser-list</artifactId> <version>0.0.1-SNAPSHOT</version> <scope>compile</scope> </dependency> </dependencies> <build> <plugins> <plugin> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-maven-plugin</artifactId> </plugin> </plugins> </build> </project>
2.2.3 启动类
/** * 描述: 项目启动类 */ @SpringBootApplication @EnableEurekaClient @EnableFeignClients @EnableCircuitBreaker public class HousePriceApplication { public static void main(String[] args) { SpringApplication.run(HousePriceApplication.class, args); } }
2.2.4 client
/** * 描述: 房源列表的Feign客户端 */ //当远端服务出现问题会进入这个类 @FeignClient(value = "house-list" ,fallback = HouseListClientHystrix.class) //有多个实例时,带有注解的人就是注入的 @Primary public interface HouseListClient { @GetMapping("/house") public List<House> houseList(); }
如果不用feign 不同服务是不能进行调用的,我们在需要使用整合服务的模块中引入依赖 ,我加了注释了,再在启动类中加入注解,并创建一个类来作为我们引入模块的feign客户端,直接从我们想要引入的服务的controller中复制即可,引入后会有提示,要引入对另一个模块的依赖,就能数显服务的整合了。
/** * 描述: 断路器实现类 */ @Component public class HouseListClientHystrix implements HouseListClient { @Override public List<House> houseList() { List<House> defaultCourses = new ArrayList<>(); House House = new House(); House.setId(1); House.setHouseId(1); House.setHouseName("默认房源"); House.setValid(1); defaultCourses.add(House); return defaultCourses; } }
发生错误时调用的类,给服务的返回是默认的返回值 @Component 注解使它成为一个组件
2.2.5 controller
/** * 描述: 房价格控制器 */ @RestController public class HousePriceController { @Autowired HousePriceService housePriceService; @Autowired HouseListClient houseListClient; @GetMapping("/price") public Integer getCoursePrice(Integer houseId) { HousePrice housePrice = housePriceService.getHousePrice(houseId); return housePrice.getPrice(); } @GetMapping("/HouseInPrice") public List<House> getHouseListInPrice(Integer houseId) { List<House> houses = houseListClient.houseList(); return houses; } @GetMapping("/houseAndPrice") public List<HouseAndPrice> getCoursesAndPrice() { List<HouseAndPrice> houseAndPrice = housePriceService.getHousesAndPrice(); return houseAndPrice; } }
2.2.6 service
/** * 描述: 房价格服务 */ public interface HousePriceService { HousePrice getHousePrice(Integer houseId); List<HouseAndPrice> getHousesAndPrice(); List<HousePrice> getHousePriceList(); }
impl
/** * 描述: 课程价格的服务实现类 */ @Service public class HousePriceServiceImpl implements HousePriceService { @Autowired HousePriceMapper housePriceMapper; @Autowired HouseListClient houseListClient; @Override public HousePrice getHousePrice(Integer houseId) { return housePriceMapper.findCoursePrice(houseId); } @Override public List<HouseAndPrice> getHousesAndPrice() { List<HouseAndPrice> houseAndPricesList = new ArrayList<>(); List<House> houses = houseListClient.houseList(); for(int i = 0;i < houses.size();i++){ House house = houses.get(i); if(house != null){ HousePrice housePrice = getHousePrice(house.getHouseId()); HouseAndPrice houseAndPrice = new HouseAndPrice(); houseAndPrice.setPrice(housePrice.getPrice()); houseAndPrice.setName(house.getHouseName()); houseAndPrice.setId(house.getId()); houseAndPrice.setHouseId(house.getHouseId()); houseAndPricesList.add(houseAndPrice); } } return houseAndPricesList; } @Override public List<HousePrice> getHousePriceList() { return housePriceMapper.getAll(); } }
第二个方法就体现除了服务的整合,我们并不用去进行多表查询,只需要调用其他服务就能快捷完成。
2.2.7 实体类
/** * 融合类 * */ public class HouseAndPrice { Integer id; Integer houseId; String name; Integer price; @Override public String toString() { return "HouseAndPrice{" + "id=" + id + ", houseId=" + houseId + ", name='" + name + '\'' + ", price=" + price + '}'; } public Integer getId() { return id; } public void setId(Integer id) { this.id = id; } public Integer getHouseId() { return houseId; } public void setHouseId(Integer houseId) { this.houseId = houseId; } public String getName() { return name; } public void setName(String name) { this.name = name; } public Integer getPrice() { return price; } public void setPrice(Integer price) { this.price = price; } }
public class HousePrice implements Serializable { Integer id; Integer houseId; Integer price; @Override public String toString() { return "HousePrice{" + "id=" + id + ", houseId=" + houseId + ", price=" + price + '}'; } public Integer getId() { return id; } public void setId(Integer id) { this.id = id; } public Integer getHouseId() { return houseId; } public void setHouseId(Integer houseId) { this.houseId = houseId; } public Integer getPrice() { return price; } public void setPrice(Integer price) { this.price = price; } }
2.2.8 mapper
/** * 描述: 房价格Mapper类 */ @Mapper @Repository public interface HousePriceMapper { @Select("SELECT * FROM house_price WHERE house_id = #{houseId}") HousePrice findCoursePrice(Integer courseId); @Select("SELECT * FROM house_price" ) List<HousePrice> getAll(); }
3 Eureka 开发
Eureka server服务注册与管理的中心 生产者,提供者
调用方:
提供者把自己的信息注册到上面,server就能掌握最新的动态,调用方去调用服务是,会先去获取最新的地址,获取地址之后再去进行实际的调用。
Eureka 开发多了获取地址这一步是对ip服务进行解耦 。
Eureka client改写
我们把强两个模块进行Eureka Client改写也很简单,只用在启动类上加注解
@EnableEurekaClient
在配置文件上进行配置
eureka.client.service-url.defaultZone=http://localhost:8000/eureka/
我们eureka端口号多少8000那项就是多少
3.1模块总览
3.2 配置文件与依赖
spring.application.name=eureka-server server.port=8000 eureka.instance.hostname=localhost #????? eureka.client.fetch-registry=false #????????? eureka.client.register-with-eureka=false eureka.client.service-url.defaultZone=http://${eureka.instance.hostname}:${server.port}/eureka/
第一个注释是获取注册表。不需要同步其他节点数据
第二个注释是是否发自己也注册上去
<?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 http://maven.apache.org/xsd/maven-4.0.0.xsd"> <parent> <artifactId>spring-cloud-house-test1</artifactId> <groupId>com.xatu</groupId> <version>0.0.1-SNAPSHOT</version> </parent> <modelVersion>4.0.0</modelVersion> <artifactId>eureak-server</artifactId> <properties> <maven.compiler.source>8</maven.compiler.source> <maven.compiler.target>8</maven.compiler.target> </properties> <name>course-eureka-server</name> <description>Spring Cloud Eureka</description> <dependencies> <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-starter-netflix-eureka-server</artifactId> </dependency> </dependencies> <build> <plugins> <plugin> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-maven-plugin</artifactId> </plugin> </plugins> </build> </project>
3.3 启动类
/** * 描述: Eureka服务端 */ //eurekaserver启动 @EnableEurekaServer @SpringBootApplication public class EurekaServerApplication { public static void main(String[] args) { SpringApplication.run(EurekaServerApplication.class, args); } }
这样就证明我们的服务已经注册上去了
4 负载均衡
4.1负载均衡策略
RandomRule表示随机策略
RoundRobinRule 表示轮询策略
Response TimeWeightedRule加权,根据每一个Server的平均响应时间动态加权
4.2 为price模块配置负载均衡
其实就是在配置文件中加一行
house-list.ribbon.NFLoadBanlancerRuleClassName=com.netflix.loadbalancer.RoundRobinRuley意思就是对house-list服务调用的时候采取的负载均衡的策略。
5 断路器
起到一个兜底的作用,有些时候一个服务出现问题,我们不希望整个系统都崩溃掉,那我们可以采取降级的手段,虽然不能返回正常的数据却可以保证系统正常运行。运用断路器我们不仅要配置配置文件,加依赖,还要书写一个短路类(参见price模块下client 下的断路器实现类)
6 网关
6.1 模块总览
6.2 配置文件与依赖
<?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 http://maven.apache.org/xsd/maven-4.0.0.xsd"> <parent> <artifactId>spring-cloud-house-test1</artifactId> <groupId>com.xatu</groupId> <version>0.0.1-SNAPSHOT</version> </parent> <modelVersion>4.0.0</modelVersion> <artifactId>house-zuul</artifactId> <properties> <maven.compiler.source>8</maven.compiler.source> <maven.compiler.target>8</maven.compiler.target> </properties> <dependencies> <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId> </dependency> <!-- 网关依赖--> <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-starter-netflix-zuul</artifactId> </dependency> </dependencies> <build> <plugins> <plugin> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-maven-plugin</artifactId> </plugin> </plugins> </build> </project>
spring.application.name=house-gateway server.port=9000 logging.pattern.console=%clr(%d{${LOG_DATEFORMAT_PATTERN:HH:mm:ss.SSS}}){faint} %clr(${LOG_LEVEL_PATTERN:-%5p}) %clr(${PID:- }){magenta} %clr(---){faint} %clr([%15.15t]){faint} %clr(%-40.40logger{39}){cyan} %clr(:){faint} %m%n${LOG_EXCEPTION_CONVERSION_WORD:%wEx} mybatis.configuration.map-underscore-to-camel-case=true eureka.client.service-url.defaultZone=http://localhost:8000/eureka/ #??????? zuul.prefix=/xatu zuul.routes.house-list.path=/list/** zuul.routes.house-list.service-id=house-list zuul.routes.house-price.path=/price/** zuul.routes.house-price.service-id=house-price
6.3 启动类
/** * 描述: 网关启动类 */ //网关注解 @EnableZuulProxy @SpringCloudApplication public class ZuulGatewayApplication { public static void main(String[] args) { SpringApplication.run(ZuulGatewayApplication.class, args); } }
6.4 过滤器
pre 过滤器在路由请求之前运行
route 过滤器可以处理请求的实际路由
post 路由请求后运行过滤器
error如果在处理请求的过程中发生错误,则过滤器将运行
这里写一个前置一个后置
/** * 描述: 前置过滤器 */ @Component public class PreRequestFilter extends ZuulFilter { //指定过滤器类别 @Override public String filterType() { return FilterConstants.PRE_TYPE; } //顺序 @Override public int filterOrder() { return 5; } //是不是走过滤器可以添加判断 @Override public boolean shouldFilter() { return true; } //通过过滤器将要实现的逻辑----打印出请求url @Override public Object run() throws ZuulException { RequestContext currentContext = RequestContext.getCurrentContext(); //获取当前请求uri System.out.println("URI:" + currentContext.getRequest().getRequestURI()); return null; } }
/** * 描述: 后置过滤器 */ @Component public class PostRequestFilter extends ZuulFilter { @Override public String filterType() { return FilterConstants.POST_TYPE; } @Override public int filterOrder() { return FilterConstants.SEND_RESPONSE_FILTER_ORDER - 1; } @Override public boolean shouldFilter() { return true; } //打印返回状态码 @Override public Object run() throws ZuulException { RequestContext currentContext = RequestContext.getCurrentContext(); int status = currentContext.getResponse().getStatus(); System.out.println("response status:" + status); return null; } }
浏览器输入http://127.0.0.1:9000/xatu/house-list/house
可以看书过滤器也实现了
总结
1 通过这个项目我们了解了SpringCloud的几个重要组件
2 数据流向
3 完成两个模块开发后进行了服务注册与发现Eureka
4 为了使服务间调用更加简便使用了Feign组件
5 使用到了负载均衡
6 使用到了熔断器
7 使用网关,并进行了过滤器的编写
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