Spring cloud 实现房源查询功能的实例代码

2022-11-13 17:11:15 实例查询功能房源

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


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

2.1.4 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。


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


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


@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


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

2.2.4 client


//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。


@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


@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


public interface HousePriceService {
 
    HousePrice getHousePrice(Integer houseId);
 
    List<HouseAndPrice> getHousesAndPrice();
    List<HousePrice> getHousePriceList();
}

impl


@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


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


@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


//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
//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


@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;
    }
}


@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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