springCloud之 Feign声明式调用搭建_java spring cloud feign-优快云博客

本文链接：https://blog.youkuaiyun.com/weixin_42941199/article/details/111592997

1.注册中心搭建

参考下述注册中心搭建
https://blog.youkuaiyun.com/weixin_42941199/article/details/111592052

2.Feign声明式服务端搭建

2.1.pom依赖引入

<?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>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.3.3.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.example</groupId>
    <artifactId>03-eureka-feign-client-provider</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>03-eureka-feign-client-provider</name>
    <description>声明式声明式调用提供者</description>

    <properties>
        <java.version>1.8</java.version>
        <spring-cloud.version>Hoxton.SR8</spring-cloud.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
            <exclusions>
                <exclusion>
                    <groupId>org.junit.vintage</groupId>
                    <artifactId>junit-vintage-engine</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
    </dependencies>

    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>${spring-cloud.version}</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>

2.2.配置文件

spring.application.name=03-eureka-feign-client-provider
server.port=8081
#注册中心访问地址
eureka.client.service-url.defaultZone=http://eureka-server-slave:9101/eureka,http://eureka-server-master:9100/eureka
#表示eureka client发送心跳给server端的频
eureka.instance.lease-renewal-interval-in-seconds=2
#表示eureka server至上一次收到client的心跳之后，等待下一次心跳的超时时间，在这个时间内若没收到下一次心跳，则将移除该instance。
#默认为90秒
#如果该值太大，则很可能将流量转发过去的时候，该instance已经不存活了。
#如果该值设置太小了，则instance则很可能因为临时的网络抖动而被摘除掉。
#该值至少应该大于leaseRenewalIntervalInSeconds
eureka.instance.lease-expiration-duration-in-seconds=10

2.3.接口发布

package com.example.controller;

import com.example.entry.User;
import org.springframework.web.bind.annotation.*;

import java.util.Map;

@RestController
public class Test {
    @RequestMapping("/test")
    public String test(){
        return "第一个服务提供者";
    }

    /*
    但当服务端是GET请求时，那么需要在请求参数前加上@RequestParam注解修饰
     */
    @RequestMapping(value="/testGetParams",method= RequestMethod.GET)
    public String testGetParams(@RequestParam("name") String name,@RequestParam("age") Integer age){
        return "第一个服务testGetParams提供者name:"+name+"  age:"+age;
    }

    @RequestMapping(value="/testPostParams",method= RequestMethod.POST)
    public String testPostParams(String name,Integer age){
        return "第一个服务testPostParams提供者name:"+name+"  age:"+age;
    }

    @RequestMapping("/testParamsMap")
    public Map<String,Object> testParamsMap(@RequestBody Map<String,Object> map){
        for(Map.Entry<String, Object> entry : map.entrySet()){
            String mapKey = entry.getKey();
            Object mapValue = entry.getValue();
            System.out.println(mapKey+":"+mapValue);
        }
        return map;
    }

    @RequestMapping("/testCustomParams")
    public User testCustomParams(@RequestBody User user){
        System.out.println(user.getId());
        return user;
    }
}

2.4.启动类编写

package com.example;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.netflix.eureka.EnableEurekaClient;

@SpringBootApplication
//激活eureka客户端
@EnableEurekaClient
public class EurekaFeignClientProvider {

    public static void main(String[] args) {
        SpringApplication.run(EurekaFeignClientProvider.class, args);
        System.out.println("声明式feign提供者启动ok");
    }

}

3.Feign声明式客户端搭建

3.1.pom依赖引入

<?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>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.3.4.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.example</groupId>
    <artifactId>03-eureka-feign-client-consumer</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>03-eureka-feign-client-consumer</name>
    <description>Demo project for Spring Boot</description>

    <properties>
        <java.version>1.8</java.version>
        <spring-cloud.version>Hoxton.SR8</spring-cloud.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
        </dependency>
        <dependency><!-- feign依赖 -->
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-openfeign</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
            <exclusions>
                <exclusion>
                    <groupId>org.junit.vintage</groupId>
                    <artifactId>junit-vintage-engine</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
    </dependencies>

    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>${spring-cloud.version}</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>

3.2.配置文件

spring.application.name=03-eureka-feign-client-consumer
eureka.client.service-url.defaultZone=http://eureka-server-slave:9101/eureka,http://eureka-server-master:9100/eureka
server.port=8080

3.3.引入要调用的接口

package com.example.sevice;

import com.example.entry.User;
import org.springframework.cloud.openfeign.FeignClient;
import org.springframework.web.bind.annotation.*;

import java.util.Map;

/**
 * @FeignClient 用于标记当前接口是一个Feign的声明式服务接口
 * Spring会为这个接口生成动态代理对象
 * 属性
 * name 用于指定注册中心的提供者服务名称
 * fallback 用于指定熔断器
 */
@FeignClient(name = "03-eureka-feign-client-provider")
public interface TestService {
    /**
     * 定义抽象方法,并使用RequestMapping标记这个方法用于访问服务提供者
     * 其中RequestMapping的参数/test应该与当前接口所标记的服务名中的服务中的
     * 某个请求路劲相同
     * @return
     */
    @GetMapping("/test")
    String test();

    /*
     *当使用Feign时，需要在请求参数前加上@RequestParam注解修饰
     */
    @GetMapping("/testGetParams")
    String testGetParams(@RequestParam("name") String name, @RequestParam("age") Integer age);
    @PostMapping("/testPostParams")
    String testPostParams(@RequestParam("name") String name, @RequestParam("age") Integer age);

    @PostMapping("/testParamsMap")
    Map<String,Object> testParamsMap(Map<String,Object> map);

    @PostMapping("/testCustomParams")
    User testCustomParams(User user);
}

3.4.接口发布

package com.example.controller;

import com.example.entry.User;
import com.example.sevice.TestService;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;

import javax.annotation.Resource;
import java.util.Map;

@RestController
public class Test {
    @Resource
    private TestService testService;

    @RequestMapping("/test")
    public Object test(){
        String result = testService.test();
        return result;
    }

    /*
    但当服务端是GET请求时，那么需要在请求参数前加上@RequestParam注解修饰
     */
    @RequestMapping("/testGetParams")
    public Object testGetParams(@RequestParam("name") String name, @RequestParam("age") Integer age){
        String result = testService.testGetParams(name,age);
        return result;
    }

    @RequestMapping("/testPostParams")
    public Object testPostParams(String name, Integer age){
        String result = testService.testGetParams(name,age);
        return result;
    }

    @RequestMapping("/testParamsMap")
    public Object testParamsMap(@RequestBody Map<String,Object> map){
        Map<String,Object> result = testService.testParamsMap(map);
        return result;
    }

    @RequestMapping("/testCustomParams")
    public Object testCustomParams(@RequestBody User user){
        User result = testService.testCustomParams(user);
        return result;
    }
}

3.5.启动类编写

package com.example;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.netflix.eureka.EnableEurekaClient;
import org.springframework.cloud.openfeign.EnableFeignClients;

@SpringBootApplication
@EnableEurekaClient
//激活声明式消费feign的支持
@EnableFeignClients
public class EurekaFeignClientConsumer {

    public static void main(String[] args) {
        SpringApplication.run(EurekaFeignClientConsumer.class, args);
        System.out.println("声明式feign消费者启动ok");
    }

}