一、概述
1.1 OpenFeign是什么
Feign是一个声明式的web服务客户端，让编写web服务客户端变得非常容易，只需要创建一个接口并在接口上添加注解即可。
微服务调用接口+@FeignClient
2.2 新建cloud-consumer-feign-order80Feign在消费端使用
cloud2020
com.atguigu.springcloud
1.0-SNAPSHOT
4.0.0
cloud-consumer-feign-order80
org.springframework.cloud
spring-cloud-starter-openfeign
org.springframework.cloud
spring-cloud-starter-netflix-eureka-client
com.atguigu.springcloud
cloud-api-commons
${project.version}
org.springframework.boot
spring-boot-starter-web
org.springframework.boot
spring-boot-starter-actuator
org.springframework.boot
spring-boot-devtools
runtime
true
org.projectlombok
lombok
true
org.springframework.boot
spring-boot-starter-test
test
server:
port: 80
eureka:
client:
register-with-eureka: false
service-url:
defaultZone: http://eureka7001.com:7001/eureka, http://eureka7002.com:7002/eureka
package com.atguigu.springcloud;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.openfeign.EnableFeignClients;
/**
* @author by XXX
* @descriptaion #
* @date 2020/6/15
*/
@SpringBootApplication
@EnableFeignClients
public class OrderFeignMain80 {
public static void main(String[] args) {
SpringApplication.run(OrderFeignMain80.class, args);
}
}
package com.atguigu.springcloud.service;
import com.atguigu.springcloud.entities.CommonResult;
import com.atguigu.springcloud.entities.Payment;
import feign.Param;
import org.springframework.cloud.openfeign.FeignClient;
import org.springframework.stereotype.Component;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import sun.rmi.runtime.Log;
/**
* @author by XXX
* @descriptaion #
* @date 2020/6/15
*/
@Component
@FeignClient(value = "CLOUD-PAYMENT-SERVICE")
public interface PaymentFeignService {
@GetMapping(value = "/payment/get/{id}")
public CommonResult getPaymentById(@PathVariable("id") Long id);
}
package com.atguigu.springcloud.controller;
import com.atguigu.springcloud.entities.CommonResult;
import com.atguigu.springcloud.entities.Payment;
import com.atguigu.springcloud.service.PaymentFeignService;
import lombok.extern.slf4j.Slf4j;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RestController;
import javax.annotation.Resource;
/**
* @author by XXX
* @descriptaion #
* @date 2020/6/15
*/
@RestController
@Slf4j
public class OrderFeignController {
@Resource
private PaymentFeignService paymentFeignService;
@GetMapping(value = "/consumer/payment/get/{id}")
public CommonResult getPaymentById(@PathVariable("id") Long id) {
return paymentFeignService.getPaymentById(id);
}
}
先启动2个eureka集群7001/7002
再启动2个微服务8001/8002
启动openFeign
http://localhost/consumer/payment/get/1
Feign自带负载均衡配置项
package com.atguigu.springcloud.controller;
import com.atguigu.springcloud.entities.CommonResult;
import com.atguigu.springcloud.entities.Payment;
import com.atguigu.springcloud.service.PaymentService;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.cloud.client.ServiceInstance;
import org.springframework.cloud.client.discovery.DiscoveryClient;
import org.springframework.web.bind.annotation.*;
import javax.annotation.Resource;
import java.util.List;
import java.util.concurrent.TimeUnit;
@RestController
@Slf4j
public class PaymentController {
@Resource
private PaymentService paymentService;
@Value("${server.port}")
private String serverPort;
@Resource
private DiscoveryClient discoveryClient;
@GetMapping(value = "/payment/discovery")
public Object discovery() {
List services = discoveryClient.getServices();
for (String element : services) {
log.info("********element: " + element);
}
List instances = discoveryClient.getInstances("CLOUD-PAYMENT-SERVICE");
for (ServiceInstance instance : instances) {
log.info(instance.getServiceId()+"\t"+instance.getHost()+"\t"+instance.getPort()+"\t"+instance.getUri());
}
return this.discoveryClient;
}
@PostMapping(value = "/payment/create")
public CommonResult create(@RequestBody Payment payment) {
int result = paymentService.create(payment);
log.info("*****插入结果：" + result + "****哈哈");
if (result > 0) { //成功
return new CommonResult(200, "插入数据库成功,serverPort: " + serverPort, result);
} else {
return new CommonResult(444, "插入数据库失败", null);
}
}
@GetMapping(value = "/payment/get/{id}")
public CommonResult getPaymentById(@PathVariable("id") Long id) {
Payment payment = paymentService.getPaymentById(id);
log.info("*****查询结果：" + payment + "哈哈哈");
if (payment != null) { //说明有数据，能查询成功
return new CommonResult(200, "查询成功,serverPort: " + serverPort, payment);
} else {
return new CommonResult(444, "没有对应记录，查询ID：" + id, null);
}
}
@GetMapping(value = "/payment/feign/timeout")
public String paymentFeignTimeout() {
try {
TimeUnit.SECONDS.sleep(3);
} catch (InterruptedException e) {
e.printStackTrace();
}
return serverPort;
}
}
package com.atguigu.springcloud.service;
import com.atguigu.springcloud.entities.CommonResult;
import com.atguigu.springcloud.entities.Payment;
import feign.Param;
import org.springframework.cloud.openfeign.FeignClient;
import org.springframework.stereotype.Component;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import sun.rmi.runtime.Log;
/**
* @author by XXX
* @descriptaion #
* @date 2020/6/15
*/
@Component
@FeignClient(value = "CLOUD-PAYMENT-SERVICE")
public interface PaymentFeignService {
@GetMapping(value = "/payment/get/{id}")
public CommonResult getPaymentById(@PathVariable("id") Long id);
@GetMapping(value = "/payment/feign/timeout")
public String paymentFeignTimeout();
}
package com.atguigu.springcloud.controller;
import com.atguigu.springcloud.entities.CommonResult;
import com.atguigu.springcloud.entities.Payment;
import com.atguigu.springcloud.service.PaymentFeignService;
import lombok.extern.slf4j.Slf4j;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RestController;
import javax.annotation.Resource;
/**
* @author by XXX
* @descriptaion #
* @date 2020/6/15
*/
@RestController
@Slf4j
public class OrderFeignController {
@Resource
private PaymentFeignService paymentFeignService;
@GetMapping(value = "/consumer/payment/get/{id}")
public CommonResult getPaymentById(@PathVariable("id") Long id) {
return paymentFeignService.getPaymentById(id);
}
@GetMapping(value = "/consumer/payment/feign/timeout")
public String paymentFeignTimeout() {
//openfeign-ribbon,客户端一般默认等待1秒钟
return paymentFeignService.paymentFeignTimeout();
}
}
测试：http://localhost/consumer/payment/feign/timeout
默认Feign客户端只等待一秒钟，但是服务端处理需要超过1秒钟，导致Feign客户端不想等待了，直接返回报错。为了避免这样的情况，有时候我们需要设置Feign客户端的超时控制。yml文件中开启配置。
OpenFeign默认支持Ribbon
server:
port: 80
eureka:
client:
register-with-eureka: false
service-url:
defaultZone: http://eureka7001.com:7001/eureka, http://eureka7002.com:7002/eureka
#设置feign客户端超时时间(OpenFeign默认支持ribbon)
ribbon:
# 指的是建立连接所用的时间，适用于网络状况正常的情况下，两端连接所用的时间
ReadTimeout: 5000
# 指的是建立连接后从服务器读取到可用资源所用的时间
ConnectTimeout: 5000
Feign提供了日志打印功能，我们可以通过配置调整日志级别，从而了解Feign中Http请求的细节。说白了就是对Feign接口的调用情况进行监控和输出
4.3 日志级别NONE：默认的，不显示任何日志；
BASIC：仅记录请求方法、URL、响应状态码及执行时间；
HEADERS：除了BASIC中定义的信息之外，还有请求和响应的头信息；
FULL：除了HEADERS中定义的信息之外，还有请求和响应的正文及元数据。
4.4 配置日志bean
package com.atguigu.springcloud.config;
import feign.Logger;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
@Configuration
public class FeignConfig {
@Bean
Logger.Level feignLoggerLevel(){
return Logger.Level.FULL;
}
}
server:
port: 80
eureka:
client:
register-with-eureka: false
service-url:
defaultZone: http://eureka7001.com:7001/eureka, http://eureka7002.com:7002/eureka
#设置feign客户端超时时间(OpenFeign默认支持ribbon)
ribbon:
# 指的是建立连接所用的时间，适用于网络状况正常的情况下，两端连接所用的时间
ReadTimeout: 5000
# 指的是建立连接后从服务器读取到可用资源所用的时间
ConnectTimeout: 5000
logging:
level:
# feign日志以什么级别监控哪个接口
com.atguigu.springcloud.service.PaymentFeignService: debug
