1.Feign的依赖
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-openfeign</artifactId>
<version>2.0.0.RELEASE</version>
</dependency>
2. 开启feign的使用注解
@EnableFeignClients
3 编写测试样例，主机可以调通，接口不可用
package com.example.demo;
import org.springframework.cloud.openfeign.FeignClient;
import org.springframework.web.bind.annotation.RequestMapping;
@FeignClient(name = "service",url = "http://baidu.com:8080")
public interface FeignTestService {
@RequestMapping("/est")
String get();
}
package com.example.demo;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.openfeign.EnableFeignClients;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
@SpringBootApplication
@RestController
@RequestMapping("/feign")
@EnableFeignClients
public class DemoApplication {
private Logger logger = LoggerFactory.getLogger(getClass());
@Autowired
private FeignTestService feignTestService;
public static void main(String[] args) {
SpringApplication.run(DemoApplication.class, args);
}
@RequestMapping("/test")
public String test() {
long start = System.currentTimeMillis();
try {
feignTestService.get();
} catch (Exception e) {
logger.error("", e);
logger.info("time:" + (System.currentTimeMillis() - start));
return "error";
}
return "test";
}
}
观察发现，总的超时时间是10s。
4.Feign的重试、超时自定义
FeignClient的默认超时时间为10s，不会开启重试机制，需要自定义配置。
//超时时间设置,开启重试机制，默认为5次（包含首次请求）
package com.example.demo;
import feign.Request;
import feign.Retryer;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
@Configuration
public class FeignConfigure {
public static int connectTimeOutMillis = 12000;//超时时间
public static int readTimeOutMillis = 12000;
@Bean
public Request.Options options() {
return new Request.Options(connectTimeOutMillis, readTimeOutMillis);
}
@Bean
public Retryer feignRetryer() {
return new Retryer.Default();
}
}
//自定义重试次数
@Bean
public Retryer feignRetryer(){
Retryer retryer = new Retryer.Default(100, 1000, 4);
return retryer;
}
5.通过配置文件修改feign的超时时间
yml文件配置：
feign:
client:
config:
remote-service: #服务名，填写default为所有服务
connectTimeout: 1000
readTimeout: 12000
https://cloud.spring.io/spring-cloud-netflix/multi/multi_spring-cloud-feign.html
6.重试、超时相关源码
/*
* Copyright 2013 Netflix, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package feign;
import static java.util.concurrent.TimeUnit.SECONDS;
/**
* Cloned for each invocation to {@link Client#execute(Request, feign.Request.Options)}.
* Implementations may keep state to determine if retry operations should continue or not.
*/
public interface Retryer extends Cloneable {
/**
* if retry is permitted, return (possibly after sleeping). Otherwise propagate the exception.
*/
void continueOrPropagate(RetryableException e);
Retryer clone();
public static class Default implements Retryer {
private final int maxAttempts;
private final long period;
private final long maxPeriod;
int attempt;
long sleptForMillis;
//默认重试次数
public Default() {
this(100, SECONDS.toMillis(1), 5);
}
public Default(long period, long maxPeriod, int maxAttempts) {
this.period = period;
this.maxPeriod = maxPeriod;
this.maxAttempts = maxAttempts;
this.attempt = 1;
}
// visible for testing;
protected long currentTimeMillis() {
return System.currentTimeMillis();
}
//重试规则
public void continueOrPropagate(RetryableException e) {
if (attempt++ >= maxAttempts) {
throw e;
}
long interval;
if (e.retryAfter() != null) {
interval = e.retryAfter().getTime() - currentTimeMillis();
if (interval > maxPeriod) {
interval = maxPeriod;
}
if (interval < 0) {
return;
}
} else {
interval = nextMaxInterval();
}
try {
Thread.sleep(interval);
} catch (InterruptedException ignored) {
Thread.currentThread().interrupt();
}
sleptForMillis += interval;
}
/**
* Calculates the time interval to a retry attempt. <br> The interval increases exponentially
* with each attempt, at a rate of nextInterval *= 1.5 (where 1.5 is the backoff factor), to the
* maximum interval.
*
* @return time in nanoseconds from now until the next attempt.
*/
//重试等待时间算法
long nextMaxInterval() {
long interval = (long) (period * Math.pow(1.5, attempt - 1));
return interval > maxPeriod ? maxPeriod : interval;
}
@Override
public Retryer clone() {
return new Default(period, maxPeriod, maxAttempts);
}
}
/**
* Implementation that never retries request. It propagates the RetryableException.
*/
//默认不重试
Retryer NEVER_RETRY = new Retryer() {
@Override
public void continueOrPropagate(RetryableException e) {
throw e;
}
@Override
public Retryer clone() {
return this;
}
};
}
//超时相关
public static class Options {
private final int connectTimeoutMillis;
private final int readTimeoutMillis;
public Options(int connectTimeoutMillis, int readTimeoutMillis) {
this.connectTimeoutMillis = connectTimeoutMillis;
this.readTimeoutMillis = readTimeoutMillis;
}
public Options() {
this(10 * 1000, 60 * 1000);
}
/**
* Defaults to 10 seconds. {@code 0} implies no timeout.
*
* @see java.net.HttpURLConnection#getConnectTimeout()
*/
public int connectTimeoutMillis() {
return connectTimeoutMillis;
}
/**
* Defaults to 60 seconds. {@code 0} implies no timeout.
*
* @see java.net.HttpURLConnection#getReadTimeout()
*/
public int readTimeoutMillis() {
return readTimeoutMillis;
}
}
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作者：VitaminZH
来源：CSDN
原文：https://blog.csdn.net/VitaminZH/article/details/80892395
版权声明：本文为博主原创文章，转载请附上博文链接！