一、在实现远程调用时可以使用feign与http远程调用，两者的关系有一下几点：
feign、http，有时候在调用第三方api的时候、使用httpclient，别人的接口不可能提供它的配置，自己项目框架是spring的，使用feign相互配置，都是okhttpclient的方式。Feign是一个接口声明式调用框架，实现了一个抽象层的逻辑，没有真正实现底层http请求，提供了一个client接口用于实现底层http操作，默认提供的实现是基于httpurlconnection，也有基于apachehttpclient的实现，且feign具有分布式负载均衡功能。
二、使用案例
需求是在本服务中调用另外一个服务中的设备上线的功能，有feign、http等可以选择，这里选择的是http调用。
@PostMapping("/mqtt/superuser")
@Transactional
public Integer loginCheck2(@RequestParam("username") String userName,
@RequestParam("clientid") String clientid){
System.out.println(userName);
System.out.println("超级管理员");
userName = "6217XXXXXXXXXXXd85/3XXXX3";
//拼接实体类跳转ibms-iot平台，上线
publishConnected(clientid, userName);
return 400;
}
private void publishConnected(String clientid, String userName) {
Connected connected = new Connected();
connected.setAction(ACTION);
connected.setClientid(clientid);
connected.setUsername(userName);
Date date = new Date();
connected.setConnected_at(date.getTime());
Map param = BeanUtil.beanToMap(connected, false, true);
String url = IotPropertiesConfig.HTTP_PREFIX + IotPropertiesConfig.IP_PORT+ UrlConstant.webHook_path;
String result = HttpUtils.postByRetry(url, param, IotPropertiesConfig.HTTP_TIMEOUT);
log.info("设备:{}上线内容的通知结果:{}",connected.getUsername(),result);
}
httpUtil工具类：
package com.setch.crodigy.utils;
import cn.hutool.http.HttpRequest;
import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.github.rholder.retry.*;
import com.google.common.base.Predicates;
import lombok.extern.slf4j.Slf4j;
import java.util.Map;
import java.util.concurrent.*;
@Slf4j
public class HttpUtils {
private static final String CONTENT_TYPE = "Content-Type";
private static final String AUTHORIZATION = "Authorization";
private static final String CONTENT_TYPE_VALUE = "application/x-www-form-urlencoded";
private static final String CONTENT_TYPE_VALUE_JSON = "application/json";
private static ObjectMapper json = new ObjectMapper();
private static ExecutorService cachedThreadPool = Executors.newCachedThreadPool();
//重试间隔
private static long sleepTime = 1L;
//重试次数
private static int attemptNumber = 5;
//设置重试机制
private final static Retryer retryer = RetryerBuilder.newBuilder()
.retryIfResult(Predicates.isNull()) // 设置自定义段元重试源
.retryIfExceptionOfType(Exception.class) // 设置异常重试源
.retryIfRuntimeException() // 设置异常重试源
.withStopStrategy(StopStrategies.stopAfterAttempt(attemptNumber)) // 设置重试次数 设置重试超时时间？？？？
.withWaitStrategy(WaitStrategies.fixedWait(sleepTime, TimeUnit.SECONDS)) // 设置每次重试间隔
.build();
public static void deviceOnline(String url, Map paramMap, int timeout) {
cachedThreadPool.execute(new Runnable() {
@Override
public void run() {
postByRetry("",null,1);
}
});
}
public static String postByRetry(String url, Map paramMap, int timeout) {
Callable task = new Callable() {
int i = 0;
@Override
public String call() throws Exception {
i++;
if(i > 1){
log.info("请求初次执行失败,开始第{}次执行！", i);
}
String result = post(url, paramMap, timeout);
return result;
}
};
String res = "";
try {
//执行任务的重试，得到返回结果
res = retryer.call(task);
} catch (ExecutionException e) {
log.error("Post ExecutionException", e);
} catch (RetryException e) {
log.error("Post RetryException", e);
}
return res;
}
public static String post(String url, Map paramMap, int timeout) throws JsonProcessingException {
String map = json.writevalueAsString(paramMap);
String result = HttpRequest
.post(url).header(CONTENT_TYPE,CONTENT_TYPE_VALUE).timeout(timeout * 1000)
.body(map).execute().body();
return result;
}
public static String post(String url, String map, int timeout) {
String result = HttpRequest
.post(url).header(CONTENT_TYPE,CONTENT_TYPE_VALUE).timeout(timeout * 1000)
.body(map).execute().body();
return result;
}
public static String post(String url, String map, int timeout,String authorization) {
String result = HttpRequest
.post(url).header(CONTENT_TYPE,CONTENT_TYPE_VALUE).header(AUTHORIZATION,authorization)
.timeout(timeout * 1000)
.body(map).execute().body();
return result;
}
public static String get(String url, int timeout,String authorization) {
String result = HttpRequest.get(url).header(CONTENT_TYPE,CONTENT_TYPE_VALUE_JSON).header(AUTHORIZATION,authorization)
.timeout(timeout * 1000).execute().body();
return result;
}
public static String delete(String url, int timeout,String authorization ,String map) {
String result = HttpRequest.delete(url).header(CONTENT_TYPE,CONTENT_TYPE_VALUE_JSON).header(AUTHORIZATION,authorization)
.timeout(timeout * 1000).body(map).execute().body();
return result;
}
public static String delete(String url, int timeout,String authorization ) {
String result = HttpRequest.delete(url).header(CONTENT_TYPE,CONTENT_TYPE_VALUE_JSON).header(AUTHORIZATION,authorization)
.timeout(timeout * 1000).execute().body();
return result;
}
}
这里的publishConnectEd(clientid,userName);使用http远程调用另外一个服务中的设备上线的接口。
String url ： 需要跳转的接口路径。（如：http://localhost:8080/user/login）
param： 远程调用时，所需参数。
HttpUtils.postByRetry() 实现http远程调用。
下面是需要被远程调用的接口
import antlr.StringUtils;
import com.setch.crodigy.service.ProductService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.domain.Sort;
import org.springframework.transaction.annotation.Transactional;
import org.springframework.web.bind.annotation.*;
import java.util.List;
@RequestMapping("/testDemo")
@RestController
public class ProductController {
@Autowired
private ProductService productService;
@PostMapping("/save")
@Transactional
public boolean saveProduct(@RequestBody Product product){
Product result = productService.save(product);
if (result != null){
return true;
}else {
return false;
}
}
}
以上是本人个人使用案例，测试成功，初次使用，若有问题欢迎大家提出指正。
