如何在Spring Boot服务应用程序中的REST服务调用之间按原样传递请求参数？

提问者：小点点

如何在Spring Boot服务应用程序中的REST服务调用之间按原样传递请求参数？

我们正在进行架构重构，将单体J2EE EJB应用程序转换为Spring服务。为了做到这一点，我通过将应用程序分解为其域的关节来创建服务。目前，我有三个，每个都通过Rest调用另一个服务。

在这个项目中，我们的最终目的是将应用程序转换为微服务，但是由于云基础设施不清楚，可能也不可能，我们决定这样做，并认为由于服务使用Rest，将来很容易进行转换。

我们的做法有意义吗？我的问题源于此。

我使用标头参数userName from Postman向UserService发送请求。

GET http://localhost:8087/users/userId?userName=12345

UserService调用另一个调用另一个的服务。服务之间的其余调用顺序如下：

UserService ---REST--> CustomerService ---REST--> AlarmService

因为我现在正在做像这样携带公共请求参数的工作，所以我需要在每个发出Rest请求的方法中设置公共标头参数，方法是将它们从传入请求带到传出请求：

@RequestMapping(value="/users/userId", method = RequestMethod.GET)
public ResponseEntity<Long> getUserId(@RequestHeader("userName") String userName) {
    ...
        HttpHeaders headers = new HttpHeaders();
        headers.setAccept(Collections.singletonList
(MediaType.APPLICATION_JSON));

        headers.set("userName", userName);

        HttpEntity<String> entity = new HttpEntity<>("parameters", headers);
        HttpEntity<Long> response =
                restTemplate.exchange(CUSTOMER_REST_SERVICE_URI,
                HttpMethod.GET, entity, Long.class);
     ...
 }

用户服务：

package com.xxx.userservice.impl;

import org.apache.log4j.Logger;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.*;
import org.springframework.web.bind.annotation.RequestHeader;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.client.RestTemplate;

import java.util.Collections;
import java.util.Map;

@RestController
public class UserController  extends AbstractService{

    Logger logger = Logger.getLogger(UserController.class.getName());

    @Autowired
    private RestTemplate restTemplate;

    private final String CUSTOMER_REST_SERVICE_HOST = "http://localhost:8085";
    private final String CUSTOMER_REST_SERVICE_URI = CUSTOMER_REST_SERVICE_HOST + "/customers/userId";

    @RequestMapping(value="/users/userId", method = RequestMethod.GET)
    public ResponseEntity<Long> getUserId(@RequestHeader("userName") String userName) {
        logger.info(""user service is calling customer service..."");
        try {

            //do the internal customer service logic

            //call other service.
            HttpHeaders headers = new HttpHeaders();
            headers.setAccept(Collections.singletonList
(MediaType.APPLICATION_JSON));
            headers.set("userName", userName);
            HttpEntity<String> entity = new HttpEntity<>("parameters", headers);

            HttpEntity<Long> response =
                    restTemplate.exchange(CUSTOMER_REST_SERVICE_URI,
                    HttpMethod.GET, entity, Long.class);

            return ResponseEntity.ok(response.getBody());
        } catch (Exception e) {
            logger.error("user service could not call customer service: ", e);
            throw new RuntimeException(e);
        }
        finally {
            logger.info("customer service called...");
        }
    }

}

客户服务：

package com.xxxx.customerservice.impl;

import java.rmi.RemoteException;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

import com.xxx.interf.CustomerService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestHeader;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class CustomerController  extends AbstractService{

    private final String ALARM_REST_SERVICE_HOST = "http://localhost:8086";
    private final String ALARM_REST_SERVICE_URI = ALARM_REST_SERVICE_HOST + "/alarms/maxAlarmCount";

    @Autowired
    private CustomerService customerService;

    @Autowired
    private RestTemplate restTemplate;

    ...

    @GetMapping(path="/customers/userId", produces = "application/json")
    public long getUserId(@RequestHeader(value="Accept") String acceptType) throws RemoteException {

        //customer service internal logic.
        customerService.getUserId();

        //customer service calling alarm service.
        return restTemplate.getForObject(ALARM_REST_SERVICE_URI, Long.class);

    }

}

报警服务：

package com.xxx.alarmservice.impl;

import com.xxx.interf.AlarmService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class PriceAlarmController extends AbstractService{

    @Autowired
    private AlarmService priceAlarmService;

    @RequestMapping("/alarms/maxAlarmCount")
    public long getMaxAlarmsPerUser() {

        // alarm service internal logic.
        return priceAlarmService.getMaxAlarmsPerUser();
    }

}

我已经尝试过这些配置和拦截器文件，但我可以将它们仅用于日志记录，并且不能通过使用它们来传输标头参数。可能是因为每个服务都有它们。此外，此拦截器仅适用于UserService，它首先使用RestTemplate发送请求。来自Postman的调用服务和第一个请求不适用于它，因为它们不像UserService那样打印任何日志消息。

常用模块：

package com.xxx.common.config;

import com.xxx.common.util.HeaderRequestInterceptor;
import org.apache.cxf.common.util.CollectionUtils;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.http.client.ClientHttpRequestInterceptor;
import org.springframework.web.client.RestTemplate;

import java.util.ArrayList;
import java.util.List;

@Configuration
public class RestTemplateConfig {

    @Bean
    public RestTemplate restTemplate() {
        RestTemplate restTemplate = new RestTemplate();

        List<ClientHttpRequestInterceptor> interceptors
                = restTemplate.getInterceptors();
        if (CollectionUtils.isEmpty(interceptors)) {
            interceptors = new ArrayList<>();
        }
        interceptors.add(new HeaderRequestInterceptor());
        restTemplate.setInterceptors(interceptors);
        return restTemplate;
    }
}

客户端Http请求拦截器：


package com.xxx.common.util;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.http.HttpRequest;
import org.springframework.http.MediaType;
import org.springframework.http.client.ClientHttpRequestExecution;
import org.springframework.http.client.ClientHttpRequestInterceptor;
import org.springframework.http.client.ClientHttpResponse;
import org.springframework.util.StreamUtils;

import java.io.IOException;
import java.nio.charset.Charset;

public class HeaderRequestInterceptor implements ClientHttpRequestInterceptor {

    private final Logger log = LoggerFactory.getLogger(this.getClass());

    @Override
    public ClientHttpResponse intercept(
            HttpRequest request,
            byte[] body,
            ClientHttpRequestExecution execution) throws IOException
    {
        log.info("HeaderRequestInterceptor....");
        logRequest(request, body);
        request.getHeaders().set("Accept", MediaType.APPLICATION_JSON_VALUE);

        ClientHttpResponse response = execution.execute(request, body);
        logResponse(response);

        return response;
    }

    private void logRequest(HttpRequest request, byte[] body) throws IOException
    {
        log.info("==========request begin=======================");
    }

    private void logResponse(ClientHttpResponse response) throws IOException
    {
        log.info("==========response begin=============");
    }

}

如何通过在单个位置使用某种拦截器或其他机制来管理常见标头信息（如userName）的传递？

共1个答案

匿名用户

在HeaderRequest estInterceptor的拦截方法中，您可以通过以下方式访问当前的超文本传输协议请求及其标头（在您的情况下为userId）：

@Override
public ClientHttpResponse intercept(HttpRequest request..
...
   HttpServletRequest httpServletRequest = ((ServletRequestAttributes) RequestContextHolder.currentRequestAttributes()).getRequest();
   String userId = httpServletRequest.getHeader("userId");
   request.getHeaders().set("userId", userId);