使用SpringBoot跨系统调用接口的方案

一、简介

项目开发中存在系统之间互调问题，又不想用dubbo，这里提供几种springboot方案：

1、使用Feign进行消费（推荐）

2、使用原始httpClient请求

3、使用RestTemplate方法

二、方案

方案一：使用Feign进行消费（推荐）

1、在maven中添加依赖

<dependency>
 <groupId>org.springframework.cloud</groupId>
 <artifactId>spring-cloud-starter-openfeign</artifactId>
 <version>2.2.2</version>
</dependency>

2、启动类上加上@EnableFeignClients

@EnableHystrix
@EnableDiscoveryClient
@EnableFeignClients(basePackages = {"com.aaa.aurora"})
@SpringBootApplication
@EnableTransactionManagement
@ComponentScan(basePackages = "com.aaa.aurora")
@ImportResource(locations= {"classpath:spring.xml","spring-security.xml"})
@MapperScan("com.aaa.aurora.mapper")
public class AuroraWebApplication {
 public static void main(String[] args) {
   SpringApplication.run(AuroraWebApplication.class, args);
  }
}

3、编写service接口

@FeignClient(url = "${pangu.url}",name = "panguUrl")
public interface PanGuService {
 @RequestMapping(value = "/pangu/restful/check",method = RequestMethod.POST)
 JSONObject check(@RequestParam(name="queryEngine") String queryEngine, @RequestParam(name="querySql") String querySql, @RequestParam(name="jobNo") String jobNo);
}

其中：pangu.url是配置在application.properties中的ip及端口

pangu.url = 192.168.1.3:8080
/pangu/restful/check是要调的接口名

4、代码中调用

 @Autowired
 private PanGuService panGuService;

 JSONObject jsonObject = null;
 try {
   jsonObject = panGuService.auroraPriviledge(PRESTO_DRIVER, query.get("sql"), user.getWorkNo());
 } catch (Exception e) {
  throw new Exception("请求系统异常");
 }
 if (PANGU_FAIL.equals(jsonObject.get("code"))) {
  LOG.info(jsonObject.get("msg").toString());
  throw new BusinessException(jsonObject.get("msg").toString());
 }

方案二：使用原始httpClient请求

使用HttpClient发送请求、接收响应很简单，一般需要如下几步即可。

1. 创建HttpClient对象。

2. 创建请求方法的实例，并指定请求URL。如果需要发送GET请求，创建HttpGet对象；如果需要发送POST请求，创建HttpPost对象。

3. 如果需要发送请求参数，可调用HttpGet、HttpPost共同的setParams(HttpParams params)方法来添加请求参数；对于HttpPost对象而言，也可调用setEntity(HttpEntity entity)方法来设置请求参数。

4. 调用HttpClient对象的execute(HttpUriRequest request)发送请求，该方法返回一个HttpResponse。

5. 调用HttpResponse的getAllHeaders()、getHeaders(String name)等方法可获取服务器的响应头；调用HttpResponse的getEntity()方法可获取HttpEntity对象，该对象包装了服务器的响应内容。程序可通过该对象获取服务器的响应内容。

6. 释放连接。无论执行方法是否成功，都必须释放连接。

public JSONObject doPost(String queryEngine, String querySql, String jobNo) {
  JSONObject jsonObject = null;
  //1.创建httpClient对象
  CloseableHttpClient client = HttpClients.createDefault();
  //2.创建请求方法的实例，并指定请求URL
  String url = "http://192.168.1.11:8080";
  HttpPost post = new HttpPost(url);
  post.setHeader("Content-Type", "application/json;charset=utf8");
  //3.参数
  AuroraPriviledge auroraPriviledge = new AuroraPriviledge();
  auroraPriviledge.setQueryEngine(queryEngine);
  auroraPriviledge.setQuerySql(querySql);
  auroraPriviledge.setJobNo(jobNo);
  String jsonString = JSON.toJSONString(auroraPriviledge);
  StringEntity entity = new StringEntity(jsonString, "UTF-8");
  post.setEntity(entity);
  //4.调用execute,返回response
  CloseableHttpResponse response = null;
  try {
   response = client.execute(post);
   HttpEntity responseEntity = response.getEntity();
  } catch (IOException e) {
   e.printStackTrace();
  } catch (Exception e) {
   e.printStackTrace();
  } finally {
   try {
    if (client != null) {
     client.close();
    }
    if (response != null) {
     response.close();
    }
   } catch (IOException e) {
    e.printStackTrace();
   }
  }
  return jsonObject;
 }

方案三：使用RestTemplate方法

1.get请求：getForObject(...)和getForEntity(...)两个方法，区别在于前者直接返回预期的对象，即返回体中的body对象，后者返回的是ResponseEntity封装类，里面包含了HTTP请求的头信息。

2.post请求：与get请求类似，只是多一个request参数，request对象会作为httpEntity进行处理。

package com.yyy.aurora;
import org.springframework.http.ResponseEntity;
import org.springframework.web.client.RestTemplate;
import java.net.URI;
import java.util.HashMap;
import java.util.Map;

/**
 * Description
 *
 * @author Bob
 * @date 2020/4/15
 **/
public class TestRest {
 public static void main(String[] args) {
  RestTemplate restTemplate = new RestTemplate();
  //get请求
  //方法一：getForEntity(String url, Class<T> responseType, Object... uriVariables),没有参数
  String url = "https://restapi.amap.com/v3/ip?key=075b6eddd825148a674dfa8a8558ac62";
  ResponseEntity<String> forEntity = restTemplate.getForEntity(url, String.class);
  System.out.println(forEntity);
  // <200,{"status":"1","info":"OK","infocode":"10000","province":"上海市","city":"上海市","adcode":"310000","rectangle":"120.8397067,30.77980118;122.1137989,31.66889673"},{Server=[Tengine], Date=[Sat, 18 Apr 2020 02:47:38 GMT], Content-Type=[application/json;charset=UTF-8], Content-Length=[167], Connection=[close], X-Powered-By=[ring/1.0.0], gsid=[011130051098158717805837600019751129378], sc=[0.071], Access-Control-Allow-Origin=[*], Access-Control-Allow-Methods=[*], Access-Control-Allow-Headers=[DNT,X-CustomHeader,Keep-Alive,User-Agent,X-Requested-With,If-Modified-Since,Cache-Control,Content-Type,key,x-biz,x-info,platinfo,encr,enginever,gzipped,poiid]}>

  String s = restTemplate.getForObject(url, String.class);
  System.out.println(s);
  // {"province":"上海市","city":"上海市","adcode":"310000","infocode":"10000","rectangle":"120.8397067,30.77980118;122.1137989,31.66889673","status":"1","info":"OK"}
  //方法一：getForEntity(String url, Class<T> responseType, Object... uriVariables),url中用占位符，传入参数
  //该方法提供了三个参数，其中var1为请求的地址(即url)，var2为请求响应body的包装类型，var3为url中的参数绑定
  url = "https://restapi.amap.com/v3/ip?key={?}";
  forEntity = restTemplate.getForEntity(url, String.class, "075b6eddd825148a674dfa8a8558ac62");
  //方法二：getForEntity(String url, Class<T> responseType, Map<String, ?> uriVariables),map传参
  url = "https://restapi.amap.com/v3/ip?key={key}";
  Map<String, Object> map = new HashMap<>();
  map.put("key", "075b6eddd825148a674dfa8a8558ac62");
  forEntity = restTemplate.getForEntity(url, String.class, map);

  //方法三：getForEntity(URI url, Class<T> responseType),uri传参
  URI uri = URI.create("https://restapi.amap.com/v3/ip?key=075b6eddd825148a674dfa8a8558ac62");
  forEntity = restTemplate.getForEntity(uri, String.class);
  //post请求,与get请求类型,只是多一个必填request对象
  //postForEntity(String url, @Nullable Object request, Class<T> responseType, Object... uriVariables)
  forEntity = restTemplate.postForEntity(url, null, String.class, "075b6eddd825148a674dfa8a8558ac62");
  s = restTemplate.postForObject(url, null, String.class, "075b6eddd825148a674dfa8a8558ac62");
 }
}

补充：SpringBoot关于系统之间的远程互相调用

1、SpringBoot关于系统之间的远程互相调用

可以采用RestTemplate方式发起Rest Http调用，提供有get、post等方式。

1、1远程工具类

此处使用Post方式，参考下面封装的HttpClient类 1.1

/**
 * Created by @kai on 2018/12/24/024.
 * Time: 13:54
 * Desc: 远程连接工具类
 */
@Service
public class HttpClient {
​
 /**
 * 根据远程地址发起访问-参数类型为form表单
 * @param url 远程地址
 * @param method 远程方法
 * @param params  方法参数
 * @return
 */
 public Object client(String url,HttpMethod method,MultiValueMap<String,String> params){
  RestTemplate restTemplate = new RestTemplate();
  HttpHeaders headers = new HttpHeaders();
  headers.add("Content-Type", "application/x-www-form-urlencoded");
  HttpEntity<MultiValueMap<String, String>> httpEntity = new HttpEntity<>(params, headers);
  ResponseEntity<String> responseEntity = restTemplate.postForEntity(url,httpEntity,String.class);
  String body = responseEntity.getBody();
  JSONObject jsonObject = JSONObject.parseObject(body);
  return jsonObject.get("data");
 }
​
 /**
 * 根据远程地址发起访问-参数类型为JSON
 * @param url 远程地址
 * @param method 远程方法
 * @param params  方法参数
 * @return
 */
 public Object clientJson(String url,HttpMethod method,Map<String,Object> params){
  RestTemplate restTemplate = new RestTemplate();
  HttpHeaders headers = new HttpHeaders();
  headers.setContentType(MediaType.APPLICATION_JSON_UTF8);
  cn.hutool.json.JSONObject jsonObject = JSONUtil.parseFromMap(params);
  HttpEntity<cn.hutool.json.JSONObject> httpEntity = new HttpEntity<>(jsonObject, headers);
  ResponseEntity<String> responseEntity = restTemplate.postForEntity(url,httpEntity,String.class);
  String body = responseEntity.getBody();
  JSONObject jsonObjectResult = JSONObject.parseObject(body);
  return jsonObjectResult.get("data");
 }
​
}

[ 1.1​]

1、2远程参数说明

工具类中提供了远程过程中传递参数的两种格式：

其中 headers.add("Content-Type", "application/x-www-form-urlencoded") 为form表单格式，支持键值对数据传输；

当参数类型为form表单时，数据需要封装成MultiValueMap<String,String>格式，前台使用controller接受时，可以直接使用 MultiValueMap 变量接收，参照代码如下 1.2

/**
 * 保存分组策略对象
 * @param
 * @return
 */
@RequestMapping(value = "/saveDocGroupPolicy",method = RequestMethod.POST)
public ApiResult saveGroupPolicy(@RequestParam MultiValueMap<String,String> paramMap,@Valid GroupStrategyIO groupStrategyIO){
 Integer userId = ShiroUtil.getExamUserId();
 List<String> userList = new ArrayList<>();
 userList.add(userId+"");
 paramMap.put("userId",userList);
 Object jsonObject = httpClient.client(ExamConfigConstants.url+"/exam/configPolicy/saveDocGroupPolicy", HttpMethod.POST, paramMap);
 return ApiResult.success(jsonObject);
}

[ 1.2] 接受参数为form对象

headers.setContentType(MediaType.APPLICATION_JSON_UTF8) 

为json数据格式

当参数为json格式时，远程服务器接受参数需加上注解@RequestBody，对于复杂参数可以使用对象接受，将对象转为Map，对数据进行加工，再将map转化为JSONObject,参照代码如下：1.3

/**
 * 保存试卷策略
 * @param paperStrategyIO 试卷策略对象
 * @return
 */
@RequestMapping(value = "/savePaperConfig")
public ApiResult savePaperConfig(@RequestBody PaperStrategyIO paperStrategyIO){
 Map<String, Object> paramMap = BeanUtil.beanToMap(paperStrategyIO);
 Integer userId = ShiroUtil.getExamUserId();
 paramMap.put("userId",userId);
 Object jsonObject = httpClient.clientJson(ExamConfigConstants.url+"/exam/paper/savePaperConfigWithMap", HttpMethod.POST, paramMap);
 return ApiResult.success(jsonObject);
}

[ 1.3​] 接收参数为复杂json串

2、后记

关于RestTemplate还有很多可调用的API,可以查看官方网站了解

http://spring.io/blog/2009/03/27/rest-in-spring-3-resttemplate

以上为个人经验，希望能给大家一个参考，也希望大家多多支持我们。如有错误或未考虑完全的地方，望不吝赐教。