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
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());
}
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;
}
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
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
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。如有错误或未考虑完全的地方，望不吝赐教。
