SpringBoot-调用外部接口（三种方式）

方式一：使用原始httpClient请求

@RequestMapping("/submit/{documentId}")
public String submit1(@PathVariable String documentId) throws ParseException {

	//将要发送的数据转换为json格式字符串
	Map<String,Object> map = task2Service.getMap(documentId);
	String jsonStr = JSON.toJSONString(map,SerializerFeature.WRITE_MAP_NULL_FEATURES,SerializerFeature.QuoteFieldNames);
	JSONObject jsonObject = JSON.parseObject(jsonStr);
	JSONObject sr = task2Service.doPost(jsonObject);
	return sr.toString();
}

使用原生的httpClient调用外部接口

public static JSONObject doPost(JSONObject date){

	String assessToken="eyJ0eXAiOiJKV1QiLCJhbGciOiJIUzUxMiJ9.eyJ4ZGFwYXBwaWQiOiIzNDgxMjU4ODk2OTI2OTY1NzYiLCJleHAiOjE2NjEyMjY5MDgsImlhdCI6MTY2MTIxOTcwOCwieGRhcHRlbmFudGlkIjoiMzAwOTgxNjA1MTE0MDUyNjA5IiwieGRhcHVzZXJpZCI6IjEwMDM0NzY2MzU4MzM1OTc5NTIwMCJ9.fZAO4kJSv2rSH0RBiL1zghdko8Npmu_9ufo6Wex_TI2q9gsiLp7XaW7U9Cu7uewEOaX4DTdpbFmMPvLUtcj_sQ";
	CloseableHttpClient client = HttpClients.createDefault();

	//需要调用的接口url
	 String url = "http://39.103.201.110:30661 /xdap-open/open/process/v1/submit";
	 HttpPost post = new HttpPost(url);

	JSONObject jsonObject = null;
	try{
		//创建请求体并添加数据
		StringEntity s = new StringEntity(data.toString());
		
		//此处相当于在header里头添加content-type等参数
        s.setContentType("application/json");
        s.setContentEncoding("UTF-8");

		post.setEntity(s);

		//此处相当于在Authorization里头添加Bear token参数信息
        post.addHeader("Authorization", "Bearer " +assessToken);
        HttpResponse res = client.execute(post);
        String response1 = EntityUtils.toString(res.getEntity());
        if (res.getStatusLine()
                .getStatusCode() == HttpStatus.SC_OK) {
            // 返回json格式：
            String result = EntityUtils.toString(res.getEntity());
            jsonObject = JSONObject.parseObject(result);
        }
	}catch(Exception e){
		throw new RuntimeException(e);
	}
	return jsonObject;
}

方式二：使用RestTemplate方法

get请求

提供了getForObject、getForEntity两种方式，其中getForEntity如下三种方法的实现：

Get–getForEntity，存在以下两种方式重载

getForEntity(Stringurl,Class responseType,Object…urlVariables)
getForEntity(URI url,Class responseType)

Get–getForEntity(URI url,Class responseType)

//该方法使用URI对象来替代之前的url和urlVariables参数来指定访问地址和参数绑定。URI是JDK java.net包下的一个类，表示一个统一资源标识符(Uniform Resource Identifier)引用。参考如下：
RestTemplate restTemplate=new RestTemplate();
UriComponents 
uriComponents=UriComponentsBuilder.fromUriString("http://USER-SERVICE/user?name={name}")
.build()
.expand("dodo")
.encode();
URI uri=uriComponents.toUri();
ResponseEntityresponseEntity=restTemplate.getForEntity(uri,String.class).getBody();

Get–getForEntity(Stringurl,Class responseType,Object…urlVariables)

//该方法提供了三个参数，其中url为请求的地址，responseType为请求响应body的包装类型，urlVariables为url中的参数绑定，该方法的参考调用如下：
// http://USER-SERVICE/user?name={name)
RestTemplate restTemplate=new RestTemplate();
Mapparams=new HashMap<>();
params.put("name","dada"); //
ResponseEntityresponseEntity=restTemplate.getForEntity("http://USERSERVICE/user?name={name}",String.class,params);

Get–getForObject，存在以下三种方式重载

getForObject(String url,Class responseType,Object...urlVariables)
getForObject(String url,Class responseType,Map urlVariables)
getForObject(URI url,Class responseType)

getForObject方法可以理解为对getForEntity的进一步封装，它通过HttpMessageConverterExtractor对HTTP的请求响应体body内容进行对象转换，实现请求直接返回包装好的对象内容。

Post请求

Post请求提供有postForEntity、postForObject和postForLocation三种方式，其中每种方式都有三种方法，下面介绍postForEntity的使用方法。

Post–postForEntity，存在以下三种方式重载

postForEntity(String url,Object request,Class responseType,Object...  uriVariables) 
postForEntity(String url,Object request,Class responseType,Map  uriVariables) 
postForEntity(URI url,Object request，Class responseType)

/**
	第二种重载方式
*/
@PostMapping("/submit2")
public Object insertFinanceCompensation(@RequestBody JSONObject jsonObject) {
    String documentId=jsonObject.get("documentId").toString();
    return task2Service.submit(documentId);
}

public String submit(String documentId){
    String assessToken="eyJ0eXAiOiJKV1QiLCJhbGciOiJIUzUxMiJ9.eyJ4ZGFwYXBwaWQiOiIzNDgxMjU4ODk2OTI2OTY1NzYiLCJleHAiOjE2NjEyMjY5MDgsImlhdCI6MTY2MTIxOTcwOCwieGRhcHRlbmFudGlkIjoiMzAwOTgxNjA1MTE0MDUyNjA5IiwieGRhcHVzZXJpZCI6IjEwMDM0NzY2MzU4MzM1OTc5NTIwMCJ9.fZAO4kJSv2rSH0RBiL1zghdko8Npmu_9ufo6Wex_TI2q9gsiLp7XaW7U9Cu7uewEOaX4DTdpbFmMPvLUtcj_sQ";
    RestTemplate restTemplate = new RestTemplate();
    //创建请求头
    HttpHeaders httpHeaders = new HttpHeaders();
    //此处相当于在Authorization里头添加Bear token参数信息
    httpHeaders.add(HttpHeaders.AUTHORIZATION, "Bearer " + assessToken);
    //此处相当于在header里头添加content-type等参数
    httpHeaders.add(HttpHeaders.CONTENT_TYPE,"application/json");
    Map<String, Object> map = getMap(documentId);
    String jsonStr = JSON.toJSONString(map);
    //创建请求体并添加数据
    HttpEntity<Map> httpEntity = new HttpEntity<Map>(map, httpHeaders);
    String url = "http://39.103.201.110:30661/xdap-open/open/process/v1/submit";
    ResponseEntity<String> forEntity = restTemplate.postForEntity(url,httpEntity,String.class);//此处三个参数分别是请求地址、请求体以及返回参数类型
    return forEntity.toString();
}

方式三：使用Feign进行消费

<dependency>
    <groupId>org.springframework.cloudgroupId>
    <artifactId>spring-cloud-starter-feignartifactId>
    <version>1.2.2.RELEASEversion>
dependency>

启动类上加上@EnableFeignClients

@SpringBootApplication
@EnableFeignClients
@ComponentScan(basePackages = {"com.definesys.mpaas", "com.xdap.*" ,"com.xdap.*"})
public class MobilecardApplication {

    public static void main(String[] args) {
        SpringApplication.run(MobilecardApplication.class, args);
    }

}

定义Controller

@Autowired
PrintService printService;

@PostMapping("/outSide")
public String test(@RequestBody TestDto testDto) {
    return printService.print(testDto);
}

Service接口以及实现类

@Service
public interface PrintService {
    public String print(TestDto testDto);
}

public class PrintServiceImpl implements PrintService {

    @Override
    public String print(TestDto testDto) {
        return "模拟外部系统的接口功能"+testDto.getId();
    }
}

构建Feigin的Service

//此处name需要设置不为空，url需要在.properties中设置
@Service
@FeignClient(url = "${outSide.url}", name = "service2")
public interface FeignService2 {
    @RequestMapping(value = "/custom/outSide", method = RequestMethod.POST)
    @ResponseBody
    public String getMessage(@Valid @RequestBody TestDto testDto);
}

定义Controller

@Autowired
FeignService2 feignService2;
//测试feign调用外部接口入口
@PostMapping("/test2")
public String test2(@RequestBody TestDto testDto) {
    return feignService2.getMessage(testDto);
}

Postman进行测试

添加Header解决方法

将token等信息放入Feign请求头中，主要通过重写RequestInterceptor的apply方法实现

定义config

@Configuration
public class FeignConfig implements RequestInterceptor {
    @Override
    public void apply(RequestTemplate requestTemplate) {
        //添加token
        requestTemplate.header("token", "eyJ0eXAiOiJKV1QiLCJhbGciOiJIUzUxMiJ9.eyJ4ZGFwYXBwaWQiOiIzNDgxMjU4ODk2OTI2OTY1NzYiLCJleHAiOjE2NjEyMjY5MDgsImlhdCI6MTY2MTIxOTcwOCwieGRhcHRlbmFudGlkIjoiMzAwOTgxNjA1MTE0MDUyNjA5IiwieGRhcHVzZXJpZCI6IjEwMDM0NzY2MzU4MzM1OTc5NTIwMCJ9.fZAO4kJSv2rSH0RBiL1zghdko8Npmu_9ufo6Wex_TI2q9gsiLp7XaW7U9Cu7uewEOaX4DTdpbFmMPvLUtcj_sQ");
    }
}

定义Service

@Service
@FeignClient(url = "${outSide.url}",name = "feignServer", configuration = FeignDemoConfig.class)
public interface TokenDemoClient {
    @RequestMapping(value = "/custom/outSideAddToken", method = RequestMethod.POST)
    @ResponseBody
    public String getMessage(@Valid @RequestBody TestDto testDto);
}

定义controller

//测试feign调用外部接口入口，加上token
@PostMapping("/testToken")
public String test4(@RequestBody TestDto testDto) {
    return tokenDemoClient.getMessage(testDto);
}