SpringBoot远程接口调用-RestTemplate使用

朱雀 2023-06-25 04:45 234阅读 0赞

在web服务中,调度远程url是常见的使用场景,最初多采用原生的HttpClient,现采用Spring整合的RestTemplate工具类进行.实操如下:

### 　　1. 配置 ###

主要用以配置远程链接的相关参数.

@Configuration
    public class RestTemplateConfig {
    
        @Bean
        public RestTemplate restTemplate(ClientHttpRequestFactory factory) {
            return new RestTemplate(factory);
        }
    
        @Bean
        public ClientHttpRequestFactory simpleClientHttpRequestFactory() {
            SimpleClientHttpRequestFactory factory = new SimpleClientHttpRequestFactory();
            factory.setConnectTimeout(15000);
            factory.setReadTimeout(5000);
            return factory;
        }
    
    }

### 　　2.实际使用 ###

此处以post请求为例,使用RestTemplate时主要有以下三种方式:postForObject/postForEntity/exchange

@Autowired
    private RestTemplate template;
    
            String url = "http://192.168.2.40:8081/channel/channelHourData/getHourNewUserData";
            // 封装参数，千万不要替换为Map与HashMap，否则参数无法传递
            MultiValueMap<String, Object> paramMap = new LinkedMultiValueMap<String, Object>();
            paramMap.add("dt", "20180416");
     
            // 1、使用postForObject请求接口
            String result = template.postForObject(url, paramMap, String.class);
            System.out.println("result1==================" + result);
     
            // 2、使用postForEntity请求接口
            HttpHeaders headers = new HttpHeaders();
            HttpEntity<MultiValueMap<String, Object>> httpEntity = new HttpEntity<MultiValueMap<String, Object>>(paramMap,headers);
            ResponseEntity<String> response2 = template.postForEntity(url, httpEntity, String.class);
            System.out.println("result2====================" + response2.getBody());
     
            // 3、使用exchange请求接口
            ResponseEntity<String> response3 = template.exchange(url, HttpMethod.POST, httpEntity, String.class);
            System.out.println("result3====================" + response3.getBody());

### 　　3.实操演示 ###

昨日在与其它服务做对接数据时,发现对方实际接收数据有误,换了几种请求方式,要么就是编码有误/要么就是请求体展示有误,随着问题排查的深入,还出现了框架层面报错类转换异常的问题

代码如下 :

// 发送请求
    
    String url = callback;
    
    HttpHeaders requestHeaders = new HttpHeaders();
    //requestHeaders.add("Content-Type","application/x-www-form-urlencoded");
    requestHeaders.add("charset","UTF-8");
    requestHeaders.setContentType(MediaType.APPLICATION_FORM_URLENCODED);
    
    LinkedMultiValueMap<String, Object> paramMap = new LinkedMultiValueMap<>();
    paramMap.add("message","Ok");
    paramMap.add("code","200");
    paramMap.add("data",data.toJSONString());
    
    HttpEntity<LinkedMultiValueMap<String,Object>> httpEntity = new HttpEntity<>(paramMap, requestHeaders);
    
    ResponseEntity<String> exchange = restTemplate.postForEntity(url,httpEntity,String.class);
    
    String resultRemote = exchange.getBody();

注意事项:

1.与接口方约定好请求头信息 , 如 此处的媒体类型值即为 :  application/x-www-form-urlencoded

2.在使用HttpEntity时,注意请求体,value需为String类型.原因在于:Spring框架在遍历请求体参数时,会强转为String,故此处code设置为 "200"

转载于:https://www.cnblogs.com/nyatom/p/9479535.html