spring boot RestTemplate 发送get请求的踩坑及解决

时间:2021-08-11 15:14:51

spring boot RestTemplate 发送get请求踩坑

闲话少说,代码说话

RestTemplate 实例

手动实例化,这个我基本不用

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RestTemplate restTemplate = new RestTemplate();

依赖注入,通常情况下我使用 java.net 包下的类构建的 SimpleClientHttpRequestFactory

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@Configuration
public class RestConfiguration {
    @Bean
    @ConditionalOnMissingBean({RestOperations.class, RestTemplate.class})
    public RestOperations restOperations() {
        SimpleClientHttpRequestFactory requestFactory = new SimpleClientHttpRequestFactory();
        requestFactory.setReadTimeout(5000);
        requestFactory.setConnectTimeout(5000);
        RestTemplate restTemplate = new RestTemplate(requestFactory);
        // 使用 utf-8 编码集的 conver 替换默认的 conver(默认的 string conver 的编码集为 "ISO-8859-1")
        List<HttpMessageConverter<?>> messageConverters = restTemplate.getMessageConverters();
        Iterator<HttpMessageConverter<?>> iterator = messageConverters.iterator();
        while (iterator.hasNext()) {
            HttpMessageConverter<?> converter = iterator.next();
            if (converter instanceof StringHttpMessageConverter) {
                iterator.remove();
            }
        }
        messageConverters.add(new StringHttpMessageConverter(Charset.forName("UTF-8")));
        return restTemplate;
    }
}

请求地址

get 请求 url 为

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http://localhost:8080/test/sendSms?phone=手机号&msg=短信内容

错误使用

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@Autowired
private RestOperations restOperations;
public void test() throws Exception{
    String url = "http://localhost:8080/test/sendSms";
    Map<String, Object> uriVariables = new HashMap<String, Object>();
    uriVariables.put("phone", "151xxxxxxxx");
    uriVariables.put("msg", "测试短信内容");
    String result = restOperations.getForObject(url, String.class, uriVariables);
}

服务器接收的时候你会发现,接收的该请求时没有参数的

正确使用

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@Autowired
private RestOperations restOperations;
public void test() throws Exception{
    String url = "http://localhost:8080/test/sendSms?phone={phone}&msg={phone}";
    Map<String, Object> uriVariables = new HashMap<String, Object>();
    uriVariables.put("phone", "151xxxxxxxx");
    uriVariables.put("msg", "测试短信内容");
    String result = restOperations.getForObject(url, String.class, uriVariables);
}

等价于

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@Autowired
private RestOperations restOperations;
public void test() throws Exception{
    String url = "http://localhost:8080/test/sendSms?phone={phone}&msg={phone}";
    String result = restOperations.getForObject(url, String.class"151xxxxxxxx", "测试短信内容");
}

springboot restTemplate访问get,post请求的各种方式

springboot中封装好了访问外部请求的方法类,那就是RestTemplate。下面就简单介绍一下,RestTemplate访问外部请求的方法。

get请求

首先get请求的参数是拼接在url后面的。所以不需要额外添加参数。但是也需要分两种情况。

1、 有请求头

由于 getForEntity() 和 getForObject() 都无法加入请求头。所以需要请求头的连接只能使用 exchange() 来访问。代码如下

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public JSONObject test(){
        try {
            RestTemplate re = new RestTemplate();
            HttpHeaders headers = new HttpHeaders();
            String url = "http://test.api.com?id=123";
            headers.set("Content-Type","application/json");
            HttpEntity<JSONObject> jsonObject= re.exchange(url, HttpMethod.GET,new HttpEntity<>(headers),JSONObject.class);
            log.info("返回:{}",jsonObject.getBody());
            return jsonObject.getBody();
        }catch (Exception e){
            log.error(e.getMessage());
        }
        return null;
    }

2、 无请求头

无需请求头的可以用三个方法实现。getForEntity() 和 getForObject() 还有 exchange() 都可以实现。下面讲前两种用的比较多的。

getForEntity()

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public JSONObject test(){
        try {
            RestTemplate re = new RestTemplate();
            String url = "http://api.help.bj.cn/apis/alarm/?id=101020100";
            HttpEntity<JSONObject> jsonObject= re.getForEntity(url,JSONObject.class);
            log.info("返回:{}",jsonObject.getBody());
            return jsonObject.getBody();
        }catch (Exception e){
            log.error(e.getMessage());
        }
        return null;
    }

getForObject()

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public JSONObject test(){
        try {
            RestTemplate re = new RestTemplate();
            String url = "http://api.help.bj.cn/apis/alarm/?id=101020100";
            JSONObject jsonObject= re.getForObject(url,JSONObject.class);
            log.info("返回:{}",jsonObject);
            return jsonObject;
        }catch (Exception e){
            log.error(e.getMessage());
        }
        return null;
    }

post请求

post请求也分几种情况

1、参数在body的form-data里面

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public static JSONObject test(){
        try {
            RestTemplate re = new RestTemplate();
            String url = "http://localhost:8101/test";
            HttpHeaders headers = new HttpHeaders();
            headers.setContentType(MediaType.MULTIPART_FORM_DATA);
            MultiValueMap<String, Object> loginJson = new LinkedMultiValueMap<>();
            loginJson.add("id", "123");
            JSONObject jsonObject= re.postForObject(url,new HttpEntity<>(loginJson,headers),JSONObject.class);
            log.info("返回:{}",jsonObject);
            return jsonObject;
        }catch (Exception e){
            log.error(e.getMessage());
        }
        return null;
    }

还可以把 postForObject 换成 postForEntity

2、参数在body的x-www-from-urlencodeed里面

只需要把请求头的setContentType改成下面即可

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headers.setContentType(MediaType.APPLICATION_FORM_URLENCODED);
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public static JSONObject test(){
        try {
            RestTemplate re = new RestTemplate();
            String url = "http://localhost:8101/test";
            HttpHeaders headers = new HttpHeaders();
            headers.setContentType(MediaType.APPLICATION_FORM_URLENCODED);
            MultiValueMap<String, Object> loginJson = new LinkedMultiValueMap<>();
            loginJson.add("id", "123");
            JSONObject jsonObject= re.postForObject(url,new HttpEntity<>(loginJson,headers),JSONObject.class);
            log.info("返回:{}",jsonObject);
            return jsonObject;
        }catch (Exception e){
            log.error(e.getMessage());
        }
        return null;
    }

3、参数在body的raw里面

spring boot RestTemplate 发送get请求的踩坑及解决

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public static JSONObject test(){
       try {
           RestTemplate re = new RestTemplate();
           String url = "http://localhost:8101/test";
           HttpHeaders headers = new HttpHeaders();
           headers.set("Content-Type","application/json");
           JSONObject jsonObject = new JSONObject();
           jsonObject.put("id","1");
           JSONObject jsonObject1 = restTemplate
                   .postForObject(url,new HttpEntity<>(jsonObject,headers),JSONObject.class);
           log.info("返回:{}",jsonObject1);
           return jsonObject;
       }catch (Exception e){
           log.error(e.getMessage());
       }
       return null;
   }

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服务器之家。

原文链接:https://blog.csdn.net/MitKey/article/details/53956520