RestTemplate 發(fā)送帶headers的GET請求
需求:發(fā)送自定義header的GET請求,header中需要插入一個(gè)簽名。
發(fā)送自定義header的POST請求
之前寫過一個(gè)類似的請求,但是是POST的。這個(gè)也摸了一段時(shí)間,自己看參數(shù)整了出來。代碼如下:
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// header填充 LinkedMultiValueMap<String, String> headers = new LinkedMultiValueMap<>(); headers.put( "Content-Type" , Collections.singletonList( "application/json;charset=UTF-8" )); headers.put( "signature" , Collections.singletonList(makeSignature(form.getNewMobile()))); // body填充 JSONObject json = new JSONObject(); json.put( "oldMobile" , mobile); json.put( "newMobile" , form.getNewMobile()); HttpEntity<String> request = new HttpEntity<String>(json.toString(), headers); // 一個(gè)單例的restTemplate RestTemplate restTemplate = HttpInvoker.getRestTemplate(); // 發(fā)送請求 ResponseEntity<String> response = restTemplate.postForEntity(whiteListURL, request, String. class ); |
很簡單的想著,只需要把上面的postForEntity()改成get的就行,但不是這樣的。
發(fā)送自定義header的GET請求
Update: 2019/12/11
從鏈接學(xué)到了一種比較友好的寫法:
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private static void getEmployees(){ final String uri = "http://localhost:8080/springrestexample/employees" ; RestTemplate restTemplate = new RestTemplate(); HttpHeaders headers = new HttpHeaders(); headers.setAccept(Arrays.asList(MediaType.APPLICATION_JSON)); HttpEntity<String> entity = new HttpEntity<String>( "parameters" , headers); ResponseEntity<String> result = restTemplate.exchange(uri, HttpMethod.GET, entity, String. class ); System.out.println(result); } |
粗略看了看postForEntity()和getForEntity()這兩個(gè)方法的實(shí)現(xiàn),都是準(zhǔn)備參數(shù),然后調(diào)用execute()方法,如下:
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// POST @Override public <T> ResponseEntity<T> postForEntity(String url, @Nullable Object request, Class<T> responseType, Object... uriVariables) throws RestClientException { RequestCallback requestCallback = httpEntityCallback(request, responseType); ResponseExtractor<ResponseEntity<T>> responseExtractor = responseEntityExtractor(responseType); return nonNull(execute(url, HttpMethod.POST, requestCallback, responseExtractor, uriVariables)); } // GET @Override @Nullable public <T> T getForObject(String url, Class<T> responseType, Map<String, ?> uriVariables) throws RestClientException { RequestCallback requestCallback = acceptHeaderRequestCallback(responseType); HttpMessageConverterExtractor<T> responseExtractor = new HttpMessageConverterExtractor<>(responseType, getMessageConverters(), logger); return execute(url, HttpMethod.GET, requestCallback, responseExtractor, uriVariables); } |
區(qū)別就在于RequestCallback實(shí)例化的時(shí)候,傳的參數(shù)不一樣。POST的時(shí)候,是將header做為參數(shù)傳給了RequestCallback。再然后就是execute()中的GET和POST參數(shù)不一樣。到這個(gè)時(shí)候,發(fā)送自定義header的GET請求,已經(jīng)很明顯了。
實(shí)例化的函數(shù),都是public的。
如果不是public的,或者說我們不能直接訪問到,還可以考慮通過反射的方式去調(diào)用相關(guān)的方法,但這里不需要用反射了。
結(jié)果
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// header填充 LinkedMultiValueMap<String, String> headers = new LinkedMultiValueMap<>(); headers.put( "Content-Type" , Collections.singletonList( "application/json;charset=UTF-8" )); headers.put( "signature" , Collections.singletonList(makeSignature(mobile))); // 獲取單例RestTemplate RestTemplate restTemplate = HttpInvoker.getRestTemplate(); HttpEntity request = new HttpEntity(headers); // 構(gòu)造execute()執(zhí)行所需要的參數(shù)。 RequestCallback requestCallback = restTemplate.httpEntityCallback(request, JSONObject. class ); ResponseExtractor<ResponseEntity<JSONObject>> responseExtractor = restTemplate.responseEntityExtractor(JSONObject. class ); // 執(zhí)行execute(),發(fā)送請求 ResponseEntity<JSONObject> response = restTemplate.execute(apiAddress + "/xxx/whitelist/check?phone=" + mobile, HttpMethod.GET, requestCallback, responseExtractor); |
雖然很簡單,但是看似不可能,自己卻做到了、完成了,就很有成就感。
RestTemplate優(yōu)雅的發(fā)送Get請求
在我們的項(xiàng)目中,如果借助RestTemplate發(fā)送帶參數(shù)的Get請求,我們可以通過拼接字符串的方式將url拼接出來,比如下面這種方式:
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String url = "http://127.0.0.1:8080/rest/get?name=" + name + "&id=" + id; ResponseEntity<RestVO> forEntity = restTemplate.getForEntity(url, RestVO. class ); |
然而這種方式不太優(yōu)雅,我們還可以通過以下幾種方式發(fā)送Get請求
方式1:使用占位符
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String url = "http://127.0.0.1:8080/rest/path/{name}/{id}" ; Map<String, Object> params = new HashMap<>(); params.put( "name" , "這是name" ); params.put( "id" , 1L); ResponseEntity<RestVO> forEntity = restTemplate.getForEntity(url, RestVO. class , params); |
Map的key要和url中的占位符一致
方式2:使用LinkedMultiValueMap和UriComponentsBuilder
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String url = "http://127.0.0.1:8080/rest/get" ; MultiValueMap<String, String> params = new LinkedMultiValueMap<>(); params.add( "name" , "這是name" ); params.add( "id" , "1" ); UriComponentsBuilder builder = UriComponentsBuilder.fromHttpUrl(url); URI uri = builder.queryParams(params).build().encode().toUri(); ResponseEntity<RestVO> forEntity = restTemplate.getForEntity(uri, RestVO. class ); return forEntity.getBody(); |
方式2看起來是最優(yōu)雅的,將參數(shù)的設(shè)置和url分離。
以上為個(gè)人經(jīng)驗(yàn),希望能給大家一個(gè)參考,也希望大家多多支持服務(wù)器之家。
原文鏈接:https://sizuoka.blog.csdn.net/article/details/86497531