/**
    String/URI url: 請(qǐng)求的URL路徑
    request: 一般設(shè)置請(qǐng)求頭和請(qǐng)求體
    responseType:請(qǐng)求完成之后返回的結(jié)果類型
    Map<String, ?>/Object... uriVariables: 用來拼接請(qǐng)求url，可以是Map<String, ?>類型或Object類型可變參數(shù)
**/
postForObject/postForEntity(String url, Object request, Class<T> responseType, Object... uriVariables)
eg：
void fun() {
    HttpHeaders headers = new HttpHeaders(); 
    headers.setContentType(MediaType.APPLICATION_JSON);
    MultiValueMap<String, Object> params = new LinkedMultiValueMap<>();
    HttpEntity<String> httpEntity = new HttpEntity<>(params, headers);
    // 注意，如果想要使用可變參數(shù)來拼接url，那這里的url一定要使用占位符{}替換，并且名稱要和可變參數(shù)名稱一樣才能在運(yùn)行時(shí)將占位符位置替換成傳入動(dòng)態(tài)參數(shù)【可變參數(shù)也可以不傳，那么這里的url就不需要占位符拼接】
    String url = "http://www.sea.com?uid={uid}&username={username}";
    String uid = "123";
    String username = "sea";
    // 因?yàn)閞esponseType用的是String類型，所以返回的是一個(gè)String類型字符串
    String result = restTemplate.postForObject(url, httpEntity, String.class, uid, username);
}
postForObject/postForEntity(String url, Object request, Class<T> responseType, Map<String, ?> uriVariables)
eg：
void fun() {
    HttpHeaders headers = new HttpHeaders(); 
    headers.setContentType(MediaType.APPLICATION_JSON);
    MultiValueMap<String, Object> params = new LinkedMultiValueMap<>();
    HttpEntity<String> httpEntity = new HttpEntity<>(params, headers);
    // 注意，如果想要使用可變參數(shù)來拼接url，那這里的url一定要使用占位符{}替換，并且名稱要和可變參數(shù)名稱一樣才能在運(yùn)行時(shí)將占位符位置替換成傳入動(dòng)態(tài)參數(shù)
    String url = "http://www.sea.com?uid={uid}&username={username}";
    Map<String, Object> params = new HashMap<>();
    String uid = "123";
    String username = "sea";
    params.put("uid", uid);
    params.put("username", username)
    // 因?yàn)閞esponseType用的是String類型，所以返回的是一個(gè)String類型字符串
    String result = restTemplate.postForObject(url, httpEntity, String.class, params);
}
postForObject/postForEntity(URI url, Object request, Class<T> responseType)
eg：
void fun() {
    HttpHeaders headers = new HttpHeaders(); 
    headers.setContentType(MediaType.APPLICATION_JSON);
    MultiValueMap<String, Object> params = new LinkedMultiValueMap<>();
    HttpEntity<String> httpEntity = new HttpEntity<>(params, headers);
    String url = "http://www.sea.com";
    MultiValueMap<String, String> multiValueMap = new LinkedMultiValueMap<>();
    multiValueMap.put("uid", 123);
    multiValueMap.put("username", "sea");
    // 不再使用可變參數(shù)綁定url，直接傳入綁定后的uri參數(shù)
    URI uri = UriComponentsBuilder.fromHttpUrl(url).queryParams(multiValueMap).build().encode().toUri();
    // 因?yàn)閞esponseType用的是String類型，所以返回的是一個(gè)String類型字符串
    String result = restTemplate.postForObject(uri, httpEntity, String.class);
}
eg: xxforEntity()
void fun() {
    Map<String, Object> map = new HashMap<>();
    map.put("uid", 123);
    map.put("username", "sea");
    HttpHeaders headers = new HttpHeaders();
    headers.setContentType(MediaType.APPLICATION_JSON);
    HttpEntity<HashMap<String, Object>> httpEntity = new HttpEntity<>(map, headers);
    String url = "http://www.sea.com";
    // 使用xxforEntity,返回的是一個(gè)ResponseEntity，里面包含了statusCode(狀態(tài)碼)、Headers(響應(yīng)頭)、body(響應(yīng)體)
    ResponseEntity<String> responseEntity = restTemplate.postForEntity(uri, httpEntity, String.class);
}

getForObject/getForEntity(String url, Class<T> responseType, Object... uriVariables)
getForObject/getForEntity(String url, Class<T> responseType, Map<String, ?> uriVariables)
getForObject/getForEntity(URI url, Class<T> responseType)
在get請(qǐng)求調(diào)用中，除了請(qǐng)求參數(shù)中少了Object request【請(qǐng)求頭和請(qǐng)求體】，其他的參數(shù)和方法調(diào)用同上面post的方法調(diào)用是一樣的