RestTemplate、HttpHeaders、HttpEntity

import org.springframework.http.HttpEntity;
import org.springframework.http.HttpHeaders;
import org.springframework.web.client.RestTemplate;

public static String handelPost(String url, String body){
   RestTemplate restTemplate = new RestTemplate();
   HttpHeaders headers = new HttpHeaders();
   HttpEntity<String> formEntity = new HttpEntity<>(body, headers);
   String str= restTemplate.postForEntity(url, formEntity, String.class).getBody();
   return str;
}

HttpEntity和@RequestBody和@ResponseBody很像。除了能夠訪問請求和響應體，HttpEntity（和子類ResponseEntity）也能訪問請求（和響應）頭

@RequestMapping("/something")

public ResponseEntity<String> handle(HttpEntity<byte[]> requestEntity) throws UnsupportedEncodingException 

{ String requestHeader = requestEntity.getHeaders().getFirst("MyRequestHeader"); byte[] requestBody = requestEntity.getBody(); // do something with request header and body HttpHeaders responseHeaders = new HttpHeaders(); responseHeaders.set("MyResponseHeader", "MyValue"); return new ResponseEntity<String>("Hello World", responseHeaders, HttpStatus.CREATED); }

  上面的例子獲取MyRequestHeader請求頭的值，讀取請求體為字節數組。還把MyResponseHeader添加到響應中，把Hello World寫到響應流中，並設置響應狀態碼為 201（創建）。

  就像@RequestBody和@ResponseBody一樣，Spring 使用HttpMessageConverter在請求和響應流之間進行轉換。