发送HttpPost请求时的HttpEntity概念

Question

我知道如何在android中发送post请求。我使用下面的示例代码：

... 
HttpPost httpPostRequest = new HttpPost(url); 
private ArrayList <NameValuePair> params = new ArrayList<NameValuePair>(); 
private ArrayList <NameValuePair> headers = new ArrayList<NameValuePair>(); 
..... 
for(int i = 0; i < headers.size(); i++) { 
    StringEntity entity = new StringEntity(headers.get(i).getValue(),"UTF-8"); 
    httpPostRequest.setEntity(entity); 
} 
if(!params.isEmpty()){ 
    HttpEntity httpEntity = new UrlEncodedFormEntity(params,HTTP.UTF_8); 
    httpPostRequest.setEntity(httpEntity); 
} 

String serverResponse = executeRequest(httpPostRequest); 
... 

我只是想知道什么是HttpEntity概念？ HttpEntity类背后有什么想法？

Answer 1

从HTTPEntity doc：可以通过HTTP消息发送或接收的实体。实体可以在requests和responses中找到，它们是可选的。