发送HttpPost请求时的HttpEntity概念

Question

我知道如何在android中发送帖子请求。我使用以下示例代码：

...
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HttpEntity的概念是什么？ HttpEntity课背后的想法是什么？

Answer 1

来自HTTPEntity doc：可以使用HTTP消息发送或接收的实体。可以在某些requests和responses中找到实体，它们是可选的。