CloseableHttpClient httpclient = HttpClients.createDefault();
HttpGet httpget = new HttpGet("https://localhost/");
CloseableHttpResponse response = httpclient.execute(httpget);
try {
 <...>
} finally {
 response.close();
}

URI uri = new URIBuilder()
  .setScheme("http")
  .setHost("www.google.com")
  .setPath("/search")
  .setParameter("q", "httpclient")
  .setParameter("btnG", "Google Search")
  .setParameter("aq", "f")
  .setParameter("oq", "")
  .build();
HttpGet httpget = new HttpGet(uri);
System.out.println(httpget.getURI());

HttpResponse response = new BasicHttpResponse(HttpVersion.HTTP_1_1, 
HttpStatus.SC_OK, "OK");
 
System.out.println(response.getProtocolVersion());
System.out.println(response.getStatusLine().getStatusCode());
System.out.println(response.getStatusLine().getReasonPhrase());
System.out.println(response.getStatusLine().toString());
//输出结果
/*
HTTP/1.1
200
OK
HTTP/1.1 200 OK
*/

HttpResponse response = new BasicHttpResponse(HttpVersion.HTTP_1_1,HttpStatus.SC_OK 
 ,"OK"); 
response.addHeader("Set-Cookie",
 "c1 = a; path = /; domain = localhost"); 
response.addHeader("Set-Cookie",
 "c2 = b; path = \"/ \",c3 = c; domain = \"localhost \""); 
 
HeaderIterator it = response.headerIterator("Set-Cookie"); 
 
while(it.hasNext()){ 
 System.out.println(it.next()); 
}

HttpResponse response = new BasicHttpResponse(HttpVersion.HTTP_1_1,HttpStatus.SC_OK 
 ,"OK"); 
response.addHeader("Set-Cookie",
 "c1 = a; path = /; domain = localhost"); 
response.addHeader("Set-Cookie",
 "c2 = b; path = \"/ \",c3 = c; domain = \"localhost \""); 
HeaderElementIterator it = new BasicHeaderElementIterator(
 response.headerIterator("Set-Cookie")); 
while(it.hasNext()){ 
 HeaderElement elem = it.nextElement(); 
 System.out.println(elem.getName()+"="+ elem.getValue()); 
 NameValuePair [] params = elem.getParameters(); 
 for(int i = 0; i <params.length; i ++){ 
  System.out。println(""+ params [i]); 
 } 
}

StringEntity myEntity = new StringEntity("important message", 
 ContentType.create("text/plain", "UTF-8"));
System.out.println(myEntity.getContentType());
System.out.println(myEntity.getContentLength());
System.out.println(EntityUtils.toString(myEntity));
System.out.println(EntityUtils.toByteArray(myEntity).length);

CloseableHttpClient httpclient = HttpClients.createDefault(); 
HttpGet httpget = new HttpGet("http：// localhost /"); 
CloseableHttpResponse response = httpclient.execute(httpget); 
try{ 
 HttpEntity entity = response.getEntity(); 
 if(entity!= null){ 
  InputStream instream = entity.getContent(); 
  try{ 
   //做一些有用的事情
  } finally { 
   instream.close(); 
  } 
 } 
} finally { 
 response.close(); 
}

CloseableHttpClient httpclient = HttpClients.createDefault(); 
HttpGet httpget = new HttpGet("http：// localhost /"); 
CloseableHttpResponse response = httpclient.execute(httpget); 
try{ 
 HttpEntity entity = response.getEntity(); 
 if(entity!= null){ 
  InputStream instream = entity.getContent(); 
  int byteOne = instream.read(); 
  int byteTwo = instream.read(); 
  //不需要休息
 } 
} finally { 
 response.close(); 
}

CloseableHttpClient httpclient = HttpClients.createDefault(); 
HttpGet httpget = new HttpGet("http：// localhost /"); 
CloseableHttpResponse response = httpclient.execute(httpget); 
try{ 
 HttpEntity entity = response.getEntity(); 
 if(entity!= null){ 
  long len = entity.getContentLength(); 
  if(len!= -1 && len <2048){ 
   System.out.println(EntityUtils.toString(entity)); 
  } else { 
   // Stream content out 
  } 
 } 
} finally { 
 response.close(); 
}

CloseableHttpResponse response = <...> 
HttpEntity entity = response.getEntity(); 
if(entity!= null){ 
 entity = new BufferedHttpEntity(entity); 
}

File file = new File("somefile.txt"); 
FileEntity entity = new FileEntity(file,
 ContentType.create("text / plain","UTF-8"));  
HttpPost httppost = new HttpPost("http：//localhost/action.do"); 
httppost.setEntity(entity);

List <NameValuePair> formparams = new ArrayList <NameValuePair>(); 
formparams.add(new BasicNameValuePair("param1","value1")); 
formparams.add(new BasicNameValuePair("param2","value2")); 
UrlEncodedFormEntity entity = new UrlEncodedFormEntity(formparams,Consts.UTF_8); 
HttpPost httppost = new HttpPost("http：//localhost/handler.do"); 
httppost.setEntity(entity);

param1=value1¶m2=value2

StringEntity entity = new StringEntity("important message",
  ContentType.create("plain / text",Consts.UTF_8)); 
entity.setChunked(true); 
HttpPost httppost = new HttpPost("http：//localhost/acrtion.do"); 
httppost.setEntity(entity);

CloseableHttpClient httpclient = HttpClients.createDefault();
HttpGet httpget = new HttpGet("http://localhost/json");
ResponseHandler<MyJsonObject> rh = new ResponseHandler<MyJsonObject>() {
 @Override
 public JsonObject handleResponse(
   final HttpResponse response) throws IOException {
  StatusLine statusLine = response.getStatusLine();
  HttpEntity entity = response.getEntity();
  if (statusLine.getStatusCode() >= 300) {
   throw new HttpResponseException(
     statusLine.getStatusCode(),
     statusLine.getReasonPhrase());
  }
  if (entity == null) {
   throw new ClientProtocolException("Response contains no content");
  }
  Gson gson = new GsonBuilder().create();
  ContentType contentType = ContentType.getOrDefault(entity);
  Charset charset = contentType.getCharset();
  Reader reader = new InputStreamReader(entity.getContent(), charset);
  return gson.fromJson(reader, MyJsonObject.class);
 }
};
MyJsonObject myjson = client.execute(httpget, rh);