Posting with HttpClient

Basic POST

CloseableHttpClient client = HttpClients.createDefault();
HttpPost httpPost = new HttpPost(HTTPCLIENT_URL);
List<NameValuePair> params = new ArrayList<NameValuePair>();
params.add(new BasicNameValuePair("username", "John"));
params.add(new BasicNameValuePair("password", "pass"));
httpPost.setEntity(new UrlEncodedFormEntity(params));

Note how we used a List of NameValuePair to include parameters in the POST request.

POST With Authorization

httpPost.setEntity(new StringEntity("test post"));
UsernamePasswordCredentials creds = new UsernamePasswordCredentials(
	"John", "pass");
httpPost.addHeader(
	new BasicScheme().authenticate(creds, httpPost, null));

POST With JSON

String json = "{\"id\":1,\"name\":\"John\"}";
StringEntity entity = new StringEntity(json);
httpPost.setEntity(entity);
httpPost.setHeader("Accept", "application/json");
httpPost.setHeader("Content-type", "application/json");

Note how we’re using the StringEntity to set the body of the request.

We’re also setting the ContentType header to application/json to give the server the necessary information about the representation of the content we’re sending.

POST With the HttpClient Fluent API

HttpResponse response = Request.Post(HTTPCLIENT_URL)
	.bodyForm(Form.form().add("username", "John")
		.add("password", "pass").build())
	.execute().returnResponse();

POST Multipart Request

MultipartEntityBuilder builder = MultipartEntityBuilder.create();
builder.addTextBody("username", "John");
builder.addTextBody("password", "pass");
builder.addBinaryBody("file", new File(FILE_PATHNAME),
	ContentType.APPLICATION_OCTET_STREAM, FILENAME);
HttpEntity multipart = builder.build();
httpPost.setEntity(multipart);

Upload a File Using HttpClient

MultipartEntityBuilder builder = MultipartEntityBuilder.create();
builder.addBinaryBody("file", new File(FILE_PATHNAME),
	ContentType.APPLICATION_OCTET_STREAM, FILENAME);
HttpEntity multipart = builder.build();
httpPost.setEntity(multipart);

Get File Upload Progress

MultipartEntityBuilder builder = MultipartEntityBuilder.create();
builder.addBinaryBody("file", new File(FILE_PATHNAME),
	ContentType.APPLICATION_OCTET_STREAM, FILENAME);
HttpEntity multipart = builder.build();
ProgressEntityWrapper.ProgressListener pListener = percentage -> assertFalse(
	Float.compare(percentage, 100) > 0);
httpPost.setEntity(new ProgressEntityWrapper(multipart, pListener));

Note that:

  • When extending FilterOutputStream to CountingOutputStream – we are overriding the write() method to count the written (transferred) bytes
  • When extending HttpEntityWrapper to ProgressEntityWrapper – we are overriding the writeTo() method to use our CountingOutputStream

Results

  • HttpClientPostTest