How do I send an HTTP POST request?

By Wayan in Apache HttpComponents 7 Comments

The following code snippet will show you how to send an HTTP post request using the Apache HttpComponents. We will send a post request to https://httpbin.org/post`, with some parameters to the request using theNameValuePair` object.

To pass these parameters to the HTTP post request we create an instance of UrlEncodedFormEntity and pass a list of NameValuePair as the arguments. And before executing the request we set this entity object to the HttpPost.setEntity() method.

Let’s see the code below:

package org.kodejava.apache.http;

import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.HttpClient;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.HttpClientBuilder;
import org.apache.http.message.BasicNameValuePair;
import org.apache.http.util.EntityUtils;

import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

public class HttpPostExample {
    public static void main(String[] args) {
        HttpClient client = HttpClientBuilder.create().build();
        HttpPost post = new HttpPost("https://httpbin.org/post");

        // Create some NameValuePair for HttpPost parameters
        List<NameValuePair> arguments = new ArrayList<>(3);
        arguments.add(new BasicNameValuePair("username", "admin"));
        arguments.add(new BasicNameValuePair("firstName", "System"));
        arguments.add(new BasicNameValuePair("lastName", "Administrator"));

        try {
            post.setEntity(new UrlEncodedFormEntity(arguments));
            HttpResponse response = client.execute(post);

            // Print out the response message
            System.out.println(EntityUtils.toString(response.getEntity()));
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

Maven Dependencies

<!-- https://search.maven.org/remotecontent?filepath=org/apache/httpcomponents/httpclient/4.5.13/httpclient-4.5.13.jar -->
<dependency>
    <groupId>org.apache.httpcomponents</groupId>
    <artifactId>httpclient</artifactId>
    <version>4.5.13</version>
</dependency>

Maven Central

Latest posts by Wayan (see all)
Views: 49,552

7 Comments

  2. You can try the code snippet below to send JSON message.

    ...
HttpClient httpClient = HttpClientBuilder.create().build();
HttpPost request = new HttpPost("http://localhost:8080/servlet");

String payload = "data={\"message\": \"Hello World\"}";
StringEntity entity = new StringEntity(payload, ContentType.APPLICATION_FORM_URLENCODED);
request.setEntity(entity);

HttpResponse response = httpClient.execute(request);
...

    If you are calling a servlet, you can get the JSON string by calling request.getParameter("data");

    Reply

Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.