http post request in java

http post request in java

• In java there are many libraries to verify http post method.one of the library easy to use httpClient.
• An HttpClient can be used to send requests and retrieve their responses. An HttpClient is created through a builder. The builder can be used to configure per-client state, like: the preferred protocol version ( HTTP/1.1 or HTTP/2 ), whether to follow redirects, a proxy, an authenticator, etc. Once built, an HttpClient is immutable, and can be used to send multiple requests.
• In order to use httpClient download httpClient jar from mvn repository or add dependency in your project.

Key notes about POST method:

• POST method is used to data to server (for creation or updation of data)
• POST request can never be cached, bookmarked and remained in browser history.
• POST request can't be bookmarked
• POST requests do not remain in browser history
• POST requests have no length restrictions.

import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.entity.StringEntity;
import org.apache.http.impl.client.HttpClientBuilder;
import org.apache.http.util.EntityUtils;
import org.json.simple.JSONObject;
import org.json.simple.parser.JSONParser;

public class PostDemo {
    public static void main(String[] args) throws Exception {

    HttpClient httpclient = HttpClientBuilder.create().build();

    // Creating a HttpPost object
    HttpPost httppost = new HttpPost("https://reqres.in/api/login");

    System.out.println("Request Type: " + httppost.getMethod());

    //adding headers
    httppost.addHeader("Content-Type", "application/json");

    String body = "{" + "    \"email\": \"eve.holt@reqres.in\"," + "    \"password\": \"cityslicka\"" + "}";

    StringEntity reqBody = new StringEntity(body);
    httppost.setEntity(reqBody);
    // Executing the post request
    HttpResponse httpresponse = httpclient.execute(httppost);

    //converting post api response to string
    String jsonString = EntityUtils.toString(httpresponse.getEntity());
    //convert api response to JSON object
    JSONParser parser = new JSONParser();
    JSONObject json = (JSONObject) parser.parse(jsonString);
    String accessToken = (String) json.get("token");

    System.out.println("Token from server=" + accessToken);
  }
}

Output:
http post request in java
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