How to build a job using the REST API and Java?

Article ID:226852648
2 minute readKnowledge base

Issue

I would like to be able to build a job remotely using the Jenkins REST API and Java. This provides a workaround for JENKINS-12543, that doesn’t require SSH Key Authentication.

Environment

Resolution

Example build:

import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.Base64;

public class Main {
  public static void main(String[] args) {
    try {
      URL url = new URL("https://localhost:8080/job/test/build"); // Jenkins URL localhost:8080, job named 'test'
      String user = "developer"; // username
      String pass = "developer"; // password or API token
      String authStr = user + ":" + pass;
      String encoding = Base64.getEncoder().encodeToString(authStr.getBytes("utf-8"));

      HttpURLConnection connection = (HttpURLConnection) url.openConnection();
      connection.setRequestMethod("POST");
      connection.setDoOutput(true);
      connection.setRequestProperty("Authorization", "Basic " + encoding);
      InputStream content = connection.getInputStream();
      BufferedReader in = new BufferedReader(new InputStreamReader(content));
      String line;
      while ((line = in.readLine()) != null) {
        System.out.println(line);
      }
    } catch (Exception e) {
      e.printStackTrace();
    }
  }
}

Obviously, replace:

  • developer:developer with your username:password

  • localhost:8080 with your Jenkins URL

  • test with your job name

Example build with String parameter:

import java.io.BufferedReader;
import java.io.DataOutputStream;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.Base64;

public class Main {
  public static void main(String[] args) {
    try {
      URL url = new URL("https://localhost:8080/job/test/buildWithParameters"); // Jenkins URL localhost:8080, job named 'test'
      String user = "developer"; // username
      String pass = "developer"; // password or API token
      String authStr = user + ":" + pass;
      String encoding = Base64.getEncoder().encodeToString(authStr.getBytes("utf-8"));

      HttpURLConnection connection = (HttpURLConnection) url.openConnection();
      connection.setRequestMethod("POST");
      connection.setDoOutput(true);
      connection.setRequestProperty("Authorization", "Basic " + encoding);

      String urlParams = "paramA=123";
      byte[] postData = urlParams.getBytes("utf-8");
      try (DataOutputStream wr = new DataOutputStream(connection.getOutputStream())) {
        wr.write(postData);
      }

      InputStream content = connection.getInputStream();
      BufferedReader in = new BufferedReader(new InputStreamReader(content));
      String line;
      while ((line = in.readLine()) != null) {
        System.out.println(line);
      }
    } catch (Exception e) {
      e.printStackTrace();
    }
  }
}

Obviously, replace:

  • developer:developer with your username:password

  • localhost:8080 with your Jenkins URL

  • test with your job name

  • paramA with your parameter name

  • 123 with your parameter value

See Remote Access API for more.

This article is part of our Knowledge Base and is provided for guidance-based purposes only. The solutions or workarounds described here are not officially supported by CloudBees and may not be applicable in all environments. Use at your own discretion, and test changes in a safe environment before applying them to production systems.