Java Quickstart

Cloud Functions is a serverless execution environment for building and connecting cloud services. With Cloud Functions you write simple, single-purpose functions that are attached to events emitted from your cloud infrastructure and services. Your function is triggered when an event being watched is fired.

This page shows you how to create and deploy a Java Cloud Function using the Cloud Console. When this function is triggered by an HTTP request, it writes a message:

package com.example;

import com.google.cloud.functions.HttpFunction;
import com.google.cloud.functions.HttpRequest;
import com.google.cloud.functions.HttpResponse;
import java.io.BufferedWriter;

public class Example implements HttpFunction {
  @Override
  public void service(HttpRequest request, HttpResponse response) throws Exception {
    BufferedWriter writer = response.getWriter();
    writer.write("Hello world!");
  }
}

Before you begin

Sign in to your Google Account.
If you don't already have one, sign up for a new account.
In the Google Cloud Console, on the project selector page, select or create a Google Cloud project.

Note: If you don't plan to keep the resources that you create in this procedure, create a project instead of selecting an existing project. After you finish these steps, you can delete the project, removing all resources associated with the project.

Go to the project selector page
Make sure that billing is enabled for your Cloud project. Learn how to confirm that billing is enabled for your project.
Enable the Cloud Functions and Cloud Build APIs.
Enable the APIs

Create a function

Open the Functions Overview page in the Cloud Console:

Go to the Cloud Functions Overview page

Make sure that the project for which you enabled Cloud Functions is selected.
Click Create function.
Name your function.
In the Trigger field, select HTTP.
In the Authentication field, select Allow unauthenticated invocations.
Click Save to save your changes, and then click Next.
In the Source code field, select Inline editor. In this exercise, you will use the default function provided in the editor.
Use the Runtime dropdown to select the desired Java runtime.

Deploy the function

At the bottom of the page, click Deploy.
After clicking Deploy, Cloud Console redirects to the Cloud Functions Overview page.

While the function is being deployed, the icon next to it is a small spinner. After it finishes deploying, the spinner turns to a green check mark:

Test the function

Display the menu for your function, and click Test function.
On the testing page, click Test the function.

The Output screen displays the text "Hello World!"

View logs

Check the logs to see your actions in the log history:

Back on the Cloud Functions Overview page, display the menu for your function, and click View logs.

Your log history appears.

Screenshot showing Logs field with 200 code, indicating success