❯ Guillaume Laforge

Gemini codelab for Java developers using LangChain4j

No need to be a Python developer to do Generative AI! If you’re a Java developer, you can take advantage of LangChain4j to implement some advanced LLM integrations in your Java applications. And if you’re interested in using Gemini, one of the best models available, I invite you to have a look at the following “codelab” that I worked on:

Codelab — Gemini for Java Developers using LangChain4j

In this workshop, you’ll find various examples covering the following use cases, in crescendo approach:

Read more...

Visualize PaLM-based LLM tokens

As I was working on tweaking the Vertex AI text embedding model in LangChain4j, I wanted to better understand how the textembedding-gecko model tokenizes the text, in particular when we implement the Retrieval Augmented Generation approach.

The various PaLM-based models offer a computeTokens endpoint, which returns a list of tokens (encoded in Base 64) and their respective IDs.

Note: At the time of this writing, there’s no equivalent endpoint for Gemini models.

So I decided to create a small application that lets users:

Read more...

Image generation with Imagen and LangChain4j

This week LangChain4j, the LLM orchestration framework for Java developers, released version 0.26.1, which contains my first significant contribution to the open source project: support for the Imagen image generation model.

Imagen is a text-to-image diffusion model that was announced last year. And it recently upgraded to Imagen v2, with even higher quality graphics generation. As I was curious to integrate it in some of my generative AI projects, I thought that would be a great first contribution to LangChain4j.

Read more...

Serving static assets with Micronaut

My go-to framework when developing Java apps or microservices is Micronaut. For the apps that should have a web frontend, I rarely use Micronaut Views and its templating support. Instead, I prefer to just serve static assets from my resource folder, and have some JavaScript framework (usually Vue.js) to populate my HTML content (often using Shoelace for its nice Web Components). However, the static asset documentation is a bit light on explanations. So, since I always forget how to configure Micronaut to serve static assets, I thought that would be useful to document this here.

Read more...

Light Mode Bookmarlet

A while ago, my friend Sylvain Wallez shared a little bookmarlet
on Twitter/X that transforms a dark mode site into light mode.
I know the trend is towards dark mode, but for a lot of people with certain vision issues,
for example with astigmatism like me, certain dark modes can very painful.

This site about vision
(and you’ll find other similar references) mentions that:

People who have myopia or astigmatism also may experience halation (from the word “halo”).
Halation occurs when light spreads past a certain boundary, creating a foggy or blurry appearance.

Read more...

Functional builder approach in Java

In Java, builders are a pretty classical pattern for creating complex objects with lots of attributes. A nice aspect of builders is that they help reduce the number of constructors you need to create, in particular when not all attributes are required to be set (or if they have default values).

However, I’ve always found builders a bit verbose with their newBuilder() / build() method combos, especially when you work with deeply nested object graphs, leading to lines of code of builders of builders of…

Read more...

URL slug or how to remove accents from strings in Java

In this article, we’ll figure out how to create slugs. Not the slobbery kind of little gastropods that crawls on the ground. Instead, we’ll see how to create the short hyphened text you can see in the URL of your web browser, and that is often a URL-friendly variation of the title of the article.

Interestingly, one of the most popular posts on my blog is an almost 20 year old article that explains how to remove accents from a string. And indeed, in slugs you would like to remove accents, among other things.

Read more...

Gemini Function Calling

A promising feature of the Gemini large language model released recently by Google DeepMind, is the support for function calls. It’s a way to supplement the model, by letting it know an external functions or APIs can be called. So you’re not limited by the knowledge cut-off of the model: instead, in the flow of the conversation with the model, you can pass a list of functions the model will know are available to get the information it needs, to complete the generation of its answer.

Read more...

Visualize and Inspect Workflows Executions

When using a service like Google Cloud Workflows, in particular as your workflows get bigger, it can be difficult to understand what’s going on under the hood. With multiple branches, step jumps, iterations, and also parallel branches and iterations, if your workflow fails during an execution, until now, you had to check the execution status, or go deep through the logs to find more details about the failed step.

I have good news for you! Workflows recently added some deeper introspection capability: you can now view the history of execution steps. From the Google Cloud console, you can see the lists of steps, and see the logical flow between them. The usual workflow visualisation will also highlight in green the successful steps, and in red the failed one. Of course, it is also possible to make a curl call to get the JSON of the list of executed steps.

Read more...

Hands on Codelabs to dabble with Large Language Models in Java

Hot on the heels of the release of Gemini, I’d like to share a couple of resources I created to get your hands on large language models, using LangChain4J, and the PaLM 2 model. Later on, I’ll also share with you articles and codelabs that take advantage of Gemini, of course.

The PaLM 2 model supports 2 modes:

  • text generation,
  • and chat.

In the 2 codelabs, you’ll need to have created an account on Google Cloud, and created a project. The codelabs will guide you through the steps to setup the environment, and show you how to use the Google Cloud built-in shell and code editor, to develop in the cloud.

Read more...