I Used Java to Build a Stock Market Prediction App | by Sam Java Dev 🖐 | Apr, 2025

Let me guess — you’ve in all probability thought no less than as soon as that predicting the inventory market is simply fancy fortune-telling, proper?

Effectively, similar right here. Till I acquired sick of watching everybody faux they’re the subsequent Wall Avenue wizard on Reddit and determined to construct my very own inventory market prediction app.

With Java. Sure, that Java. The one everybody likes to hate. Or hates to like.

However earlier than we dive into the code jungle, let me take you again a bit.

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It began after I misplaced 50 bucks betting on a “secure” inventory choose from TikTok. Yeah, sensible.

I believed: There’s acquired to be a greater method to do that.

Spoiler: there may be. Nevertheless it entails knowledge, fashions, APIs, and sufficient espresso to make a barista involved in your well being.

So, I did what any barely unhinged developer would do — I made a decision to construct my very own inventory predictor. Utilizing Java. As a result of I like ache, apparently.

Individuals say Java is outdated. Clunky. Verbose. And so they’re proper.

Nevertheless it’s additionally steady, mature, and has a bajillion libraries able to do the heavy lifting.

I wished one thing dependable for backend processing. Not some stylish language that breaks each different week with a brand new replace.

So Java it was. Decide me, I don’t care.

Step 1️⃣: Scraping Inventory Knowledge (The Not-So-Wonderful Starting)

First, we’d like knowledge. A lot of it. I used the Alpha Vantage API. It’s free, largely sane, and offers you day by day time collection knowledge.

Right here’s how I did it:

public class StockDataFetcher {
non-public static last String API_KEY = "YOUR_API_KEY";
non-public static last String BASE_URL = "https://www.alphavantage.co/question?operate=TIME_SERIES_DAILY&image=%s&apikey=%s";
public…