# Java Viewer

Free online Java viewer. Open .java source files directly in your browser without uploading them.

> Canonical page: https://elysiatools.com/en/viewers/java

- **Category:** Text Files

- **Supported formats:** .java

## Overview

This Java viewer renders source files locally in your browser. Java is a class-based, object-oriented language that runs on the JVM and powers enterprise backends, Android apps, and large systems. Pick a sample or choose your own .java file to inspect classes, methods, and generics with highlighting.

## When to use

- You have a Java file and want to read it without an editor.
- You need to inspect classes, methods, or generics quickly.
- You are on a device without a code editor and need to browse a .java file.

## How it works

- Select a built-in sample or choose your own .java file.
- The viewer renders the source with syntax highlighting in the browser, with no upload.
- Inspect the code, then switch samples or load another file any time.

## Use cases

- Reviewing classes, interfaces, and generics.
- Inspecting records, sealed types, and stream pipelines.
- Browsing Java code on any device.

## Samples

- **Java Invalid Variable Names**: Java code demonstrating invalid variable names including numbers at start, special characters, and Java keywords
- **Classes & Generics**: A Java class with an inner class, generics, and a main method
- **Records & Streams**: Modern Java with sealed interfaces, records, and stream pipelines
- **Concurrency**: Java concurrency with ExecutorService, Future, and ConcurrentHashMap

## Frequently asked questions

### Is this Java viewer free?

Yes. It runs in your browser for free and needs no registration or installation.

### Are my Java files uploaded?

No. Files opened from your device stay on your device. Only public sample files come from the server.

### Does it compile or run the Java code?

No. The viewer shows the source with highlighting; it does not compile or execute it.

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