20 Most Useful Java Cheat Sheets For Developers | 2025 Edition

First appeared in 1996, Java is one of the most popular programming languages for developing application software and deploying it in a cross-platform computing environment. It is widely used in smartphones, embedded devices, supercomputers and enterprise servers. Currently, Java is the third most popular language on Github, after JavaScript and Python.

We all know the importance of programming cheat sheets, especially for beginners. It helps you save a lot of time and accomplish a particular task. We have gathered some of the most useful and complete cheat sheet that will increase your productivity. Let’s begin.

20. Java Fundamentals Cheat Sheet

Format: PDF and OnlineWebpage

It’s a small and very basic cheat sheet for beginners, which includes Java data types, conversions, string methods, arithmetic operator, and text formatting details.

19. Java Midterm Cheat Sheet

Format: PDF and OnlineWebpage

This is a brief cheat sheet containing String methods, abstract classes, interface, array methods, vocabulary, loops, math method, escape sequence and much more.

18. Java EE Security Essentials

Format: PDF and OnlineWebpage

This is a detailed cheat sheet that explores web module security, authentication authorization, application client security and EJB module security with in-depth examples.

17. Java Quick Reference

Format: PDF

It’s basic cheat sheet for beginners to check out logical operators, flow control, array and class syntax, arithmetic operators, keywords and Java extension packages.

16. APIs of Common Libraries

Format: OnlineWebpage

This cheat sheet summarizes the most commonly used Java language features, including, math library, Java library cells, type conversion, anatomy of while-loop, break statements, arrays, command line, graphs, redirection and piping.

15. OverAPI Java

Format: OnlineWebpage

OverAPI contains almost all basic and commonly used elements of data structure, string, object oriented topic, and classes. Clicking on each element would take you to the new webpage that provides the description of the element (that you’ve clicked) along with examples.

14. Using XML in Java

Format: PDF and OnlineWebpage

Since Java is a diverse platform, it has numerous solutions for working with XML. This detailed guide offers an overview of different XML processing technologies in Java, along with a use case of each technology.

13. Java Collections Cheat Sheet

Format: PDF

All Java programs have one thing in common – they all use Java collections. This brief cheat sheet will help you know about the collections framework, correct use cases, implementation details and how to choose the appropriate collection type.

12. Java 8 Best Practices

Format: PDF and OnlineWebpage

This cheat sheet (created by Rebellabs) uncovers the hot topics of the Java 8 – default methods, lambdas, streams and using optional to represent absent values.

11. Java For Dummies

Format: OnlineWebpage

You can divide your Java program into several categories. This cheat sheet would tell you about all those categories. It includes keywords, literals and identifiers in the Java API.

10. Core Java Concurrency

Format: PDF and OnlineWebpage

It’s a long cheat sheet that helps programmers working with multi-threaded code understand the concepts of core concurrency and how to apply them. It covers inbuilt Java features such as thread, concurrent collections, Locks, thread coordination abstraction and executors.

9. Java Generics Cheat Sheet

Format: PDF

Java Generic cheat sheet provides an overview Generic basics, wildcards, intersection types, method overloading, recursive generics and covariance.

8. Java Elements

Format: JPG and OnlineWebpage

Keep this cheat sheet for a quick reference while learning Java. It contains the basic code structure, data types, functions and inputs and outputs.

7. Java Cheat Sheet for C++ Programmers

Format: PDF and OnlineWebpage

As the name suggests, the cheat sheet is for those who regularly code in C++ language and all of the sudden have switched to Java. It explains the concept of Java by comparing it with the concepts of C++. Moreover, it also shows what Java has that C++ don’t and vice versa.

6. Java OOP Concept

Format: PDF and OnlineWebpage

The cheat sheet contains all elements that will strengthen your understanding on Java object oriented programming paradigm. It contains the basic components, including inheritance, override, encapsulation, HashMap, HashList, interface, attribute and access modifier, and constructor.

5. Java 8+ Cheat Sheet

Format: OnlineWebpage

This cheat sheet is based on Cay Horstmann’s lecture (who has written more than dozen of programming books for students and professionals). It is published on Github and includes lambda expression, collections, streams and optional information.

4. Java GUI Development

Format: PDF and OnlineWebpage

To build standalone Java applications, one can use either SWT (Standard Widget Toolkit) or Java Swing. Both methods share some commonality, but each has its own benefits. This reference guide will help you get started with either.

3. Java Vs. Python

Format: JPG and OnlineWebpage

We all have seen big debates between static and dynamic typing among many programming languages. Well, this infographics is nowhere similar to any kind of debate, but it compares the two world’s most popular languages.

Read: 20+ Helpful Python Cheat Sheet of 2017

2. Java Glossary

Format: OnlineWebpage

This is a quick summary of the Java language syntax. It only contains the elements that you may be likely to forget, including control structure, literals, links, primitives, immutables, Javadoc, and more.

1. Core Java

Format: PDF and OnlineWebpage

Read: What’s New In Java 9 | 19 Added Features and Changes

The cheat sheet gives you an overview of key aspects of the Java language and references on the core library, most commonly used tools and new Java 8 features.

Written by
Varun Kumar

I am a professional technology and business research analyst with more than a decade of experience in the field. My main areas of expertise include software technologies, business strategies, competitive analysis, and staying up-to-date with market trends.

I hold a Master's degree in computer science from GGSIPU University. If you'd like to learn more about my latest projects and insights, please don't hesitate to reach out to me via email at varunkmr09@gmail.com.

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