10 Tips to Increase Your Java Performance

Sub-par coding and design are the two biggest contributors to poor Java performance, but that doesn't make the jobs of developers any easier. In reality, a number of things contribute to Java performance, just as many things can stand in an app's way of functioning with the speed and efficiency you'd like to see.

If you're currently working on a development project, don't feel like every Java performance issue comes down to the fundamentals. In many cases, you can tune performance long after the initial development phase without going back to square one—you just need to know where to focus your efforts.

Here are ten tips to increase your Java performance with as little work as possible.

1. Avoid Pursuing Unwarranted Optimization

It might sound contradictory to not pursue every optimization possible, but in reality, this is a surefire way to waste resources with potentially very little payoff.

You should always follow best practices and clean coding standards, but you shouldn't go out of your way to "optimize" until you know that there's a need.

For instance, don't replace a standard library or build some complex workaround just because you believe it will improve Java performance. Prematurely optimizing things usually just makes code harder to read and harder to maintain while wasting precious development resources.

Meanwhile, you'll typically see the very little payoff, especially if you're focusing on non-critical functions in the application.

2. Prove The Need for Optimization in Advance

If you're pursuing optimization, you should be doing so because you have proven that it is necessary through planning and testing.

You can do this by specifying Java performance metrics and then testing your application to determine where it isn't meeting your standards.

From there, you can take a planned and efficient approach to the optimization where necessary.

3. Use Profiling Tools to Discover Bottlenecks

Instead of manually digging around to find bottlenecks, it's best to use a profiler that can provide detailed information about your code.

Profilers help you understand the most critical parts of your code and pinpoint where there's room for improvement.

Oftentimes, you'll end up surprised by where your Java performance issues are sprouting from, and that means the tool just saved you countless hours searching for that unsuspected source.

4. Focus On Big Wins, Not Quick Wins

A profiler will help you come up with a list of bottlenecks where performance needs to improve, so the next step is prioritizing those bottlenecks so you know where you should focus your efforts first.

Quick wins will help you start seeing results sooner, which can motivate the team, but that also puts the big wins further out.  

Typically, it's suggested that you start with the biggest Java performance issues first and work your way down the list.

This will allow you to see the biggest possible improvement, and that might be enough to help you hit your goals, meaning you won't have to address all the problems after all. That reduces your overall effort and, ultimately, helps you get to your goals in less time.

5. Use Primitives When You Can

Aside from the broader, goal-setting type tips we've just discussed, here's a more specific tip for tuning Java performance in your app: Use primitives when you can.

Primitive types help you avoid overhead and improve Java performance compared to wrapper classes.

For example, that means you should opt for int over integer and so on, allowing your Java Virtual Machine (JVM) to store the value in the stack, not the heap, thereby reducing memory consumption.

6. Be Sure to Cache Expensive Resources

Database connections and other expensive resources should always be cached when possible.

Caching will help you avoid repeated executions of frequently used or expensive code snippets, allowing you to reuse resources instead of creating new ones again and again.

However, remember that the cache itself creates overhead, so you'll need additional memory to store the reusable resources. You might also need to implement cache management to remove outdated resources often.

7. Opt for Stored Procedures Over Queries

Long queries that you call while processing can quickly bog down Java performance, which is why you should always make use of stored procedures when you can.

Stored procedures are stored just like objects, pre-compiled in the database, and ready to be quickly executed.

They have the same logic as a query when compiled, but they offer efficiencies in multiple areas—they even reduce network traffic and data transfer.

8. Avoid The Big Decimal Class

The BigDecimal class allows for precise decimal values, which is useful in some scenarios but can otherwise hamper the performance of your application when over-used.

This class takes a great deal of memory to handle calculations, so if precision isn't a constraint, or if you're sure it won't exceed the long or double limitations, avoid using this class wherever possible.

9. Don't Overuse Big Objects

Some classes in Java act as data holders, which make them heavy objects that can weigh down performance.

Think about database connection objects, session objects, and system configuration objects—all of these are big objects that you should minimize the use of.

When you have to use a big object, use the SIngleton pattern so that a single instance of that object is created and then reused or cloned when necessary rather than created again from scratch.

10. Keep Testing to Monitor Performance

Setting up a performance testing environment is an absolute must-do if you're concerned about the performance of your Java app.

Once you have that environment running, in tandem with tools like a profiler, it's essential that you use it often.

Every time a new version is put into works, you should test the performance, check for bottlenecks, and prioritize any optimization tasks.

If you get in the habit of doing that, performance will become part of everyday development instead of an after-thought.

At Adservio, we believe in doing just that—making performance part of your core strategy.

Contact our team today to learn how we can help your company build better digital experiences.