Mindfire is a software service provider specializing in small-team offshore software development with a focus on creating efficient, readable, and high-performance applications. The document offers tips for optimizing Java applications, such as using profiling tools to identify bottlenecks, avoiding premature optimization, and effectively managing string concatenation. Mindfire emphasizes its experience in Java projects and invites potential clients to explore its services for application migration and modernization.

1. Mindfire is a software service provider, with
unrelenting focus on small-team offshore software
development using Agile methods.

2. It’s one thing to write a code that works. But what about
readable, concise, and clean code? That’s another matter
entirely.
Creating an app that solves a problem is not that hard either.
What about an app that not only solves the problem but is
also easy to use? That’s what we want!
You could apply the same reasoning for multiple software
properties. Let’s focus on the vital one: performance.
Issues faced with applications:
Slow Application:
Your application may not respond well because it’s spending
too much time cleaning up garbage rather than running the
necessary processes.

3. Application consumes too much memory:
The application’s memory usage is related to the number and
size of live objects in the Java virtual machine (JVM) at any
point in time. This can be because of valid objects needed to
stay in Java heap memory or maybe because the programmer
forgot to remove the unwanted object’s reference (known as
‘memory leaks’ in Java parlance).
Why opt for JAVA performance tuning?
Java optimization identifies misbehaving or underperforming
code, configurations, frameworks, libraries, and, potentially,
even hardware. When you identify a component as an
optimization target, you can rework and retest the system.
If the Java performance optimization target is remediated, the
system as a whole will perform better.

4. 8 Tips to speed up applications with JAVA performance tuning
1. Don’t optimize before it’s necessary
This sounds simple but is often ignored by many companies. You
need to follow standard best practices to implement your use cases
efficiently.
But that doesn’t imply you should replace the standard libraries or
make complex optimizations without asserting that it’s necessary.
Premature optimization takes huge time and makes the code hard
to read.
To make it even worse, these optimizations rarely have any benefits
because you’re spending an extensive amount of time optimizing
non-critical parts of the application.
So, how to need what you need to optimize?
First, you need to define how fast your application code needs to
be, e.g., by specifying a maximum response time for the API calls or
the number of records you want to import within a time frame.
Once you’re done with that, you can measure which parts of your
application are slow and need to be improved.

5. 2. Use a profiler to detect the real bottleneck.
Once you follow the first recommendation and figure out the
parts of your application you have to improve, ask yourself
where to begin?
You can cover this question in two ways:
● You can take a look at the code and start with the part that
looks suspicious or where it might create problems.
● Or you can use a profiler and get detailed information about
the performance of each part of your code.
It should be obvious that the profiler-based approach gives
you a better understanding of the code’s performance
implications and allows you to focus on the critical parts.
And if you used a profiler, you may be surprised to know what
parts of your code created the performance issues.

6. 3. Create a performance test suite for complete
application
This is another tip that helps you avoid a bunch of unexpected
problems that often occur once you deploy your performance
improvement to production.
You need always to define a performance test suite that works
over the whole application. Run it before and after you work
on the performance improvement.
These test runs will help you determine the functional and
performance side effects of the change and make sure that you
don’t root for an update that caused more harm than good.
That is essentially important if you work on components used
by several various parts of your application, like caches or
databases.

7. 4. Work on the most significant bottleneck first.
And after you have made your test suite and analyzed the
application with a profiler, you have an array of issues to
address to improve the performance.
That’s good, but it doesn’t answer the question of where you
should begin. You can focus on the quick wins or start with
the most important issue.
It can be tempting to start with the quick wins as you will be
able to show initial results soon. Sometimes, that is necessary
to convince other team members that the performance
analysis was worth the effort.

8. 5. Use StringBuilder to concatenate strings programmatically.
There are different options to concatenate Strings in Java. You can
use a simple + or +=, the good old StringBuilder or StringBuffer.
So, which should you prefer?
The answer is based on the code that concatenates the String. If
you’re adding new content to your String, for instance, you need to
use the StringBuilder.
It’s simple to use and gives a better performance than StringBuffer.
But keep in mind that StringBuilder, compared to StringBuffer, is
not thread-safe and may not be a good fit for all cases.
That creates a new StringBuilder, including the provided String
and a capacity for 16 extra characters. Once you add more
characters to the StringBuilder, your JVM dynamically increases
the size of the StringBuilder.
If you are familiar with the characters that your String contains,
you can give that number to another constructor method to
instantiate a StringBuilder using the defined capacity.

9. Why use StringBuilder?
StringBuilder is speedy and takes less memory than a string when
performing concatenations. This is mainly because the string is
immutable in Java. The concatenation of two string objects
includes creating a new object.
StringBuilder lets you add characters to an object, and you can call
it every time you need to use the string representation. So,
StringBuilder is useful when a mutable string is required without
the performance overhead to construct lots of strings along the
way.
6. Use + to concatenate Strings in one statement
When you used your first application in Java, someone probably
guided you that you shouldn’t concatenate Strings with +. That’s
right if you’re concatenating Strings in the application logic.
Strings are immutable. The result of each String concatenation is
stored in a new String object. That needs additional memory, and
it slows down your application. This happens especially when
you’re concatenating multiple Strings in a loop.

10. Why use String?
Being immutable automatically makes the String thread safer since
they won’t be altered when accessed from multiple threads. That’s
why immutable objects, in general, can be shared in multiple
threads running simultaneously.
These objects cannot be modified; they can only be shared
between threads, cutting the need for synchronization. Also, it can
create a String object without the help of a new operator.
The String class can implement the Comparable interface, unlike
StringBuilder. Since a string object is immutable, its hash code can
be cached at the time of creation, which should be used multiple
times without calculation.
7. Checking current log levels
This should be the obvious recommendation, but unfortunately,
you can find multiple codes that ignore it. Before you craft a debug
message, you should first check the current log level.
Otherwise, you can create a string with your log message to be
ignored afterward.

11. Conclusion
Optimizing an application to get the most effective
performance isn’t easy.
You can take easy steps to improve the application’s
performance, even if you’re not a performance tuning expert.
Most of the recommendations given in this post aren’t hard to
apply to your code.
Like other businesses, if you too are looking to migrate or
modernize your applications, Mindfire Solutions can be your
partner of choice. We have gained significant experience over
the years working on Java projects. We have a team of highly
skilled and certified software professionals, who have
developed many custom solutions for our global clients over
the years.
Here are a few interesting projects we have worked upon for
migration and modernization. Click here to know more:

12. PMS (Practice Management System) Modernization
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