Java Coding Tips And Tricks
Java is a multifunctional, class-based, object-oriented programming language with less implementation dependency. It is a technical platform where you can develop different applications. Java is fast, reliable, and highly secured. It is popularly used to develop Java applications on laptops, data centers, game consoles, supercomputers, cell phones, and many more.
Java is one of the commonest programming languages, whether, for Windows applications, web applications, mobile devices, networks, consumer electronics, or hardcover devices; in fact, you can find Java everywhere. More than 3 billion devices use Java, and over 9 million developers write code in Java. It is as common with developers as react.js and the most widely used development platforms.
However, before you think of learning any language, it is important to learn some tips and tricks to make it clearer.
Build and Deployment
During building applications, you can speed up the process by using build tools. As a Java developer, it is essential that you are familiar with tools such as Ant, Maven, and Gradle.
Maven is the most popular; it enables you to download remote dependencies and automatically perform manual tasks that are often required for deployment, such as Copying files, clearing caches, and injecting properties.
Know the Difference Between Array and ArrayList
It is often difficult for developers to decide whether to use an Array type data structure or ArrayList type. Both have several characteristics and must be used in different situations. Arrays are fixed in size, but ArrayList is variable in size. Changing the elements in the ArrayList is much easier than changing the Array.
Interface is Better Than Abstract Class
Java doesn’t have multiple inheritances, but the UI makes it easy to implement something like multiple inheritances without utilizing the extended keyword. If things don’t go as planned, you always need an interface. An abstract class does not give the liberty to have multiple modes, but they have abstract methods.
Unit and Integration Testing
One way to test the accuracy of logging and source code behavior is to run unit tests. Tests allow you to identify software bugs that have resulted from recent changes to the source code. High test code coverage is helpful if you want to continue feature implementation without performing a large number of manual tests. Some of the technologies that support unit and integration tests are Junit, TestNG, AspectJ, AssertJ, Mockito, and PowerMock.
The first thing you will think about when you see String Concatenate is concatenating strings with the ‘+’ operator. However, did you know that this is not the best and only way to do the job? There are four methods to do this.
- Use the “+” operator: This is the easiest way to concatenate multiple strings, but it uses extra memory and reduces your program’s performance speed, especially when dealing with multiple strings in a loop. But this does not mean you should avoid this method totally. You can still use this to concatenate strings into a single statement.
- The concat( ) method: This is a rarely used method. You have a better performance than when you use the ‘+’ operator; however, much slower.
- Using StringBuffer: You have a much faster performance with this than when you use the two methods above. StringBuffer has been synchronized for multi-threaded operations, making this method thread-safe. This is not as fast as the StringBuilder due to the synchronous approach.
- Append method of StringBuilder class: This is the same as the StringBuffer; however, the StringBuilder lacks synchronization for multi-threaded operations. If you are making a loop with multiple strings, then StringBuilder is the best choice.
Avoiding Memory Leaks by Simple Tricks
Deterioration of software performance is usually due to Memory leaks. Because Java does automate memory management, developers have little control. However, there are still some standard procedures that can be used to protect against memory leaks.
- Ensure the database connections are often released after completing the query.
- Try to utilize the Finally block always.
- Instances in Static Tables must be released.
- Store cases in static tables.
Encode in JSON
Better to Avoid BigDecimal and BigInteger
You can also choose BigDecimal and BigInteger, which are the precise way to represent numbers. If you want to use float numbers with several accuracies or deal with money when accuracy is required, then BigDecimal may be your choice. But it requires more memory, the algorithm is a little more complicated to use than twice the memory, and it slows down all calculations significantly.
Therefore, it is highly recommended to avoid BigDecimal and BigInteger and only use them when there is no other method.
Optimize Your Code with Profilers
Writing and compiling the code is not enough to achieve the desired result. We need to write code with the best possible performance. The best method to do this is to analyze what is going on behind the code, the memory allocation, the areas to be improved, and the impact of using one coding approach on the other. The best tool applicable for this is the Java Profiler.
Java Profiler is a tool to monitor the construction and operation of Java bytecodes at the JVM level. With these profilers, you can determine performance, memory usage, memory leaks, etc. Then, in your program, you can easily find out what needs to be changed, adjusted, or deleted.
There are several profilers available, such as JProfiler, XRebel, and New Relic. However, each profiler has a distinct character, best suited to specific aspects of performance failure. Therefore, the profiler must be selected based on the level of analysis required. You can combine multiple profilers to get the best results.
Float and Double
These two data types represent float numbers, or rather, this double number is a known fact.
It is strongly recommended that you use Double Float twice, especially if you cannot guarantee that your number will be within the specified “Float” range.
Note, however, that the cost is twice as much. It’s expensive because it takes up twice as much space as a Float.