At present, programmers use Java for developing a variety of desktop, web, and mobile applications. Each new version of Java also comes with new features to meet the emerging trends in software development. But the developers still have to explore ways to keep the Java code organized, clean, and maintainable. Often mistakes committed by Java programmers directly affect the functionality of the software and quality of its source code. The Java programming mistakes made by individual developers differ. But both beginners and experienced Java programmers end up making a number of common mistakes. That is why; it becomes essential for Java programmers to identify and avoid some common mistakes.

10 Common Java Programming Mistakes Java Programmers Must Avoid

1) Not Conveying Precise Meaning of Code Elements

While writing Java code, programmers create several new classes, methods, variables, and packages. But they often forget to name the code elements appropriately. Often the name of a code element does not convey their meaning or usage precisely. Hence, the developers find it daunting to modify or maintain the code in future. The Java programmers can easily make the code maintainable by following proper naming conventions and choose names that describe the code elements clearly.

2) Using Regular Expressions

Many programmers use regular expressions frequently in Java code. They forget the adverse impact of regular expressions on the performance of the Java application. It is always important for programmers to use regular expressions in computation-intensive code sections. If a programmer wants to use regular expressions in computation-intensive code sections, he must prevent the regular expressions from being executed frequently by caching the pattern reference.

3)  Ignoring the Amount of Memory Consumed by Various Methods

Often Java programmers ignore the amount of memory consumed by individual methods. They affect the performance of the application adversely by calling the memory expensive methods directly. When they call an expensive method directly, the program requires additional time to calculate value and deliver results. The developers can easily keep the application’s performance intact by calling the cache instead of the method.

4)  Keeping Resources Blocked

The performance of the Java application is impacted adversely when the program keeps accessing a file or network connection consistently. The programmers must check when the program does not need the resources. They must write specific code to release the resources as soon as the program stops accessing them. Likewise, the developers must monitor the exceptions thrown during program execution to identify the resources to be released.

5) Ignoring Memory Leaks

As Java supports automatic memory management, the programmers are not required to allocate and free memory manually. Hence, they often forget to check how the program allocates and releases memory. But a Java program can keep referencing to an object unnecessarily due to specific memory allocation problems. The everlasting object references prevent the garbage collector from removing objects from the heap and results in memory leaks. The programmers must check if an object is not being referred unnecessarily and focus on the objects referencing each other to avoid memory leaks.

6) Using Null References Unnecessarily

While writing Java code, programmers often use null references to distinguish the variables that do not refer to any object or array. They also have option to assign null to any variable of reference type. But the programmers must avoid using null references unnecessarily to avoid generating NullPointerException. They can easily avoid NullPointerException by returning empty arrays or collections from methods.

7) Using Recursions

The latest version of Java comes with functional programming features. That is why, programmers use recursions while writing code in Java 8. But recursions affect the performance and functionality of the Java application adversely. For instance, recursions may affect the processing of Java code based on compilers. Likewise, the tail-recursive of recursion can also affect the algorithm negatively. Sometimes the code goes for a toss when the compiler does not recognize tail-recursive. The programmers must make it a practice to use iteration instead of recursions.

8) Ignoring Causes of Compile Time Error

Often simple mistakes committed by Java programmers at the time of writing code results in compile time errors. For instance, compile time error will occur if the name of the Java file does not match exactly with the name of the public class contained in the associated files. Likewise, compile time error may also occur due to inappropriate casing of code elements, mismatch between open and close brackets, and omission of semi-colons. The programmers can easily prevent the compile time errors by reviewing the code consistently.

9) Not Handling Exceptions

Both novice and experience Java programmers do not handle exceptions properly. They forget the simple fact that each exception is thrown due to specific issues. They must resolve the issues effectively to prevent exception throwing. There are always chances that the Java program can throw the exceptions again in a number of ways – adding message to log or showing error dialog to users. Hence, the programmers must analyze the exception thrown and handle them in the most appropriate way.

10) Not Using Existing Java Libraries

The developers have option to choose from a wide range of Java libraries based on their precise needs. Most of the existing Java libraries are also open source and free, while being supported by robust communities. But many developers ignore the existing Java libraries, and end up writing code from the scratch. The developers can easily reduce development time by taking advantage of existing Java libraries. Likewise, they can also use specific Java development tools to accomplish common programming tasks without writing additional code.

The mistakes committed by Java developers can be divided into five broad categories – system errors, semantic errors, logical errors, system errors, runtime errors. Hence, they detect most of the mistakes at the time of code compilation or execution. The programmers can easily identify various types of errors by monitoring and reviewing the Java code consistently. They can even consider using specialized code quality tools to identify and eliminate these errors during the code writing process.