At the advent of the career as a Java programmer, aspirants face many intriguing situations where one might be asked to tune the code for better performance even though the code works fine and gives the desired results. A significant amount of experience and deeper knowledge of Java is required to optimize and integrate the code further. Successful Java programmers often make coding a cakewalk because they know some of the exceptional best practices of the trade, while practitioners usually tend to ignore such advices. However, it is highly recommended by successful java programmers to follow the below nine useful practices to become one among them.
- Instance fields should not be made public:
It is never advisable to declare a class field as public in Java. By making the instance field public, it becomes available in a wider scope and becomes vulnerable to bugs.
For example, while creating a public array of length ‘5’, programmers might be sitting assured that all the five fields will always remain to hold the assigned values. However, with declaration as public, someone might accidentally access the fields and insert a bug.
- Avoid unnecessary Object creation:
Larger number of objects creation should never be encouraged as it degrades the performance of the code by utilizing higher memory. Make a practice to create objects only when it becomes completely necessary. While working on optimization of a code, this is the first aspect to be taken care by the apt programmers.
- The scope of Local Variables must be limited:
Limiting the scope of local variables is very helpful as it in turn enhances the readability of Java code, makes it less error-prone and the entire code becomes more maintainable.
It is a great habit to declare a variable just before the command where it is intended to be used. Moreover, assign values to the local variables right while declaring it. If initial values cannot be assigned, NULL can be a good choice for temporary value assignment.
- Be careful while using Strings:
Strings generally acquire more memory space and when two strings need to be concatenated, the resulting string becomes even more memory consuming. So it is advisable to handle the strings very carefully when the requirement warrants the use of concatenation of strings in a ‘for’ loop. If ignored, this will result in slower performance due to heavy memory utilization.
String objects should always be instantiated directly instead of using its constructors.
- Minimize the use of floating Point numbers:
Naïve programmers often use floating points for even exact quantities like currency amounts just because they are not sure about the possible values of the variable. However, it is a very bad idea and should never be encouraged. Floating points are better used with mathematical measurements that have an inexact value. BigDecimal is an optimum type that used for currency measures.
- Get rid of Mutable classes in Java code:
Immutable class restricts any scope of modifications within it. A class can be made immutable by declaring all its constructors as private and by creating a public static method to instantiate and return an object.
Immutable classes are secure and lay a great foundation to build new objects upon it. Although these are manageable and safe, it can bring performance issues in the code. So, as a Java programmer, professionals have to be wise enough to choose only smaller classes as immutable.
- Use the standard Library extensively:
For the best practice, use the standard library function with zero hesitation as this is tested, bug-free and widely used by all Java programmers. Coding is quite fun and in the trial of being adventurous, beginners may tend to reinvent the pre-written functions again on their own. However, it is quite foolish to do such stuffs and by this, they are more likely to insert unwanted bugs in the code.
- Choose empty Collections over NULL values:
It is a common practice to return arrays or collections with NULL if there are no values to be returned. However, it may burden with more work later in the code to do some if-else testing to check these NULL values. So, top Java programmers often return empty collections instead of NULL values. It saves a lot of time by avoiding the possible if-else checks.
- Interfaces are better than Abstract Classes:
Programmers may implement multiple interfaces in a class whereas they cannot inherit multiple classes. To address this drawback of Java, programmers create more interfaces and implement multiples of it.
But one thing must be kept in mind that addition of new methods in an interface is not easy. For that, the class that implements the interface needs to be broken. A good Java developers start coding interfaces only when they are sure about all the methods to be declared in the interface.
Although these are not mandatory rules for scripting in Java, but are some effective practices, which are tested and have been proved useful for writing efficient codes. These best Java practices are helpful for both fresh engineers and experienced coders; sticking to the good practices certainly gives some edge over others.