6 Best Practices for Java Developers

Being a Java developer is a privilege. In the world of Java, a lot is already done, and still, there is a lot to do. A bunch of experts is ready to help you learn all the time. So, instead of learning from your own experience, it is wiser to learn from experts. Here I am presenting some expert suggestions that will increase the efficiency of your Java code.

1. Use Strings Carefully

If two Strings are concatenated using the + operator in a for loop, then it creates a new String Object, every time. This wastes memory and increases performance time. Also, constructors should be avoided while instantiating a String Object, and instantiation should happen directly. Here is some code:

    //Slower Instantiation
    String bad = new String("Hello World");
    
    //Faster Instantiation
    String good = "Hello World!";

2. Avoid Unnecessary Object Creation

One of Java’s most expensive operations (in terms of memory utilization) is object creation. So, it is recommended that Objects should only be created or initialized if necessary. The following code gives an example:

    import java.util.ArrayList;
    import java.util.List;
    
    public class Books {
    private List books;
    
        public List getBooks() {
            //Initialize if required
            if(null == books) {
                books = new ArrayList();
            }
            return books;
        }
    }

3. Return Empty Collections Instead of Null

If a program returns a collection that does not have any value, make sure an Empty collection is returned rather than Null elements. It will save a lot of if-else checking on Null Elements. The code below will help you:

public List getBooks() {
        if (null == books) {
        books = new ArrayList();
        }
        return books;
        }

4. Avoid Memory Leaks

Memory leaks often cause performance degradation of software. Since Java manages memory automatically, the developers do not have much control. But there are still some standard practices that can be used to protect your application from memory leakages.

• Always release database connections when querying is complete.
• Try to use a Finally block as often as possible.
• Release instances stored in Static Tables.

5. Use Manual Operation if Necessary

For computing power, Java offers two options:

1. Multiplication:

    double square = double a * double a;                            // Optimized
    double cube = double a * double a * double a;                   // Non-optimized
    double cube = double a * double square;                         // Optimized
    double quad = double a * double a * double a * double a;            // Non-optimized
    double quad = double square * double square;                    // Optimized

2. Math.pow(double base, double exponent):

The pow method is used to calculate where multiplication is not possible (base^exponent).

    double cube = Math.pow(base, exponent);

Math.pow() Should be used only when necessary. For example, if the exponent is a fractional value. The Math.pow() method is typically around 300–600 times slower than multiplication.

6. Try Not to Use For Loops With Indexes

Try to avoid usingfor loop with an index variable if you can replace it with the enhanced for loop or forEach . Often, the index variable is error-prone, as we may accidentally alter it in the loop’s body, or we may start the index from 1 instead of 0.

Let see the following example that iterates over an array of Strings:

    String[] names = {"Alice", "Bob", "Carol", "David", "Eric", "Frank"};
    for (int i = 0; i < names.length; i++) {
          doSomething(names[i]);
    }

The index variable i in this for loop can be altered accidentally, which may cause unexpected results. We can solve this problem by using an enhanced for loop like this:

    for (String aName :names){
         doSomething(aName);
    }

This does remove not only potential issues but also makes the code cleaner and more concise.

Conclusion

Always try to follow best practices; it will save your time and energy.

Happy Coding! :)