Explore 'final', 'finalize', and 'finally' Keywords in Java Programming. Discover Differences and Effective Uses of These Keywords and Their Functions

Java is a versatile programming language that provides developers with a wide range of tools to make their code more efficient, clean, Ex'final', 'finalize', and 'finally' Keywords in Java: Usage Overviewplore 'final', 'finalize', and 'finally' Keywords in Java Programminand secure. However, Java's vast abstractions Exploring the Usage of 'final', 'finalize', and 'finally' Keywords and features can sometimes confuse developers, especially when it comes to three critical keywords: final, finalize, and finally. In this blog post, we'll be discussing the functions of each of these keywords and how they contribute to the Java programming language.

Final Keyword

In Java, the final keyword is used to indicate that a value cannot be changed. If a variable is marked as final, its value becomes immutable, and you cannot reassign it during runtime. Likewise, if a method is marked as final, it cannot be overridden by derived classes. In essence, final is a modifier that provides compile-time and runtime protection against accidental changes to variables, classes, or methods.

Final Variables

Final variables are used to represent constants, such as pi or the number of days in a week, which should not change during runtime. To declare a final variable, the keyword final is used in the variable declaration. Consider the following code example:

final int DAYS_IN_A_WEEK = 7;

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Final Methods

Final methods are used to indicate that the method cannot be overridden by derived classes. When a method is marked as final, it makes the code more secure and predictable, as the behaviour of the method cannot be changed by other classes.

Consider the following code example:

class Shape {
  final void draw() {
    // code here
  }
}

class Circle extends Shape {
  void draw() { // compile-time error
    // code here
  }
}

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Final Classes

In Java, final classes are classes that cannot be inherited by other classes. When a class is marked as final, no other class can extend it, whether through inheritance or inner classes. Final classes are often used in libraries and frameworks to ensure that the functionality they provide is not compromised, modified or extended.

Finalize Method

The finalize() method is called by the garbage collector before an object is destroyed to perform any final cleanup or resource deallocation. The finalize method comes with the Object class, and you can override it in your classes to implement specific cleanup behaviours.

However, it's recommended that you do not rely on the finalize() method to clean up resources, but instead use the try-with-resources statement or a final block to release resources.

Consider the following example:

class MyClass {
  protected void finalize() throws Throwable {
    try {
      // cleanup code here
    } finally {
      super.finalize();
    }
  }
}

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Finally Keyword

The final keyword is used in Java's try-catch-finally statement to add a block of code that is executed after a try block has completed execution. The final block is executed regardless of whether an exception is thrown or not, making it useful for resource deallocation and cleanup.

Consider the following code example:

try {
  // code here
} catch (Exception e) {
  // handle exception here
} finally {
  // cleanup code here
}

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Conclusion

In conclusion, final, finalize, and finally are essential keywords in Java that provide programmers with a wide range of tools to improve their code's reliability, security, and efficiency. Final variables, methods, and classes protect against accidental changes; finalize methods to perform necessary cleanup tasks, and finally, statements make it easier to deallocate resources and handle exceptions. By understanding the purpose of each keyword, Java developers can take advantage of their distinct features and create efficient and effective code.