Decoding the BackingStoreException in Java: An In-depth Understanding
Java, the powerful programming language, has earned its reputation through its robust error/exception handling mechanism. Among the exception errors, the one we are dissecting today is the BackingStoreException. This article provides you with a detailed understanding of this exception in Java and highlights how to handle it effectively.
Understanding Exception in Java
Before we delve into the specifics of BackingStoreException, let’s understand what an exception in java is. An exception is an unanticipated event that occurs during the execution of a program, disrupting its regular flow. Java, being an object-oriented language, handles exceptions by employing five keywords: try, catch, throw, throws, and finally.
For instance, take a look at this simple exception handling example:
public class Main {
public static void main(String[] args) {
try {
int[] myNumbers = {1, 2, 3};
System.out.println(myNumbers[10]); // Out of bound Access
} catch (Exception e) {
System.out.println("An error occurred.");
} finally {
System.out.println("The 'try catch' is finished.");
}
}
}
Above, we have caught exceptions that may be thrown within the try block with the catch bloc and the finally block is always executed.
BackingStoreException: What is it?
BackingStoreException comes under the umbrella of the Exception class and mainly relates to the Preference API in java. It is thrown to indicate an operation could not be completed due to a failure in the backing store or persistence support. This type of exception is encountered when there’s an error during the preference data’s reading, writing, or updating operations.
For example, the preference node data does not exist, or the current Java virtual machine is not allowed to contact the backing store; these scenarios necessitate Java to throw a BackingStoreException.
public class BackingStoreException
extends Exception
It belongs to java.util.prefs package and extends the Exception class. Its constructors include BackingStoreException(String paramString) and BackingStoreException(Throwable paramThrowable).
Let’s decipher this a bit with a basic example:
import java.util.prefs.BackingStoreException;
import java.util.prefs.Preferences;
public class Main {
public static void main(String[] args) {
Preferences prefs = Preferences.userRoot();
try {
System.out.println("Children names:");
String children[] = prefs.childrenNames();
for (int i = 0; children != null && i < children.length; i++) {
System.out.println(children[i]);
}
} catch (BackingStoreException bse) {
bse.printStackTrace();
}
}
}
In this code, we are trying to print out the child nodes under the root node of the user preferences tree. If an error occurs during the retrieval of the names of the child nodes, a BackingStoreException is thrown.
How to handle BackingStoreException?
Like any other exception, BackingStoreException can be managed well within a try/catch statement. The code inside the try block comes under direct surveillance. If any abnormal conditions occur, the catch block is immediately asked to catch the dispatch exception and take corrective measures.
Preferences prefs = Preferences.userRoot();
try {
prefs.clear();
} catch (BackingStoreException bse) {
bse.printStackTrace();
}
Here, the clear() method is used to remove all the key-value pairs in the preference node calling the method. If a failure occurs during this operation due to a backing store issue, it results in a BackingStoreException.
Wrapping it up
When playing with the Preferences API in Java, BackingStoreException can often emerge as an obstacle. Through our detailed article, we hope that you would not only understand what triggers this exception but also handle it correctly. With the power of effective exception handling, you can ensure your Java programs run flawlessly.
Practice makes a programmer perfect. Thus, play around more with the code and get a hands-on feel of how things work. Happy coding!