Topic 8.1: Handling Exceptions - Differentiate among checked exceptions, unchecked exceptions, and Errors Flashcards
These are difficult or impossible to recover from, whereas exceptions are meant for application-specific error handling and can be caught and handled within the code.
How do errors differ from exceptions in terms of recoverability?
What do errors represent in Java, and how are they different from exceptions?
These in Java represent exceptional conditions that are usually not expected to be caught or handled by the application code.
They are different from exceptions, which are used for application-specific error handling.
These occur in situations where the JVM or underlying system encounters severe issues that disrupt the normal execution of the program.
How does the Java compiler treat unchecked exceptions?
The Java compiler does not enforce the handling of unchecked exceptions, giving developers the flexibility to choose whether to handle them or not. They are not required to be caught or declared in the method signature.
Example of this:
public void readFile(String fileName) {
try {
// Code that reads data from the file
} catch (IOException e) {
// Exception handling code
}
}
Provide an example of handling a checked exception with a try-catch block
What are the differences between the “throw” and “throws” keywords in Java’s exception handling?
The “throw” keyword is used to explicitly throw an exception from within a method or block.
On the other hand, the “throws” keyword is used in a method signature to declare checked exceptions that the method may throw, indicating that the caller of the method should handle these exceptions.
Provide an example of a method declaration with a checked exception.
Example of this:
public void readFile(String fileName) throws IOException {
// Code that reads data from the file
}
Example of this:
public void readFile(String fileName) throws IOException {
// Code that reads data from the file
}
Provide an example of a method declaration with a checked exception.
Developers can avoid encountering these exceptions by following proper coding practices, such as:
- performing null checks
- validating input
- and avoiding division by zero.
How can developers avoid encountering unchecked exceptions in Java programs?
How do errors differ from exceptions in terms of recoverability?
These are difficult or impossible to recover from, whereas exceptions are meant for application-specific error handling and can be caught and handled within the code.
What are the key components of Java’s exception-handling mechanism?
The key components of this are:
- Try block
- Catch block
- Multiple catch blocks
- Finally block
- Throw and Throws keywords
Why is encountering unchecked exceptions considered a programming error in Java?
Encountering these is generally considered a programming error because they indicate bugs or issues in the code that need to be addressed during development.
Proper coding practices and testing are essential to minimize their occurrence.
What is the role of the catch block in Java’s exception handling?
This follows the try block and contains code that handles the exception.
It specifies the type of exception it can handle, and when a matching exception occurs in the try block, the control transfers to the corresponding block for handling.
What types of issues are errors in Java typically reserved for?
These in Java are typically reserved for serious issues, such as:
- resource exhaustion
- unrecoverable failures.
They are caused by problems at the system level or limitations in the hardware or JVM environment.
These are derived from the java.lang.Error class.
They indicate severe issues that may render the application unstable or unrecoverable, and they are not typically meant to be caught or handled by the application code.
From which class are Java errors derived, and what do they indicate?
The key components of this are:
- Try block
- Catch block
- Multiple catch blocks
- Finally block
- Throw and Throws keywords
What are the key components of Java’s exception-handling mechanism?
These in Java are typically reserved for serious issues, such as:
- resource exhaustion
- unrecoverable failures.
They are caused by problems at the system level or limitations in the hardware or JVM environment.
What types of issues are errors in Java typically reserved for?
Why are errors usually not handled by the application code?
These are usually not handled by the application code because they represent severe issues that may not have a straightforward solution within the application.
They are caused by problems at:
- the system level
- or environmental limitations.
This follows the try block and contains code that handles the exception.
It specifies the type of exception it can handle, and when a matching exception occurs in the try block, the control transfers to the corresponding block for handling.
What is the role of the catch block in Java’s exception handling?
Provide an example of handling a checked exception with a try-catch block
Example of this:
public void readFile(String fileName) {
try {
// Code that reads data from the file
} catch (IOException e) {
// Exception handling code
}
}
How do you handle checked exceptions in Java methods?
Any method that may throw a checked exception must either declare it in its method signature using the ‘throws’ keyword or handle it with a try-catch block.
