Java exceptions are events that occur during program execution that disrupt the normal flow of control. These events can be caused by a variety of reasons, such as errors in user input, hardware malfunctions, or programming mistakes. Java provides a built-in mechanism for handling exceptions, which involves the use of try-catch blocks and other language constructs.
Here are some common Java exception topics:
1. Types of exceptions: Java provides two main types of exceptions: checked exceptions and unchecked exceptions. Checked exceptions are checked at compile time, and the code must handle them or declare them to be thrown. Unchecked exceptions are not checked at compile time, and they typically represent more serious errors that are difficult to recover from.
2. Exception handling: Java's exception handling mechanism involves the use of try-catch blocks, which allow code to attempt an operation and catch any exceptions that occur. When an exception is thrown, the runtime system looks for a catch block that can handle the exception.
3. Throwing exceptions: Java code can also explicitly throw exceptions using the throw keyword. This is useful when a method encounters an error condition that cannot be handled locally.
4. Exception hierarchy: Java provides a hierarchy of exception classes, which allows for more precise handling of exceptions. The top-level exception class is Throwable, which is divided into two sub-classes: Error and Exception. The Error class represents serious system errors that cannot be recovered from, while the Exception class represents recoverable errors.
5. Custom exceptions: Java code can define its own custom exception classes by extending the Exception or RuntimeException classes. This is useful for creating more specific exception types that can be caught and handled separately from the built-in exception classes.
Overall, understanding Java exceptions is essential for writing robust and reliable programs, as it allows developers to anticipate and handle errors that may occur during program execution.
