In Java, an exception is an object that represents an error that occurred during the execution of a program. When an error occurs in a Java program, an exception is thrown, which disrupts the normal flow of the program's instructions.
Exceptions are objects that belong to a hierarchy of classes defined in the java.lang package. The Throwable class is the superclass of all exceptions, and it has two subclasses: Error and Exception. The Error class represents serious errors that cannot be handled by the program, while the Exception class represents exceptions that can be handled by the program.
There are several types of exceptions in Java, including checked exceptions and unchecked exceptions. Checked exceptions are exceptions that must be handled by the program, either by catching the exception or by declaring the exception in the method's throws clause. Unchecked exceptions are exceptions that do not have to be handled by the program, and they include runtime exceptions and errors.
To handle exceptions in Java, you can use the try...catch statement or the try...catch...finally statement. The try...catch statement allows you to specify a block of code that may throw an exception, and a separate block of code to handle the exception if it is thrown. The try...catch...finally statement allows you to specify a block of code that may throw an exception, a separate block of code to handle the exception if it is thrown, and a separate block of code to be executed regardless of whether an exception is thrown.