Error vs Exception

Error 

Introduction:

In Java, an "Error" is a subclass of the java.lang.Throwable class and represents serious issues that usually occur at runtime and are beyond the control of the Java application. Errors typically indicate problems that the application cannot recover from and often lead to the termination of the program. Some of the common java errors are :

1. OutOfMemoryError: OutOfMemoryError occurs when the Java Virtual Machine (JVM) runs out of memory due to memory leaks, excessive usage, or insufficient heap space.

2. StackOverflowError: StackOverflowError Occurs when a program recurses too deeply, causing the call stack to exceed its limit. It happens with recursive functions that lack a proper termination condition.

3. NoClassDefFoundError: NoClassDefFoundError Occurs when the JVM can't find a class definition needed at runtime. Caused by a missing or incorrect classpath or a required JAR file.

4. LinkageError: LinkageError Occurs when there is a problem with linking classes at runtime, often due to incompatible versions or dependencies between classes.

5. InternalError: InternalError Indicates a serious internal issue within the JVM or Java runtime environment, requiring investigation by the JVM vendor.

6. AbstractMethodError: AbstractMethodError Occurs when a class doesn't implement an abstract method from its superclass or interface due to version mismatch.

7. AssertionError:  AssertionError is thrown when an assertion fails in Java. Assertions are typically used during development to check certain conditions and are usually disabled in production environments.

Exception

Introduction:

In Java, an "exception" is a situation that arises during the execution of a program due to some unexpected condition or event. Exceptions can be caused by various factors such as invalid input, file not found, network issues, arithmetic errors, etc. They are represented by classes that extend either java.lang.Exception (checked exceptions) or java.lang.RuntimeException (unchecked exceptions). Exceptions are typically recoverable and can be caught and handled within the program to allow it to continue its execution gracefully. Some of the common exception are given below:

1. NullPointerException: Occurs when you try to access or call a method on an object that is null, meaning it does not reference any actual instance.

2. NumberFormatException: Occurs when you try to convert a string to a numeric type (like int or double), but the string does not contain a valid number.

3. FileNotFoundException: Occurs when you try to access a file that does not exist or cannot be found at the specified location.

4. ArithmeticException: Occurs when there is an arithmetic error, such as dividing by zero.

5. ArrayIndexOutOfBoundsException: Occurs when you try to access an array element using an index that is outside the valid range of the array.

6. IOException: A general input/output exception that can occur when there is an issue with reading or writing to a file or stream.

7. ClassNotFoundException: Occurs when the JVM cannot find the definition of a class that is required at runtime.

Error vs Exception:

Exception:

An exception is a situation that arises during the execution of a Java program due to some unexpected conditions or events.

Exceptions can be caused by various factors such as invalid input, file not found, network issues, arithmetic errors, etc.

Exceptions are typically recoverable, meaning they can be caught and handled within the program, allowing it to continue its execution gracefully.

In Java, exceptions are represented by classes that extend either java.lang.Exception (checked exceptions) or java.lang.RuntimeException (unchecked exceptions).

Checked exceptions must be explicitly caught or declared in the method's signature, whereas unchecked exceptions (also known as runtime exceptions) do not need to be declared explicitly in the method signature.

Error:

An error, on the other hand, is a serious issue that usually indicates a problem beyond the control of the program, such as running out of memory (OutOfMemoryError) or a stack overflow (StackOverflowError).

Errors are generally unrecoverable, and they often lead to the termination of the application.

Unlike exceptions, errors are not meant to be caught or handled programmatically because they indicate critical issues that can't be resolved during runtime.