What does java.lang.Runtime Exception mean?

The java.lang.RuntimeException class in Java is a crucial component for handling unexpected issues during the execution of an application without causing it to crash. Runtime exceptions, such as invalid user input or external resource problems, are identified only during runtime, and can be managed using a try-catch block, as illustrated in a simple example where dividing by zero raises a RuntimeException. Unlike checked exceptions, which require explicit handling and are often associated with file I/O or database access, RuntimeExceptions are unchecked and do not mandate explicit handling, typically arising from programming errors that should be corrected by the developer. Examples of such errors include NullPointerException and ArrayIndexOutOfBoundsException, which signify unrecoverable conditions that should generally be addressed in the code rather than being caught during execution. An error message like java.lang.RuntimeException: null indicates a RuntimeException was thrown without a specific error message, underscoring the importance of providing meaningful messages for easier debugging. Tools like Rollbar can automate error monitoring and triaging, facilitating more confident deployment of production code by allowing real-time tracking and management of errors.