# Package ch.qos.logback.core.util

Contains various utility classes.

Interface Summary
DelayStrategy: A strategy for computing a delay.
InvocationGate

Class Summary
CachingDateFormatter: A synchronized implementation of SimpleDateFormat which uses caching internally.
CloseUtil: Static utility method for `Closeable` objects.
ContentTypeUtil: Various utility methods for processing strings representing context types.
ContextUtil
COWArrayList<E>: A GC-free lock-free thread-safe implementation of the `List` interface for use cases where iterations over the list vastly out-number modifications on the list.
DatePatternToRegexUtil: This class is concerned with computing a regex corresponding to a date pattern (in `SimpleDateFormat` format).
DefaultInvocationGate: This class serves as a gateway for invocations of a "costly" operation on a critical execution path.
Duration: Duration instances represent a lapse of time.
EnvUtil
ExecutorServiceUtil: Static utility methods for manipulating an `ExecutorService`.
FileSize: Instances of this class represent the size of a file.
FileUtil
FixedDelay: A default `DelayStrategy` that implements a simple fixed delay.
InterruptUtil: Allows masking of interrupt flag if previously the flag is already set.
JNDIUtil: A simple utility class to create and use a JNDI Context.
Loader: Load resources (or images) from various sources.
LocationUtil: A static utility method that converts a string that describes the location of a resource into a `URL` object.
OptionHelper
StatusListenerConfigHelper
StatusPrinter
StringCollectionUtil: Static utility methods for working with collections of strings.
SystemInfo
TimeUtil

Enum Summary
AggregationType: AggregationType classifies how one object is contained within another object.

Exception Summary
DynamicClassLoadingException
IncompatibleClassException
PropertySetterException: Thrown when an error is encountered whilst attempting to set a property using the `PropertySetter` utility class.