Apache-Commons

The Apache Commons Lang ObjectUtils class from the Apache Commons Lang3 library has many static utility methods operating on Object instances.

The Apache Commons ComparatorUtils provides utils for creating and using comparators from org.apache.commons.collections4.comparators package.

The Apache Commons Collections SetUtils class has utility methods and decorators for Set and SortedSet instances.

In this post, we will explore all the utility methods and decorators for List instances in the Apache Commons Collections ListUtils class.

The Apache Commons BidiMap (a bidirectional map) is an interface using which we can perform a lookup on a map in either direction.

The ThreadUtils class from the Apache Commons Lang library has helper methods for working with Java threads and ThreadGroups.

Apache Commons IO FileAlterationMonitor is a runnable to notify the registered observers at specified time interval with file system changes

In this post, we learn about the Apache Commons IO FileAlterationObserver - using which we can observe the state of files and directories.

The Apache Commons Lang CharSet represents a set of characters. This post covers the Apache Commons Lang CharSet and CharSetUtils class.

We will learn about the Apache Commons Lang RandomStringUtils class for generating random strings for simple use cases in this post.