Uses of Class
java.lang.Thread

Packages that use Thread 
Package Description
java.lang
Provides classes that are fundamental to the design of the Java programming language.
java.util.concurrent
Utility classes commonly useful in concurrent programming.
java.util.concurrent.locks
Interfaces and classes providing a framework for locking and waiting for conditions that is distinct from built-in synchronization and monitors.
javax.swing.text
Provides classes and interfaces that deal with editable and noneditable text components.