Install libcommons-lang3-java-doc by entering the following commands in the terminal:
sudo apt update sudo apt install libcommons-lang3-java-doc
Description:
Documentation for extension of the java.lang package (for Java 5+)
The Commons Lang components contains a set of Java classes that provide helper methods for standard Java classes, especially those found in the java.lang package in the JDK 5+. . Commons Lang 3.x use a different package (org.apache.commons.lang3) than the previous versions (org.apache.commons.lang), allowing it to be used at the same time as an earlier version. . Commons Lang 3.x is only compatible with JDK 1.5+ . This package contains the API documentation of libcommons-lang3-java.
Homepage: http://commons.apache.org/lang/
Version: 3.5-2ubuntu1
Section: universe/doc