ABSTRACT
This chapter provides introduction of libraries, packages, and modules and organizing code into packages also Maven and Grandle. Java library classes are a collection of predefined classes in packages that are made available to programmers as part of the Java installation process. Library classes make it easier for programmers to do their jobs by providing built-in methods for ordinary and non-trivial activities like accepting input from the user, presenting output to the user, and so on. The Clone() method avoids the need for subsequent processing to generate a duplicate of an object. A Java module can define which Java packages it contains and which should be visible to other Java modules that utilize it. A Java module must additionally describe which other Java modules are required to complete its task.
