JavaDoc
JavaDoc
JavaDoc is used to generate API documentation in HTML format from comments in the source code.
In IDEs, JavaDoc comments are often visible by hovering over the method, allowing the user to read explanatory tooltips that can inform their programming.
File Access
The java.io.File class can be used to represent file objects. With an object of the File class, the properties, its existence, and its path can be accessed.
The java.util.Scanner class allows reading from a File object.
To write to files, a FileWriter object can be used.
Packages
Types (classes, interfaces, enumerations) can be organised into packages for easier management.
To create a package, add a package statement at the top of the source file package PACKAGE_NAME;. Package name is written in all lower case, with the . as a separator.
To use a public package member from outside its package:
- Use the Fully Qualified Name (FQN) to refer to the member
Fully Qualified Name
Type name prefixed by the package name.
- Import package/specific package member
Remark
Importing a package does not import its sub-packages.
JAR
JAR
Java Archive files are used to deliver Java applications. They generally contain Java classes, and other resources.
To run JAR files, the command java -jar FILENAME.
To build JAR files, build tools/IDE can package the application into a JAR file.
JavaFX
JavaFX is used to build Java-based GUIs.
Varargs
Syntactic sugar
Syntax within a programming language that is designed to make things easier to read or to express.
Variable arguments (Varargs) allows writing a method with a variable number of arguments.
Example
The main method is an example of this.
public static void main(String ...args)allows for command line running of the code with multiple arguments.