1. Streams, File I/O and Scanner class
Anubhav chaturvedi

3. File Descriptors an abstract indicator for accessing a file ( int )
The three standard descriptors in unistd.h:
Standard Input : STDIN_FILENO
Standard Output : STDOUT_FILENO
Standard Error : STDERR_FILENO

4. Standard Streams

5. Let’s make life simple

6. Adding Layers of abstraction

7. The java.io package

8. EchoConsole.java example

9. CopyFile.java example

10. ExchangeStreams.java example

11. Why two constructors and how are they different?
There are two ways to initialize FileInputStream… why?
FileInputStream(String name)
and
FileInputStream(File file)

12. Internal implementation
public FileInputStream(String name) throws FileNotFoundException { this(name != null ? new File(name) : null); }

13. Why two different classes – FileReader and FileInputStream?
Unicode Character Encoding
2 byte vs 1 byte transfer
Byte stream and character stream
The Readers and Writers are Character streams

14. All seems to be good so far But there is one problem…

15. IT’S NOT SIMPLE ENOUGH

16. Adding another Layer of abstraction

17. Scanner.java java.util package
More complex and useful than other available classes
Abstraction level attained:
Read Files and Streams
Perform Regex operation
Checking and getting available data types contained in the string

18. ScannerReadingFile.java example

19. Reference