1. CSG2H3 Object Oriented Programming
Java I/O

2. Computer and Me

3. Input / Output
Input :
Keyboard
File
Output
Screen
file

4. Java Stream Sequence of data of undetermined length
Input streams move data into a Java program usually from an external source
System.in
Output streams move data from a Java program to an external target.
System.out

5. Java Stream
A Java stream is composed of discrete bytes (characters) of data
Byte streams
Character streams

6. Byte Streams FileInputStream BufferedInputStream InputStream
FilterInputStream
DataInputStream
Object
FileOutputStream
BufferedOutputStream
OutputStream
FilterOutputStream
DataOutputStream
PrintStream

7. Character Streams BufferedReader Reader InputStreamReader FileReader
Object
BufferedWriter
writer
OutputStreamWriter
FileWriter
PrintWriter

8. Snippet Code : Write String

9. Snippet Code : Read String

10. CSG2H3 Object Oriented Programming
Object Persistence

11. Object Persistence
Persistence is the property of an object through which its existence transcends time
(i.e. the object continues to exist after its creator ceases to exist)
and/or space
(i. e. the objects location moves from the address space in which it was created).

12. Object Persistence
the ability of an object to survive the lifetime of the OS process in which it resides
relevant for objects with an internal state
The state needs to be retained between object deactivation and object activation

13. Live-time Object Illustration
Instantiation
Object used in program
Some-time Object Saved//Resurect into/from Storage
Object destroyed

14. Object Oriented Live as an Object constructor Save as an Object
serializing
Read as an Object
De-serializing

15. Persistence Object To File
Must be able to transform to binary (implements java.io.Serializable)
BinaryStream
Using io.stream mechanism FileOutputStream
Write Object to File
Using method writeObject() in ObjectOutputStream
Object in File
Open file with FileInputStream class
ReadObject in File
Using method readObject() in ObjectInputStream
Object
Object ready to use

16. Snippet Code : Write Object

17. Snippet Code : Read Object

18. Object Relational Mapping

19. Object Relational Mapping
a programming technique for converting data between incompatible type systems in object- oriented programming languages
object-oriented (OO) objects are almost always non-scalar values
However, many popular database products such as structured query language database management systems (SQL DBMS) can only store and manipulate scalar values

20. Object Relational Mapping
The programmer must either convert the object values into groups of simpler values for storage in the database (and convert them back upon retrieval), or only use simple scalar values within the program.
Object-relational mapping is used to implement the first approach

21. Java Hibernate

22. Java Persistence API (JPA)

23. Question?

24. Credits
Music : Yonezawa Madoka - Oui! Ai Kotoba (Instrumental)