CSE205 Lecture 25

Object-Oriented Programming and Data Structures
Serialization and Final Review
(202204)

Transcript

1. jgs CSE 205 Object-Oriented Programming and Data Structures Lecture 25: Serialization Dr. Javier Gonzalez-Sanchez javiergs@asu.edu javiergs.engineering.asu.edu | javiergs.com PERALTA 230U Office Hours: By appointment
2. Javier Gonzalez-Sanchez | CSE205 | Fall 2021 | 2 jgs Exceptions There are many exception types available in Java: § ArithmeticException, § FileNotFoundException, § ArrayIndexOutOfBoundsException, § SecurityException, § etc. § The parent of all is the class Exception
3. jgs
4. Javier Gonzalez-Sanchez | CSE205 | Fall 2021 | 4 jgs Example
5. Javier Gonzalez-Sanchez | CSE205 | Fall 2021 | 5 jgs finally Statement § The finally statement lets you execute code, after try...catch, regardless of the result
6. Javier Gonzalez-Sanchez | CSE205 | Fall 2021 | 6 jgs Example
7. jgs throw
8. Javier Gonzalez-Sanchez | CSE205 | Fall 2021 | 8 jgs Definition § The throw statement allows you to create a custom error
9. Javier Gonzalez-Sanchez | CSE205 | Fall 2021 | 9 jgs Example
10. Javier Gonzalez-Sanchez | CSE205 | Fall 2021 | 10 jgs Example
11. jgs Serialization
12. Javier Gonzalez-Sanchez | CSE205 | Fall 2021 | 12 jgs I/O Streams § An I/O Stream represents an input source or an output destination
13. Javier Gonzalez-Sanchez | CSE205 | Fall 2021 | 13 jgs BufferedReader PrintWriter I/O Streams binary FileInputStream FileOutputStream FileReader FileWriter char FileReader FileWriter lines
14. Javier Gonzalez-Sanchez | CSE205 | Fall 2021 | 14 jgs Serialization § Java provides a mechanism, called serialization where an object can be represented as a sequence of bytes that includes the object's data as well as information about the object's type and the types of data stored in the object.
15. Javier Gonzalez-Sanchez | CSE205 | Fall 2021 | 15 jgs I/O Streams BufferedReader PrintWriter binary FileInputStream FileOutputStream FileReader FileWriter char FileReader FileWriter lines ObjectInputStream ObjectOutputStream FileInputStream FileOutputStream objects
16. Javier Gonzalez-Sanchez | CSE205 | Fall 2021 | 16 jgs Serialization § the process is JVM independent –an object can be serialized on one platform and deserialized on an entirely different platform. § Classes ObjectInputStream and ObjectOutputStream are high-level streams that contain the methods for serializing and deserializing an object.
17. Javier Gonzalez-Sanchez | CSE205 | Fall 2021 | 17 jgs Step 1
18. Javier Gonzalez-Sanchez | CSE205 | Fall 2021 | 18 jgs Serializable For a class to be serialized, two conditions must be met: § The class must implement the java.io.Serializable interface. § All the fields in the class must be serializable. § If you do not want a field to be serializable, mark is as transient, such as public transient int grade;
19. Javier Gonzalez-Sanchez | CSE205 | Fall 2021 | 19 jgs Step 2
20. Javier Gonzalez-Sanchez | CSE205 | Fall 2021 | 20 jgs Step 3
21. Javier Gonzalez-Sanchez | CSE205 | Fall 2021 | 21 jgs Serialization § The try/catch block tries to catch a ClassNotFoundException, which is declared by the readObject() method. § For a JVM to be able to deserialize an object, it must be able to find the bytecode for the class. If the JVM can't find a class during the deserialization of an object, it throws a ClassNotFoundException. § Notice that the return value of readObject() is an Object. Thus, casting is needed.
22. jgs Topics to Review
23. Javier Gonzalez-Sanchez | CSE205 | Fall 2021 | 23 jgs Topics per Week
24. Javier Gonzalez-Sanchez | CSE205 | Fall 2021 | 24 jgs
25. jgs The following slides shows some examples related to some topics This is NOT a comprehensive list of topics Topics in the exam can be found Weeks 2 to 16 (Lectures 1 to 24)
26. Javier Gonzalez-Sanchez | CSE205 | Fall 2021 | 26 jgs Questions
27. jgs CSE 205 Object-Oriented Programming and Data Structures Javier Gonzalez-Sanchez, Ph.D. javiergs@asu.edu Fall 2021 Copyright. These slides can only be used as study material for the class CSE205 at Arizona State University. They cannot be distributed or used for another purpose.