Specific Case Pattern Decorate Pattern JAVA Optional and Generic

1. Code Review（I）
➔Tsai Chia-Ping
➔chia7712@gmail.com
1

2. Agenda
• Specific Case Pattern
• Decorate Pattern
• JAVA Optional and Generic
2/15

3. YOU HATE the STATEMENT
3/15
You must lock the resource before opening …

4. YOU KILL the
STATEMENT
4/15
Replace the null value by a do-nothing class
?

5. Engineer is always
SINGLETON
5/15
Singleton
pattern
Singleton
pattern
?

6. Coding is YOUR
life
6/15
Query the data with
3 optional arguments
1) filter
2) limit
3) offset

7. YOU always work
for the
OLDER SPEC
7/15
WAIT...The order should be
1) limit
2) filter
3) offset
? ? ?

8. 8/15

9. YOU have a DREAM
9/15
Query the data with
3 optional arguments
1) filter
2) limit
3) offset
Iterator<T> iter = …
iter = withFilter(iter);
iter = withLimit(iter);
iter = withOffset(iter);
return iter
WAIT...The order should be
1) limit
2) filter
3) offset
Iterator<T> iter = …
iter = withLimit(iter);
iter = withFilter(iter);
iter = withOffset(iter);
return iter

10. 10/15

11. God could not be everywhere, and therefore
he made ENGINEER
11/15
WAIT...The order should be
1) limit
2) filter
3) offset
Query the data with
3 optional arguments
1) filter
2) limit
3) offset

12. What can We do for this code (1/2)
12/15

13. Redundant Statement
13/15

14. What can We do for this code (2/2)
14/15

15. Compiler is
your best
FRIEND
15/15
1. Unchecked type
2. The input argument is checked
java.lang.ClassCastException
(Dataset.Column cannot be cast to java.lang.Integer)

16. QA