My Tech Notes - Java Coding Practices

Java Coding Practices : Simple rules to Optimise your code and make it work faster

http://www.capitalware.com/dl/docs/WhitePaperJavaCodingPractices.pdf

1. Garbage collection 
2. Loop optimisation 
3. Data Structures
4. Synchronization
5. Exception Handling - A simple performance improvement can be achieved by placing the try-catch block outside any loops.

• Set -  no particular order, sets are slower than most other collection objects. No duplicates
•  HashSet -  HashSet stores the object in random order.There is no guarantee that the element we  inserted first in the HashSet  will be printed first in the output
• TreeSet - Elements are sorted according to the natural ordering of its elements in TreeSet
• List -  A list has the characteristics that objects are stored in a linear manner
• ArrayList  - Ordered list the order in which elements are entered is maintained
• Vector - Dynamic array. Synchronised 
• Stack  - LIFO last in first out 
• LinkedList - Internally uses doubly linked list faster than array list 
• Hash - Maps involve pairs of objects, a key and the object itself.
• Hash Map - no order in key value pair stored. 
• Tree Map - ordered by key
• Linked Hash Map - insertion order maintained. 
• Hash table - synchronised hash table  

Others Notes: 

Thread synchronization is defined as a mechanism which ensures that two or more concurrent processes or threads do not simultaneously execute some particular program segment known as mutual exclusion.

Some useful links : 
http://tutorials.jenkov.com/java-collections/stack.html