[birt-dev] Implement a buffer layer in RAFileInputStream.

["Houqiang Yan" <hyan@xxxxxxxxxxx>]

Title: Implement a buffer layer in RAFileInputStream.

- Summary:

- Bugzilla Bug (s) Resolved:
None

- Description:
Implement a buffer layer in RAFileInputStream.

- Tests Description:
Manually Test

- Notes to Build Team:

- Notes to Developers:
The BufferedInputStream wrapper for the RAFileInputStream can be removed after you don’t see any issues with this checkin.

- Notes to QA:  
 
- Notes to Documentation:  

- Files Edited:
"/org.eclipse.birt.core/src/org/eclipse/birt/core/archive/RAFileInputStream.java"

- Files Added:

- Files Deleted