[HDFS-9951] Use string constants for XML tags in OfflineImageReconstructor

• Type: Improvement
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Fix Version/s: 2.8.0, 3.0.0-alpha1
• Target Version/s: 2.8.0
• Tags: tools
• Assignee: Yiqun Lin
• Reporter: Yiqun Lin
• Created: 14/Mar/16 07:14
• Updated: 30/Aug/16 01:18
• Resolved: 21/Mar/16 18:52

Description

In class OfflineImageReconstructor, it uses many SectionProcessors to process xml files and load the subtree of the XML into a Node structure. But there are lots of places that node removes key by directively writing value in methods rather than define them first. Like this:

Node expiration = directive.removeChild("expiration");

We could improve this to define them in Node and them invoked like this way:

Node expiration=directive.removeChild(Node.CACHE_MANAGER_SECTION_EXPIRATION);

And it will be good to manager node key's name in the future.