[RANGER-1377] Improve codestyle, java api usage

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 0.7.0
• Fix Version/s: 1.0.0
• Component/s: Ranger
• Labels: code-cleanup
• Flags: Patch
• Assignee: Zsombor Gegesy
• Reporter: Zsombor Gegesy
• Created: 12/Feb/17 14:27
• Updated: 11/Sep/17 01:30
• Resolved: 05/Apr/17 16:36

Description

There are several generally considered best practice writing Java code, it is better to follow them.
Instead of:

• var.equals("somestring") use "somestring".equals(var)
• collection.size() > 0 use !collection.isEmpty()
• instead of using a for loop to add items to a collection, use 'addAll'
• str.indexOf("something") >= 0 use str.contains("something")
• "" + var use String.valueOf(var)
• stringBuilder.append("a" + b + "c") use stringBuilder.append("a").append(b).append("c")
• "something "+ a.toString() use "something " + a