KYLIN-3597 fix sonar issues

[whuwb]

Fix sonar issues

[INFO] ------------------------------------------------------------------------
[INFO] Reactor Summary for Apache Kylin 2.6.0-SNAPSHOT:
[INFO]
[INFO] Apache Kylin ....................................... SUCCESS [ 8.621 s]
[INFO] Apache Kylin - Core Common ......................... SUCCESS [ 16.452 s]
[INFO] Apache Kylin - Core Metadata ....................... SUCCESS [ 52.959 s]
[INFO] Apache Kylin - Core Dictionary ..................... SUCCESS [06:04 min]
[INFO] Apache Kylin - Core Cube ........................... SUCCESS [01:29 min]
[INFO] Apache Kylin - Core Metrics ........................ SUCCESS [ 1.754 s]
[INFO] Apache Kylin - Core Job ............................ SUCCESS [ 47.255 s]
[INFO] Apache Kylin - Core Storage ........................ SUCCESS [ 8.095 s]
[INFO] Apache Kylin - MapReduce Engine .................... SUCCESS [ 23.348 s]
[INFO] Apache Kylin - Spark Engine ........................ SUCCESS [ 8.221 s]
[INFO] Apache Kylin - Hive Source ......................... SUCCESS [ 6.699 s]
[INFO] Apache Kylin - DataSource SDK ...................... SUCCESS [ 11.649 s]
[INFO] Apache Kylin - Jdbc Source ......................... SUCCESS [ 20.404 s]
[INFO] Apache Kylin - Kafka Source ........................ SUCCESS [ 5.919 s]
[INFO] Apache Kylin - Cache ............................... SUCCESS [ 9.387 s]
[INFO] Apache Kylin - HBase Storage ....................... SUCCESS [ 46.270 s]
[INFO] Apache Kylin - Query ............................... SUCCESS [ 14.726 s]
[INFO] Apache Kylin - Metrics Reporter Hive ............... SUCCESS [ 1.079 s]
[INFO] Apache Kylin - Metrics Reporter Kafka .............. SUCCESS [ 0.854 s]
[INFO] Apache Kylin - REST Server Base .................... SUCCESS [ 26.286 s]
[INFO] Apache Kylin - REST Server ......................... SUCCESS [02:02 min]
[INFO] Apache Kylin - JDBC Driver ......................... SUCCESS [ 8.589 s]
[INFO] Apache Kylin - Assembly ............................ SUCCESS [ 16.929 s]
[INFO] Apache Kylin - Tool ................................ SUCCESS [ 12.207 s]
[INFO] Apache Kylin - Tool Assembly ....................... SUCCESS [ 4.185 s]
[INFO] Apache Kylin - Integration Test .................... SUCCESS [ 02:46 h]
[INFO] Apache Kylin - Tomcat Extension .................... SUCCESS [ 5.503 s]
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 03:02 h
[INFO] Finished at: 2019-01-14T21:54:56Z
[INFO] ------------------------------------------------------------------------

[asfgit]

Can one of the admins verify this patch?

[coveralls]

Pull Request Test Coverage Report for Build 4058

• 2 of 25 (8.0%) changed or added relevant lines in 2 files are covered.
• 5 unchanged lines in 3 files lost coverage.
• Overall coverage increased (+0.0004%) to 26.848%

---

Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
core-cube/src/main/java/org/apache/kylin/cube/CubeInstance.java	2	5	40.0%
core-cube/src/main/java/org/apache/kylin/cube/cuboid/algorithm/greedy/GreedyAlgorithm.java	0	20	0.0%

Files with Coverage Reduction	New Missed Lines	%
core-dictionary/src/main/java/org/apache/kylin/dict/lookup/cache/RocksDBLookupTable.java	1	81.08%
core-metadata/src/main/java/org/apache/kylin/source/datagen/ColumnGenerator.java	1	81.08%
core-cube/src/main/java/org/apache/kylin/cube/cuboid/algorithm/greedy/GreedyAlgorithm.java	3	0.0%

Totals
Change from base Build 4047:	0.0004%
Covered Lines:	18618
Relevant Lines:	69346

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💛 - Coveralls

[codecov-io]

Codecov Report

Merging #430 into master will decrease coverage by <.01%.
The diff coverage is 4%.

@@             Coverage Diff              @@
##             master     #430      +/-   ##
============================================
- Coverage     24.38%   24.38%   -0.01%     
- Complexity     4941     4942       +1     
============================================
  Files          1143     1143              
  Lines         69347    69346       -1     
  Branches       9885     9883       -2     
============================================
- Hits          16910    16909       -1     
+ Misses        50733    50732       -1     
- Partials       1704     1705       +1

Impacted Files	Coverage Δ	Complexity Δ
.../cube/cuboid/algorithm/greedy/GreedyAlgorithm.java	0% <0%> (ø)	0 <0> (ø)	⬇️
.../main/java/org/apache/kylin/cube/CubeInstance.java	38.98% <20%> (+1.08%)	52 <0> (+2)	⬆️
...he/kylin/dict/lookup/cache/RocksDBLookupTable.java	72.97% <0%> (-5.41%)	6% <0%> (-1%)
...g/apache/kylin/source/datagen/ColumnGenerator.java	70.94% <0%> (-1.36%)	8% <0%> (ø)

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[shaofengshi]

LGTM