#1172, for comments

[tuohai666]

Fixes #1172.

[coveralls]

Pull Request Test Coverage Report for Build 5066

• 55 of 91 (60.44%) changed or added relevant lines in 11 files are covered.
• 5 unchanged lines in 3 files lost coverage.
• Overall coverage decreased (-0.0009%) to 63.037%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
sharding-core/src/main/java/io/shardingsphere/core/routing/router/sharding/ParsingSQLRouter.java	4	5	80.0%
sharding-opentracing/src/main/java/io/shardingsphere/opentracing/listener/SQLExecuteEventListener.java	13	15	86.67%
sharding-opentracing/src/main/java/io/shardingsphere/opentracing/listener/RootInvokeEventListener.java	6	9	66.67%
sharding-jdbc/src/main/java/io/shardingsphere/core/jdbc/adapter/AbstractConnectionAdapter.java	20	23	86.96%
sharding-opentracing/src/main/java/io/shardingsphere/opentracing/listener/GetConnectionEventListener.java	0	7	0.0%
sharding-opentracing/src/main/java/io/shardingsphere/opentracing/listener/CloseConnectionEventListener.java	0	8	0.0%
sharding-core/src/main/java/io/shardingsphere/core/executor/sql/execute/SQLExecuteCallback.java	0	12	0.0%

Files with Coverage Reduction	New Missed Lines	%
sharding-orchestration/sharding-orchestration-reg/src/main/java/io/shardingsphere/orchestration/reg/newzk/client/zookeeper/base/Holder.java	1	70.49%
sharding-core/src/main/java/io/shardingsphere/core/executor/sql/execute/SQLExecuteCallback.java	1	0.0%
sharding-opentracing/src/main/java/io/shardingsphere/opentracing/listener/GetConnectionEventListener.java	3	0.0%

Totals
Change from base Build 5062:	-0.0009%
Covered Lines:	7961
Relevant Lines:	12629

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💛 - Coveralls