refactor jdbc local transaction.

[cherrylzhao]

refactor jdbc local transaction.

[coveralls]

Pull Request Test Coverage Report for Build 4950

• 13 of 22 (59.09%) changed or added relevant lines in 1 file are covered.
• 2 unchanged lines in 2 files lost coverage.
• Overall coverage decreased (-0.1%) to 64.275%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
sharding-jdbc/src/main/java/io/shardingsphere/core/jdbc/adapter/AbstractConnectionAdapter.java	13	22	59.09%

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	78.26%
sharding-orchestration/sharding-jdbc-orchestration-spring/sharding-jdbc-orchestration-spring-namespace/src/main/java/io/shardingsphere/jdbc/orchestration/spring/datasource/OrchestrationMasterSlaveDataSourceFactoryBean.java	1	66.67%

Totals
Change from base Build 4949:	-0.1%
Covered Lines:	8204
Relevant Lines:	12764

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💛 - Coveralls