* unit test LogicSchema#getDataSources

* powermock.version extracted

* 1. remove powermock-api-mockito2
2. Apache copyright added, and several code style corrected
3. replace assertEquals with assertThat

* delete blank lines

* add a group of testcases: DerivedLiteralExpressionSegmentTest,DerivedParameterMarkerExpressionSegmentTest,InsertValueContextTest

* generic type added for MethodInvocation

* EqualsAndHashCode added for class of DerivedParameterMarkerExpressionSegment and DerivedLiteralExpressionSegment

* Generic Subtypes added for InsertValueContext's constructor

* Testcased added for InsertValueContext

* copyright added

* the unused test case LogicSchemaTest deleted

* 1. remove EqualsAndHashCode in class of DerivedLiteralExpressionSegment and DerivedParameterMarkerExpressionSegment
2. remove unnecessary blank lines
3. change "List<? extends Object>" back to List<Object>

* remove convenience class MethodInvocation

* InsertValueContext's generic subtype support changed back to original

* 1. remove unused import of EqualsAndHashCode,Getter,RequiredArgsConstructor and SneakyThrows
2. InsertValueContext's generic subtype support changed back to original
3. remove unnecessary blank lines
4. add final key word for TestCase class
5. remove unnecessary class definition of MethodInvocation

* generic type added to InsertValueContext's constructor

* 1. generic type removed for  InsertValueContext's constructor
2. generic type added for Collections.singletonList invocation

* 1. Lists.<ExpressionSegment>newArrayList changed to Collections.<ExpressionSegment>singleton

* 1. revert to the original indent

* 1. add a blank line for end of file
2. set "Keep indents on empty lines" in IDE, and the starting indents reserved
3. variable of result changed to  valueFromInsertValueContext

* for checkstyle

* refactor SQLLoggerTest

* add DAL grammar

* supplement for dal grammar

* fix mysqlkeyword.g4 format

* fix dcl grammar

* fix dcl g4 and fix mysql create user testcase

* add ParameterBuilderFactory

* group token generator

* add TableMetasAware

* move EncryptCondition's logic from RewriteStatementFactory to WhereEncryptColumnTokenGenerator

* remove EncryptConditions

* rename WhereClauseEncryptConditionEngine to EncryptConditionEngine

* refactor EncryptConditionEngine.createEncryptConditions()

* add ShardingRuleAware & EncryptRuleAware

* refactor SelectEncryptItemTokenGenerator

* add QueryWithCipherColumnAware

* refactor SQLRewriteEngine's constructor

* add SQLTokenGenerators

* refactor SQLTokenGenerators

* avoid to using singleton for SQLTokenGenerator

* move SQLTokenGenerateEngine to builder package

* rename BaseTokenGenerateEngine to SQLTokenGeneratorBuilder

* add ShardingConditionsAware

* remove RewriteStatement.shardingConditions

* refactor InsertGeneratedKeyNameTokenGenerator

* refactor InsertRegularNamesTokenGenerator.isNeedToGenerateSQLToken()

* refactor InsertRegularNamesTokenGenerator

* add PreviousSQLTokensAware to split generate key and encrypt column's SQL token generator

* add GeneratedKeyAware

* remove InsertRewriteStatement.generatedKey

* move InsertRewriteStatement's logic to SQLRewriteEngine

* remove RewriteStatement

* check codes by checkstyle

* #3088, Use ANTLR parse SQL-92

* #3088, add other database types

* #3088, for test case

* #3142, parse SQLs which database types are unidentified using SQL92 parser

* add DAL grammar

* supplement for dal grammar

* fix mysqlkeyword.g4 format

* fix dcl grammar

* #3088, Use ANTLR parse SQL-92

* #3088, add other database types

* #3088, for test case

* change seq of SelectSQLStatementContext.projectionsContext

* rename sharding-core-optimize to sharding-core-preprocessor

* remove SQLRouteResult.encryptStatementContext

* rename SQLRouteResult.shardingStatementContext to sqlStatementContext

* rename SelectItemsContext to ProjectionsContext

* rename SelectItem to Projection

* rename SelectItem to Projection

* add hint query context for sharding-proxy

* implement HintShowStatusExecutor&HintShowTableStatusExecutor

* complete test for hint in  sharding-proxy

* refactor HintShowTableStatusExecutor.java

* add database_only for HintShowTableStatusExecutor.java

* format HintManager

* delete @Getter on HintShowTableStatusCommand

* Refactor HintManager&ShardingRule&HintShowTableStatusExecutor

* transfer BackendConnection to HintShowTableStatusExecutor

* Refactor HintCommandExecutorFactoryTest

* Refactor HintCommandExecutorFactory

* Refactor HintCommandExecutor use MergedResult

* delete HintShowStatusResult

* Refactor HintManager

* Refactor ShardingCTLShowBackendHandler

* Reactor AbstractHintQueryExecutor

* Refactor hint for sharding-proxy

* delete unused @RequiredArgsConstructor

* Refactor Hintmanager

* Refactor HintShowTableStatusExecutor

* rename OptimizedStatement to SQLStatementContext

* rename Tables to TablesContext

* move tablecontext to table package

* rename InsertValue to InsertValueContext

* rename GroupBy to GroupByContext

* refactor PaginationTest

* rename OrderBy to OrderByContext

* rename Pagination to PaginationContext

* rename SelectItems to SelectItemsContext

* add DAL grammar

* supplement for dal grammar

* fix mysqlkeyword.g4 format

* move sharding segment to common segment

* remove sharding package

* rename org.apache.shardingsphere.core.optimize.api to org.apache.shardingsphere.core.optimize

* move XXXOptimizedStatement to impl package

* refactor groupby and orderby

* remove useless resources

* refactor OptimizedStatement

* refactor SelectOptimizedStatement.containsSubquery()

* add test case for SelectOptimizedStatement.isSameGroupByAndOrderByItems()

* remove SelectItems.tableMetas

* remove SelectItems.tables

* move XXXSelectItem to impl package

* move Column to route module

* refactor package name of segment

* add todo

2. add UT.

* change position of EncryptCondition's positionValueMap & positionIndexMap

* move generate EncryptConditions from optimize to rewrite module

* remove EncryptConditionOptimizedStatement.encryptConditions

* move encrypt condition to rewrite module

* remove EncryptWhereOptimizeEngine

* remove useless parameter for EncryptOptimizeEngineFactory.newInstance()

* remove EncryptTransparentOptimizedStatement

* remove EncryptOptimizedStatement

* remove ShardingTransparentOptimizedStatement

* remove ShardingOptimizedStatement

* remove rule parameter for OptimizeEngine.optimize()

* remove EncryptOptimizeEngineFactory

* rename ShardingOptimizeEngineFactory to OptimizedStatementFactory

* rename ShardingSelectOptimizedStatement to SelectOptimizedStatement

* Fix SCTL statement execute error with comment

* Add  SCTLUtils class to trim sql

* 
1. modify MySQLAuthenticationHandler's login method to return Optional<ProxyUser>.
2. check response41 database with ProxyUser's database.
3. add UT.

* resolve conflicts.

* try CI check again.

* 
1. move schema judgement to MySQLAuthenticationHandler.
2. modify UT.

* 
1. modify the input parameter of MySQLAuthenticationHandler.login().
2. modify UT.

* try CI check again.

* 
1. add ER_DBACCESS_DENIED_ERROR in MySQLServerErrorCode.
2. modify the result of MySQLAuthenticationHandler.login() to Optional<MySQLServerErrorCode>.
3. modify UT classes.

* delete ShardingDropIndexOptimizedStatement

* avoid using ShardingConditionOptimizedStatement

* remove ShardingConditionOptimizedStatement

* decouple GeneratedKey and columnNames

* refactor InsertClauseShardingConditionEngine

* refactor InsertClauseShardingConditionEngine's constructor

* move GeneratedKey from optimize module to route module

* rename package name org.apache.shardingsphere.core.optimize.sharding.segment.select to org.apache.shardingsphere.core.optimize.sharding.segment

* merge ShardingInsertOptimizedStatement and EncryptInsertOptimizedStatement to InsertOptimizedStatement

* rename OptimizedStatement.getSQLStatement() to getSqlStatement

* remove ShardingOptimizeEngine & EncryptOptimizeEngine

* move constant of derived values from optimize module to rewrite module

* Update StandardRoutingEngineTest.java

* Update ComplexRoutingEngineTest.java

* Merge branch 'dev' of https://github.com/apache/incubator-shardingsphere into issue3061

# Conflicts:
#	sharding-core/sharding-core-route/src/test/java/org/apache/shardingsphere/core/route/type/complex/ComplexRoutingEngineTest.java
#	sharding-core/sharding-core-route/src/test/java/org/apache/shardingsphere/core/route/type/standard/StandardRoutingEngineTest.java

* Fix spring-boot-plugin version missing bug.

* Support jdk1.7 to change frontend-maven-plugin version

* For #3032, add missing dcl test cases for select with functions grammars.

* For #3032, add missing dcl test cases for select with functions grammars 2nd.

* For #3047, Refactor TableBroadcastRoutingEngineTest

* For #3047, Add some unit test for exception

* For checkstyle

* For #3047, Add unit test log SQL shard with parameters

* For #3047, Add unit test for SPIRoutingHook

* For #3047, Add unit test for RoutingUnit

* For #3047, Add unit test for RoutingResult

* For #3047, Add unit test for BatchRouteUnit

* For #3047, Add unit test for MasterInstanceBroadcastRoutingEngine

* For #3047, Add unit test for MasterSlaveRouter

* For #3047, Add unit test for ShardingMasterSlaveRouter

* For #3047, Add equals and toString unit test for BatchRouteUnit, RouteUnit and SQLUnit

* For #3047, Refactor StandardRoutingEngineTest

* For #3047, Refactor ComplexRoutingEngineTest

* For #3047, Refactor AbstractSQLRouteTest and for checkstyle

* For #3047, Add assertToString for RoutingUnit and TableUnit

* For #3047, Add unit test for RoutingEngineFactory

* For #3047, Add unit test for insert

* For #3047, Conflict resolution

* For #3047, Add unit test for InlineShardingStrategy

* remove RoutingResultValidator

* rename org.apache.shardingsphere.core.route.router.sharding.validator.statement to org.apache.shardingsphere.core.route.router.sharding.validator

* update javadoc

* add judge to whether routed data sources belong to configured data sources