com.espertech.esper.epl.db
Class DatabasePollingViewableFactory

java.lang.Object
  com.espertech.esper.epl.db.DatabasePollingViewableFactory

public class DatabasePollingViewableFactory
extends java.lang.Object

Factory for a view onto historical data via SQL statement.

Field Summary

static java.lang.String

SAMPLE_WHERECLAUSE_PLACEHOLDER Placeholder name for SQL-where clause substitution.

Constructor Summary

DatabasePollingViewableFactory()

Method Summary

static HistoricalEventViewable

createDBStatementView(int statementId, int streamNumber, DBStatementStreamSpec databaseStreamSpec, DatabaseConfigService databaseConfigService, EventAdapterService eventAdapterService, EPStatementAgentInstanceHandle epStatementAgentInstanceHandle, SQLColumnTypeConversion columnTypeConversionHook, SQLOutputRowConversion outputRowConversionHook, boolean enableJDBCLogging, DataCacheFactory dataCacheFactory, StatementContext statementContext) Creates the viewable for polling via database SQL query.

protected static java.lang.String

lexSampleSQL(java.lang.String querySQL) Lexes the sample SQL and inserts a "where 1=0" where-clause.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

SAMPLE_WHERECLAUSE_PLACEHOLDER

public static final java.lang.String SAMPLE_WHERECLAUSE_PLACEHOLDER

Placeholder name for SQL-where clause substitution.

See Also:

Constant Field Values

Constructor Detail

DatabasePollingViewableFactory

public DatabasePollingViewableFactory()

Method Detail

createDBStatementView

public static HistoricalEventViewable createDBStatementView(int statementId,
                                                            int streamNumber,
                                                            DBStatementStreamSpec databaseStreamSpec,
                                                            DatabaseConfigService databaseConfigService,
                                                            EventAdapterService eventAdapterService,
                                                            EPStatementAgentInstanceHandle epStatementAgentInstanceHandle,
                                                            SQLColumnTypeConversion columnTypeConversionHook,
                                                            SQLOutputRowConversion outputRowConversionHook,
                                                            boolean enableJDBCLogging,
                                                            DataCacheFactory dataCacheFactory,
                                                            StatementContext statementContext)
                                                     throws ExprValidationException

Creates the viewable for polling via database SQL query.

Parameters:

streamNumber - is the stream number of the view

databaseStreamSpec - provides the SQL statement, database name and additional info

databaseConfigService - for getting database connection and settings

eventAdapterService - for generating event beans from database information

epStatementAgentInstanceHandle - is the statements-own handle for use in registering callbacks with services

columnTypeConversionHook - hook for statement-specific column conversion

outputRowConversionHook - hook for statement-specific row conversion

enableJDBCLogging - indicator to enable JDBC logging

Returns:

viewable providing poll functionality

Throws:

ExprValidationException - if the validation failed

lexSampleSQL

protected static java.lang.String lexSampleSQL(java.lang.String querySQL)
                                        throws ExprValidationException

Lexes the sample SQL and inserts a "where 1=0" where-clause.

Parameters:

querySQL - to inspect using lexer

Returns:

sample SQL with where-clause inserted

Throws:

ExprValidationException - to indicate a lexer problem