package org.drools.decisiontable;
/*
* Copyright 2005 JBoss Inc
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
import java.io.InputStream;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import org.drools.decisiontable.model.DRLOutput;
import org.drools.decisiontable.model.Package;
import org.drools.decisiontable.parser.DecisionTableParser;
import org.drools.decisiontable.parser.DefaultRuleSheetListener;
import org.drools.decisiontable.parser.RuleSheetListener;
import org.drools.decisiontable.parser.xls.ExcelParser;
/**
* @author <a href="mailto:michael.neale@gmail.com"> Michael Neale </a>
*
* This class handles the input XLS and CSV and extracts the rule DRL, ready for
* pumping into drools.
*/
public class SpreadsheetCompiler {
/**
* Generates DRL from the input stream containing the spreadsheet.
*
* @param pkg
* Uses this package definition as the default definitions for the spreadsheet
* @param xlsStream
* The stream to the spreadsheet. Uses the first worksheet found
* for the decision tables, ignores others.
* @return DRL xml, ready for use in drools.
*/
public String compile(final org.drools.rule.Package pkg,
final InputStream xlsStream,
final InputType type) {
return compile( xlsStream,
type,
new DefaultRuleSheetListener( pkg ) );
}
/**
* Generates DRL from the input stream containing the spreadsheet.
*
* @param xlsStream
* The stream to the spreadsheet. Uses the first worksheet found
* for the decision tables, ignores others.
* @return DRL xml, ready for use in drools.
*/
public String compile(final InputStream xlsStream,
final InputType type) {
return compile( xlsStream,
type,
new DefaultRuleSheetListener() );
}
/**
* Generates DRL from the input stream containing the spreadsheet.
*
* @param xlsStream
* The stream to the spreadsheet. Uses the first worksheet found
* for the decision tables, ignores others.
* @param type
* The type of the file - InputType.CSV or InputType.XLS
* @param listener
*
* @return DRL xml, ready for use in drools.
*/
public String compile(final InputStream xlsStream,
final InputType type,
final RuleSheetListener listener) {
final DecisionTableParser parser = type.createParser( listener );
parser.parseFile( xlsStream );
final Package rulePackage = listener.getRuleSet();
final DRLOutput out = new DRLOutput();
rulePackage.renderDRL( out );
return out.getDRL();
}
/**
* Convenience implementation, taking rules from the classpath. It is
* recommended to use the stream version, as you can then change rules
* dynamically. (that is a lot of the benefit of rule engines !).
*
* @param classPathResource
* full class path to the spreadsheet you wish to convert to DRL.
* Uses the first worksheet for the decision tables.
* @return DRL.
*/
public String compile(final String classPathResource,
final InputType inputType) {
final InputStream stream = this.getClass().getResourceAsStream( classPathResource );
try {
final String drl = compile( stream,
inputType );
return drl;
} finally {
closeStream( stream );
}
}
/**
* Looks for a named worksheet to find the decision tables on. Only works
* with XLS format spreadsheets (as they have multiple worksheets).
*
* @param stream
* The stream of the decision tables (spreadsheet) IN XLS format !!
* @param worksheetName
* The name of the worksheet that the decision tables live on.
* @return DRL, ready to go.
*/
public String compile(final InputStream stream,
final String worksheetName) {
final RuleSheetListener listener = getRuleSheetListener( stream,
worksheetName );
final Package rulePackage = listener.getRuleSet();
final DRLOutput out = new DRLOutput();
rulePackage.renderDRL( out );
return out.getDRL();
}
private RuleSheetListener getRuleSheetListener(final InputStream stream,
final String worksheetName) {
final RuleSheetListener listener = new DefaultRuleSheetListener();
final Map sheetListeners = new HashMap();
final List listeners = new ArrayList();
listeners.add(listener);
sheetListeners.put( worksheetName,
listeners );
final ExcelParser parser = new ExcelParser( sheetListeners );
parser.parseFile( stream );
return listener;
}
private void closeStream(final InputStream stream) {
try {
stream.close();
} catch ( final Exception e ) {
System.err.print( "WARNING: Wasn't able to " + "correctly close stream for decision table. " + e.getMessage() );
}
}
}