/*
* Copyright 2005 Red Hat, Inc. and/or its affiliates.
*
* 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.
*/
package org.drools.decisiontable;
import org.drools.core.io.impl.FileSystemResource;
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;
import org.drools.template.model.DRLOutput;
import org.drools.template.model.Package;
import org.drools.template.parser.DataListener;
import org.kie.api.io.Resource;
import org.kie.internal.io.ResourceFactory;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.io.IOException;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
/**
*
* This class handles the input XLS and CSV and extracts the rule DRL, ready for
* pumping into drools.
*/
public class SpreadsheetCompiler {
protected static final transient Logger logger = LoggerFactory.getLogger(SpreadsheetCompiler.class);
/**
* Generates DRL from the input stream containing the spreadsheet.
*
* @param showPackage
* tells it to print or not print any package statements in 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(boolean showPackage,
final InputStream xlsStream,
final InputType type) {
return compile( xlsStream,
type,
new DefaultRuleSheetListener( showPackage ) );
}
/**
* 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() );
}
public String compile(final Resource resource,
final InputType type) {
return compile( resource,
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) {
type.createParser( listener ).parseFile( xlsStream );
return listenerToString( listener );
}
public String compile(final Resource resource,
final InputType type,
final RuleSheetListener listener) {
parseResource( type.createParser( listener ), resource );
return listenerToString( listener );
}
public String listenerToString( RuleSheetListener listener ) {
final Package rulePackage = listener.getRuleSet();
final DRLOutput out = new DRLOutput();
rulePackage.renderDRL( out );
return out.getDRL();
}
private void parseResource( DecisionTableParser parser, Resource resource ) {
if (resource instanceof FileSystemResource) {
parser.parseFile( ( (FileSystemResource) resource ).getFile() );
} else {
try {
parser.parseFile( resource.getInputStream() );
} catch (IOException e) {
throw new RuntimeException( e );
}
}
}
/**
* 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) {
return compile( ResourceFactory.newInputStreamResource( stream ), worksheetName );
}
public String compile(final Resource resource,
final String worksheetName) {
final RuleSheetListener listener = getRuleSheetListener( resource,
worksheetName );
return listenerToString( listener );
}
private RuleSheetListener getRuleSheetListener(final Resource resource,
final String worksheetName) {
final DefaultRuleSheetListener listener = new DefaultRuleSheetListener();
listener.setWorksheetName(worksheetName);
final Map<String, List<DataListener>> sheetListeners = new HashMap<String, List<DataListener>>();
final List<DataListener> listeners = new ArrayList<DataListener>();
listeners.add(listener);
sheetListeners.put( worksheetName, listeners );
parseResource( new ExcelParser( sheetListeners ), resource );
return listener;
}
private void closeStream(final InputStream stream) {
try {
stream.close();
} catch ( final Exception e ) {
logger.warn("WARNING: Wasn't able to " + "correctly close stream for decision table. " + e.getMessage());
}
}
}