/*
* 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.
*/
package org.drools.decisiontable.parser.xls;
import org.apache.poi.openxml4j.exceptions.InvalidFormatException;
import org.apache.poi.ss.usermodel.Cell;
import org.apache.poi.ss.usermodel.CellValue;
import org.apache.poi.ss.usermodel.DataFormatter;
import org.apache.poi.ss.usermodel.FormulaEvaluator;
import org.apache.poi.ss.usermodel.Row;
import org.apache.poi.ss.usermodel.Sheet;
import org.apache.poi.ss.usermodel.Workbook;
import org.apache.poi.ss.usermodel.WorkbookFactory;
import org.apache.poi.ss.util.CellRangeAddress;
import org.drools.decisiontable.parser.DecisionTableParser;
import org.drools.template.parser.DataListener;
import org.drools.template.parser.DecisionTableParseException;
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.Locale;
import java.util.Map;
import static java.lang.String.format;
/**
* Parse an excel spreadsheet, pushing cell info into the SheetListener interface.
*/
public class ExcelParser
implements
DecisionTableParser {
private static final Logger log = LoggerFactory.getLogger( ExcelParser.class );
public static final String DEFAULT_RULESHEET_NAME = "Decision Tables";
private Map<String, List<DataListener>> _listeners = new HashMap<String, List<DataListener>>();
private boolean _useFirstSheet;
/**
* Define a map of sheet name to listener handlers.
* @param sheetListeners map of String to SheetListener
*/
public ExcelParser( final Map<String, List<DataListener>> sheetListeners ) {
this._listeners = sheetListeners;
}
public ExcelParser( final List<DataListener> sheetListeners ) {
this._listeners.put( ExcelParser.DEFAULT_RULESHEET_NAME,
sheetListeners );
this._useFirstSheet = true;
}
public ExcelParser( final DataListener listener ) {
List<DataListener> listeners = new ArrayList<DataListener>();
listeners.add( listener );
this._listeners.put( ExcelParser.DEFAULT_RULESHEET_NAME,
listeners );
this._useFirstSheet = true;
}
public void parseFile( InputStream inStream ) {
try {
Workbook workbook = WorkbookFactory.create( inStream );
if ( _useFirstSheet ) {
Sheet sheet = workbook.getSheetAt( 0 );
processSheet( sheet, _listeners.get( DEFAULT_RULESHEET_NAME ) );
} else {
for ( String sheetName : _listeners.keySet() ) {
Sheet sheet = workbook.getSheet( sheetName );
if ( sheet == null ) {
throw new IllegalStateException( "Could not find the sheetName (" + sheetName
+ ") in the workbook sheetNames." );
}
processSheet( sheet,
_listeners.get( sheetName ) );
}
}
} catch ( InvalidFormatException e ) {
throw new DecisionTableParseException( "An error occurred opening the workbook. It is possible that the encoding of the document did not match the encoding of the reader.",
e );
} catch ( IOException e ) {
throw new DecisionTableParseException( "Failed to open Excel stream, " + "please check that the content is xls97 format.",
e );
}
}
private CellRangeAddress[] getMergedCells( Sheet sheet ) {
CellRangeAddress[] ranges = new CellRangeAddress[ sheet.getNumMergedRegions() ];
for ( int i = 0; i < ranges.length; i++ ) {
ranges[ i ] = sheet.getMergedRegion( i );
}
return ranges;
}
private void processSheet( Sheet sheet,
List<? extends DataListener> listeners ) {
int maxRows = sheet.getLastRowNum();
CellRangeAddress[] mergedRanges = getMergedCells( sheet );
DataFormatter formatter = new DataFormatter( Locale.ENGLISH );
FormulaEvaluator formulaEvaluator = sheet.getWorkbook().getCreationHelper().createFormulaEvaluator();
for ( int i = 0; i <= maxRows; i++ ) {
Row row = sheet.getRow( i );
int lastCellNum = row != null ? row.getLastCellNum() : 0;
newRow( listeners, i, lastCellNum );
for ( int cellNum = 0; cellNum < lastCellNum; cellNum++ ) {
Cell cell = row.getCell( cellNum );
if ( cell == null ) {
continue;
}
double num = 0;
CellRangeAddress merged = getRangeIfMerged( cell,
mergedRanges );
int mergedColStart = DataListener.NON_MERGED;
if ( merged != null ) {
cell = sheet.getRow(merged.getFirstRow()).getCell(merged.getFirstColumn());
mergedColStart = cell.getColumnIndex();
}
switch ( cell.getCellType() ) {
case Cell.CELL_TYPE_FORMULA:
String cellValue = null;
try {
newCell(listeners,
i,
cellNum,
formatter.formatCellValue(cell, formulaEvaluator),
mergedColStart);
} catch (RuntimeException e) {
// This is thrown if an external link cannot be resolved, so try the cached value
log.warn("Cannot resolve externally linked value: " + formatter.formatCellValue(cell));
String cachedValue = tryToReadCachedValue(cell);
newCell(listeners,
i,
cellNum,
cachedValue,
mergedColStart);
}
break;
case Cell.CELL_TYPE_NUMERIC:
num = cell.getNumericCellValue();
default:
if (num - Math.round(num) != 0) {
newCell(listeners,
i,
cellNum,
String.valueOf(num),
mergedColStart);
} else {
newCell(listeners,
i,
cellNum,
formatter.formatCellValue(cell),
mergedColStart);
}
}
}
}
finishSheet( listeners );
}
private String tryToReadCachedValue( Cell cell ) {
DataFormatter formatter = new DataFormatter( Locale.ENGLISH );
String cachedValue;
switch ( cell.getCachedFormulaResultType() ) {
case Cell.CELL_TYPE_NUMERIC:
double num = cell.getNumericCellValue();
if ( num - Math.round( num ) != 0 ) {
cachedValue = String.valueOf( num );
} else {
cachedValue = formatter.formatCellValue( cell );
}
break;
case Cell.CELL_TYPE_STRING:
cachedValue = cell.getStringCellValue();
break;
case Cell.CELL_TYPE_BOOLEAN:
cachedValue = String.valueOf( cell.getBooleanCellValue() );
break;
case Cell.CELL_TYPE_ERROR:
cachedValue = String.valueOf( cell.getErrorCellValue() );
break;
default:
throw new DecisionTableParseException( format( "Can't read cached value for cell[row=%d, col=%d, value=%s]!",
cell.getRowIndex(), cell.getColumnIndex(), cell ) );
}
return cachedValue;
}
private String getCellValue( final CellValue cv ) {
switch ( cv.getCellType() ) {
case Cell.CELL_TYPE_BOOLEAN:
return Boolean.toString( cv.getBooleanValue() );
case Cell.CELL_TYPE_NUMERIC:
return String.valueOf( cv.getNumberValue() );
}
return cv.getStringValue();
}
CellRangeAddress getRangeIfMerged( Cell cell,
CellRangeAddress[] mergedRanges ) {
for ( int i = 0; i < mergedRanges.length; i++ ) {
CellRangeAddress r = mergedRanges[ i ];
if ( r.isInRange( cell.getRowIndex(), cell.getColumnIndex() ) ) {
return r;
}
}
return null;
}
private void finishSheet( List<? extends DataListener> listeners ) {
for ( DataListener listener : listeners ) {
listener.finishSheet();
}
}
private void newRow( List<? extends DataListener> listeners,
int row,
int cols ) {
for ( DataListener listener : listeners ) {
listener.newRow( row,
cols );
}
}
public void newCell( List<? extends DataListener> listeners,
int row,
int column,
String value,
int mergedColStart ) {
for ( DataListener listener : listeners ) {
listener.newCell( row,
column,
value,
mergedColStart );
}
}
}