package org.openswing.swing.pivottable.tablemodelreaders.server;
import javax.swing.table.TableModel;
import java.io.*;
import org.openswing.swing.util.dataconverters.java.DataConverter;
import org.openswing.swing.util.dataconverters.java.*;
import org.openswing.swing.pivottable.java.InputFilter;
import java.util.Iterator;
import java.util.HashMap;
/**
* <p>Title: OpenSwing Framework</p>
* <p>Description: CSV File reader, used in PivotTableEngine to read data to analyze.</p>
* <p>Copyright: Copyright (C) 2006 Mauro Carniel</p>
*
* <p> This file is part of OpenSwing Framework.
* This library is free software; you can redistribute it and/or
* modify it under the terms of the (LGPL) Lesser General Public
* License as published by the Free Software Foundation;
*
* GNU LESSER GENERAL PUBLIC LICENSE
* Version 2.1, February 1999
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the Free
* Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*
* The author may be contacted at:
* maurocarniel@tin.it</p>
*
* @author Mauro Carniel
* @version 1.0
*/
public class CSVFileReader implements Reader {
/** CSV file to read */
private File csvFile = null;
/** input stream related to CSV file */
private BufferedReader in = null;
/** current line just read */
private String currentLine = null;
/** current line just read */
private Object[] currentLineTokens = null;
/** attribute names */
private String[] attributeNames = null;
/** data converters */
private DataConverter[] dataConverters = null;
/** collection of pairs <column name,column index> */
private HashMap indexes = new HashMap();
/** fields delimiter */
private static final String DELIM = ";";
/**
* Create a reader of a CSV file, used in PivotTableEngine.
* @param csvFile CSV file to read
* @param attribute names that identifies CSF file columns
* @param dataConverters converters to use to parse data read from file
*/
public CSVFileReader(File csvFile,String[] attributeNames,DataConverter[] dataConverters) {
this.csvFile = csvFile;
this.attributeNames = attributeNames;
this.dataConverters = dataConverters;
for(int i=0;i<attributeNames.length;i++)
indexes.put(attributeNames[i],new Integer(i));
}
/**
* Initialize reading.
* @param inputFilter optional input filter, used to skip rows
* @return <code>true</code> if specified file has been correctly opened, <code>false</code> otherwise
*/
public boolean initializeScrolling(InputFilter inputFilter) {
try {
in = new BufferedReader(new InputStreamReader(new FileInputStream(csvFile)));
return true;
}
catch (Exception ex) {
return false;
}
}
/**
* Get next row to read.
* Note: this method can be called ONLY if "initializeScrolling" method has already been invoked.
* @param inputFilter optional input filter, used to skip rows
* @return <code>true</code> if there exists a row, <code>false</code> if no other rows are available
*/
public final boolean nextRow(InputFilter inputFilter) {
try {
Iterator it = null;
currentLine = in.readLine();
splitLine();
boolean skipRow;
while(currentLine!=null && inputFilter!=null) {
it = inputFilter.getFilteredColumnNames();
String colName = null;
skipRow = false;
while(it.hasNext()) {
colName = it.next().toString();
skipRow = inputFilter.skipRow(colName,getValueAt(((Integer)indexes.get(colName)).intValue()));
if (skipRow)
break;
}
if (!skipRow)
break;
currentLine = in.readLine();
splitLine();
}
if (currentLine==null)
in.close();
}
catch (Exception ex) {
currentLineTokens = null;
return false;
}
return currentLine!=null;
}
private void splitLine() {
if (currentLine==null)
currentLineTokens = null;
else {
try{
if (currentLine.trim().length()==0 ){
currentLineTokens = null;
return;
}
if (currentLineTokens==null)
currentLineTokens = new Object[attributeNames.length];
else
for(int i=0;i<currentLineTokens.length;i++)
currentLineTokens[i] = null;
boolean bContinue = true;
int i = 0;
int j = 0;
int ind;
while(bContinue){
ind = currentLine.indexOf(DELIM,j);
if(ind == -1){
ind = currentLine.length();
bContinue = false;
if (j>ind)
continue;
} else {
// found ;
// check if pattern has an odd number of " chars, until ; char
if (isOdd(currentLine,j,ind)) {
// case: "xyz;xyz";
ind = getRightEdge(currentLine,ind); // ind = index of char next to righr delimiter of "
}
}
String value = ind==currentLine.length()?
currentLine.substring(j) :
currentLine.substring(j,ind);
value = decodePattern(value); //replace "" patterns with "
j = ind+1;
if (value!=null && value.length()==0)
value = null;
try {
currentLineTokens[i] = dataConverters[i].decodeValue(value);
} catch (DataConverterException ex) {
currentLineTokens[i] = null;
}
i++;
if (i>=currentLineTokens.length)
break;
}
} catch(Exception ec){
currentLineTokens = null;
}
// currentcurrentLineTokens = currentcurrentLine.split(",");
}
}
/**
* @return check if "pattern" argument has an odd or event number of " chars, until the ; char
* Examples:
* """x -> true
* "x -> true
* ""x -> false
* """"x -> false
* x" -> false
*/
private boolean isOdd(String pattern,int index,int end) {
int odd = 0;
for(int i=index;i<end;i++)
if (pattern.charAt(i)=='\"')
odd++;
return odd%2==1;
}
/**
* @param index ; char index
* @return index of char next to ", that is the right DELIMiter of the field
* Examples:
* "xyz;xyz";
* "xyz"";xyz;xyz";
* "xyz"";xyz;xyz"
*/
private int getRightEdge(String pattern,int index) {
int odd = 0;
for(int i=index;i<pattern.length();i++)
if (pattern.charAt(i)=='\"')
odd++;
else {
if (odd%2==0)
odd = 0;
else
return i;
}
return pattern.length();
}
/**
* Search for "" patterns and replace them with "
* Remove left/right " DELIMiters, if there exist.
*/
private String decodePattern(String pattern) {
if (pattern.length()==0)
return pattern;
StringBuffer aux = new StringBuffer("");
for(int i=0;i<pattern.length();i++)
if (pattern.charAt(i)=='\"' && i+1<pattern.length() && pattern.charAt(i+1)=='\"') {
aux.append( "\"" );
i++;
}
else
aux.append( String.valueOf(pattern.charAt(i)) );
if (aux.charAt(0)=='\"' && aux.charAt(aux.length()-1)=='\"')
return aux.substring(1,aux.length()-1);
return aux.toString();
}
/**
* @param col column index
* @return value stored at column index, related to current row
*/
public final Object getValueAt(int col) {
if (currentLineTokens==null)
return null;
return currentLineTokens[col];
// try {
// return dataConverters[col].decodeValue(currentcurrentLineTokens[col]);
// }
// catch (DataConverterException ex) {
// return null;
// }
}
/**
* @return number of columns defined in TableModel
*/
public final int getColumnCount() {
return attributeNames.length;
}
/**
* @param column index
* @return column name defined in TableModel, related to the specified column index
*/
public final String getColumnName(int index) {
return attributeNames[index];
}
}