/* ===========================================================
* JFreeChart : a free chart library for the Java(tm) platform
* ===========================================================
*
* (C) Copyright 2000-2011, by Object Refinery Limited and Contributors.
*
* Project Info: http://www.jfree.org/jfreechart/index.html
*
* This library is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation; either version 2.1 of the License, or
* (at your option) any later version.
*
* 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 Lesser General Public
* License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
* USA.
*
* [Oracle and Java are registered trademarks of Oracle and/or its affiliates.
* Other names may be trademarks of their respective owners.]
*
* --------
* CSV.java
* --------
* (C) Copyright 2003-2008, by Object Refinery Limited.
*
* Original Author: David Gilbert (for Object Refinery Limited);
* Contributor(s): -;
*
* Changes
* -------
* 24-Nov-2003 : Version 1 (DG);
*
*/
package org.jfree.data.io;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.Reader;
import java.util.List;
import org.jfree.data.category.CategoryDataset;
import org.jfree.data.category.DefaultCategoryDataset;
/**
* A utility class for reading {@link CategoryDataset} data from a CSV file.
* This initial version is very basic, and won't handle errors in the data
* file very gracefully.
*/
public class CSV {
/** The field delimiter. */
private char fieldDelimiter;
/** The text delimiter. */
private char textDelimiter;
/**
* Creates a new CSV reader where the field delimiter is a comma, and the
* text delimiter is a double-quote.
*/
public CSV() {
this(',', '"');
}
/**
* Creates a new reader with the specified field and text delimiters.
*
* @param fieldDelimiter the field delimiter (usually a comma, semi-colon,
* colon, tab or space).
* @param textDelimiter the text delimiter (usually a single or double
* quote).
*/
public CSV(char fieldDelimiter, char textDelimiter) {
this.fieldDelimiter = fieldDelimiter;
this.textDelimiter = textDelimiter;
}
/**
* Reads a {@link CategoryDataset} from a CSV file or input source.
*
* @param in the input source.
*
* @return A category dataset.
*
* @throws IOException if there is an I/O problem.
*/
public CategoryDataset readCategoryDataset(Reader in) throws IOException {
DefaultCategoryDataset dataset = new DefaultCategoryDataset();
BufferedReader reader = new BufferedReader(in);
List<String> columnKeys = null;
int lineIndex = 0;
String line = reader.readLine();
while (line != null) {
if (lineIndex == 0) { // first line contains column keys
columnKeys = extractColumnKeys(line);
}
else { // remaining lines contain a row key and data values
extractRowKeyAndData(line, dataset, columnKeys);
}
line = reader.readLine();
lineIndex++;
}
return dataset;
}
/**
* Extracts the column keys from a string.
*
* @param line a line from the input file.
*
* @return A list of column keys.
*/
private List<String> extractColumnKeys(String line) {
List<String> keys = new java.util.ArrayList<String>();
int fieldIndex = 0;
int start = 0;
for (int i = 0; i < line.length(); i++) {
if (line.charAt(i) == this.fieldDelimiter) {
if (fieldIndex > 0) { // first field is ignored, since
// column 0 is for row keys
String key = line.substring(start, i);
keys.add(removeStringDelimiters(key));
}
start = i + 1;
fieldIndex++;
}
}
String key = line.substring(start, line.length());
keys.add(removeStringDelimiters(key));
return keys;
}
/**
* Extracts the row key and data for a single line from the input source.
*
* @param line the line from the input source.
* @param dataset the dataset to be populated.
* @param columnKeys the column keys.
*/
private void extractRowKeyAndData(String line,
DefaultCategoryDataset dataset,
List<String> columnKeys) {
Comparable rowKey = null;
int fieldIndex = 0;
int start = 0;
for (int i = 0; i < line.length(); i++) {
if (line.charAt(i) == this.fieldDelimiter) {
if (fieldIndex == 0) { // first field contains the row key
String key = line.substring(start, i);
rowKey = removeStringDelimiters(key);
}
else { // remaining fields contain values
Double value = Double.valueOf(
removeStringDelimiters(line.substring(start, i))
);
dataset.addValue(
value, rowKey,
columnKeys.get(fieldIndex - 1)
);
}
start = i + 1;
fieldIndex++;
}
}
Double value = Double.valueOf(
removeStringDelimiters(line.substring(start, line.length()))
);
dataset.addValue(
value, rowKey, columnKeys.get(fieldIndex - 1)
);
}
/**
* Removes the string delimiters from a key (as well as any white space
* outside the delimiters).
*
* @param key the key (including delimiters).
*
* @return The key without delimiters.
*/
private String removeStringDelimiters(String key) {
String k = key.trim();
if (k.charAt(0) == this.textDelimiter) {
k = k.substring(1);
}
if (k.charAt(k.length() - 1) == this.textDelimiter) {
k = k.substring(0, k.length() - 1);
}
return k;
}
}