The CSVQuoter is a helper class to encode a string for the CSV file format. : CSV File « Development Class « Java
The CSVQuoter is a helper class to encode a string for the CSV file format.
/**
*
* JFreeReport : a free Java reporting library
*
*
* Project Info: http://reporting.pentaho.org/
*
* (C) Copyright 2001-2007, by Object Refinery Ltd, Pentaho Corporation and Contributors.
*
* 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., 59 Temple Place, Suite 330,
* Boston, MA 02111-1307, USA.
*
* [Java is a trademark or registered trademark of Sun Microsystems, Inc.
* in the United States and other countries.]
*
* ------------
* CSVQuoter.java
* ------------
* (C) Copyright 2001-2007, by Object Refinery Ltd, Pentaho Corporation and Contributors.
*/
/**
* The <code>CSVQuoter</code> is a helper class to encode a string for the CSV file
* format.
*
* @author Thomas Morgner.
*/
public class CSVQuoter
{
/**
* The separator used in the CSV file.
*/
private char separator;
/**
* The quoting character or a single quote.
*/
private char quate;
/**
* The double quote. This is a string containing the quate two times.
*/
private String doubleQuate;
/**
* Creates a new CSVQuoter, which uses a comma as the default separator.
*/
public CSVQuoter ()
{
this(',', '"');
}
/**
* Creates a new <code>CSVQuoter</code>, which uses the defined separator.
*
* @param separator the separator.
* @throws NullPointerException if the given separator is <code>null</code>.
*/
public CSVQuoter (final char separator)
{
this(separator, '"');
}
/**
* Creates a new CSVQuoter with the given separator and quoting character.
*
* @param separator the separator
* @param quate the quoting character
*/
public CSVQuoter (final char separator, final char quate)
{
this.separator = separator;
this.quate = quate;
this.doubleQuate = String.valueOf(quate) + quate;
}
/**
* Encodes the string, so that the string can safely be used in CSV files. If the string
* does not need quoting, the original string is returned unchanged.
*
* @param original the unquoted string.
* @return The quoted string
*/
public String doQuoting (final String original)
{
if (isQuotingNeeded(original))
{
final StringBuffer retval = new StringBuffer();
retval.append(quate);
applyQuote(retval, original);
retval.append(quate);
return retval.toString();
}
else
{
return original;
}
}
/**
* Decodes the string, so that all escape sequences get removed. If the string was not
* quoted, then the string is returned unchanged.
*
* @param nativeString the quoted string.
* @return The unquoted string.
*/
public String undoQuoting (final String nativeString)
{
if (isQuotingNeeded(nativeString))
{
final StringBuffer b = new StringBuffer(nativeString.length());
final int length = nativeString.length() - 1;
int start = 1;
int pos = start;
while (pos != -1)
{
pos = nativeString.indexOf(doubleQuate, start);
if (pos == -1)
{
b.append(nativeString.substring(start, length));
}
else
{
b.append(nativeString.substring(start, pos));
start = pos + 1;
}
}
return b.toString();
}
else
{
return nativeString;
}
}
/**
* Tests, whether this string needs to be quoted. A string is encoded if the string
* contains a newline character, a quote character or the defined separator.
*
* @param str the string that should be tested.
* @return true, if quoting needs to be applied, false otherwise.
*/
private boolean isQuotingNeeded (final String str)
{
if (str.indexOf(separator) != -1)
{
return true;
}
if (str.indexOf('\n') != -1)
{
return true;
}
if (str.indexOf(quate, 1) != -1)
{
return true;
}
return false;
}
/**
* Applies the quoting to a given string, and stores the result in the StringBuffer
* <code>b</code>.
*
* @param b the result buffer
* @param original the string, that should be quoted.
*/
private void applyQuote (final StringBuffer b, final String original)
{
// This solution needs improvements. Copy blocks instead of single
// characters.
final int length = original.length();
for (int i = 0; i < length; i++)
{
final char c = original.charAt(i);
if (c == quate)
{
b.append(doubleQuate);
}
else
{
b.append(c);
}
}
}
/**
* Gets the separator used in this quoter and the CSV file.
*
* @return the separator (never <code>null</code>).
*/
public char getSeparator ()
{
return separator;
}
/**
* Returns the quoting character.
*
* @return the quote character.
*/
public char getQuate ()
{
return quate;
}
}
