Mega Code Archive
Truncate text on a whitespace boundary (near a specified length)
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/**********************************************************************************
*
* Copyright (c) 2003, 2004 The Regents of the University of Michigan, Trustees of Indiana University,
* Board of Trustees of the Leland Stanford, Jr., University, and The MIT Corporation
*
* Licensed under the Educational Community License Version 1.0 (the "License");
* By obtaining, using and/or copying this Original Work, you agree that you have read,
* understand, and will comply with the terms and conditions of the Educational Community License.
* You may obtain a copy of the License at:
*
* http://cvs.sakaiproject.org/licenses/license_1_0.html
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
* INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE
* AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
* DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*
**********************************************************************************/
public class Utils {
private static final int MINIMUM_SUPPORTED_LENGTH = 4;
/**
* Truncate text on a whitespace boundary (near a specified length). The
* length of the resultant string will be in the range:<br>
* <code> (requested-length * .25) ~ (requested-length * 1.5) </code>
*
* @param text
* Text to truncate
* @param length
* Target length
* @return Truncated text
*/
public static String truncateAtWhitespace(String text, int length) {
int desired, lowerBound, upperBound;
/*
* Make sure we have a reasonable length to work with
*/
if (length < MINIMUM_SUPPORTED_LENGTH) {
throw new IllegalArgumentException("Requested length too short (must be "
+ MINIMUM_SUPPORTED_LENGTH + " or greated)");
}
/*
* No need to truncate - the original string "fits"
*/
if (text.length() <= length) {
return text;
}
/*
* Try to find whitespace befor the requested maximum
*/
lowerBound = length / 4;
upperBound = length + (length / 2);
for (int i = length - 1; i > lowerBound; i--) {
if (Character.isWhitespace(text.charAt(i))) {
return text.substring(0, i);
}
}
/*
* No whitespace - look beyond the desired maximum
*/
for (int i = (length); i < upperBound; i++) {
if (Character.isWhitespace(text.charAt(i))) {
return text.substring(0, i);
}
}
/*
* No whitespace, just truncate the text at the requested length
*/
return text.substring(0, length);
}
}
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