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'databene commons' is an open source Java library by Volker Bergmann.
It provides extensions to the Java core library by utility classes, abstract concepts
and concrete implementations.
/*
* Copyright (C) 2004-2015 Volker Bergmann ([email protected]).
* All rights reserved.
*
* 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.databene.commons.converter;
import org.databene.commons.ConversionException;
/**
* Extracts a sub string from a string.
* Created: 26.02.2010 10:55:11
* @since 0.5.0
* @author Volker Bergmann
*/
public class SubstringExtractor extends ThreadSafeConverter {
private int from;
private Integer to;
public SubstringExtractor() {
this(0);
}
public SubstringExtractor(int from) {
this(from, null);
}
public SubstringExtractor(int from, Integer to) {
super(String.class, String.class);
this.from = from;
this.to = to;
}
public void setFrom(int from) {
this.from = from;
}
public void setTo(Integer to) {
this.to = to;
}
@Override
public String convert(String sourceValue) throws ConversionException {
if (sourceValue == null)
return null;
int startIndex = relativeIndex(from, sourceValue);
if (startIndex >= sourceValue.length())
return "";
if (to == null) {
return sourceValue.substring(startIndex);
} else {
int endIndex = relativeIndex(to, sourceValue);
if (endIndex < startIndex)
return "";
if (endIndex > sourceValue.length())
endIndex = sourceValue.length();
return sourceValue.substring(startIndex, endIndex);
}
}
private static int relativeIndex(int index, String sourceValue) {
return (index >= 0 ? index : sourceValue.length() + index);
}
}