org.supercsv.cellprocessor.Truncate Maven / Gradle / Ivy
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/*
* Copyright 2007 Kasper B. Graversen
*
* 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.supercsv.cellprocessor;
import org.supercsv.cellprocessor.ift.BoolCellProcessor;
import org.supercsv.cellprocessor.ift.DateCellProcessor;
import org.supercsv.cellprocessor.ift.DoubleCellProcessor;
import org.supercsv.cellprocessor.ift.LongCellProcessor;
import org.supercsv.cellprocessor.ift.StringCellProcessor;
import org.supercsv.exception.SuperCsvCellProcessorException;
import org.supercsv.util.CsvContext;
/**
* Ensure that Strings or String-representations of objects are truncated to a maximum size. If you desire, you can
* append a String to denote that the data has been truncated (e.g. "...").
*
* As of 2.0.0, this functionality was moved from the {@link Trim} processor to this processor, to allow a clear
* distinction between trimming and truncating.
*
* @author Kasper B. Graversen
* @author James Bassett
*/
public class Truncate extends CellProcessorAdaptor implements BoolCellProcessor, DateCellProcessor,
DoubleCellProcessor, LongCellProcessor, StringCellProcessor {
private static final String EMPTY_STRING = "";
private final int maxSize;
private final String suffix;
/**
* Constructs a new Truncate processor, which truncates a String to ensure it is no longer than the
* specified size.
*
* @param maxSize
* the maximum size of the String
* @throws IllegalArgumentException
* if {@code maxSize <= 0}
*/
public Truncate(final int maxSize) {
this(maxSize, EMPTY_STRING);
}
/**
* Constructs a new Truncate processor, which truncates a String to ensure it is no longer than the
* specified size, then appends the suffix String to indicate that the String has been truncated.
*
* @param maxSize
* the maximum size of the String
* @param suffix
* the String to append if the input is truncated (e.g. "...")
* @throws IllegalArgumentException
* if {@code maxSize <= 0}
* @throws NullPointerException
* if suffix is null
*/
public Truncate(final int maxSize, final String suffix) {
checkPreconditions(maxSize, suffix);
this.maxSize = maxSize;
this.suffix = suffix;
}
/**
* Constructs a new Truncate processor, which truncates a String to ensure it is no longer than the
* specified size, then appends the suffix String to indicate that the String has been truncated and
* calls the next processor in the chain.
*
* @param maxSize
* the maximum size of the String
* @param suffix
* the String to append if the input is truncated (e.g. "...")
* @param next
* the next processor in the chain
* @throws IllegalArgumentException
* if {@code maxSize <= 0}
* @throws NullPointerException
* if suffix or next is null
*/
public Truncate(final int maxSize, final String suffix, final StringCellProcessor next) {
super(next);
checkPreconditions(maxSize, suffix);
this.maxSize = maxSize;
this.suffix = suffix;
}
/**
* Constructs a new Truncate processor, which truncates a String to ensure it is no longer than the
* specified size, then calls the next processor in the chain.
*
* @param maxSize
* the maximum size of the String
* @param next
* the next processor in the chain
* @throws IllegalArgumentException
* if {@code maxSize <= 0}
* @throws NullPointerException
* if next is null
*/
public Truncate(final int maxSize, final StringCellProcessor next) {
this(maxSize, EMPTY_STRING, next);
}
/**
* Checks the preconditions for creating a new Truncate processor.
*
* @param maxSize
* the maximum size of the String
* @param suffix
* the String to append if the input is truncated (e.g. "...")
* @throws IllegalArgumentException
* if {@code maxSize <= 0}
* @throws NullPointerException
* if suffix is null
*/
private static void checkPreconditions(final int maxSize, final String suffix) {
if( maxSize <= 0 ) {
throw new IllegalArgumentException(String.format("maxSize should be > 0 but was %d", maxSize));
}
if( suffix == null ) {
throw new NullPointerException("suffix should not be null");
}
}
/**
* {@inheritDoc}
*
* @throws SuperCsvCellProcessorException
* if value is null
*/
public Object execute(final Object value, final CsvContext context) {
validateInputNotNull(value, context);
final String stringValue = value.toString();
final String result;
if( stringValue.length() <= maxSize ) {
result = stringValue;
} else {
result = stringValue.substring(0, maxSize) + suffix;
}
return next.execute(result, context);
}
}