Trim.java

package org.supercsv.cellprocessor;

import org.supercsv.cellprocessor.ift.StringCellProcessor;
import org.supercsv.exception.NullInputException;
import org.supercsv.exception.SuperCSVException;
import org.supercsv.util.CSVContext;

/**
 * Ensure that Strings or String-representations of objects has a maximum size. If you desire, you can append a string
 * to denote that the data has been trimmed.
 * 
 * @author Kasper B. Graversen
 */
public class Trim extends CellProcessorAdaptor implements StringCellProcessor {
int maxSize;
String trimPostfix = "";

/** Trim strings to ensure a maximum size */
public Trim(final int maxSize) {
	super(NullObjectPattern.INSTANCE);
	if( maxSize < 1 ) { throw new SuperCSVException("argument maxSize must be > 0", this); }
	this.maxSize = maxSize;
}

/**
 * Trim strings to ensure a maximum size. If a string is trimmed, it will get the <code>trimPostfix</code> string
 * appended (e.g. "..." to show it has been trimmed)
 */
public Trim(final int maxSize, final String trimPostfix) {
	this(maxSize);
	this.trimPostfix = trimPostfix;
}

/**
 * Trim strings to ensure a maximum size. If a string is trimmed, it will get the <code>trimPostfix</code> string
 * appended (e.g. "...")
 */
public Trim(final int maxSize, final String trimPostfix, final StringCellProcessor next) {
	this(maxSize, next);
	this.trimPostfix = trimPostfix;
}

/** Trim strings to ensure a maximum size */
public Trim(final int maxSize, final StringCellProcessor next) {
	super(next);
	this.maxSize = maxSize;
}

/**
 * @throws SuperCSVException
 *             when the value is some value that cannot be translated into a boolean value {@inheritDoc}
 */
@Override
public Object execute(final Object value, final CSVContext context) {
	if( value == null ) { throw new NullInputException("Input cannot be null on line " + context.lineNumber + " at column " + context.columnNumber, context, this); }
	final String sval = value.toString(); // cast
	
	String result;
	if( sval.length() <= maxSize ) {
		result = sval;
	} else {
		result = sval.substring(0, maxSize) + trimPostfix;
	}
	
	return next.execute(result, context);
}
}