/*
* 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.encoder;
import java.util.HashSet;
import java.util.Set;
import org.supercsv.prefs.CsvPreference;
import org.supercsv.util.CsvContext;
/**
* A selective CsvEncoder implementation - only the desired column numbers (if any) are encoded. Use with caution -
* disabling encoding may increase performance but at the risk of invalid CSV.
*
* @author James Bassett
* @since 2.1.0
*/
public class SelectiveCsvEncoder extends DefaultCsvEncoder {
private final Set<Integer> columnNumbers = new HashSet<Integer>();
/**
* Constructs a new <tt>SelectiveCsvEncoder</tt> that encodes columns by column number. If no column numbers are
* supplied (i.e. no parameters) then no columns will be encoded.
*
* @param columnsToEncode
* the column numbers to encode
*/
public SelectiveCsvEncoder(final int... columnsToEncode) {
if( columnsToEncode == null ) {
throw new NullPointerException("columnsToEncode should not be null");
}
for( final Integer columnToEncode : columnsToEncode ) {
columnNumbers.add(columnToEncode);
}
}
/**
* Constructs a new <tt>SelectiveCsvEncoder</tt> that encodes columns if the element representing that column in the
* supplied array is true.
*
* @param columnsToEncode
* boolean array representing columns to encode (true indicates a column should be encoded).
*/
public SelectiveCsvEncoder(final boolean[] columnsToEncode) {
if( columnsToEncode == null ) {
throw new NullPointerException("columnsToEncode should not be null");
}
for( int i = 0; i < columnsToEncode.length; i++ ) {
if( columnsToEncode[i] ) {
columnNumbers.add(i + 1); // column numbers start at 1
}
}
}
/**
* {@inheritDoc}
*/
public String encode(final String input, final CsvContext context, final CsvPreference preference) {
return columnNumbers.contains(context.getColumnNumber()) ? super.encode(input, context, preference) : input;
}
}
|