/*
* 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 java.util.Map;
import org.supercsv.cellprocessor.ift.BoolCellProcessor;
import org.supercsv.cellprocessor.ift.CellProcessor;
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;
/**
* Maps from one object to another, by looking up a <tt>Map</tt> with the input as the key, and returning its
* corresponding value.
*
* @since 1.50
* @author Dominique De Vito
* @author James Bassett
*/
public class HashMapper extends CellProcessorAdaptor implements BoolCellProcessor, DateCellProcessor,
DoubleCellProcessor, LongCellProcessor, StringCellProcessor {
private final Map<Object, Object> mapping;
private final Object defaultValue;
/**
* Constructs a new <tt>HashMapper</tt> processor, which maps from one object to another, by looking up a
* <tt>Map</tt> with the input as the key, and returning its corresponding value. If no mapping is found, then
* <tt>null</tt> is returned.
*
* @param mapping
* the Map
* @throws NullPointerException
* if mapping is null
* @throws IllegalArgumentException
* if mapping is empty
*/
public HashMapper(final Map<Object, Object> mapping) {
this(mapping, (Object) null);
}
/**
* Constructs a new <tt>HashMapper</tt> processor, which maps from one object to another, by looking up a
* <tt>Map</tt> with the input as the key, and returning its corresponding value. If no mapping is found, then the
* supplied default value is returned.
*
* @param mapping
* the Map
* @param defaultValue
* the value to return if no mapping is found
* @throws NullPointerException
* if mapping is null
* @throws IllegalArgumentException
* if mapping is empty
*/
public HashMapper(final Map<Object, Object> mapping, final Object defaultValue) {
super();
checkPreconditions(mapping);
this.mapping = mapping;
this.defaultValue = defaultValue;
}
/**
* Constructs a new <tt>HashMapper</tt> processor, which maps from one object to another, by looking up a
* <tt>Map</tt> with the input as the key, and returning its corresponding value. If no mapping is found, then
* <tt>null</tt> is returned. Regardless of whether a mapping is found, the next processor in the chain will be
* called.
*
* @param mapping
* the Map
* @param next
* the next processor in the chain
* @throws NullPointerException
* if mapping or next is null
* @throws IllegalArgumentException
* if mapping is empty
*/
public HashMapper(final Map<Object, Object> mapping, final CellProcessor next) {
this(mapping, null, next);
}
/**
* Constructs a new <tt>HashMapper</tt> processor, which maps from one object to another, by looking up a
* <tt>Map</tt> with the input as the key, and returning its corresponding value. If no mapping is found, then the
* supplied default value is returned. Regardless of whether a mapping is found, the next processor in the chain
* will be called.
*
* @param mapping
* the Map
* @param defaultValue
* the value to return if no mapping is found
* @param next
* the next processor in the chain
* @throws NullPointerException
* if mapping or next is null
* @throws IllegalArgumentException
* if mapping is empty
*/
public HashMapper(final Map<Object, Object> mapping, final Object defaultValue, final CellProcessor next) {
super(next);
checkPreconditions(mapping);
this.mapping = mapping;
this.defaultValue = defaultValue;
}
/**
* Checks the preconditions for creating a new HashMapper processor.
*
* @param mapping
* the Map
* @throws NullPointerException
* if mapping is null
* @throws IllegalArgumentException
* if mapping is empty
*/
private static void checkPreconditions(final Map<Object, Object> mapping) {
if( mapping == null ) {
throw new NullPointerException("mapping should not be null");
} else if( mapping.isEmpty() ) {
throw new IllegalArgumentException("mapping should not be empty");
}
}
/**
* {@inheritDoc}
*
* @throws SuperCsvCellProcessorException
* if value is null
*/
public Object execute(final Object value, final CsvContext context) {
validateInputNotNull(value, context);
Object result = mapping.get(value);
if( result == null ) {
result = defaultValue;
}
return next.execute(result, context);
}
}
|