org.databene.commons.converter.NumberFormatBasedConverter Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of databene-commons Show documentation
Show all versions of databene-commons Show documentation
'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.
The newest version!
/*
* 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 java.text.DecimalFormat;
import java.text.DecimalFormatSymbols;
import java.text.NumberFormat;
import java.text.ParseException;
import org.databene.commons.ConversionException;
import org.databene.commons.NullSafeComparator;
/**
* Holds a {@link NumberFormat} and exhibits properties for its configuration.
* Created: 26.02.2010 08:37:23
* @param the object type to convert from
* @param the object type to convert to
* @since 0.5.0
* @author Volker Bergmann
*/
public abstract class NumberFormatBasedConverter extends AbstractConverter implements Cloneable {
// constants -------------------------------------------------------------------------------------------------------
protected static final String DEFAULT_DECIMAL_PATTERN = "0.#";
protected static final char DEFAULT_DECIMAL_SEPARATOR = '.';
protected static final char DEFAULT_GROUPING_SEPARATOR = ',';
protected static final String DEFAULT_NULL_STRING = "";
// attributes ------------------------------------------------------------------------------------------------------
private String pattern;
private char decimalSeparator;
private char groupingSeparator;
protected DecimalFormat format;
/** The string used to represent null values */
private String nullString;
// constructors ----------------------------------------------------------------------------------------------------
public NumberFormatBasedConverter(Class sourceType, Class targetType) {
this(sourceType, targetType, DEFAULT_DECIMAL_PATTERN);
}
public NumberFormatBasedConverter(Class sourceType, Class targetType, String pattern) {
super(sourceType, targetType);
setPattern(pattern);
setDecimalSeparator(DEFAULT_DECIMAL_SEPARATOR);
setGroupingSeparator(DEFAULT_GROUPING_SEPARATOR);
setNullString(DEFAULT_NULL_STRING);
}
// properties ------------------------------------------------------------------------------------------------------
public String getPattern() {
return pattern;
}
public void setPattern(String pattern) {
this.pattern = pattern;
this.format = new DecimalFormat(pattern);
setDecimalSeparator(decimalSeparator);
}
public char getDecimalSeparator() {
return decimalSeparator;
}
public void setGroupingSeparator(char groupingSeparator) {
this.groupingSeparator = groupingSeparator;
updateFormat();
}
public char getGroupingSeparator() {
return decimalSeparator;
}
public void setDecimalSeparator(char decimalSeparator) {
this.decimalSeparator = decimalSeparator;
updateFormat();
}
private void updateFormat() {
DecimalFormatSymbols newSymbols = new DecimalFormatSymbols();
if (groupingSeparator != 0)
newSymbols.setGroupingSeparator(groupingSeparator);
newSymbols.setDecimalSeparator(this.decimalSeparator);
format.setDecimalFormatSymbols(newSymbols);
}
public String getNullString() {
return nullString;
}
public void setNullString(String nullString) {
this.nullString = nullString;
}
protected String format(Number input) {
return (input != null ? format.format(input) : nullString);
}
protected Number parse(String input) throws ConversionException {
if (input == null || NullSafeComparator.equals(input, nullString))
return null;
try {
Number result = format.parse(input);
return result;
} catch (ParseException e) {
throw new ConversionException("Error parsing " + input + " as number");
}
}
// java.lang.Object overrides --------------------------------------------------------------------------------------
@Override
public String toString() {
return getClass().getSimpleName() + '[' + pattern + ']';
}
@Override
public boolean isThreadSafe() {
return false;
}
@Override
public boolean isParallelizable() {
return true;
}
@SuppressWarnings("unchecked")
@Override
public Object clone() {
try {
NumberFormatBasedConverter copy = (NumberFormatBasedConverter) super.clone();
copy.format = (DecimalFormat) format.clone();
return copy;
} catch (CloneNotSupportedException e) {
throw new RuntimeException(e);
}
}
}