NumberConverter.java
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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.apache.commons.beanutils2.converters;
import java.math.BigDecimal;
import java.math.BigInteger;
import java.text.DecimalFormat;
import java.text.DecimalFormatSymbols;
import java.text.NumberFormat;
import java.text.ParsePosition;
import java.util.Calendar;
import java.util.Date;
import java.util.Locale;
import org.apache.commons.beanutils2.ConversionException;
/**
* {@link org.apache.commons.beanutils2.Converter} implementation that handles conversion to and from <strong>java.lang.Number</strong> objects.
* <p>
* This implementation handles conversion for the following {@link Number} types.
* <ul>
* <li>{@link Byte}</li>
* <li>{@link Short}</li>
* <li>{@link Integer}</li>
* <li>{@link Long}</li>
* <li>{@link Float}</li>
* <li>{@link Double}</li>
* <li>{@link java.math.BigDecimal}</li>
* <li>{@link java.math.BigInteger}</li>
* </ul>
*
* <h2>String Conversions (to and from)</h2> This class provides a number of ways in which number conversions to/from Strings can be achieved:
* <ul>
* <li>Using the default format for the default Locale, configure using:
* <ul>
* <li>{@code setUseLocaleFormat(true)}</li>
* </ul>
* </li>
* <li>Using the default format for a specified Locale, configure using:
* <ul>
* <li>{@code setLocale(Locale)}</li>
* </ul>
* </li>
* <li>Using a specified pattern for the default Locale, configure using:
* <ul>
* <li>{@code setPattern(String)}</li>
* </ul>
* </li>
* <li>Using a specified pattern for a specified Locale, configure using:
* <ul>
* <li>{@code setPattern(String)}</li>
* <li>{@code setLocale(Locale)}</li>
* </ul>
* </li>
* <li>If none of the above are configured the {@code toNumber(String)} method is used to convert from String to Number and the Number's {@code toString()}
* method used to convert from Number to String.</li>
* </ul>
*
* <p>
* <strong>N.B.</strong>Patterns can only be specified using the <em>standard</em> pattern characters and NOT in <em>localized</em> form (see
* {@link java.text.DecimalFormat}). For example to cater for number styles used in Germany such as {@code 0.000,00} the pattern is specified in the normal form
* {@code 0,000.00</code> and the locale set to <code>Locale.GERMANY}
*
* @param <N> The default value type.
* @since 1.8.0
*/
public abstract class NumberConverter<N extends Number> extends AbstractConverter<N> {
private static final Integer ZERO = Integer.valueOf(0);
private static final Integer ONE = Integer.valueOf(1);
private String pattern;
private final boolean allowDecimals;
private boolean useLocaleFormat;
private Locale locale;
/**
* Constructs a <strong>java.lang.Number</strong> <em>Converter</em> that throws a {@code ConversionException} if a error occurs.
*
* @param allowDecimals Indicates whether decimals are allowed
*/
public NumberConverter(final boolean allowDecimals) {
this.allowDecimals = allowDecimals;
}
/**
* Constructs a {@link Number} <em>Converter</em> that returns a default value if an error occurs.
*
* @param allowDecimals Indicates whether decimals are allowed
* @param defaultValue The default value to be returned
*/
public NumberConverter(final boolean allowDecimals, final N defaultValue) {
this.allowDecimals = allowDecimals;
setDefaultValue(defaultValue);
}
/**
* Convert an input Number object into a String.
*
* @param value The input value to be converted
* @return the converted String value.
* @throws IllegalArgumentException if an error occurs converting to a String
*/
@Override
protected String convertToString(final Object value) {
String result = null;
if (useLocaleFormat && value instanceof Number) {
final NumberFormat format = getFormat();
format.setGroupingUsed(false);
result = format.format(value);
if (log().isDebugEnabled()) {
log().debug(" Converted to String using format '" + result + "'");
}
} else {
result = value.toString();
if (log().isDebugEnabled()) {
log().debug(" Converted to String using toString() '" + result + "'");
}
}
return result;
}
/**
* Convert the input object into a Number object of the specified type.
*
* @param <T> Target type of the conversion.
* @param targetType Data type to which this value should be converted.
* @param value The input value to be converted.
* @return The converted value.
* @throws Throwable if an error occurs converting to the specified type
*/
@Override
protected <T> T convertToType(final Class<T> targetType, final Object value) throws Throwable {
final Class<?> sourceType = value.getClass();
// Handle Number
if (value instanceof Number) {
return toNumber(sourceType, targetType, (Number) value);
}
// Handle Boolean
if (value instanceof Boolean) {
return toNumber(sourceType, targetType, ((Boolean) value).booleanValue() ? ONE : ZERO);
}
// Handle Date --> Long
if (value instanceof Date && Long.class.equals(targetType)) {
return targetType.cast(Long.valueOf(((Date) value).getTime()));
}
// Handle Calendar --> Long
if (value instanceof Calendar && Long.class.equals(targetType)) {
return targetType.cast(Long.valueOf(((Calendar) value).getTime().getTime()));
}
// Convert all other types to String & handle
final String stringValue = toTrim(value);
if (stringValue.isEmpty()) {
return handleMissing(targetType);
}
// Convert/Parse a String
Number number = null;
if (useLocaleFormat) {
final NumberFormat format = getFormat();
number = parse(sourceType, targetType, stringValue, format);
} else {
if (log().isDebugEnabled()) {
log().debug(" No NumberFormat, using default conversion");
}
number = toNumber(sourceType, targetType, stringValue);
}
// Ensure the correct number type is returned
return toNumber(sourceType, targetType, number);
}
/**
* Gets a NumberFormat to use for Conversion.
*
* @return The NumberFormat.
*/
private NumberFormat getFormat() {
NumberFormat format = null;
if (pattern != null) {
if (locale == null) {
if (log().isDebugEnabled()) {
log().debug(" Using pattern '" + pattern + "'");
}
format = new DecimalFormat(pattern);
} else {
if (log().isDebugEnabled()) {
log().debug(" Using pattern '" + pattern + "'" + " with Locale[" + locale + "]");
}
final DecimalFormatSymbols symbols = new DecimalFormatSymbols(locale);
format = new DecimalFormat(pattern, symbols);
}
} else if (locale == null) {
if (log().isDebugEnabled()) {
log().debug(" Using default Locale format");
}
format = NumberFormat.getInstance();
} else {
if (log().isDebugEnabled()) {
log().debug(" Using Locale[" + locale + "] format");
}
format = NumberFormat.getInstance(locale);
}
if (!allowDecimals) {
format.setParseIntegerOnly(true);
}
return format;
}
/**
* Gets the Locale for the <em>Converter</em> (or {@code null} if none specified).
*
* @return The locale to use for conversion
*/
public Locale getLocale() {
return locale;
}
/**
* Gets the number format pattern used to convert Numbers to/from a {@link String} (or {@code null} if none specified).
* <p>
* See {@link java.text.DecimalFormat} for details of how to specify the pattern.
*
* @return The format pattern.
*/
public String getPattern() {
return pattern;
}
/**
* Gets whether decimals are allowed in the number.
*
* @return Whether decimals are allowed in the number
*/
public boolean isAllowDecimals() {
return allowDecimals;
}
/**
* Convert a String into a {@code Number} object.
*
* @param sourceType the source type of the conversion
* @param targetType The type to convert the value to
* @param value The String date value.
* @param format The NumberFormat to parse the String value.
* @return The converted Number object.
* @throws ConversionException if the String cannot be converted.
*/
private Number parse(final Class<?> sourceType, final Class<?> targetType, final String value, final NumberFormat format) {
final ParsePosition pos = new ParsePosition(0);
final Number parsedNumber = format.parse(value, pos);
if (pos.getErrorIndex() >= 0 || pos.getIndex() != value.length() || parsedNumber == null) {
String msg = "Error converting from '" + toString(sourceType) + "' to '" + toString(targetType) + "'";
if (format instanceof DecimalFormat) {
msg += " using pattern '" + ((DecimalFormat) format).toPattern() + "'";
}
if (locale != null) {
msg += " for locale=[" + locale + "]";
}
if (log().isDebugEnabled()) {
log().debug(" " + msg);
}
throw new ConversionException(msg);
}
return parsedNumber;
}
/**
* Sets the Locale for the <em>Converter</em>.
*
* @param locale The locale to use for conversion
*/
public void setLocale(final Locale locale) {
this.locale = locale;
setUseLocaleFormat(true);
}
/**
* Sets a number format pattern to use to convert Numbers to/from a {@link String}.
* <p>
* See {@link java.text.DecimalFormat} for details of how to specify the pattern.
*
* @param pattern The format pattern.
*/
public void setPattern(final String pattern) {
this.pattern = pattern;
setUseLocaleFormat(true);
}
/**
* Sets whether a format should be used to convert the Number.
*
* @param useLocaleFormat {@code true} if a number format should be used.
*/
public void setUseLocaleFormat(final boolean useLocaleFormat) {
this.useLocaleFormat = useLocaleFormat;
}
/**
* Default String to Number conversion.
* <p>
* This method handles conversion from a String to the following types:
* <ul>
* <li>{@link Byte}</li>
* <li>{@link Short}</li>
* <li>{@link Integer}</li>
* <li>{@link Long}</li>
* <li>{@link Float}</li>
* <li>{@link Double}</li>
* <li>{@link java.math.BigDecimal}</li>
* <li>{@link java.math.BigInteger}</li>
* </ul>
*
* @param sourceType The type being converted from
* @param targetType The Number type to convert to
* @param value The String value to convert.
* @return The converted Number value.
*/
private Number toNumber(final Class<?> sourceType, final Class<?> targetType, final String value) {
// Byte
if (targetType.equals(Byte.class)) {
return Byte.valueOf(value);
}
// Short
if (targetType.equals(Short.class)) {
return Short.valueOf(value);
}
// Integer
if (targetType.equals(Integer.class)) {
return Integer.valueOf(value);
}
// Long
if (targetType.equals(Long.class)) {
return Long.valueOf(value);
}
// Float
if (targetType.equals(Float.class)) {
return Float.valueOf(value);
}
// Double
if (targetType.equals(Double.class)) {
return Double.valueOf(value);
}
// BigDecimal
if (targetType.equals(BigDecimal.class)) {
return new BigDecimal(value);
}
// BigInteger
if (targetType.equals(BigInteger.class)) {
return new BigInteger(value);
}
final String msg = toString(getClass()) + " cannot handle conversion from '" + toString(sourceType) + "' to '" + toString(targetType) + "'";
if (log().isWarnEnabled()) {
log().warn(" " + msg);
}
throw new ConversionException(msg);
}
/**
* Convert any Number object to the specified type for this <em>Converter</em>.
* <p>
* This method handles conversion to the following types:
* <ul>
* <li>{@link Byte}</li>
* <li>{@link Short}</li>
* <li>{@link Integer}</li>
* <li>{@link Long}</li>
* <li>{@link Float}</li>
* <li>{@link Double}</li>
* <li>{@link java.math.BigDecimal}</li>
* <li>{@link java.math.BigInteger}</li>
* </ul>
*
* @param sourceType The type being converted from
* @param targetType The Number type to convert to
* @param value The Number to convert.
* @return The converted value.
*/
private <T> T toNumber(final Class<?> sourceType, final Class<T> targetType, final Number value) {
// Correct Number type already
if (targetType.equals(value.getClass())) {
return targetType.cast(value);
}
// Byte
if (targetType.equals(Byte.class)) {
final long longValue = value.longValue();
if (longValue > Byte.MAX_VALUE) {
throw ConversionException.format("%s value '%s' is too large for %s", toString(sourceType), value, toString(targetType));
}
if (longValue < Byte.MIN_VALUE) {
throw ConversionException.format("%s value '%s' is too small %s", toString(sourceType), value, toString(targetType));
}
return targetType.cast(Byte.valueOf(value.byteValue()));
}
// Short
if (targetType.equals(Short.class)) {
final long longValue = value.longValue();
if (longValue > Short.MAX_VALUE) {
throw ConversionException.format("%s value '%s' is too large for %s", toString(sourceType), value, toString(targetType));
}
if (longValue < Short.MIN_VALUE) {
throw ConversionException.format("%s value '%s' is too small %s", toString(sourceType), value, toString(targetType));
}
return targetType.cast(Short.valueOf(value.shortValue()));
}
// Integer
if (targetType.equals(Integer.class)) {
final long longValue = value.longValue();
if (longValue > Integer.MAX_VALUE) {
throw ConversionException.format("%s value '%s' is too large for %s", toString(sourceType), value, toString(targetType));
}
if (longValue < Integer.MIN_VALUE) {
throw ConversionException.format("%s value '%s' is too small %s", toString(sourceType), value, toString(targetType));
}
return targetType.cast(Integer.valueOf(value.intValue()));
}
// Long
if (targetType.equals(Long.class)) {
return targetType.cast(Long.valueOf(value.longValue()));
}
// Float
if (targetType.equals(Float.class)) {
if (value.doubleValue() > Float.MAX_VALUE) {
throw ConversionException.format("%s value '%s' is too large for %s", toString(sourceType), value, toString(targetType));
}
return targetType.cast(Float.valueOf(value.floatValue()));
}
// Double
if (targetType.equals(Double.class)) {
return targetType.cast(Double.valueOf(value.doubleValue()));
}
// BigDecimal
if (targetType.equals(BigDecimal.class)) {
if (value instanceof Float || value instanceof Double) {
return targetType.cast(new BigDecimal(value.toString()));
}
if (value instanceof BigInteger) {
return targetType.cast(new BigDecimal((BigInteger) value));
}
if (value instanceof BigDecimal) {
return targetType.cast(new BigDecimal(value.toString()));
}
return targetType.cast(BigDecimal.valueOf(value.longValue()));
}
// BigInteger
if (targetType.equals(BigInteger.class)) {
if (value instanceof BigDecimal) {
return targetType.cast(((BigDecimal) value).toBigInteger());
}
return targetType.cast(BigInteger.valueOf(value.longValue()));
}
final String msg = toString(getClass()) + " cannot handle conversion to '" + toString(targetType) + "'";
if (log().isWarnEnabled()) {
log().warn(" " + msg);
}
throw new ConversionException(msg);
}
/**
* Provide a String representation of this number converter.
*
* @return A String representation of this number converter
*/
@Override
public String toString() {
final StringBuilder buffer = new StringBuilder();
buffer.append(toString(getClass()));
buffer.append("[UseDefault=");
buffer.append(isUseDefault());
buffer.append(", UseLocaleFormat=");
buffer.append(useLocaleFormat);
if (pattern != null) {
buffer.append(", Pattern=");
buffer.append(pattern);
}
if (locale != null) {
buffer.append(", Locale=");
buffer.append(locale);
}
buffer.append(']');
return buffer.toString();
}
}