org.joda.convert.factory.ByteObjectArrayStringConverterFactory Maven / Gradle / Ivy
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/*
* Copyright 2010-present Stephen Colebourne
*
* 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.joda.convert.factory;
import org.joda.convert.StringConverter;
import org.joda.convert.StringConverterFactory;
import org.joda.convert.TypedStringConverter;
/**
* Factory for {@code StringConverter} providing support for Byte object array
* as a sequence of two letter hex codes for each byte plus '--' for null.
*
* This is intended as a human readable format, not a compact format.
*
* To use, simply register the instance with a {@code StringConvert} instance.
*
* This class is immutable and thread-safe.
*
* @since 1.5
*/
public final class ByteObjectArrayStringConverterFactory implements StringConverterFactory {
/**
* Singleton instance.
*/
public static final StringConverterFactory INSTANCE = new ByteObjectArrayStringConverterFactory();
/**
* Restricted constructor.
*/
private ByteObjectArrayStringConverterFactory() {
}
//-----------------------------------------------------------------------
/**
* Finds a converter by type.
*
* @param cls the type to lookup, not null
* @return the converter, null if not found
* @throws RuntimeException (or subclass) if source code is invalid
*/
@Override
public StringConverter findConverter(Class cls) {
if (cls == Byte[].class) {
return ByteArrayStringConverter.INSTANCE;
}
return null;
}
//-----------------------------------------------------------------------
@Override
public String toString() {
return getClass().getSimpleName();
}
//-----------------------------------------------------------------------
enum ByteArrayStringConverter implements TypedStringConverter {
INSTANCE {
@Override
public String convertToString(Byte[] array) {
if (array.length == 0) {
return "";
}
StringBuilder buf = new StringBuilder(array.length);
for (int i = 0; i < array.length; i++) {
if (array[i] == null) {
buf.append('-').append('-');
} else {
int b = array[i].byteValue();
buf.append(HEX.charAt((b & 0xF0) >>> 4)).append(HEX.charAt(b & 0x0F));
}
}
return buf.toString();
}
@Override
public Byte[] convertFromString(Class cls, String str) {
if (str.length() == 0) {
return EMPTY;
}
if (str.length() % 2 == 1) {
throw new IllegalArgumentException("Invalid Byte[] string");
}
Byte[] array = new Byte[str.length() / 2];
for (int i = 0; i < array.length; i++) {
String in = str.substring(i * 2, i * 2 + 2);
if (in.equals("--")) {
array[i] = null;
} else {
array[i] = (byte) Integer.parseInt(in, 16);
}
}
return array;
}
@Override
public Class getEffectiveType() {
return Byte[].class;
}
};
private static final Byte[] EMPTY = new Byte[0];
private static final String HEX = "0123456789ABCDEF";
}
}