org.joda.convert.factory.CharObjectArrayStringConverterFactory Maven / Gradle / Ivy
Show all versions of joda-convert Show documentation
/*
* 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 java.util.Arrays;
import org.joda.convert.StringConverter;
import org.joda.convert.StringConverterFactory;
import org.joda.convert.TypedStringConverter;
/**
* Factory for {@code StringConverter} providing support for Character object arrays
* as a string, using backslash as an escape.
*
* Double backslash is a backslash.
* One backslash followed by a dash is null.
*
* To use, simply register the instance with a {@code StringConvert} instance.
*
* This class is immutable and thread-safe.
*
* @since 1.5
*/
public final class CharObjectArrayStringConverterFactory implements StringConverterFactory {
/**
* Singleton instance.
*/
public static final StringConverterFactory INSTANCE = new CharObjectArrayStringConverterFactory();
/**
* Restricted constructor.
*/
private CharObjectArrayStringConverterFactory() {
}
//-----------------------------------------------------------------------
/**
* 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 == Character[].class) {
return CharecterArrayStringConverter.INSTANCE;
}
return null;
}
//-----------------------------------------------------------------------
@Override
public String toString() {
return getClass().getSimpleName();
}
//-----------------------------------------------------------------------
enum CharecterArrayStringConverter implements TypedStringConverter {
INSTANCE {
@Override
public String convertToString(Character[] array) {
if (array.length == 0) {
return "";
}
var buf = new StringBuilder(array.length * 8);
for (var element : array) {
if (element == null) {
buf.append("\\-");
} else {
var ch = element.charValue();
if (ch == '\\') {
buf.append("\\\\");
} else {
buf.append(ch);
}
}
}
return buf.toString();
}
@Override
public Character[] convertFromString(Class cls, String str) {
if (str.length() == 0) {
return EMPTY;
}
var adjusted = str;
var array = new Character[adjusted.length()];
var arrayPos = 0;
int pos;
while ((pos = adjusted.indexOf('\\')) >= 0) {
for (var i = 0; i < pos; i++) {
array[arrayPos++] = adjusted.charAt(i);
}
if (adjusted.charAt(pos + 1) == '\\') {
array[arrayPos++] = '\\';
} else if (adjusted.charAt(pos + 1) == '-') {
array[arrayPos++] = null;
} else {
throw new IllegalArgumentException("Invalid Character[] string, incorrect escape");
}
adjusted = adjusted.substring(pos + 2);
}
for (var i = 0; i < adjusted.length(); i++) {
array[arrayPos++] = adjusted.charAt(i);
}
return Arrays.copyOf(array, arrayPos);
}
@Override
public Class getEffectiveType() {
return Character[].class;
}
};
private static final Character[] EMPTY = new Character[0];
}
}