OptionalLongStringConverter.java
/*
* 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;
import java.lang.reflect.Method;
/**
* Parse the string format of OptionalLong from Java 8.
* <p>
* This is loaded by reflection only when using Java 8.
*/
final class OptionalLongStringConverter
implements TypedStringConverter<Object> {
private static final Class<?> TYPE;
private static final Object EMPTY;
private static final Method METHOD_OF;
private static final Method METHOD_IS_PRESENT;
private static final Method METHOD_GET;
static {
try {
TYPE = Class.forName("java.util.OptionalLong");
EMPTY = TYPE.getDeclaredMethod("empty").invoke(null);
METHOD_OF = TYPE.getDeclaredMethod("of", long.class);
METHOD_IS_PRESENT = TYPE.getDeclaredMethod("isPresent");
METHOD_GET = TYPE.getDeclaredMethod("getAsLong");
} catch (Exception ex) {
throw new IllegalStateException(ex);
}
}
OptionalLongStringConverter() {
}
@Override
public String convertToString(Object object) {
try {
Object isPresent = METHOD_IS_PRESENT.invoke(object);
return Boolean.TRUE.equals(isPresent) ? String.valueOf(METHOD_GET.invoke(object)) : "";
} catch (Exception ex) {
throw new IllegalArgumentException(ex);
}
}
@Override
public Object convertFromString(Class<? extends Object> cls, String str) {
if ("".equals(str)) {
return EMPTY;
}
long value = Long.parseLong(str);
try {
return METHOD_OF.invoke(null, value);
} catch (Exception ex) {
throw new IllegalArgumentException(ex);
}
}
@Override
public Class<?> getEffectiveType() {
return TYPE;
}
}