/**
*
* Copyright (c) 2006-2017, Speedment, Inc. 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 com.speedment.runtime.core.util;
import com.speedment.common.function.OptionalBoolean;
import java.util.Optional;
import java.util.OptionalDouble;
import java.util.OptionalInt;
import java.util.OptionalLong;
import static com.speedment.runtime.core.util.StaticClassUtil.instanceNotAllowed;
/**
* A utility class for converting optional types to their boxed equivalents.
*
* @author Emil Forslund
* @author Simon Jonasson
*/
public final class OptionalUtil {
/**
* If the specified object is an {@code Optional}, the inner value will be
* returned. Otherwise, the object is returned directly.
*
* @param potentiallyOptional the object that might be an {@code Optional}
* @return the object or its inner value
*/
public static Object unwrap(Object potentiallyOptional) {
if (potentiallyOptional instanceof Optional<?>) {
return unwrap((Optional<?>) potentiallyOptional);
} else {
return potentiallyOptional;
}
}
/**
* Returns the inner value of the {@code Optional} unless the optional
* is {@code null}, in which case {@code null} is returned.
*
* @param <T> the inner type
* @param optional the optional
* @return the inner value or {@code null}
*/
public static <T> T unwrap(@SuppressWarnings("OptionalUsedAsFieldOrParameterType") Optional<T> optional) {
if (optional == null) {
return null;
}
return optional.orElse(null);
}
/**
* Convert an optional value to a boxed one. If the inner value is
* empty, {@code null} will be returned.
*
* @param optional the optional value (or null)
* @return the inner value or {@code null}
*/
public static Integer unwrap(@SuppressWarnings("OptionalUsedAsFieldOrParameterType") OptionalInt optional) {
return optional == null
? null
: optional.isPresent() ? optional.getAsInt() : null;
}
/**
* Convert an optional value to a boxed one. If the inner value is
* empty, {@code null} will be returned.
*
* @param optional the optional value (or null)
* @return the inner value or {@code null}
*/
public static Boolean unwrap(OptionalBoolean optional) {
return optional == null
? null
: optional.isPresent() ? optional.getAsBoolean() : null;
}
/**
* Convert an optional value to a boxed one. If the inner value is
* empty, {@code null} will be returned.
*
* @param optional the optional value (or null)
* @return the inner value or {@code null}
*/
public static Long unwrap(@SuppressWarnings("OptionalUsedAsFieldOrParameterType") OptionalLong optional) {
return optional == null
? null
: optional.isPresent() ? optional.getAsLong() : null;
}
/**
* Convert an optional value to a boxed one. If the inner value is
* empty, {@code null} will be returned.
*
* @param optional the optional value (or null)
* @return the inner value or {@code null}
*/
public static Double unwrap(@SuppressWarnings("OptionalUsedAsFieldOrParameterType") OptionalDouble optional) {
return optional == null
? null
: optional.isPresent() ? optional.getAsDouble() : null;
}
/**
* Wraps the specified nullable value in an {@code OptionalLong}.
*
* @param l the value
* @return the wrapped optional
*/
public static OptionalLong ofNullable(Long l) {
if (l == null) {
return OptionalLong.empty();
} else {
return OptionalLong.of(l);
}
}
/**
* Wraps the specified nullable value in an {@code OptionalInteger}.
*
* @param i the value
* @return the wrapped optional
*/
public static OptionalInt ofNullable(Integer i) {
if (i == null) {
return OptionalInt.empty();
} else {
return OptionalInt.of(i);
}
}
/**
* Wraps the specified nullable value in an {@code OptionalDouble}.
*
* @param d the value
* @return the wrapped optional
*/
public static OptionalDouble ofNullable(Double d) {
if (d == null) {
return OptionalDouble.empty();
} else {
return OptionalDouble.of(d);
}
}
/**
* Wraps the specified nullable value in an {@code OptionalBoolean}.
*
* @param b the value
* @return the wrapped optional
*/
public static OptionalBoolean ofNullable(Boolean b) {
if (b == null) {
return OptionalBoolean.empty();
} else {
return OptionalBoolean.of(b);
}
}
/**
* Parses the specified value into an optional unless it is {@code null},
* in which case an empty optional is returned.
*
* @param value the value (or null)
* @return the wrapped optional
*/
public static OptionalLong parseLong(String value) {
if (value == null) {
return OptionalLong.empty();
} else {
return OptionalLong.of(Long.parseLong(value));
}
}
/**
* Parses the specified value into an optional unless it is {@code null},
* in which case an empty optional is returned.
*
* @param value the value (or null)
* @return the wrapped optional
*/
public static OptionalInt parseInt(String value) {
if (value == null) {
return OptionalInt.empty();
} else {
return OptionalInt.of(Integer.parseInt(value));
}
}
/**
* Parses the specified value into an optional unless it is {@code null},
* in which case an empty optional is returned.
*
* @param value the value (or null)
* @return the wrapped optional
*/
public static OptionalDouble parseDouble(String value) {
if (value == null) {
return OptionalDouble.empty();
} else {
return OptionalDouble.of(Double.parseDouble(value));
}
}
/**
* Parses the specified value into an optional unless it is {@code null},
* in which case an empty optional is returned.
*
* @param value the value (or null)
* @return the wrapped optional
*/
public static OptionalBoolean parseBoolean(String value) {
if (value == null) {
return OptionalBoolean.empty();
} else {
return OptionalBoolean.of(Boolean.parseBoolean(value));
}
}
/**
* Utility classes should not be instantiated.
*/
private OptionalUtil() {
instanceNotAllowed(getClass());
}
}