diff options
Diffstat (limited to 'src/main/java/org/uic/barcode/asn1/datatypes/Optional.java')
-rw-r--r-- | src/main/java/org/uic/barcode/asn1/datatypes/Optional.java | 96 |
1 files changed, 0 insertions, 96 deletions
diff --git a/src/main/java/org/uic/barcode/asn1/datatypes/Optional.java b/src/main/java/org/uic/barcode/asn1/datatypes/Optional.java deleted file mode 100644 index 757ba29..0000000 --- a/src/main/java/org/uic/barcode/asn1/datatypes/Optional.java +++ /dev/null @@ -1,96 +0,0 @@ -package org.uic.barcode.asn1.datatypes; - -import java.util.NoSuchElementException; -import java.util.Objects; - -/** Represents optional values. - * - * Should be replaced by java.util.Optional from Java 8, when project moves to Java 8. - * - * @param <T> type of contained elements */ -public class Optional<T> { - - private final T element; - private final boolean isPresent; - - private Optional(T element, boolean isPresent) { - this.element = element; - this.isPresent = isPresent; - } - - /** @return true if the Option contains a value */ - public boolean isPresent() { - return isPresent; - } - - /** @return the element if the option is not empty - * @throws java.util.NoSuchElementException if the option is empty */ - public T get() { - if (isPresent) { - return element; - } else { - throw new NoSuchElementException("None.get"); - } - } - - /** @return the value, if present, otherwise return {@code other} - * @param other the value to be returned if there is no value present */ - public T orElse(T other) { - return isPresent() ? get() : other; - } - - /** - * Indicates whether some other object is "equal to" this Optional. The - * other object is considered equal if: - * <ul> - * <li>it is also an {@code Optional} and; - * <li>both instances have no value present or; - * <li>the present values are "equal to" each other via {@code equals()}. - * </ul> - * - * @param obj an object to be tested for equality - * @return {code true} if the other object is "equal to" this object - * otherwise {@code false} - */ - @Override - public boolean equals(Object obj) { - if (this == obj) { - return true; - } - - if (!(obj instanceof Optional)) { - return false; - } - - Optional<?> other = (Optional<?>) obj; - return Objects.equals(element, other.element); - } - - /** - * Returns the hash code value of the present value, if any, or 0 (zero) if - * no value is present. - * - * @return hash code value of the present value or 0 if no value is present - */ - @Override - public int hashCode() { - return Objects.hashCode(element); - } - - /** Returns an Option containing the value. - * - * @param <A> the type of the value - * @param element contained value - * @return a new Option that contains the value */ - public static <A> Optional<A> of(final A element) { - return new Optional<A>(element, true); - } - - /** Returns an empty option. - * - * @param <A> - * @return an empty Option */ - public static <A> Optional<A> empty() { - return new Optional<A>(null, false); - } -} |