import com.google.common.annotations.Beta;
import com.google.common.util.concurrent.FluentFuture;
import com.google.common.util.concurrent.Futures;
-import com.google.common.util.concurrent.ListenableFuture;
import com.google.common.util.concurrent.SettableFuture;
import java.util.concurrent.CompletableFuture;
import java.util.function.Consumer;
import java.util.function.Function;
import java.util.function.Supplier;
-import javax.annotation.concurrent.ThreadSafe;
import org.eclipse.jdt.annotation.NonNullByDefault;
import org.eclipse.jdt.annotation.Nullable;
*/
@Beta
@NonNullByDefault
-@ThreadSafe
-public final class CheckedValue<T, E extends Exception> extends Variant<T, E> {
- private CheckedValue(final T value) {
+public class CheckedValue<T, E extends Exception> extends Either<T, E> {
+ protected CheckedValue(final T value) {
super(value);
}
- private CheckedValue(final E violation, final @Nullable Void dummy) {
+ protected CheckedValue(final E violation, final @Nullable Void dummy) {
super(violation, dummy);
}
* Create a new instance containing an {@link Exception}.
*
* @param cause Throwable
+ * @param <T> Value type
+ * @param <E> Exception type
* @return A new instance
* @throws NullPointerException if {@code cause} is null
*/
* Create a new instance containing specified value.
*
* @param value Value
+ * @param <T> Value type
+ * @param <E> Exception type
* @return A new instance
* @throws NullPointerException if {@code value} is null
*/
* Convert a Variant into a {@link CheckedValue}, converting the second value into an exception.
*
* @param variant Input variant
+ * @param mapper Mapping function from second alternative to an exception
+ * @param <T> First alternative type
+ * @param <U> Second alternative type
+ * @param <E> Exception type
* @return Resulting {@link CheckedValue}
*/
- public static <T, U, E extends Exception> CheckedValue<T, E> ofVariant(final Variant<T, U> variant,
+ public static <T, U, E extends Exception> CheckedValue<T, E> ofVariant(final Either<T, U> variant,
final Function<U, E> mapper) {
requireNonNull(mapper);
- return variant.isFirst() ? new CheckedValue(variant.first())
- : new CheckedValue(mapper.apply(variant.second()), null);
+ return variant.isFirst() ? new CheckedValue<>(variant.first())
+ : new CheckedValue<>(mapper.apply(variant.second()), null);
}
/**
* @return Contained value
* @throws IllegalStateException if an error string is present.
*/
- public T get() {
+ public final T get() {
if (isFirst()) {
return first();
}
* string.
* @throws IllegalStateException if a value is present.
*/
- public E getException() {
+ public final E getException() {
if (isSecond()) {
return second();
}
*
* @return True if a value is present.
*/
- public boolean isPresent() {
+ public final boolean isPresent() {
return isFirst();
}
* @param consumer block to be executed if a value is present
* @throws NullPointerException if value is present and {@code consumer} is null
*/
- public void ifPresent(final Consumer<? super T> consumer) {
+ public final void ifPresent(final Consumer<? super T> consumer) {
if (isFirst()) {
consumer.accept(first());
}
@SuppressWarnings("unchecked")
public <X extends Exception> CheckedValue<T, X> mapException(final Function<? super E, X> mapper) {
requireNonNull(mapper);
- if (isFirst()) {
- return (CheckedValue<T, X>) this;
- }
- return new CheckedValue<>(mapper.apply(second()), null);
+ return isFirst() ? (CheckedValue<T, X>) this : new CheckedValue<>(mapper.apply(second()), null);
}
-
@SuppressWarnings("unchecked")
public <U> CheckedValue<U, E> flatMap(final Function<? super T, CheckedValue<U, E>> mapper) {
requireNonNull(mapper);
* @param other Replacement value
* @return Contained value or {code other}
*/
- public T orElse(final T other) {
+ public final T orElse(final T other) {
return isFirst() ? first() : other;
}
* @return Contained value or supplier's value
* @throws NullPointerException if {@code supplier} is null
*/
- public T orElseGet(final Supplier<T> supplier) {
+ public final T orElseGet(final Supplier<T> supplier) {
requireNonNull(supplier);
return isFirst() ? first() : supplier.get();
}
* @return Contained value
* @throws E When there is no contained value
*/
- public <X extends Throwable> T orElseThrow() throws E {
+ public final T orElseThrow() throws E {
if (isFirst()) {
return first();
}
* Return contained value if present or throw the exception alternative mapped through provided mapper.
*
* @param exceptionMapper Exception mapper
+ * @param <X> Thrown exception type
* @return Contained value
* @throws NullPointerException if {@code exceptionMapper} is null
* @throws X When there is no contained value
*/
- public <X extends Throwable> T orElseThrow(final Function<E, X> exceptionMapper) throws X {
+ public final <X extends Throwable> T orElseThrow(final Function<E, X> exceptionMapper) throws X {
requireNonNull(exceptionMapper);
if (isFirst()) {
return first();
* Return contained value if present or throw the exception supplied by supplier.
*
* @param supplier Exception supplier
+ * @param <X> Thrown exception type
* @return Contained value
* @throws NullPointerException if {@code exceptionMapper} is null
* @throws X When there is no contained value
*/
- public <X extends Throwable> T orElseThrow(final Supplier<X> supplier) throws X {
+ public final <X extends Throwable> T orElseThrow(final Supplier<X> supplier) throws X {
requireNonNull(supplier);
if (isFirst()) {
return first();
* @return True if this call has transitioned the future to a completed state, false otherwise.
* @throws NullPointerException if {code future} is null
*/
- public boolean completeFuture(final CompletableFuture<T> future) {
+ public final boolean completeFuture(final CompletableFuture<T> future) {
return isFirst() ? future.complete(first()) : future.completeExceptionally(second());
}
* @return True if this call has transitioned the future to a completed state, false otherwise.
* @throws NullPointerException if {code future} is null
*/
- public boolean completeFuture(final SettableFuture<T> future) {
+ public final boolean completeFuture(final SettableFuture<T> future) {
return isFirst() ? future.set(first()) : future.setException(second());
}
*
* @return A {@link CompletableFuture}.
*/
- public CompletableFuture<T> toCompletableFuture() {
- if (isFirst()) {
- return CompletableFuture.completedFuture(first());
- }
- // FIXME: Java 9: use CompletableFuture.failedFuture()
- final CompletableFuture<T> future = new CompletableFuture<>();
- future.completeExceptionally(second());
- return future;
+ public final CompletableFuture<T> toCompletableFuture() {
+ return isFirst() ? CompletableFuture.completedFuture(first()) : CompletableFuture.failedFuture(second());
}
/**
*
* @return A {@link FluentFuture}.
*/
- public FluentFuture<T> toFluentFuture() {
- final ListenableFuture<T> future;
- if (isFirst()) {
- future = Futures.immediateFuture(first());
- } else {
- future = Futures.immediateFailedFuture(second());
- }
- return FluentFuture.from(future);
+ public final FluentFuture<T> toFluentFuture() {
+ return FluentFuture.from(isFirst() ? Futures.immediateFuture(first())
+ : Futures.immediateFailedFuture(second()));
}
}