hu.akarnokd.rxjava2.Try Maven / Gradle / Ivy
/**
* Copyright 2015 David Karnok and Netflix, Inc.
*
* 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 hu.akarnokd.rxjava2;
import hu.akarnokd.rxjava2.internal.functions.Objects;
/**
* Container for either a value of type T or a Throwable.
*
* @param the value type
*/
public final class Try {
/** The value. */
final T value;
/** The error or null if this holds a value. */
final Throwable error;
private Try(T value, Throwable error) {
this.value = value;
this.error = error;
}
/**
* Constructs a Try instance by wrapping the given value.
*
* @param the value type
* @param value the value to wrap
* @return the created Try instance
*/
public static Try ofValue(T value) {
// TODO ? Objects.requireNonNull(value);
return new Try(value, null);
}
/**
* Constructs a Try instance by wrapping the given Throwable.
*
* Null Throwables are replaced by NullPointerException instance in this Try.
*
* @param the value type
* @param e the exception to wrap
* @return the new Try instance holding the exception
*/
public static Try ofError(Throwable e) {
return new Try(null, e != null ? e : new NullPointerException());
}
/**
* Returns the value or null if the value is actually null or if this Try holds an error instead.
* @return the value contained
* @see #hasValue()
*/
public T value() {
return value;
}
/**
* Returns the error or null if this Try holds a value instead.
*
* @return the Throwable contained or null
*
*/
public Throwable error() {
return error;
}
/**
* Returns true if this Try holds an error.
* @return true if this Try holds an error
*/
public boolean hasError() {
return error != null;
}
/**
* Returns true if this Try holds a value.
* @return true if this Try holds a value
*/
public boolean hasValue() {
return error == null;
}
@Override
public boolean equals(Object other) {
if (other instanceof Try) {
Try o = (Try) other;
return Objects.equals(value, o.value)
&& Objects.equals(error, o.error);
}
return false;
}
@Override
public int hashCode() {
return Objects.hashCode(value) + Objects.hashCode(error);
}
@Override
public String toString() {
if (error != null) {
return "Try[ " + error + " ]";
}
return "Try[" + value + "]";
}
}