/*
* Copyright 2017 the original author or authors.
*
* 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.gradle.api.internal.provider;
import org.gradle.api.provider.Provider;
import org.gradle.internal.UncheckedException;
import java.util.concurrent.Callable;
public class DefaultProvider<T> implements Provider<T> {
public static final String NON_NULL_VALUE_EXCEPTION_MESSAGE = "Needs to set a non-null value before it can be retrieved";
private final Callable<T> value;
public DefaultProvider(Callable<T> value) {
assert value != null : "value cannot be null";
this.value = value;
}
@Override
public T get() {
T evaluatedValue = getOrNull();
if (evaluatedValue == null) {
throw new IllegalStateException(NON_NULL_VALUE_EXCEPTION_MESSAGE);
}
return evaluatedValue;
}
@Override
public T getOrNull() {
try {
return value.call();
} catch (Exception e) {
throw new UncheckedException(e);
}
}
@Override
public boolean isPresent() {
return getOrNull() != null;
}
@Override
public String toString() {
return String.format("value: %s", getOrNull());
}
}