Java tutorial
/* * Copyright (c) 2015 Spotify AB. * * Licensed to the Apache Software Foundation (ASF) under one * or more contributor license agreements. See the NOTICE file * distributed with this work for additional information * regarding copyright ownership. The ASF licenses this file * to you 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.spotify.heroic.test; import com.google.common.collect.ImmutableList; import lombok.RequiredArgsConstructor; import java.lang.reflect.Type; import java.util.ArrayList; import java.util.List; import java.util.Optional; @RequiredArgsConstructor public class ValueSuppliers { private final List<ValueSupplier> suppliers; public Optional<Object> lookup(final Type type, final boolean secondary, final String name) { return suppliers.stream().map(s -> s.supply(type, secondary, name)).filter(Optional::isPresent) .map(Optional::get).findFirst(); } public static ValueSuppliers empty() { return new ValueSuppliers(ImmutableList.of()); } @FunctionalInterface public interface ValueSupplier { Optional<Object> supply(Type type, boolean secondary, String name); } public static Builder builder() { return new Builder(); } public static class Builder { private final List<ValueSupplier> suppliers = new ArrayList<>(); public Builder supplier(final ValueSupplier supplier) { suppliers.add(supplier); return this; } public ValueSuppliers build() { return new ValueSuppliers(ImmutableList.copyOf(suppliers)); } } }