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; import com.google.common.base.Joiner; import com.google.common.collect.ImmutableList; import com.google.common.collect.ImmutableMultimap; import com.google.common.collect.Multimap; import com.spotify.heroic.common.Duration; import com.spotify.heroic.filter.Filter; import com.spotify.heroic.grammar.QueryParser; import lombok.Data; import java.util.Arrays; import java.util.Collection; import java.util.List; import java.util.Optional; @Data public class ExtraParameters { public static final ParameterSpecification CONFIGURE = ParameterSpecification.parameter("configure", "Automatically configure all backends."); public static final Joiner SCOPE_JOINER = Joiner.on('.'); private final List<String> scope; private final Multimap<String, String> parameters; public boolean containsAny(String... keys) { return Arrays.stream(keys).anyMatch(parameters::containsKey); } public Optional<Filter> getFilter(String key, QueryParser parser) { final Collection<String> values = parameters.get(key); if (values.isEmpty()) { return Optional.empty(); } return Optional.of(parser.parseFilter(values.iterator().next())); } public Optional<Integer> getInteger(String key) { try { return get(key).map(Integer::parseInt); } catch (final NumberFormatException e) { throw new IllegalStateException("Key " + key + " exists, but does not contain a valid numeric value", e); } } public Optional<String> get(String key) { return getEntry(key).stream().findFirst(); } public boolean contains(String key) { return parameters.containsKey(key); } public String require(final String key) { return get(key).orElseThrow(() -> new IllegalStateException(key + ": is a required parameter")); } public boolean contains(ParameterSpecification parameter) { return contains(parameter.getName()); } public List<String> getAsList(final String key) { return ImmutableList.copyOf(getEntry(key)); } public Optional<Boolean> getBoolean(final String key) { return get(key).map(s -> "true".equals(s) || "yes".equals(s)); } public Optional<Duration> getDuration(String key) { try { return get(key).map(Duration::parseDuration); } catch (final Exception e) { throw new IllegalStateException("Key " + key + " exists, but does not contain a valid duration value", e); } } public ExtraParameters scope(final String scope) { return new ExtraParameters(ImmutableList.<String>builder().addAll(this.scope).add(scope).build(), parameters); } private Collection<String> getEntry(String key) { return Optional.ofNullable(parameters.get(entryKey(key))).orElseGet(ImmutableList::of); } private String entryKey(final String key) { if (scope.isEmpty()) { return key; } return SCOPE_JOINER.join(ImmutableList.<String>builder().addAll(scope).add(key).build()); } public static ExtraParameters empty() { return new ExtraParameters(ImmutableList.of(), ImmutableMultimap.of()); } public static ExtraParameters ofList(final List<String> input) { final ImmutableMultimap.Builder<String, String> result = ImmutableMultimap.builder(); for (final String entry : input) { final int index = entry.indexOf('='); if (index < 0) { result.put(entry, ""); } else { result.put(entry.substring(0, index), entry.substring(index + 1)); } } return new ExtraParameters(ImmutableList.of(), result.build()); } }