| /* |
| * 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 org.apache.druid.query.extraction; |
| |
| import com.fasterxml.jackson.annotation.JsonCreator; |
| import com.fasterxml.jackson.annotation.JsonProperty; |
| import com.fasterxml.jackson.annotation.JsonTypeName; |
| import com.google.common.base.Preconditions; |
| import com.google.common.base.Strings; |
| import com.google.common.collect.ImmutableMap; |
| import org.apache.druid.common.config.NullHandling; |
| import org.apache.druid.java.util.common.StringUtils; |
| import org.apache.druid.query.lookup.LookupExtractor; |
| |
| import javax.annotation.Nullable; |
| import java.io.ByteArrayOutputStream; |
| import java.io.IOException; |
| import java.util.Collections; |
| import java.util.List; |
| import java.util.Map; |
| import java.util.stream.Collectors; |
| |
| @JsonTypeName("map") |
| public class MapLookupExtractor extends LookupExtractor |
| { |
| private final Map<String, String> map; |
| |
| private final boolean isOneToOne; |
| |
| @JsonCreator |
| public MapLookupExtractor( |
| @JsonProperty("map") Map<String, String> map, |
| @JsonProperty("isOneToOne") boolean isOneToOne |
| ) |
| { |
| this.map = Preconditions.checkNotNull(map, "map"); |
| this.isOneToOne = isOneToOne; |
| } |
| |
| @JsonProperty |
| public Map<String, String> getMap() |
| { |
| return ImmutableMap.copyOf(map); |
| } |
| |
| @Nullable |
| @Override |
| public String apply(@Nullable String key) |
| { |
| String keyEquivalent = NullHandling.nullToEmptyIfNeeded(key); |
| if (keyEquivalent == null) { |
| // keyEquivalent is null only for SQL Compatible Null Behavior |
| // otherwise null will be replaced with empty string in nullToEmptyIfNeeded above. |
| return null; |
| } |
| return NullHandling.emptyToNullIfNeeded(map.get(keyEquivalent)); |
| } |
| |
| @Override |
| public List<String> unapply(@Nullable final String value) |
| { |
| String valueToLookup = NullHandling.nullToEmptyIfNeeded(value); |
| if (valueToLookup == null) { |
| // valueToLookup is null only for SQL Compatible Null Behavior |
| // otherwise null will be replaced with empty string in nullToEmptyIfNeeded above. |
| // null value maps to empty list when SQL Compatible |
| return Collections.emptyList(); |
| } |
| return map.entrySet() |
| .stream() |
| .filter(entry -> entry.getValue().equals(valueToLookup)) |
| .map(entry -> entry.getKey()) |
| .collect(Collectors.toList()); |
| } |
| |
| @Override |
| @JsonProperty("isOneToOne") |
| public boolean isOneToOne() |
| { |
| return isOneToOne; |
| } |
| |
| @Override |
| public byte[] getCacheKey() |
| { |
| try { |
| final ByteArrayOutputStream outputStream = new ByteArrayOutputStream(); |
| for (Map.Entry<String, String> entry : map.entrySet()) { |
| final String key = entry.getKey(); |
| final String val = entry.getValue(); |
| if (!Strings.isNullOrEmpty(key)) { |
| outputStream.write(StringUtils.toUtf8(key)); |
| } |
| outputStream.write((byte) 0xFF); |
| if (!Strings.isNullOrEmpty(val)) { |
| outputStream.write(StringUtils.toUtf8(val)); |
| } |
| outputStream.write((byte) 0xFF); |
| } |
| return outputStream.toByteArray(); |
| } |
| catch (IOException ex) { |
| // If ByteArrayOutputStream.write has problems, that is a very bad thing |
| throw new RuntimeException(ex); |
| } |
| } |
| |
| @Override |
| public boolean canIterate() |
| { |
| return true; |
| } |
| |
| @Override |
| public Iterable<Map.Entry<String, String>> iterable() |
| { |
| return map.entrySet(); |
| } |
| |
| @Override |
| public boolean equals(Object o) |
| { |
| if (this == o) { |
| return true; |
| } |
| if (o == null || getClass() != o.getClass()) { |
| return false; |
| } |
| |
| MapLookupExtractor that = (MapLookupExtractor) o; |
| |
| return map.equals(that.map); |
| } |
| |
| @Override |
| public int hashCode() |
| { |
| return map.hashCode(); |
| } |
| |
| } |