io.druid.query.UnionDataSource.java Source code

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Here is the source code for io.druid.query.UnionDataSource.java

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/*
 * Druid - a distributed column store.
 * Copyright 2012 - 2015 Metamarkets Group 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 io.druid.query;

import com.fasterxml.jackson.annotation.JsonCreator;
import com.fasterxml.jackson.annotation.JsonProperty;
import com.google.common.base.Function;
import com.google.common.base.Preconditions;
import com.google.common.collect.Iterables;
import com.google.common.collect.Lists;

import java.util.List;

public class UnionDataSource implements DataSource {
    @JsonProperty
    private final List<TableDataSource> dataSources;

    @JsonCreator
    public UnionDataSource(@JsonProperty("dataSources") List<TableDataSource> dataSources) {
        Preconditions.checkNotNull(dataSources, "dataSources cannot be null for unionDataSource");
        this.dataSources = dataSources;
    }

    @Override
    public List<String> getNames() {
        return Lists.transform(dataSources, new Function<TableDataSource, String>() {
            @Override
            public String apply(TableDataSource input) {
                return Iterables.getOnlyElement(input.getNames());
            }
        });
    }

    @JsonProperty
    public List<TableDataSource> getDataSources() {
        return dataSources;
    }

    @Override
    public boolean equals(Object o) {
        if (this == o) {
            return true;
        }
        if (o == null || getClass() != o.getClass()) {
            return false;
        }

        UnionDataSource that = (UnionDataSource) o;

        if (!dataSources.equals(that.dataSources)) {
            return false;
        }

        return true;
    }

    @Override
    public int hashCode() {
        return dataSources.hashCode();
    }

    @Override
    public String toString() {
        return "UnionDataSource{" + "dataSources=" + dataSources + '}';
    }
}