io.druid.query.extraction.StringFormatExtractionFn.java Source code

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Here is the source code for io.druid.query.extraction.StringFormatExtractionFn.java

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/*
* Licensed to Metamarkets Group Inc. (Metamarkets) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. Metamarkets 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 io.druid.query.extraction;

import com.fasterxml.jackson.annotation.JsonCreator;
import com.fasterxml.jackson.annotation.JsonProperty;
import com.fasterxml.jackson.annotation.JsonValue;
import com.google.common.base.Preconditions;
import com.google.common.base.Strings;
import io.druid.java.util.common.StringUtils;

import java.nio.ByteBuffer;

/**
 *
 */
public class StringFormatExtractionFn extends DimExtractionFn {
    public static enum NullHandling {
        NULLSTRING, EMPTYSTRING, RETURNNULL;

        @JsonCreator
        public static NullHandling forValue(String value) {
            return value == null ? NULLSTRING : NullHandling.valueOf(value.toUpperCase());
        }

        @JsonValue
        public String toValue() {
            return name().toLowerCase();
        }
    }

    private final String format;
    private final NullHandling nullHandling;

    @JsonCreator
    public StringFormatExtractionFn(@JsonProperty("format") String format,
            @JsonProperty("nullHandling") NullHandling nullHandling) {
        Preconditions.checkArgument(!Strings.isNullOrEmpty(format), "format string should not be empty");
        this.format = format;
        this.nullHandling = nullHandling == null ? NullHandling.NULLSTRING : nullHandling;
    }

    public StringFormatExtractionFn(String format) {
        this(format, NullHandling.NULLSTRING);
    }

    @JsonProperty
    public String getFormat() {
        return format;
    }

    @JsonProperty
    public NullHandling getNullHandling() {
        return nullHandling;
    }

    @Override
    public byte[] getCacheKey() {
        byte[] bytes = StringUtils.toUtf8(format);
        return ByteBuffer.allocate(2 + bytes.length).put(ExtractionCacheHelper.CACHE_TYPE_ID_STRING_FORMAT)
                .put((byte) nullHandling.ordinal()).put(bytes).array();
    }

    @Override
    public String apply(String value) {
        if (value == null) {
            if (nullHandling == NullHandling.RETURNNULL) {
                return null;
            }
            if (nullHandling == NullHandling.EMPTYSTRING) {
                value = "";
            }
        }
        return Strings.emptyToNull(String.format(format, value));
    }

    @Override
    public boolean preservesOrdering() {
        return false;
    }

    @Override
    public ExtractionType getExtractionType() {
        return ExtractionType.MANY_TO_ONE;
    }

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

        StringFormatExtractionFn that = (StringFormatExtractionFn) o;

        if (nullHandling != that.nullHandling) {
            return false;
        }
        return format.equals(that.format);
    }

    @Override
    public int hashCode() {
        int result = format.hashCode();
        result = 31 * result + nullHandling.ordinal();
        return result;
    }

    @Override
    public String toString() {
        return "StringFormatExtractionFn{" + "format='" + format + '\'' + ", nullHandling=" + nullHandling + '}';
    }
}