com.cloudera.cdk.morphline.hadoop.sequencefile.ParseTextMyWritableBuilder.java Source code

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Here is the source code for com.cloudera.cdk.morphline.hadoop.sequencefile.ParseTextMyWritableBuilder.java

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/*
 * Copyright 2013 Cloudera 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 com.cloudera.cdk.morphline.hadoop.sequencefile;

import java.io.DataInput;
import java.io.DataOutput;
import java.io.IOException;
import java.util.Collection;
import java.util.Collections;

import org.apache.commons.lang.NotImplementedException;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.io.WritableComparable;

import com.cloudera.cdk.morphline.api.Command;
import com.cloudera.cdk.morphline.api.CommandBuilder;
import com.cloudera.cdk.morphline.api.MorphlineContext;
import com.cloudera.cdk.morphline.api.Record;
import com.cloudera.cdk.morphline.base.AbstractCommand;
import com.cloudera.cdk.morphline.base.Fields;
import com.typesafe.config.Config;

/**
 * Command that does custom parsing of MyWritable fields into output record
 */
public final class ParseTextMyWritableBuilder implements CommandBuilder {

    @Override
    public Collection<String> getNames() {
        return Collections.singletonList("parseTextMyWritable");
    }

    @Override
    public Command build(Config config, Command parent, Command child, MorphlineContext context) {
        return new ParseTextMyWritable(this, config, parent, child, context);
    }

    private static final class ParseTextMyWritable extends AbstractCommand {
        private final String keyField;
        private final String valueField;

        public ParseTextMyWritable(CommandBuilder builder, Config config, Command parent, Command child,
                MorphlineContext context) {
            super(builder, config, parent, child, context);
            this.keyField = getConfigs().getString(config, ReadSequenceFileBuilder.CONFIG_KEY_FIELD,
                    Fields.ATTACHMENT_BODY);
            this.valueField = getConfigs().getString(config, ReadSequenceFileBuilder.CONFIG_VALUE_FIELD,
                    Fields.ATTACHMENT_BODY);
        }

        @Override
        protected boolean doProcess(Record inputRecord) {
            Record outputRecord = inputRecord.copy();

            // change key
            Text myTextKey = (Text) inputRecord.getFirstValue(this.keyField);
            outputRecord.replaceValues(this.keyField, MyWritable.keyStr(myTextKey));
            // change value
            MyWritable myWritableValue = (MyWritable) inputRecord.getFirstValue(this.valueField);
            outputRecord.replaceValues(this.valueField, MyWritable.valueStr(myWritableValue));
            return super.doProcess(outputRecord);
        }
    }

    /**
     * Writable derived class for testing.
     */
    public static class MyWritable implements WritableComparable {
        private String prefix;
        private int suffix;

        /**
         * Empty constructor for Writable
         */
        public MyWritable() {
        }

        public MyWritable(String prefix, int suffix) {
            this.prefix = prefix;
            this.suffix = suffix;
        }

        public void readFields(DataInput in) throws IOException {
            this.prefix = in.readUTF();
            this.suffix = in.readInt();
        }

        public void write(DataOutput out) throws IOException {
            out.writeUTF(this.prefix);
            out.writeInt(this.suffix);
        }

        public int compareTo(Object o) {
            throw new NotImplementedException("not implemented!");
        }

        public String getPrefix() {
            return prefix;
        }

        public int getSuffix() {
            return suffix;
        }

        public static String keyStr(Text key) {
            // do something recognizable
            return key.toString().toUpperCase();
        }

        public static String valueStr(MyWritable value) {
            // do something recognizable
            return value.getSuffix() + value.getPrefix();
        }
    }
}