PairWritable.java

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/*******************************************************************************
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use these files 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.
 *
 * Copyright 2014 - Juan Pino, Aurelien Waite, William Byrne
 *******************************************************************************/
package uk.ac.cam.eng.extraction.hadoop.datatypes;

import java.io.DataInput;
import java.io.DataOutput;
import java.io.IOException;

import org.apache.hadoop.io.Writable;

class PairWritable<F extends Writable, S extends Writable> implements
                Writable {

        public F first;
        public S second;

        public static <F extends Writable, S extends Writable> PairWritable<F, S> createPair(
                        F f, S s) {
                return new PairWritable<F, S>(f, s);
        }

        /*
         * (non-Javadoc)
         * 
         * @see java.lang.Object#hashCode()
         */
        @Override
        public int hashCode() {
                final int prime = 31;
                int result = 1;
                result = prime * result + ((first == null) ? 0 : first.hashCode());
                result = prime * result + ((second == null) ? 0 : second.hashCode());
                return result;
        }

        /*
         * (non-Javadoc)
         * 
         * @see java.lang.Object#equals(java.lang.Object)
         */
        @Override
        public boolean equals(Object obj) {
                if (this == obj)
                        return true;
                if (obj == null)
                        return false;
                if (getClass() != obj.getClass())
                        return false;
                PairWritable<?, ?> other = (PairWritable<?, ?>) obj;
                if (first == null) {
                        if (other.first != null)
                                return false;
                } else if (!first.equals(other.first))
                        return false;
                if (second == null) {
                        if (other.second != null)
                                return false;
                } else if (!second.equals(other.second))
                        return false;
                return true;
        }

        public PairWritable(F first, S second) {

                this.first = first;
                this.second = second;
        }

        public PairWritable(Class<F> classF, Class<S> classS) {
                try {
                        this.first = classF.newInstance();
                        this.second = classS.newInstance();
                } catch (InstantiationException | IllegalAccessException e) {
                        throw new RuntimeException(e);
                }
        }

        public void set(F f, S s) {
                first = f;
                second = s;
        }

        public void setFirst(F f) {
                first = f;
        }

        public void setSecond(S s) {
                second = s;
        }

        @Override
        public void readFields(DataInput in) throws IOException {
                first.readFields(in);
                second.readFields(in);
        }

        @Override
        public void write(DataOutput out) throws IOException {
                first.write(out);
                second.write(out);
        }

        public F getFirst() {
                return first;
        }

        public S getSecond() {
                return second;
        }

        @Override
        public String toString() {
                StringBuilder builder = new StringBuilder(first.toString());
                builder.append("\t").append(second.toString());
                return builder.toString();
        }

}