org.apache.giraph.graph.DefaultVertexValueFactory.java Source code

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Here is the source code for org.apache.giraph.graph.DefaultVertexValueFactory.java

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/*
 * 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.giraph.graph;

import org.apache.giraph.conf.ImmutableClassesGiraphConfiguration;
import org.apache.hadoop.io.NullWritable;
import org.apache.hadoop.io.Writable;

/**
 * Default {@link VertexValueFactory} that simply uses the default
 * constructor for the vertex value class.
 *
 * @param <V> Vertex value
 */
public class DefaultVertexValueFactory<V extends Writable> implements VertexValueFactory<V> {
    /** Cached vertex value class. */
    private Class<V> vertexValueClass;

    @Override
    public void initialize(ImmutableClassesGiraphConfiguration<?, V, ?, ?> configuration) {
        vertexValueClass = configuration.getVertexValueClass();
    }

    @Override
    public V createVertexValue() {
        if (vertexValueClass == NullWritable.class) {
            return (V) NullWritable.get();
        } else {
            try {
                return vertexValueClass.newInstance();
            } catch (InstantiationException e) {
                throw new IllegalArgumentException("createVertexValue: Failed to instantiate", e);
            } catch (IllegalAccessException e) {
                throw new IllegalArgumentException("createVertexValue: Illegally accessed", e);
            }
        }
    }
}