org.trend.hgraph.EdgeIterable.java Source code

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Here is the source code for org.trend.hgraph.EdgeIterable.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.trend.hgraph;

import java.io.IOException;
import java.util.Iterator;

import org.apache.commons.lang.Validate;
import org.apache.hadoop.hbase.client.HTableInterface;
import org.apache.hadoop.hbase.client.Result;
import org.apache.hadoop.hbase.client.ResultScanner;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * @author scott_miao
 *
 */
public class EdgeIterable implements Iterable<com.tinkerpop.blueprints.Edge> {

    private static final Logger LOG = LoggerFactory.getLogger(EdgeIterable.class);

    private Graph graph;
    private HTableInterface table;
    private ResultScanner rs;

    /**
     * @param rs
     */
    protected EdgeIterable(HTableInterface table, ResultScanner rs, Graph graph) {
        super();
        Validate.notNull(table, "table shall always not be null");
        Validate.notNull(rs, "rs shall always not be null");
        Validate.notNull(graph, "graph shall always not be null");
        this.table = table;
        this.rs = rs;
        this.graph = graph;
    }

    @Override
    public Iterator<com.tinkerpop.blueprints.Edge> iterator() {
        final Iterator<Result> r = this.rs.iterator();
        return new Iterator<com.tinkerpop.blueprints.Edge>() {

            @Override
            public boolean hasNext() {
                return r.hasNext();
            }

            @Override
            public com.tinkerpop.blueprints.Edge next() {
                return new Edge(r.next(), graph);
            }

            @Override
            public void remove() {
                throw new UnsupportedOperationException();
            }

        };
    }

    /* (non-Javadoc)
     * @see java.lang.Object#finalize()
     */
    @Override
    protected void finalize() throws Throwable {
        super.finalize();
        try {
            this.rs.close();
            this.graph.returnTable(this.table);
        } catch (Exception e) {
            LOG.error("finalize error", e);
            throw e;
        }
    }

}