org.cloudata.core.client.RowIterator.java Source code

Introduction

Here is the source code for org.cloudata.core.client.RowIterator.java

Source

/**
 * 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.cloudata.core.client;

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

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

/**
 * @author jindolk
 *
 */
public class RowIterator implements Iterator<Row> {
    private static final Log LOG = LogFactory.getLog(RowIterator.class.getName());
    private CTable ctable;
    private RowFilter rowFilter;
    private Row[] rows;
    private int index;
    private Row.Key previousRowKey;
    private int pageSize;

    public RowIterator(CTable ctable, RowFilter rowFilter) throws IOException {
        this.ctable = ctable;
        this.rowFilter = rowFilter;
        pageSize = rowFilter.getPageSize();
        rows = ctable.gets(rowFilter);

        if (rows != null && rows.length > 0) {
            previousRowKey = rows[rows.length - 1].getKey();
        }
        index = -1;
    }

    /* (non-Javadoc)
     * @see java.util.Iterator#hasNext()
     */
    @Override
    public boolean hasNext() {
        if (rows != null && index >= rows.length - 1) {
            try {
                rowFilter.setPagingInfo(pageSize, previousRowKey);
                rows = ctable.gets(rowFilter);
                if (rows != null && rows.length > 0) {
                    previousRowKey = rows[rows.length - 1].getKey();
                }
            } catch (IOException e) {
                LOG.error("Can't get next rows:" + e.getMessage(), e);
            }
            index = -1;
        }
        return rows != null;
    }

    /* (non-Javadoc)
     * @see java.util.Iterator#next()
     */
    @Override
    public Row next() {
        if (rows != null && index >= rows.length - 1) {
            try {
                rowFilter.setPagingInfo(pageSize, previousRowKey);
                rows = ctable.gets(rowFilter);
                if (rows != null && rows.length > 0) {
                    previousRowKey = rows[rows.length - 1].getKey();
                } else {
                    return null;
                }
            } catch (IOException e) {
                LOG.error("Can't get next rows:" + e.getMessage(), e);
            }
            index = -1;
        }
        index++;

        return rows[index];
    }

    /* (non-Javadoc)
     * @see java.util.Iterator#remove()
     */
    @Override
    public void remove() {
    }
}