co.nubetech.hiho.mapreduce.lib.db.GenericDBWritable.java Source code

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Here is the source code for co.nubetech.hiho.mapreduce.lib.db.GenericDBWritable.java

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/**
 * Copyright 2010 Nube Technologies
 * 
 * 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 co.nubetech.hiho.mapreduce.lib.db;

import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.SQLException;
import java.util.ArrayList;

import org.apache.log4j.Logger;

import co.nubetech.apache.hadoop.DBWritable;

public class GenericDBWritable implements DBWritable, org.apache.hadoop.mapred.lib.db.DBWritable {

    final static Logger logger = Logger.getLogger(co.nubetech.hiho.mapreduce.lib.db.GenericDBWritable.class);

    private ArrayList<ColumnInfo> columns;
    private ArrayList values;

    public GenericDBWritable() {
    }

    public GenericDBWritable(ArrayList<ColumnInfo> meta, ArrayList values) {
        this.columns = meta;
        this.values = values;
    }

    public static ArrayList<ColumnInfo> populateColumnInfo(ResultSetMetaData meta) throws SQLException {
        ArrayList<ColumnInfo> columns = new ArrayList<ColumnInfo>();

        for (int i = 0; i < meta.getColumnCount(); ++i) {
            ColumnInfo info = new ColumnInfo(i, meta.getColumnType(i + 1), meta.getColumnName(i + 1));
            columns.add(info);
        }
        return columns;
    }

    /**
     * Sets the fields of the object in the {@link PreparedStatement}.
     * 
     * @param statement
     *            the statement that the fields are put into.
     * @throws SQLException
     */
    public void write(PreparedStatement statement) throws SQLException {
        for (int i = 0; i < values.size(); ++i) {
            statement.setObject(i + 1, values.get(i));
        }
    }

    public void setColumns(ArrayList<ColumnInfo> cols) {
        this.columns = cols;
    }

    public ArrayList<ColumnInfo> getColumns() {
        return columns;
    }

    /**
     * Reads the fields of the object from the {@link ResultSet}.
     * 
     * @param resultSet
     *            the {@link ResultSet} to get the fields from.
     * @throws SQLException
     */
    public void readFields(ResultSet resultSet) throws SQLException {
        values = new ArrayList();
        for (int i = 0; i < columns.size(); ++i) {
            values.add(resultSet.getObject(i + 1));
            logger.debug("Added resultset to " + values.get(i));
        }
    }

    public ArrayList getValues() {
        return values;
    }

}