PostgresToSeq.java Source code

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Here is the source code for PostgresToSeq.java

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/*
 * Copyright (c) 2010 the original author or authors.
 *
 * 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.
 */

// for PostgreSQL's JDBC
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;

//import java.io.BufferedReader;
//import java.io.FileReader;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.SequenceFile;
import org.apache.hadoop.io.SequenceFile.Writer;
import org.apache.hadoop.io.Text;

public class PostgresToSeq {
    public static void main(String args[]) throws Exception {
        if (args.length != 2) {
            System.err.println("Arguments: [input postgres table] [output sequence file]");
            return;
        }
        String inputFileName = args[0];
        String outputDirName = args[1];
        Configuration configuration = new Configuration();
        FileSystem fs = FileSystem.get(configuration);
        Writer writer = new SequenceFile.Writer(fs, configuration, new Path(outputDirName + "/chunk-0"), Text.class,
                Text.class);
        Connection c = null;
        Statement stmt = null;
        try {
            Class.forName("org.postgresql.Driver");
            c = DriverManager.getConnection("jdbc:postgresql://192.168.50.170:5432/uzeni", "postgres", "dbwpsdkdl");
            c.setAutoCommit(false);
            System.out.println("Opened database successfully");
            stmt = c.createStatement();
            ResultSet rs = stmt.executeQuery("SELECT * FROM " + inputFileName);
            int count = 0;
            Text key = new Text();
            Text value = new Text();

            while (rs.next()) {
                String seq = rs.getString("seq");
                String rep = rs.getString("rep");
                String body = rs.getString("body");
                String category = rep;
                String id = seq;
                String message = body;
                key.set("/" + category + "/" + id);
                value.set(message);
                writer.append(key, value);
                count++;
            }
            rs.close();
            stmt.close();
            c.close();
            writer.close();
            System.out.println("Wrote " + count + " entries.");
        } catch (Exception e) {
            System.err.println(e.getClass().getName() + ": " + e.getMessage());
            System.exit(0);
        }
    }
}