kern/src/de/memtext/db/ValueRandomizer.java

package de.memtext.db;
import java.io.BufferedWriter;
import java.io.FileWriter;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.Enumeration;
import java.util.Random;
import java.util.Vector;
/**
 * Randomizes values in a database.
 * Reads all values of a given table column (select distinct x from..) and
 * multiplies all occurences of a single value (e.g. 150) with a factor between
 * minFactor and maxFactor (e.g. 150*1.1 -> all entries with 150 become 165)
 *
 * if boolean printOutOnly is true the update sql statements are only logged
 * to console, not performed
 * */
public class ValueRandomizer {
	//private static String driver = "org.hsqldb.jdbcDriver";
	private static String driver = "org.postgresql.Driver";
	//private static String dbUrl = "jdbc:hsqldb:hsql://localhost:9999";
	private static String dbUrl = "jdbc:postgresql://localhost:5432/superx";
	private static String username = "superx"; //"joolap";
	private static String password = ""; //"loopja3000";
	private static String tablename = "cob_busa";
	private static String colname = "betrag"; //"value";
	private static String datenart = "DOUBLE"; //or "INTEGER";

	private static double minFactor = 0.6;
	private static double maxFactor = 1.8;

	private static boolean printOutOnly = false;
	private static Statement stat;
	private static Random r = new Random();
	public static void main(String args[]) {
	
		try {
			Class.forName(driver);
			Connection conn;
			System.out.println("establishing connection to " + dbUrl);
			conn = DriverManager.getConnection(dbUrl, username, password);
			stat = conn.createStatement();
			System.out.println("done.");
			out();
			stat.close();
						conn.close();
				System.exit(-1);
				
				
			//alle werte einlesen
			Vector werte = readDistinctValues();
			if (datenart.toUpperCase().equalsIgnoreCase("DOUBLE")) {
				//massiveRandomizeDouble(werte);
				randomize(werte);
			} else //integer
				{
				massiveRandomizeInteger(werte);
			}
			
			System.out.println("Randomizierung erfolgreich beendet");
		} catch (Exception e) {
			System.out.println(e.toString());
			System.exit(0);
		}

	}
	/**
	 * randomizes in categories of values 
	 * only for double
	 * @param werte
	 */
	private static void randomize(Vector werte) {
		int categories = 15;
		int valuesPerCategory = (int) werte.size() / categories;
		StringBuffer updates = new StringBuffer();
		float limit = 0, limit2;
		for (int i = 1; i < categories; i++) {
			limit =
				(float) ((Double) werte.get(i * valuesPerCategory))
					.doubleValue();
			updates.append(
				"update "
					+ tablename
					+ " set "
					+ colname
					+ "="
					+ colname
					+ "*"
					+ getRndFactor()
					+ " where "
					+ colname
					+ ">"
					+ limit);
			if (i > 1) {
				limit2 =
					(float) ((Double) werte.get((i - 1) * valuesPerCategory))
						.doubleValue();
				updates.append(" and " + colname + "<" + limit2);
			}
			updates.append(";\n");
		}
		limit =
			(float) ((Double) werte.get((categories - 1) * valuesPerCategory))
				.doubleValue();
		updates.append(
			"update "
				+ tablename
				+ " set "
				+ colname
				+ "="
				+ colname
				+ "*"
				+ getRndFactor()
				+ " where "
				+ colname
				+ "<"
				+ limit
				+ ";");

		System.out.println(updates);
	}
	/**
	 *  * multiplies all occurences of a single value (e.g. 150) with a factor between
	* minFactor and maxFactor (e.g. 150*1.1 -> all entries with 150 become 165)
	
	 * @param werte
	 * @throws SQLException
	 */
	private static void massiveRandomizeInteger(Vector werte)
		throws SQLException {
		Integer einWert;
		String upd = null;
		for (Enumeration en = werte.elements(); en.hasMoreElements();) {
			einWert = (Integer) en.nextElement();
			int neuerwert = (int) (einWert.intValue() * getRndFactor());
			upd =
				"update "
					+ tablename
					+ " set "
					+ colname
					+ "="
					+ neuerwert
					+ " where "
					+ colname
					+ "="
					+ einWert.toString()
					+ ";";

			if (printOutOnly)
				System.out.println(upd);
			else
				stat.executeUpdate(upd);
		}

	}
	/**
	 *  * multiplies all occurences of a single value (e.g. 150) with a factor between
	 * minFactor and maxFactor (e.g. 150*1.1 -> all entries with 150 become 165)
	
	 * @param werte
	 * @throws SQLException
	 */
	private static void massiveRandomizeDouble(Vector werte)
		throws SQLException {
		Double einWert;
		double zufallswert;
		String upd;
		int i = 0;
		int count = werte.size();
		for (Enumeration en = werte.elements(); en.hasMoreElements();) {
			einWert = (Double) en.nextElement();
			i++;
			zufallswert = einWert.doubleValue() * getRndFactor();
			upd =
				"update "
					+ tablename
					+ " set "
					+ colname
					+ "="
					+ zufallswert
					+ " where "
					+ colname
					+ "="
					+ einWert
					+ ";";
			if (printOutOnly)
				System.out.println(upd);
			else {
				stat.executeUpdate(upd);
				if (i % 20 == 0)
					System.out.println("Done " + i + " updates of " + count);
			}

		}
	}
	private static float getRndFactor() {
		double rnd = Math.abs(r.nextDouble());
		while (rnd < minFactor)
			rnd += minFactor;
		while (rnd > maxFactor)
			rnd -= 0.05;
		return (float) rnd;
	}
	private static Vector readDistinctValues() throws SQLException {
		Vector werte = new Vector();
		ResultSet rs = null;
		Object item;
		System.out.println(
			"Alle werte einlesen:"
				+ "select distinct "
				+ colname
				+ " from "
				+ tablename
				+ " order by 1 DESC");

		rs =
			stat.executeQuery(
				"select distinct "
					+ colname
					+ " from "
					+ tablename
					+ " order by "
					+ colname
					+ " DESC");
		while (rs.next()) {
			item = rs.getObject(1);
			werte.add(item);
		}
		rs.close();
		return werte;
	}

	private static void out() {
				try {
					FileWriter fw =
								new FileWriter("c:\\cygwin\\home\\superx\\cob_busa.unl");
							BufferedWriter bw = new BufferedWriter(fw);
							StringBuffer buf = new StringBuffer();

			ResultSet rs = stat.executeQuery("select * from cob_busa");

			int cols = 20;String s;Object o;
			while (rs.next()) {
				for (int i = 1; i <= cols; i++)
					{o=rs.getObject(i);
					if (o==null) s="";
					else s=o.toString();
					
						buf.append(s.trim() + "^");} 
				buf.append("^\n");

			}
			rs.close();

			bw.write(buf.toString());
			bw.close();
			fw.close();
		} catch (Exception e) {
			e.printStackTrace();
		}
		System.out.println("done");
	}
}