import java.sql.Connection;
import java.sql.Driver;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.Enumeration;
import java.util.logging.LogManager;

import org.apache.derby.iapi.services.monitor.Monitor;


public class Main {
    private Connection con;

    public Main() {
    }

    public void start() throws Exception {
        System.out.println("Starting");

        Class.forName("org.apache.derby.jdbc.EmbeddedDriver");
        con = DriverManager.getConnection("jdbc:derby:db");

//      Class.forName("org.hsqldb.jdbc.JDBCDriver");
//      con = DriverManager.getConnection("jdbc:hsqldb:file:mymemdb;shutdown=true", "SA", "");

        try {
            // If we comment the following lines and don't run the statements the
            // leak does not happen
            Statement stmt = con.createStatement();
            stmt.execute("CREATE TABLE TEST (A VARCHAR(12))");
            stmt.execute("DROP TABLE TEST");
            stmt.close();
            stmt = null;
        }
        catch (Exception e) {
            e.printStackTrace();
        }
    }

    public void stop() throws Exception {
        System.out.println("Stopping");

        try {
            con.close();
            con = null;
        }
        catch (Exception e) {
            e.printStackTrace();
        }

        try {
            DriverManager.getConnection("jdbc:derby:db;shutdown=true");
        } catch (SQLException e) {
            if ("Database 'db' shutdown.".equals(e.getMessage()) || "Database 'db' not found.".equals(e.getMessage())) {
                // ignore, we're shutting down
            } else {
                throw e;
            }
        }
        try {
            DriverManager.getConnection("jdbc:derby:;shutdown=true");
        } catch (SQLException e) {
            if ("Derby system shutdown.".equals(e.getMessage()) || "Database 'db' not found.".equals(e.getMessage())) {
                // ignore, we're shutting down
            } else {
                throw e;
            }
        }

        // This shuts down the derby.antiGC thread
        Monitor.getMonitor().shutdown();

        // Ensure that we unload all JDBC drivers
        Enumeration<Driver> enumeration = DriverManager.getDrivers();

        while(enumeration.hasMoreElements()) {
            Driver driver = enumeration.nextElement();
            DriverManager.deregisterDriver(driver);
        }

        LogManager.getLogManager().reset();
    }

    @Override
    protected void finalize() throws Throwable {
        System.out.println("******** Main just got finalized!");
        super.finalize();
    }
}

import java.io.File;
import java.lang.reflect.Method;
import java.net.URL;

public class Test {
    public static void main(String[] args) throws Exception {
        URL[] urls = new URL[] {
            new File("../Test1/bin/").toURI().toURL(),
            new File("../Test1/lib/derby.jar").toURI().toURL(),
//          new File("../Test1/lib/javadb.jar").toURI().toURL(),
            new File("../Test1/lib/hsqldb.jar").toURI().toURL(),
        };
        ClassLoader classLoader = new TestClassloader(urls);

        Class<?> clz = classLoader.loadClass("Main");

        Object o = clz.newInstance();

        try {
            Method m = o.getClass().getMethod("start");
            m.invoke(o);
            m = null;
        }
        catch (Exception e) {
            e.printStackTrace();
        }

        try {
            Method m = o.getClass().getMethod("stop");
            m.invoke(o);
            m = null;
        }
        catch (Exception e) {
            e.printStackTrace();
        }

        o = null;

        clz = null;

        classLoader = null;

        while (true) {
            System.gc();
            Thread.yield();
        }
    }
}


import java.net.URL;
import java.net.URLClassLoader;
import java.net.URLStreamHandlerFactory;


public class TestClassloader extends URLClassLoader {

    public TestClassloader(URL[] urls) {
        super(urls);
        // TODO Auto-generated constructor stub
    }

    public TestClassloader(URL[] urls, ClassLoader parent) {
        super(urls, parent);
        // TODO Auto-generated constructor stub
    }

    public TestClassloader(URL[] urls, ClassLoader parent,
            URLStreamHandlerFactory factory) {
        super(urls, parent, factory);
        // TODO Auto-generated constructor stub
    }

    @Override
    protected void finalize() throws Throwable {
        System.out.println("******** TestClassloader just got finalized!");
        super.finalize();
    }
}