findfile.java

Java写的含有一个jdbc驱动的小型数据库数据库引擎

/*
 * FindFile.java
 *
 * Copyright (c) 2001, The HSQL Development Group
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * Redistributions of source code must retain the above copyright notice, this
 * list of conditions and the following disclaimer.
 *
 * Redistributions in binary form must reproduce the above copyright notice,
 * this list of conditions and the following disclaimer in the documentation
 * and/or other materials provided with the distribution.
 *
 *
 * Neither the name of the HSQL Development Group nor the names of its
 * contributors may be used to endorse or promote products derived from this
 * software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE FOR
 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * This package is based on HypersonicSQL, originally developed by Thomas Mueller.
 *
 */
package org.hsqldb.util;

import java.sql.*;
import java.io.*;

/**
 * Class declaration
 *
 *
 * @version 1.0.0.1
 */
class FindFile {

    /**
     * main method declaration
     *
     *
     * @param arg
     */
    public static void main(String arg[]) {

	// Exceptions may occur
	try {

	    // Load the HSQL Database Engine JDBC driver
	    Class.forName("org.hsqldb.jdbcDriver");

	    // Connect to the database
	    // It will be create automatically if it does not yet exist
	    // 'testfiles' in the URL is the name of the database
	    // "sa" is the user name and "" is the (empty) password
	    Connection conn =
		DriverManager.getConnection("jdbc:hsqldb:testfiles",
					    "sa", "");

	    // Check the command line parameters
	    if (arg.length == 1) {

		// One parameter:
		// Find and print the list of files that are like this
		listFiles(conn, arg[0]);
	    } else if (arg.length == 2 && arg[0].equals("-init")) {

		// Command line parameters: -init pathname
		// Init the database and fill all file names in
		fillFileNames(conn, arg[1]);
	    } else {

		// Display the usage info
		System.out.println("Usage:");
		System.out.println("java FindFile -init .");
		System.out.println("  Re-create database from directory '.'");
		System.out.println("java FindFile name");
		System.out.println("  Find files like 'name'");
	    }

	    // Finally, close the connection
	    conn.close();
	} catch (Exception e) {

	    // Print out the error message
	    System.out.println(e);
	    e.printStackTrace();
	}
    }

    // Search in the database and list out files like this

    /**
     * Method declaration
     *
     *
     * @param conn
     * @param name
     *
     * @throws SQLException
     */
    static void listFiles(Connection conn, String name) throws SQLException {
	System.out.println("Files like '" + name + "'");

	// Convert to upper case, so the search is case-insensitive
	name = name.toUpperCase();

	// Create a statement object
	Statement stat = conn.createStatement();

	// Now execute the search query
	// UCASE: This is a case insensitive search
	// ESCAPE ':' is used so it can be easily searched for '\'
	ResultSet result = stat.executeQuery("SELECT Path FROM Files WHERE "
					     + "UCASE(Path) LIKE '%" + name
					     + "%' ESCAPE ':'");

	// Moves to the next record until no more records
	while (result.next()) {

	    // Print the first column of the result
	    // could use also getString("Path")
	    System.out.println(result.getString(1));
	}

	// Close the ResultSet - not really necessary, but recommended
	result.close();
    }

    // Re-create the database and fill the file names in

    /**
     * Method declaration
     *
     *
     * @param conn
     * @param root
     *
     * @throws SQLException
     */
    static void fillFileNames(Connection conn,
			      String root) throws SQLException {
	System.out.println("Re-creating the database...");

	// Create a statement object
	Statement stat = conn.createStatement();

	// Try to drop the table
	try {
	    stat.executeUpdate("DROP TABLE Files");
	} catch (SQLException e) {

	    // Ignore Exception, because the table may not yet exist
	}

	// For compatibility to other database, use varchar(255)
	// In HSQL Database Engine, length is unlimited, like Java Strings
	stat.execute("CREATE TABLE Files"
		     + "(Path varchar(255),Name varchar(255))");

	// Close the Statement object, it is no longer used
	stat.close();

	// Use a PreparedStatement because Path and Name could contain '
	PreparedStatement prep =
	    conn.prepareCall("INSERT INTO Files (Path,Name) VALUES (?,?)");

	// Start with the 'root' directory and recurse all subdirectories
	fillPath(root, "", prep);

	// Close the PreparedStatement
	prep.close();
	System.out.println("Finished");
    }

    // Fill the file names, using the PreparedStatement

    /**
     * Method declaration
     *
     *
     * @param path
     * @param name
     * @param prep
     *
     * @throws SQLException
     */
    static void fillPath(String path, String name,
			 PreparedStatement prep) throws SQLException {
	File f = new File(path);

	if (f.isFile()) {

	    // Clear all Parameters of the PreparedStatement
	    prep.clearParameters();

	    // Fill the first parameter: Path
	    prep.setString(1, path);

	    // Fill the second parameter: Name
	    prep.setString(2, name);

	    // Its a file: add it to the table
	    prep.execute();
	} else if (f.isDirectory()) {
	    if (!path.endsWith(File.separator)) {
		path += File.separator;
	    }

	    String list[] = f.list();

	    // Process all files recursivly
	    for (int i = 0; list != null && i < list.length; i++) {
		fillPath(path + list[i], list[i], prep);
	    }
	}
    }

}