HSQLDB example source code file (RCData.java)

This example HSQLDB source code file (RCData.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - HSQLDB tags/keywords

bufferedreader, classnotfoundexception, default_jdbc_driver, exception, exception, illegalaccessexception, illegalargumentexception, illegalargumentexception, io, ioexception, ioexception, jdbc, net, network, rcdata, sql, string, string, stringtokenizer, util

The HSQLDB RCData.java source code

/* Copyright (c) 2001-2008, 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 HSQL DEVELOPMENT GROUP, HSQLDB.ORG,
 * 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.
 */


package org.hsqldb.util;

import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.IOException;
import java.net.MalformedURLException;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.util.Properties;
import java.util.StringTokenizer;

/* $Id: RCData.java,v 1.17 2007/05/13 15:27:37 fredt Exp $ */

/**
 * All the info we need to connect up to a database.
 *
 * @author Blaine Simpson unsaved@users
 */
public class RCData {

    public static final String DEFAULT_JDBC_DRIVER   = "org.hsqldb.jdbcDriver";
    private String             defaultJdbcDriverName = DEFAULT_JDBC_DRIVER;

    public void setDefaultJdbcDriver(String defaultJdbcDriverName) {
        this.defaultJdbcDriverName = defaultJdbcDriverName;
    }

    public String getDefaultJdbcDriverName() {
        return defaultJdbcDriverName;
    }

    /**
     * Just for testing and debugging.
     *
     * N.b. this echoes passwords!
     */
    public void report() {
        System.err.println("urlid: " + id + ", url: " + url + ", username: "
                           + username + ", password: " + password);
    }

    /**
     * Creates a RCDataObject by looking up the given key in the
     * given authentication file.
     *
     * @param dbKey Key to look up in the file.
     * @param file File containing the authentication information.
     */
    public RCData(File file, String dbKey) throws Exception {

        if (file == null) {
            throw new IllegalArgumentException("RC file name not specified");
        }

        if (!file.canRead()) {
            throw new IOException("Please set up authentication file '" + file
                                  + "'");
        }

        // System.err.println("Using RC file '" + file + "'");
        StringTokenizer tokenizer = null;
        boolean         thisone   = false;
        String          s;
        String          keyword, value;
        int             linenum = 0;
        BufferedReader  br      = new BufferedReader(new FileReader(file));

        while ((s = br.readLine()) != null) {
            ++linenum;

            s = s.trim();

            if (s.length() == 0) {
                continue;
            }

            if (s.charAt(0) == '#') {
                continue;
            }

            tokenizer = new StringTokenizer(s);

            if (tokenizer.countTokens() == 1) {
                keyword = tokenizer.nextToken();
                value   = "";
            } else if (tokenizer.countTokens() > 1) {
                keyword = tokenizer.nextToken();
                value   = tokenizer.nextToken("").trim();
            } else {
                try {
                    br.close();
                } catch (IOException e) {}

                throw new Exception("Corrupt line " + linenum + " in '" + file
                                    + "':  " + s);
            }

            if (dbKey == null) {
                if (keyword.equals("urlid")) {
                    System.out.println(value);
                }

                continue;
            }

            if (keyword.equals("urlid")) {
                if (value.equals(dbKey)) {
                    if (id == null) {
                        id      = dbKey;
                        thisone = true;
                    } else {
                        try {
                            br.close();
                        } catch (IOException e) {}

                        throw new Exception("Key '" + dbKey + " redefined at"
                                            + " line " + linenum + " in '"
                                            + file);
                    }
                } else {
                    thisone = false;
                }

                continue;
            }

            if (thisone) {
                if (keyword.equals("url")) {
                    url = value;
                } else if (keyword.equals("username")) {
                    username = value;
                } else if (keyword.equals("driver")) {
                    driver = value;
                } else if (keyword.equals("charset")) {
                    charset = value;
                } else if (keyword.equals("truststore")) {
                    truststore = value;
                } else if (keyword.equals("password")) {
                    password = value;
                } else if (keyword.equals("libpath")) {
                    libpath = value;
                } else {
                    try {
                        br.close();
                    } catch (IOException e) {}

                    throw new Exception("Bad line " + linenum + " in '" + file
                                        + "':  " + s);
                }
            }
        }

        try {
            br.close();
        } catch (IOException e) {}

        if (dbKey == null) {
            return;
        }

        if (url == null || username == null || password == null) {
            throw new Exception("url or username or password not set "
                                + "for '" + dbKey + "' in file '" + file
                                + "'");
        }

        if (libpath != null) {
            throw new IllegalArgumentException(
                "Sorry, 'libpath' not supported yet");
        }
    }

    /**
     * Convenience constructor for backward compatibility.
     *
     * @see #RCData(String,String,String,String,String,String,String,String)
     */
    public RCData(String id, String url, String username, String password,
                  String driver, String charset,
                  String truststore) throws Exception {
        this(id, url, username, password, driver, charset, truststore, null);
    }

    /**
     * <p>Creates a new RCData object.
     *
     * <p>The parameters driver, charset, truststore, and libpath are optional.
     * Setting these parameters to <code>NULL will set them to their
     * default values.
     *
     * @param id The identifier for these connection settings
     * @param url The URL of the database to connect to
     * @param username The username to log in as
     * @param password The password of the username
     * @param driver The JDBC driver to use
     * @param charset The character set to use
     * @param truststore The trust store to use
     * @param libpath The JDBC library to add to CLASSPATH
     * @throws Exception if the a non-optional parameter is set to <code>NULL
     */
    public RCData(String id, String url, String username, String password,
                  String driver, String charset, String truststore,
                  String libpath) throws Exception {

        this.id         = id;
        this.url        = url;
        this.username   = username;
        this.password   = password;
        this.driver     = driver;
        this.charset    = charset;
        this.truststore = truststore;
        this.libpath    = libpath;

        if (libpath != null) {
            throw new IllegalArgumentException(
                "Sorry, 'libpath' not supported yet");
        }

        if (id == null || url == null || username == null
                || password == null) {
            throw new Exception("id, url, username, or password was not set");
        }
    }

    String id         = null;
    String url        = null;
    String username   = null;
    String password   = null;
    String driver     = null;
    String charset    = null;
    String truststore = null;
    String libpath    = null;

    /**
     * Gets a JDBC Connection using the data of this RCData object.
     *
     * @return New JDBC Connection
     */
    public Connection getConnection()
    throws ClassNotFoundException, InstantiationException,
           IllegalAccessException, SQLException, MalformedURLException {
        return getConnection(null, null, null);
    }

    /**
     * Gets a JDBC Connection using the data of this RCData object with
     * specified override elements
     *
     * @return New JDBC Connection
     */
    public Connection getConnection(String curDriver, String curCharset,
                                    String curTrustStore)
                                    throws ClassNotFoundException,
                                           InstantiationException,
                                           IllegalAccessException,
                                           MalformedURLException,
                                           SQLException {

        Properties sysProps = System.getProperties();

        if (curDriver == null) {

            // If explicit driver not specified
            curDriver = ((driver == null) ? DEFAULT_JDBC_DRIVER
                                          : driver);
        }

        if (curCharset == null && charset != null) {
            curCharset = charset;
        }

        if (curTrustStore == null && truststore != null) {
            curTrustStore = truststore;
        }

        if (curCharset == null) {
            sysProps.remove("sqlfile.charset");
        } else {
            sysProps.put("sqlfile.charset", curCharset);
        }

        if (curTrustStore == null) {
            sysProps.remove("javax.net.ssl.trustStore");
        } else {
            sysProps.put("javax.net.ssl.trustStore", curTrustStore);
        }

        String urlString = null;

        try {
            urlString = expandSysPropVars(url);
        } catch (IllegalArgumentException iae) {
            throw new MalformedURLException(iae.getMessage() + " for URL '"
                                            + url + "'");
        }

        String userString = null;

        try {
            userString = expandSysPropVars(username);
        } catch (IllegalArgumentException iae) {
            throw new MalformedURLException(iae.getMessage()
                                            + " for user name '" + username
                                            + "'");
        }

        String passwordString = null;

        try {
            passwordString = expandSysPropVars(password);
        } catch (IllegalArgumentException iae) {
            throw new MalformedURLException(iae.getMessage()
                                            + " for password");
        }

        // As described in the JDBC FAQ:
        // http://java.sun.com/products/jdbc/jdbc-frequent.html;
        // Why doesn't calling class.forName() load my JDBC driver?
        // There is a bug in the JDK 1.1.x that can cause Class.forName()
        // to fail. // new org.hsqldb.jdbcDriver();
        /* This does register the new driver instance, as can be shown by
         * DriverManager.getDrivers(), but somehow the registered driver
         * does not pick up the URL, and the result is always:
         *     No suitable driver
        DriverManager.registerDriver((Driver)
        ((libpath == null) ? Class.forName(curDriver)
                           : (new URLClassLoader(new URL[] {
                                  new URL("file:///" + libpath)
                              })).loadClass(curDriver)).newInstance());
        */
        Class.forName(curDriver);

        return DriverManager.getConnection(urlString, userString,
                                           passwordString);
    }

    static public String expandSysPropVars(String inString) {

        String outString = new String(inString);
        int    varOffset, varEnd;
        String varVal, varName;

        while (true) {

            // Recursive substitution for ${x} variables.
            varOffset = outString.indexOf("${");

            if (varOffset < 0) {
                break;
            }

            varEnd = outString.indexOf('}', varOffset + 2);

            if (varEnd < 0) {
                break;
            }

            varName = outString.substring(varOffset + 2, varEnd);

            if (varName.length() < 1) {
                throw new IllegalArgumentException("Bad variable setting");
            }

            varVal = System.getProperty(varName);

            if (varVal == null) {
                throw new IllegalArgumentException(
                    "No Java system property with name '" + varName + "'");
            }

            outString = outString.substring(0, varOffset) + varVal
                        + outString.substring(varEnd + 1);
        }

        return outString;
    }
}