enhproperties.java

Java的面向对象数据库系统的源代码

// You can redistribute this software and/or modify it under the terms of
// the Infozone Software License version 2 published by the Infozone Group
// (http://www.infozone-group.org).
//
// Copyright (C) @year@ by The Infozone Group. All rights reserved.
//
// $Id: EnhProperties.java,v 1.2 2003/03/12 12:30:26 per_nyfelt Exp $

package org.infozone.tools;

import java.io.*;
import java.util.*;


/**
EnhProperties has methods to store/update the value of a property to handle
such dynamic properties.
<p>
In addition the Properties EnhProperties can hold not only String properties
but most of other primitive types and raw objects. Non-string properties are
internaly stored as Strings.
<p>
Setup extends java.util.Properties. So the system properties can be used as
defaults.

@author <a href="http://www.softwarebuero.de/">SMB</a>
@version $Revision: 1.2 $Date: 2003/03/12 12:30:26 $
*/
public class EnhProperties extends Properties {

    /**
    An Observable object that is responsible for this properties. Directly
    extending the class is not possible because it already extends Properties.
    */
    protected EnhObservable	observable;


    public EnhProperties() {
        observable = new EnhObservable();
        }


    public EnhProperties (Properties _defaults) {
        super (_defaults);
        observable = new EnhObservable();
        }


    public void addObserver (Observer _observer) {
        observable.addObserver (_observer);
        }


    public void removeObserver (Observer _observer) {
        observable.deleteObserver (_observer);
        }


    public void notifyObservers() {
        observable.notifyObservers (this);
        }


    public boolean hasChanged() {
        return observable.hasChanged();
        }


    /**
    @param properties
    @param keyPrefix
    */
    public void addProperties (Properties properties, String keyPrefix) {
        observable.setChanged();
        for (Enumeration e=properties.keys(); e.hasMoreElements();) {
            String key = (String)e.nextElement();
            if (key.startsWith (keyPrefix)) {
               // System.out.println (key);
                String val = properties.getProperty (key, "");
                setStringProperty (key, val);
                }
            }
        }


    /**
    @param _val
    @param _key
    */
    public synchronized void setStringProperty (String _key, String _val) {
        observable.setChanged();
        super.put (_key, _val);
        }


    /**
    @param _key
    @param _default The default value to use if no property is found.
    */
    public String stringProperty (String _key, String _default) {
        return super.getProperty (_key, _default);
        }


    /**
    @param _key
    @param _default The default value to use if no property is found.
    */
    public String[] stringsProperty (String _key, String _default) {
        String propList = stringProperty( _key, _default );
        Vector v = new Vector();

        StringTokenizer st = new StringTokenizer( propList, " \t,", false );
        while (st.hasMoreTokens()) {
            String token = st.nextToken();
           // System.out.println ("'" + token + "'");
            v.addElement( token );
        }

        String[] result = new String[v.size()];
        v.copyInto( result );
        return result;
        }


    /**
    @param _val
    @param _key
    */
    public void setProperty (String _key, Object _val) {
        observable.setChanged();
        try {
            ByteArrayOutputStream buf = new ByteArrayOutputStream (1024);
            ObjectOutputStream out = new ObjectOutputStream (buf);
            out.writeObject (_val);
            out.close();

            MimeBase64Encoder encoder = new MimeBase64Encoder();
            encoder.translate (buf.toByteArray());

            setStringProperty (_key, new String (encoder.getCharArray()));
            }
        catch (Exception e) {
            throw new RuntimeException (e.getMessage());
            }
        }


    /**
    @param _key
    @param _default The default value to use if no property is found.
    */
    public Object property (String _key, Object _default) {
        try {
            String result = stringProperty (_key, (String)_default);
            if (result != null) {
                MimeBase64Decoder decoder = new MimeBase64Decoder();
                decoder.translate (result.toCharArray());

                ObjectInputStream in = new ResolvingObjectInputStream (new ByteArrayInputStream (decoder.getByteArray()));
                return in.readObject();
                }
            else
                return null;
            }
        catch (Exception e) {
            throw new RuntimeException (e.getMessage());
            }
        }


    /**
    @param _val
    @param _key
    */
    public void setIntProperty (String _key, int _val) {
        setStringProperty (_key, String.valueOf (_val));
        }


    /**
    @param _key
    @param _default The default value to use if no property is found.
    */
    public int intProperty (String _key, int _default) {
        String result = stringProperty (_key, String.valueOf (_default));
        return Integer.parseInt (result);
        }


    /**
    @param _key
    @param _default The default value to use if no property is found.
    */
    public long longProperty (String _key, long _default) {
        String result = stringProperty (_key, String.valueOf (_default));
        return Long.valueOf (result).longValue();
        }


    /**
    @param _key
    @param _default The default value to use if no property is found.
    */
    public boolean booleanProperty (String _key, boolean _default) {
        String result = stringProperty (_key, String.valueOf (_default));
        return Boolean.valueOf (result).booleanValue();
        }


    /**
    @param _val
    @param _key
    */
    public void setLongProperty (String _key, long _val) {
        setStringProperty (_key, String.valueOf (_val));
        }


    /**
    @param _val
    @param _key
    */
    public void setBooleanProperty (String _key, boolean _val) {
        setStringProperty (_key, String.valueOf (_val));
        }


    /**
    @param
    @param keyPrefix
    @param printPrefix
    */
//    public void print (PrintStream out, String keyPrefix, String printPrefix) {
//        DxTreeSet sortedProps = new DxTreeSet (new DxStringComparator());
//        for (Enumeration e=propertyNames(); e.hasMoreElements();) {
//            String key = (String)e.nextElement();
//            String val = stringProperty (key, "(not set)");
//            //avoid printing "object" properties
//            //currently not supported!!!
//            if (key.startsWith (keyPrefix) && !val.startsWith("[object]")) {
//                sortedProps.add (printPrefix + key + " = " + val);
//                }
//            }
//        for (DxIterator it=sortedProps.iterator(); it.next()!=null;)
//            out.println (it.object().toString());
//        }

    }


/**
@author <a href="http://www.softwarebuero.de/">SMB</a>
@version $Revision: 1.2 $Date: 2003/03/12 12:30:26 $
*/
class EnhObservable extends Observable {

   public EnhObservable() {
       super();
       }


   public void setChanged() {
       super.setChanged();
       }

   }