configuration.java

velocity 的脚本语言的全部代码集合

                             * use this.
                             */
                            file = new File(value);
                        }
                        else
                        {   
                            /* 
                             * We have a relative path, and we have
                             * two possible forms here. If we have the
                             * "./" form then just strip that off first
                             * before continuing.
                             */
                            if (value.startsWith("." + fileSeparator))
                            {
                                value = value.substring(2);
                            }
                            
                            file = new File(basePath + value);
                        }
                        
                        if (file != null && file.exists() && file.canRead())
                        {
                            load ( new FileInputStream(file));
                        }
                    }
                    else
                    {
                        addProperty(key,value);
                        //setProperty(key,value);
                    }                       
                }
            }
        }
        catch (NullPointerException e)
        {
            /*
             * Should happen only when EOF is reached.
             */
            return;
        }
    }

    /**
     *  Gets a property from the configuration.
     *
     *  @param key property to retrieve
     *  @return value as object. Will return user value if exists,
     *          if not then default value if exists, otherwise null
     */
    public Object getProperty( String key)
    {
        /*
         *  first, try to get from the 'user value' store
         */
        Object o = this.get(key);

        if ( o == null)
        {
            /*
             *  if there isn't a value there, get it from the
             *  defaults if we have them
             */
            if (defaults != null)
            {
                o = defaults.get(key);
            }
        }

        return o;
    }
    
    /**
     * Add a property to the configuration. If it already
     * exists then the value stated here will be added
     * to the configuration entry. For example, if
     *
     * resource.loader = file
     *
     * is already present in the configuration and you
     *
     * addProperty("resource.loader", "classpath")
     *
     * Then you will end up with a Vector like the
     * following:
     *
     * ["file", "classpath"]
     *
     * @param String key
     * @param String value
     */
    //public void setProperty(String key, Object token)
    public void addProperty(String key, Object token)
    {

        // $$$ GMJ : remove after 1.1 release
        // for deprecation help
        deprecationCrutch.addProperty( key, token );

        Object o = this.get(key);

        /*
         *  $$$ GMJ
         *  FIXME : post 1.0 release, we need to not assume
         *  that a scalar is a String - it can be an Object
         *  so we should make a little vector-like class
         *  say, Foo that wraps (not extends Vector),
         *  so we can do things like
         *  if ( !( o instanceof Foo) )
         *  so we know it's our 'vector' container
         *
         *  This applies throughout
         */
        
        if (o instanceof String)
        {
            Vector v = new Vector(2);
            v.addElement(o);
            v.addElement(token);
            put(key, v);
        }
        else if (o instanceof Vector)
        {
            ((Vector) o).addElement(token);
        }
        else
        {
            /*
             * This is the first time that we have seen
             * request to place an object in the 
             * configuration with the key 'key'. So
             * we just want to place it directly into
             * the configuration ... but we are going to
             * make a special exception for String objects
             * that contain "," characters. We will take
             * CSV lists and turn the list into a vector of
             * Strings before placing it in the configuration.
             * This is a concession for Properties and the
             * like that cannot parse multiple same key
             * values.
             */
            if (token instanceof String &&
                ((String)token).indexOf(PropertiesTokenizer.DELIMITER) > 0)
            {
                PropertiesTokenizer tokenizer = 
                    new PropertiesTokenizer((String)token);
                    
                while (tokenizer.hasMoreTokens())
                {
                    String value = tokenizer.nextToken();
                    
                    /*
                     * we know this is a string, so make sure it
                     * just goes in rather than risking vectorization
                     * if it contains an escaped comma
                     */
                    addStringProperty(key,value);
                }
            }
            else
            {
                /*
                 * We want to keep track of the order the keys
                 * are parsed, or dynamically entered into
                 * the configuration. So when we see a key
                 * for the first time we will place it in
                 * an ArrayList so that if a client class needs
                 * to perform operations with configuration
                 * in a definite order it will be possible.
                 */

                /*
                 * safety check
                 */

                if( !containsKey( key ) )
                {
                    keysAsListed.add(key);
                }

                /*
                 * and the value
                 */
                put(key, token);
            }                
        }
    }


    /**
     *  Sets a string property w/o checking for commas - used
     *  internally when a property has been broken up into
     *  strings that could contain escaped commas to prevent
     *  the inadvertant vectorization.
     *
     *  Thanks to Leon Messerschmidt for this one.
     *
     */
    private  void addStringProperty(String key, String token)
    {
        Object o = this.get(key);

        /*
         *  $$$ GMJ
         *  FIXME : post 1.0 release, we need to not assume
         *  that a scalar is a String - it can be an Object
         *  so we should make a little vector-like class
         *  say, Foo that wraps (not extends Vector),
         *  so we can do things like
         *  if ( !( o instanceof Foo) )
         *  so we know it's our 'vector' container
         *
         *  This applies throughout
         */

        /*
         *  do the usual thing - if we have a value and 
         *  it's scalar, make a vector, otherwise add
         *  to the vector
         */
 
        if (o instanceof String)
        {
            Vector v = new Vector(2);
            v.addElement(o);
            v.addElement(token);
            put(key, v);
        }
        else if (o instanceof Vector)
        {
            ((Vector) o).addElement(token);
        }
        else
        {
            if( !containsKey( key ) )
            {
                keysAsListed.add(key);
            }

            put( key, token);
        }
    }

    /**
     * Set a property, this will replace any previously
     * set values. Set values is implicitly a call
     * to clearProperty(key), addProperty(key,value).
     *
     * @param String key
     * @param String value
     */
    public void setProperty(String key, Object value)
    {
        clearProperty(key);
        addProperty(key,value);
    }
    
    /**
     * Save the properties to the given outputstream.
     *
     * @param output An OutputStream.
     * @param header A String.
     * @exception IOException.
     */
    public synchronized void save(OutputStream output,
                                  String Header)
        throws IOException
    {
        if(output != null)
        {
            PrintWriter theWrtr = new PrintWriter(output);
            if(Header != null)
            {
                theWrtr.println(Header);
            }
            Enumeration theKeys = keys();
            while(theKeys.hasMoreElements())
            {
                String key = (String) theKeys.nextElement();
                Object value = get((Object) key);
                if(value != null)
                {
                    if(value instanceof String)
                    {
                        StringBuffer currentOutput = new StringBuffer();
                        currentOutput.append(key);
                        currentOutput.append("=");
                        currentOutput.append((String) value);
                        theWrtr.println(currentOutput.toString());
                    }
                    else if(value instanceof Vector)
                    {
                        Vector values = (Vector) value;
                        Enumeration valuesEnum = values.elements();
                        while(valuesEnum.hasMoreElements())
                        {
                            String currentElement = 
                                   (String) valuesEnum.nextElement();
                            StringBuffer currentOutput = new StringBuffer();
                            currentOutput.append(key);
                            currentOutput.append("=");
                            currentOutput.append(currentElement);
                            theWrtr.println(currentOutput.toString());
                        }
                    }
                }    
                theWrtr.println();
                theWrtr.flush();
            }    
        }        
    }

    /**
     * Combines an existing Hashtable with this Hashtable.
     *
     * Warning: It will overwrite previous entries without warning.
     *
     * @param Configuration
     */
    public void combine (Configuration c)
    {
        for (Iterator i = c.getKeys() ; i.hasNext() ;)
        {
            String key = (String) i.next();
            //clearProperty(key);
            setProperty( key, c.get(key) );
        }
    }
    
    /**
     * Clear a property in the configuration.
     *
     * @param String key to remove along with corresponding value.
     */
    public void clearProperty(String key)
    {
        // $$$ GMJ : remove after 1.1 release
        // for deprecation help
        deprecationCrutch.clearProperty( key  );

        if (containsKey(key))
        {
            /*
             * we also need to rebuild the keysAsListed or else
             * things get *very* confusing
             */

            for(int i = 0; i < keysAsListed.size(); i++)
            {
                if ( ( (String) keysAsListed.get(i)).equals( key ) )
                {
                    keysAsListed.remove(i);
                    break;
                }
            }

            remove(key);
        }            
    }

    /**
     * Get the list of the keys contained in the configuration
     * repository.
     *
     * @return An Iterator.
     */
    public Iterator getKeys()
    {
        return keysAsListed.iterator();
    }

    /**
     * Get the list of the keys contained in the configuration
     * repository that match the specified prefix.
     *
     * @param prefix The prefix to test against.
     * @return An Iterator of keys that match the prefix.
     */
    public Iterator getKeys(String prefix)
    {
        Iterator keys = getKeys();
        ArrayList matchingKeys = new ArrayList();
        
        while( keys.hasNext() )
        {
            Object key = keys.next();
            
            if( key instanceof String && ((String) key).startsWith(prefix) )
            {
                matchingKeys.add(key);
            }
        }
        return matchingKeys.iterator();
    }

    /**
     * Create a Configurations object that is a subset
     * of this one. Take into account duplicate keys
     * by using the setProperty() in Configuration.
     *
     * @param String prefix
     */
    public Configuration subset(String prefix)
    {
        Configuration c = new Configuration();
        Iterator keys = getKeys();
        boolean validSubset = false;
        
        while( keys.hasNext() )
        {
            Object key = keys.next();
            
            if( key instanceof String && ((String) key).startsWith(prefix) )
            {
                if (!validSubset)
                {
                    validSubset = true;
                }
                
                String newKey = null;
                
                /*
                 * Check to make sure that c.subset(prefix) doesn't
                 * blow up when there is only a single property
                 * with the key prefix. This is not a useful
                 * subset but it is a valid subset.
                 */
                if ( ((String)key).length() == prefix.length())
                {
                    newKey = prefix;
                }
                else
                {
                    newKey = ((String)key).substring(prefix.length() + 1);
                }                    
                
                /*
                 * Make sure to use the setProperty() method and not
                 * just put(). setProperty() takes care of catching
                 * all the keys in the order they appear in a
                 * properties files or the order they are set
                 * dynamically.
                 */

                c.setProperty(newKey, get(key));
            }
        }
        
        if (validSubset)
        {
            return c;
        }
        else
        {
            return null;
        }
    }

    /**
     * Display the configuration for debugging
     * purposes.
     */
    public void display()
    {
        Iterator i = getKeys();
        
        while (i.hasNext())
        {
            String key = (String) i.next();
            Object value = get(key);
            System.out.println(key + " => " + value);
        }
    }