/**************************************************************
 *                              Basic Algorithms, Spring, 2001, Professor Yap
 * Digraph class:
 *    based on the Graph Integer
 *    are integers from 1 to n.  It depends
 *    on another simple Edge interface.
 *
 **************************************************************/
  

LOADING PROPERTIES:


public void load(InputStream inStream)
          throws IOException

    Reads a property list (key and element pairs) from the input stream. 

    Every property occupies one line of the input stream. Each line is terminated by a line terminator (\n or \r or
    \r\n). Lines from the input stream are processed until end of file is reached on the input stream. 

    A line that contains only whitespace or whose first non-whitespace character is an ASCII # or ! is ignored
    (thus, # or ! indicate comment lines). 

    Every line other than a blank line or a comment line describes one property to be added to the table (except
    that if a line ends with \, then the following line, if it exists, is treated as a continuation line, as described below).
    The key consists of all the characters in the line starting with the first non-whitespace character and up to, but
    not including, the first ASCII =, :, or whitespace character. All of the key termination characters may be
    included in the key by preceding them with a \. Any whitespace after the key is skipped; if the first
    non-whitespace character after the key is = or :, then it is ignored and any whitespace characters after it are
    also skipped. All remaining characters on the line become part of the associated element string. Within the
    element string, the ASCII escape sequences \t, \n, \r, \\, \", \', \ (a backslash and a space), and \\uxxxx
    are recognized and converted to single characters. Moreover, if the last character on the line is \, then the next
    line is treated as a continuation of the current line; the \ and line terminator are simply discarded, and any
    leading whitespace characters on the continuation line are also discarded and are not part of the element string.

    As an example, each of the following four lines specifies the key "Truth" and the associated element value
    "Beauty": 

     Truth = Beauty
            Truth:Beauty
     Truth                  :Beauty
     

    As another example, the following three lines specify a single property: 

     fruits                         apple, banana, pear, \
                                      cantaloupe, watermelon, \
                                      kiwi, mango
     

    The key is "fruits" and the associated element is: 

    "apple, banana, pear, cantaloupe, watermelon,kiwi, mango"

    Note that a space appears before each \ so that a space will appear after each comma in the final result; the \,
    line terminator, and leading whitespace on the continuation line are merely discarded and are not replaced by
    one or more other characters. 

    As a third example, the line: 

    cheeses
     

    specifies that the key is "cheeses" and the associated element is the empty string.

    Parameters:
        in - the input stream.
    Throws:
        IOException - if an error occurred when reading from the input stream.

c void store(OutputStream out,
                  String header)
           throws IOException

    Writes this property list (key and element pairs) in this Properties table to the output stream in a format
    suitable for loading into a Properties table using the load method. 

    Properties from the defaults table of this Properties table (if any) are not written out by this method. 

    If the header argument is not null, then an ASCII # character, the header string, and a line separator are first
    written to the output stream. Thus, the header can serve as an identifying comment. 

    Next, a comment line is always written, consisting of an ASCII # character, the current date and time (as if
    produced by the toString method of Date for the current time), and a line separator as generated by the
    Writer. 

    Then every entry in this Properties table is written out, one per line. For each entry the key string is written,
    then an ASCII =, then the associated element string. Each character of the element string is examined to see
    whether it should be rendered as an escape sequence. The ASCII characters \, tab, newline, and carriage return
    are written as \\, \t, \n, and \r, respectively. Characters less than and characters greater than ~ are written
    as \\uxxxx for the appropriate hexadecimal value xxxx. Space characters, but not embedded or trailing space
    characters, are written with a preceding \. The key and value characters #, !, =, and : are written with a
    preceding slash to ensure that they are properly loaded. 

    After the entries have been written, the output stream is flushed. The output stream remains open after this
    method returns.
    Parameters:
        out - an output stream.
        header - a description of the property list.
    Throws:
        ClassCastException - if this Properties object contains any keys or values that are not Strings.



getProperty

public String getProperty(String key)

    Searches for the property with the specified key in this property list. If the key is not found in this property list,
    the default property list, and its defaults, recursively, are then checked. The method returns null if the
    property is not found.
    Parameters:
        key - the property key.
    Returns:
        the value in this property list with the specified key value.
    See Also: 
        defaults



getProperty

public String getProperty(String key,
                          String defaultValue)

    Searches for the property with the specified key in this property list. If the key is not found in this property list,
    the default property list, and its defaults, recursively, are then checked. The method returns the default value
    argument if the property is not found.
    Parameters:
        key - the hashtable key.
        defaultValue - a default value.
    Returns:
        the value in this property list with the specified key value.
    See Also: 
        defaults



propertyNames

public Enumeration propertyNames()

    Returns an enumeration of all the keys in this property list, including the keys in the default property list.
    Returns:
        an enumeration of all the keys in this property list, including the keys in the default property list.
    See Also: 
        Enumeration, defaults



list

public void list(PrintStream out)

    Prints this property list out to the specified output stream. This method is useful for debugging.
    Parameters:
        out - an output stream.



list

public void list(PrintWriter out)

    Prints this property list out to the specified output stream. This method is useful for debugging.
    Parameters:
        out - an output stream.
    Since: 
        JDK1.1