Java-like properties class for mapping string names to string values. More...

#include <src/main/decaf/util/Properties.h>

Public Member Functions
	Properties ()
	Properties (const Properties &src)
virtual	~Properties ()
Properties &	operator= (const Properties &src)
	Assignment Operator.
bool	isEmpty () const
	Returns true if the properties object is empty.
int	size () const
const char *	getProperty (const std::string &name) const
	Looks up the value for the given property.
std::string	getProperty (const std::string &name, const std::string &defaultValue) const
	Looks up the value for the given property.
std::string	setProperty (const std::string &name, const std::string &value)
	Sets the value for a given property.
bool	hasProperty (const std::string &name) const
	Check to see if the Property exists in the set.
std::string	remove (const std::string &name)
	Removes the property with the given name.
std::vector< std::string >	propertyNames () const
	Returns an enumeration of all the keys in this property list, including distinct keys in the default property list if a key of the same name has not already been found from the main properties list.
std::vector< std::pair < std::string, std::string > >	toArray () const
	Method that serializes the contents of the property map to an array.
void	copy (const Properties &source)
	Copies the contents of the given properties object to this one, if the given Properties instance in NULL then this List is not modified.
Properties *	clone () const
	Clones this object.
void	clear ()
	Clears all properties from the map.
bool	equals (const Properties &source) const
	Test whether two Properties objects are equivalent.
std::string	toString () const
	Formats the contents of the Properties Object into a string that can be logged, etc.
void	load (decaf::io::InputStream *stream)
	Reads a property list (key and element pairs) from the input byte stream.
void	load (decaf::io::Reader *reader)
	Reads a property list (key and element pairs) from the input character stream in a simple line-oriented format.
void	store (decaf::io::OutputStream *out, const std::string &comment)
	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(InputStream) method.
void	store (decaf::io::Writer *writer, const std::string &comments)
	Writes this property list (key and element pairs) in this Properties table to the output character stream in a format that can be read by the load(Reader) method.

Protected Attributes
decaf::lang::Pointer< Properties >	defaults
	Default list used to answer for any keys not found in the properties list, can be filled in by another implementation of this class.

Detailed Description

Java-like properties class for mapping string names to string values.

The Properties list contains a key value pair of properties that can be loaded and stored to a stream. Each Properties instance can contain an internal Properties list that contains default values for keys not found in the Properties List.

The Properties list if a Thread Safe class, it can be shared amongst objects in multiple threads without the need for additional synchronization.

Since: 1.0

Constructor & Destructor Documentation

decaf::util::Properties::Properties ( )

decaf::util::Properties::Properties ( const Properties & src )

virtual decaf::util::Properties::~Properties ( )

virtual

Member Function Documentation

void decaf::util::Properties::clear ( )

Clears all properties from the map.

Properties* decaf::util::Properties::clone ( ) const

Clones this object.

Returns: a replica of this object.

void decaf::util::Properties::copy ( const Properties & source )

Copies the contents of the given properties object to this one, if the given Properties instance in NULL then this List is not modified.

Parameters

source The source properties object.

bool decaf::util::Properties::equals ( const Properties & source ) const

Test whether two Properties objects are equivalent.

Two Properties Objects are considered equivalent when they each contain the same number of elements and each key / value pair contained within the two are equal.

This comparison does not check the contents of the Defaults instance.

Parameters

source The Properties object to compare this instance to.

Returns: true if the contents of the two Properties objects are the same.

const char* decaf::util::Properties::getProperty ( const std::string & name ) const

Looks up the value for the given property.

Parameters

name	The name of the property to be looked up.

Returns: the value of the property with the given name, if it exists. If it does not exist, returns NULL.

std::string decaf::util::Properties::getProperty	(	const std::string &	name,
		const std::string &	defaultValue
	)		const

Looks up the value for the given property.

Parameters

name	The name of the property to be looked up.
defaultValue	The value to be returned if the given property does not exist.

Returns: The value of the property specified by name, if it exists, otherwise the defaultValue.

bool decaf::util::Properties::hasProperty ( const std::string & name ) const

Check to see if the Property exists in the set.

Parameters

name	The property name to check for in this properties set.

Returns: true if property exists, false otherwise.

bool decaf::util::Properties::isEmpty ( ) const

Returns true if the properties object is empty.

Returns: true if empty

void decaf::util::Properties::load ( decaf::io::InputStream * stream )

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

The input stream is in a simple line-oriented format as specified in load(Reader) and is assumed to use the ISO 8859-1 character encoding.

This method does not close the stream upon its return.

Parameters

stream The stream to read the properties data from.

Exceptions

IOException	if there is an error while reading from the stream.
IllegalArgumentException	if malformed data is found while reading the properties.
NullPointerException	if the passed stream is Null.

void decaf::util::Properties::load ( decaf::io::Reader * reader )

Reads a property list (key and element pairs) from the input character stream in a simple line-oriented format.

Properties are processed in terms of lines. There are two kinds of line, natural lines and logical lines. A natural line is defined as a line of characters that is terminated either by a set of line terminator characters (
or or
) or by the end of the stream. A natural line may be either a blank line, a comment line, or hold all or some of a key-element pair. A logical line holds all the data of a key-element pair, which may be spread out across several adjacent natural lines by escaping the line terminator sequence with a backslash character . Note that a comment line cannot be extended in this manner; every natural line that is a comment must have its own comment indicator, as described below. Lines are read from input until the end of the stream is reached.

A natural line that contains only white space characters is considered blank and is ignored. A comment line has an ASCII '#' or '!' as its first non-white space character; comment lines are also ignored and do not encode key-element information. In addition to line terminators, this format considers the characters space (' '), tab (''), and form feed ('') to be white space.

If a logical line is spread across several natural lines, the backslash escaping the line terminator sequence, the line terminator sequence, and any white space at the start of the following line have no affect on the key or element values. The remainder of the discussion of key and element parsing (when loading) will assume all the characters constituting the key and element appear on a single natural line after line continuation characters have been removed. Note that it is not sufficient to only examine the character preceding a line terminator sequence to decide if the line terminator is escaped; there must be an odd number of contiguous backslashes for the line terminator to be escaped. Since the input is processed from left to right, a non-zero even number of 2n contiguous backslashes before a line terminator (or elsewhere) encodes n backslashes after escape processing.

The key contains all of the characters in the line starting with the first non-white space character and up to, but not including, the first unescaped '=', ':', or white space character other than a line terminator. All of these key termination characters may be included in the key by escaping them with a preceding backslash character; for example,

\:\=

would be the two-character key ":=". Line terminator characters can be included using and
escape sequences. Any white space after the key is skipped; if the first non-white space character after the key is '=' or ':', then it is ignored and any white space characters after it are also skipped. All remaining characters on the line become part of the associated element string; if there are no remaining characters, the element is the empty string "". Once the raw character sequences constituting the key and element are identified, escape processing is performed as described above.

As an example, each of the following three 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 white space 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 "".

Characters in keys and elements can be represented in escape sequences similar to those used for character and string literals (see §3.3 and §3.10.6 of the Java Language Specification). The differences from the character escape sequences and Unicode escapes used for characters and strings are:

Octal escapes are not recognized.
The character sequence does not represent a backspace character.
The method does not treat a backslash character, \, before a non-valid escape character as an error; the backslash is silently dropped. For example, in a C++ string the sequence "\z" would cause a compile time error. In contrast, this method silently drops the backslash. Therefore, this method treats the two character sequence "\b" as equivalent to the single character 'b'.
Escapes are not necessary for single and double quotes; however, by the rule above, single and double quote characters preceded by a backslash still yield single and double quote characters, respectively.

This method does not close the Reader upon its return.

Parameters

reader The Reader that provides an character stream as input.

Exceptions

IOException	if there is an error while reading from the stream.
IllegalArgumentException	if malformed data is found while reading the properties.
NullPointerException	if the passed stream is Null.

Properties& decaf::util::Properties::operator= ( const Properties & src )

Assignment Operator.

Parameters

src	The Properties list to copy to this List.

Returns: a reference to this List for use in chaining.

std::vector<std::string> decaf::util::Properties::propertyNames ( ) const

Returns an enumeration of all the keys in this property list, including distinct keys in the default property list if a key of the same name has not already been found from the main properties list.

Returns: a set of keys in this property list where the key and its corresponding value are strings, including the keys in the default property list.

std::string decaf::util::Properties::remove ( const std::string & name )

Removes the property with the given name.

Parameters

name	The name of the property to remove.

Returns: the previous value of the property if set, or empty string.

std::string decaf::util::Properties::setProperty	(	const std::string &	name,
		const std::string &	value
	)

Sets the value for a given property.

If the property already exists, overwrites the value.

Parameters

name	The name of the value to be written.
value	The value to be written.

Returns: the old value of the property or empty string if not set.

int decaf::util::Properties::size ( ) const

Returns: The number of Properties in this Properties Object.

void decaf::util::Properties::store	(	decaf::io::OutputStream *	out,
		const std::string &	comment
	)

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(InputStream) method.

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

This method outputs the comments, properties keys and values in the same format as specified in store(Writer), with the following differences:

The stream is written using the ISO 8859-1 character encoding.
Characters not in Latin-1 in the comments are written as for their appropriate unicode hexadecimal value xxxx.
Characters less than and characters greater than in property keys or values are written as for the appropriate hexadecimal value xxxx.

After the entries have been written, the output stream is flushed. The output stream remains open after this method returns.

Parameters

out	The OutputStream instance to write the properties to.
comment	A description of these properties that is written to the output stream.

Exceptions

IOException	if there is an error while writing from the stream.
NullPointerException	if the passed stream is Null.

void decaf::util::Properties::store	(	decaf::io::Writer *	writer,
		const std::string &	comments
	)

Writes this property list (key and element pairs) in this Properties table to the output character stream in a format that can be read by the load(Reader) method.

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

If the comments argument is not empty, then an ASCII # character, the comments string, and a line separator are first written to the output stream. Thus, the comments can serve as an identifying comment. Any one of a line feed ('
'), a carriage return (''), or a carriage return followed immediately by a line feed in comments is replaced by a line separator generated by the Writer and if the next character in comments is not character # or character ! then an ASCII # is written out after that line separator.

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. For the key, all space characters are written with a preceding \ character. For the element, leading space characters, but not embedded or trailing space characters, are written with a preceding \ character. The key and element characters #, !, =, and : are written with a preceding backslash 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

writer	The Writer instance to use to output the properties.
comments	A description of these properties that is written before writing the properties.

Exceptions

IOException	if there is an error while writing from the stream.
NullPointerException	if the passed stream is Null.

std::vector< std::pair< std::string, std::string > > decaf::util::Properties::toArray ( ) const

Method that serializes the contents of the property map to an array.

Returns: list of pairs where the first is the name and the second is the value.

std::string decaf::util::Properties::toString ( ) const

Formats the contents of the Properties Object into a string that can be logged, etc.

Returns: string value of this object.

Field Documentation

decaf::lang::Pointer<Properties> decaf::util::Properties::defaults

protected

Default list used to answer for any keys not found in the properties list, can be filled in by another implementation of this class.

The documentation for this class was generated from the following file:

src/main/decaf/util/Properties.h

Public Member Functions

Protected Attributes

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation

Field Documentation