List of all members.
Propertiesclass represents a persistent set of properties.
Properties can be saved to a stream or loaded from a stream. Each key and its corresponding value in the property list is a string.
A property list can contain another property list as its "defaults"; this second property list is searched if the property key is not found in the original property list.
Properties inherits from
putAll methods can be applied to a
Properties object. Their use is strongly discouraged as they allow the caller to insert entries whose keys or values are not
setProperty method should be used instead. If the
save method is called on a "compromised"
Properties object that contains a non-
String key or value, the call will fail.
When saving properties to a stream or loading them from a stream, the ISO 8859-1 character encoding is used. For characters that cannot be directly represented in this encoding, Unicode escapes are used; however, only a single 'u' character is allowed in an escape sequence. The native2ascii tool can be used to convert property files to and from other character encodings.
native2ascii tool for Windows
Public Member Functions
|Properties (const Ref< Properties > &defaults=0)|
|Creates an empty property list with the specified defaults. |
|virtual Ref< String >||setProperty (const Ref< String > &key, const Ref< String > &value)|
|Calls the |
|virtual Ref< String >||getProperty (const Ref< String > &key, const Ref< String > &defaultValue=0) const|
|Searches for the property with the specified key in this property list. |
|virtual Ref< Set >||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. |
|virtual void||load (const Ref< InputStream > &inStream)|
|Reads a property list (key and element pairs) from the input stream. |
|virtual void||store (const Ref< OutputStream > &out, const String &header=nilCString) const|
|Writes this property list (key and element pairs) in this |
|virtual String||toString () const|
|return the properties contents in string. |
Creates an empty property list with the specified defaults.
|virtual Ref<String> java::io::Properties::setProperty||(||const Ref< String > &||key,|
|const Ref< String > &||value|
Provided for parallelism with the
getProperty method. Enforces use of strings for property keys and values. The value returned is the result of the
Hashtable call to
|key||the key to be placed into this property list.|
|value||the value corresponding to |
nullif it did not have one.
|virtual Ref<String> java::io::Properties::getProperty||(||const Ref< String > &||key,|
|const Ref< 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
null if the property is not found.
|key||the property key.|
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.
Reads a property list (key and element pairs) from the input stream.
The stream is assumed to be using the ISO 8859-1 character encoding; that is each byte is one Latin1 character. Characters not in Latin1, and certain special characters, can be represented in keys and elements using 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 used for characters and strings are:
does not represent a backspace character.
</code>, before a non-valid escape character as an error; the backslash is silently dropped. For example, in a Java 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
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.
IllegalArgumentException is thrown if a malformed Unicode escape appears in the input.
This method processes input in terms of lines. A natural line of input is terminated either by a set of line terminator characters (
) or by the end of the file. A natural line may be either a blank line, a comment line, or hold some part of a key-element pair. The logical line holding all the data for a key-element pair may be spread out across several adjacent natural lines by escaping the line terminator sequence with a backslash character,
</code>. 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. If a logical line is continued over several natural lines, the continuation lines receive further processing, also described below. Lines are read from the input stream until end of file is reached.
A natural line that contains only white space characters is considered blank and is ignored. A comment line has an ASCII
'!' 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 method considers the characters space (
'\u0020'), tab (
'\u0009'), and form feed (
'\u000C') 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 the following line have no affect on the key or element values. The remainder of the discussion of key and element parsing 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 to see 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
escape sequences. Any white space after the key is skipped; if the first non-white space character after the key is
':', 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
Truth = Beauty
As another example, the following three lines specify a single property:
fruits apple, banana, pear, \
cantaloupe, watermelon, \
The key is
"fruits" and the associated element is:
"apple, banana, pear, cantaloupe, watermelon, kiwi, mango" Note that a space appears before each
</code> so that a space will appear after each comma in the final result; the
</code>, 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:
specifies that the key is
"cheeses" and the associated element is the empty string
inStream the input stream. IOException if an error occurred when reading from the input stream. IllegalArgumentException if the input stream contains a malformed Unicode escape sequence.
|virtual void java::io::Properties::store||(||const Ref< OutputStream > &||out,|
|const String &|| header = |
The stream is written using the ISO 8859-1 character encoding.
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 key and element strings is examined to see whether it should be rendered as an escape sequence. The ASCII characters
</code>, tab, form feed, newline, and carriage return are written as
, respectively. Characters less than
\u0020 and characters greater than
\u007E are written as
\uxxxx for the appropriate hexadecimal value xxxx. For the key, all space characters are written with a preceding
</code> character. For the element, leading space characters, but not embedded or trailing space characters, are written with a preceding
</code> character. The key and element characters
: 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.
out an output stream. header a description of the property list. IOException if writing this property list to the specified output stream throws an
ClassCastException if this
Properties object contains any keys or values that are not
out is null.
|virtual String java::io::Properties::toString||(||)|| const
return the properties contents in string.
Reimplemented from java::lang::Object.