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java.lang.Objectjava.util.Dictionary<K,V>
java.util.Hashtable<java.lang.Object,java.lang.Object>
java.util.Properties
com.jaxfront.core.util.LanguageEnhancedProperties
public class LanguageEnhancedProperties
The Properties
class represents a persistent set of
properties. The 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.
Because Properties
inherits from Hashtable
, the
put
and 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
Strings
. The setProperty
method should be used
instead. If the store
or 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.
Constructor Summary | |
---|---|
LanguageEnhancedProperties()
Creates an empty property list with no default values. |
|
LanguageEnhancedProperties(LanguageEnhancedProperties defaults)
Creates an empty property list with the specified defaults. |
Method Summary | |
---|---|
void |
load(java.io.InputStream inStream)
Reads a property list (key and element pairs) from the input stream. |
void |
load(java.io.Reader input)
|
void |
save(java.io.OutputStream out,
java.lang.String header)
Deprecated. This method does not throw an IOException if an I/O error occurs while saving the property list. As of the Java 2 platform v1.2, the preferred way to save a properties list is via the store(OutputStream out,
String header) method. |
void |
store(java.io.OutputStream out,
java.lang.String header)
Calls the store(OutputStream out, String header) method
with the JAXFront.getDefaultFileEncoding! |
void |
store(java.io.Writer out,
java.lang.String header)
Calls the store(Writer out, String header) method
without any encodings! |
Methods inherited from class java.util.Properties |
---|
getProperty, getProperty, list, list, loadFromXML, propertyNames, setProperty, storeToXML, storeToXML |
Methods inherited from class java.util.Hashtable |
---|
clear, clone, contains, containsKey, containsValue, elements, entrySet, equals, get, hashCode, isEmpty, keys, keySet, put, putAll, remove, size, toString, values |
Methods inherited from class java.lang.Object |
---|
getClass, notify, notifyAll, wait, wait, wait |
Constructor Detail |
---|
public LanguageEnhancedProperties()
public LanguageEnhancedProperties(LanguageEnhancedProperties defaults)
defaults
- the defaults.Method Detail |
---|
public void load(java.io.InputStream inStream) throws java.io.IOException
\b
does not
represent a backspace character.
\
, 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 'b'
.
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 (\n
or \r
or
\r\n
) 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, \
. 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
'#'
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 method considers the characters space
(' '
, '\u0020'
), tab
('\t'
, '\u0009'
), and form feed
('\f'
, '\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 \r
and
\n
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 :BeautyAs another example, the following three lines specify a single property:
fruits apple, banana, pear, \ cantaloupe, watermelon, \ kiwi, mangoThe 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:
cheesesspecifies that the key is
"cheeses"
and the associated
element is the empty string ""
.
load
in class java.util.Properties
inStream
- the input stream.
java.io.IOException
- if an error occurred when reading from the
input stream.
java.lang.IllegalArgumentException
- if the input stream contains a
malformed Unicode escape sequence.public void load(java.io.Reader input) throws java.io.IOException
java.io.IOException
public void save(java.io.OutputStream out, java.lang.String header)
store(OutputStream out,
String header)
method.
store(OutputStream out, String header)
method
and suppresses IOExceptions that were thrown.
Uses the JAXFront.getDefaultFileEncoding!
save
in class java.util.Properties
out
- an output stream.header
- a description of the property list.
java.lang.ClassCastException
- if this Properties
object
contains any keys or values that are not Strings
.public void store(java.io.OutputStream out, java.lang.String header) throws java.io.IOException
store(OutputStream out, String header)
method
with the JAXFront.getDefaultFileEncoding!
store
in class java.util.Properties
out
- an output stream.header
- a description of the property list.
java.lang.ClassCastException
- if this Properties
object
contains any keys or values that are not Strings
.
java.io.IOException
public void store(java.io.Writer out, java.lang.String header) throws java.io.IOException
store(Writer out, String header)
method
without any encodings!
out
- an output stream.header
- a description of the property list.
java.lang.ClassCastException
- if this Properties
object
contains any keys or values that are not Strings
.
java.io.IOException
|
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