com.jaxfront.core.util
Class LanguageEnhancedProperties

java.lang.Object
  java.util.AbstractMap<K,V>
      java.util.HashMap
          com.jaxfront.core.util.LanguageEnhancedProperties

All Implemented Interfaces:

java.io.Serializable, java.lang.Cloneable, java.util.Map

Direct Known Subclasses:

NLS

public class LanguageEnhancedProperties
extends java.util.HashMap

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.

Since:

JDK1.0

See Also:

native2ascii tool for Solaris, native2ascii tool for Windows, Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from class java.util.AbstractMap

java.util.AbstractMap.SimpleEntry<K,V>, java.util.AbstractMap.SimpleImmutableEntry<K,V>

Constructor Summary

LanguageEnhancedProperties()
Creates an empty property list with no default values.

LanguageEnhancedProperties(int size)

LanguageEnhancedProperties(int size, float loadFactor)

LanguageEnhancedProperties(LanguageEnhancedProperties defaults)
Creates an empty property list with the specified defaults.

Method Summary

java.lang.String	getProperty(java.lang.String key)
void	load(java.io.InputStream inStream) Reads a property list (key and element pairs) from the input stream.
void	load(java.io.Reader input)
java.lang.Object	setProperty(java.lang.String key, java.lang.String value)
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.HashMap

clear, clone, containsKey, containsValue, entrySet, get, isEmpty, keySet, put, putAll, remove, size, values

Methods inherited from class java.util.AbstractMap

equals, hashCode, toString

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.util.Map

equals, hashCode

Constructor Detail

LanguageEnhancedProperties

public LanguageEnhancedProperties()

Creates an empty property list with no default values.

LanguageEnhancedProperties

public LanguageEnhancedProperties(int size)

LanguageEnhancedProperties

public LanguageEnhancedProperties(int size,
                                  float loadFactor)

LanguageEnhancedProperties

public LanguageEnhancedProperties(LanguageEnhancedProperties defaults)

Creates an empty property list with the specified defaults.

Parameters:

defaults - the defaults.

Method Detail

getProperty

public java.lang.String getProperty(java.lang.String key)

load

public void load(java.io.InputStream inStream)
          throws java.io.IOException

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:

• Octal escapes are not recognized.
• The character sequence \b 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 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'.
• 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.

An 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                  :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 "".

Parameters:

inStream - the input stream.

Throws:

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.

load

public void load(java.io.Reader input)
          throws java.io.IOException

Throws:

java.io.IOException

setProperty

public java.lang.Object setProperty(java.lang.String key,
                                    java.lang.String value)

store

public void store(java.io.OutputStream out,
                  java.lang.String header)
           throws java.io.IOException

Calls the store(OutputStream out, String header) method with the JAXFront.getDefaultFileEncoding!

Parameters:

out - an output stream.

header - a description of the property list.

Throws:

java.lang.ClassCastException - if this Properties object contains any keys or values that are not Strings.

java.io.IOException

store

public void store(java.io.Writer out,
                  java.lang.String header)
           throws java.io.IOException

Calls the store(Writer out, String header) method without any encodings!

Parameters:

out - an output stream.

header - a description of the property list.

Throws:

java.lang.ClassCastException - if this Properties object contains any keys or values that are not Strings.

java.io.IOException