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Oracle Fusion Middleware Java API Reference for Oracle Extension SDK 11g Release 2 (11.1.2.2.0) E17493-03 |
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java.lang.Object
oracle.javatools.parser.AbstractLexer
oracle.javatools.parser.properties.PropertiesLexer
public class PropertiesLexer
The PropertiesLexer
is an implementation of the Lexer
interface for a *.properties or *.rts file. Although *.rts are somewhat compatible with *.properties files, the lexing rules provided by this module is tailored to *.properties files. The format of an *.rts file is described by the following excerpt from the RTS JavaDoc documentation:
Specification of the RTS source file format: An RTS source file is a text file description of a set of string resources. Each such resource consists of an identifying key and its associated string.
The format of an RTS source file has been designed for compatibility with java ".properties" files" so that a java ".properties" file may serve as a valid RTS source file. RTS source files differ from ".properties" files by allowing keys to be any Unicode string and by providing rules for associating comments with resources.
Each line in a source file may represent a resource, a comment or be blank. Any line consisting only of whitespace is considered blank. Any line in which the first non-whitespace character is a # or a ! is a comment. All other lines represent string resources.
A line representing a string resource consists of a key/value pair. The key is represented by the text beginning with the first non-whitespace character continuing up to (but not including) the the next non-escaped whitespace, =, or : character. To represent a key that contains whitespace, =, or :'s, one may escape any such character by preceding it with a \. The precise escape mechanism is as follows: \ followed by any character is treated as the character itself (with no syntactic meaning attached) except in cases where that character is a:
The string value consists of the text from the first non-whitespace character following the key up until end of the line. As with java ".properties" files, if the first non-whitespace character is a : or an =, then the string resource begins with the first non-whitespace character following the : or =. The escape character, \, may be used to represent a string beginning with whitespace. If the line representing a string resource ends with an non-escaped \, the resource definition is continued onto the next line, starting with the first non-escaped whitespace character.
Comments in an RTS source file may be associated with resources so that a comment can contain information about a particular entry. A resource is associated with the comment that immediately preceeds it. There may be blank lines between the comment and the resource -- however, blank line lines between comment lines cause the separated lines to be treated as different comments -- so that only the last comment is associated with a subsequent resource. A line containg only a # or ! is not treated as a blank.
In the following example, key1 is associated with comment lines 1-3 while key 2 is associated with comment lines 5 and 6 (but not 4).
# Example RTS source file # comment_line_1 # comment_line_2 # comment_line_3 key1 = string_1 # comment_line_4 # comment_line_5 # comment_line_6 key2 = string_2
There are a couple quirks of the *.properties files (at least based on the implementation of PropertyResourceBundle
) which are followed here:
Because of these quirks, the lexing for a *.rts file may not completely follow the formats of an *.rts file (which may be more relaxed.)
This lexer does not assist in the deciphering of the contents of the actual property definition. Use the DefinitionLexer for this purpose.
This lexer requires a normalized buffer with only '\n' EOL characters.
Lexer
, PropertiesTokens
Nested Class Summary |
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Nested classes/interfaces inherited from class oracle.javatools.parser.AbstractLexer |
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AbstractLexer.DefaultLexerToken |
Field Summary |
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Fields inherited from class oracle.javatools.parser.AbstractLexer |
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currentPos, textBuffer |
Fields inherited from interface oracle.javatools.parser.properties.PropertiesTokens |
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TK_COMMENT, TK_DEFINITION |
Fields inherited from interface oracle.javatools.parser.Lexer |
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TK_EOF, TK_NOT_FOUND |
Constructor Summary | |
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PropertiesLexer() Constructs a default PropertiesLexer with a starting position of 0. |
Method Summary | |
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void |
backup() Unlexes the last found token. |
int |
lex(LexerToken lexedToken) Scans the text buffer at the current position and returns the token that was found. |
void |
setPosition(int offset) Sets the current lex (read) position to the given offset in the buffer. |
void |
setSkipComments(boolean skipComments) Sets whether the PropertiesLexer should generate tokens for comments in the *.properties and *.rts files. |
static java.lang.String |
tokenToString(int token) Utility routine to map the token to a string representation of the token (for debug printing.) |
static java.lang.String |
tokenToText(int token) Utility routine to map the token to the original text (if retrievable) of the token (for debug printing.) |
Methods inherited from class oracle.javatools.parser.AbstractLexer |
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createLexerToken, getTextBuffer, setTextBuffer |
Methods inherited from class java.lang.Object |
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clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
Constructor Detail |
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public PropertiesLexer()
PropertiesLexer
with a starting position of 0. Clients must call setTextBuffer()
to initialize the text buffer used for the Lexer. To start lexing from an offset other than 0, call setPosition()
.Method Detail |
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public void setSkipComments(boolean skipComments)
PropertiesLexer
should generate tokens for comments in the *.properties and *.rts files.skipComments
- true to ignore comments in token generationpublic int lex(LexerToken lexedToken)
lexedToken
instance passed in to the call.lex
in interface Lexer
lex
in class AbstractLexer
lexedToken
- the instance passed in where token info is storedlexedToken.getToken()
(for convenience)public void backup()
lex()
will return the last token and offset information found.backup
in interface Lexer
backup
in class AbstractLexer
public void setPosition(int offset)
setPosition
in interface Lexer
setPosition
in class AbstractLexer
offset
- the offset for the next lex()
operation.public static java.lang.String tokenToString(int token)
token
- the token to mappublic static java.lang.String tokenToText(int token)
token
- the token to map
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Oracle Fusion Middleware Java API Reference for Oracle Extension SDK 11g Release 2 (11.1.2.2.0) E17493-03 |
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