BasicHeaderToken

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com.springsource.util.osgi.manifest.parse.standard
Class BasicHeaderToken

java.lang.Object
  com.springsource.util.osgi.manifest.parse.standard.BasicHeaderToken

All Implemented Interfaces:: HeaderToken

public final class BasicHeaderToken
extends java.lang.Object
implements HeaderToken
extends java.lang.Object
implements HeaderToken

Instances of BasicHeaderToken represent tokens lexed from the input data.

Internals:

A BasicHeaderToken effectively encapsulates the start and end of the token within the input data and some bitflag information that was learned during lexing that can benefit parsing. To avoid unnecessary chopping up of the input data, each token holds a reference to the complete headertext - and should the token ever need to be extracted we can grab the piece of interest. Sometimes the token values are never used and it would be a waste to chop up the data and create an unnecessary array. Due to the way the grammar is defined to support parameter values, there is a notion in a HeaderToken of extension. The grammar defines a token to be ([a-z][A-Z][0-9]_-)+ but in order to allow things like 1.2.3 and com.foo.bar as parameter values without needing them to be quoted it defines an extended token that is allowed for parameter values. The lexer only knows about Tokens. However, it understands the notion of extension, which at its simplest means a sequence of tokens with dots between them. So for any token it can have the IS_EXTENDED bitflag set - and if that is set the token is the start of an extended token, and it ends at the extendedEndOffset. Concurrent Semantics
Threadsafe.

Author:: Andy Clement

Field Summary
`private static byte`	`ATTRIBUTE_NAME`
`private byte`	`bits`
`private static byte`	`DIRECTIVE_NAME`
`private int`	`endoffset`
`private int`	`extendedEndOffset`
`private static byte`	`FOLLOWED_BY_SPACE`
`private char[]`	`headerText`
`private static byte`	`IS_EXTENDED`
`private HeaderTokenKind`	`kind`
`private static byte`	`SPACED`
`private static byte`	`STARTED_WITH_LETTER`
`private int`	`startoffset`

Constructor Summary
`private`	`BasicHeaderToken(char[] headerText, HeaderTokenKind kind, int start, int end)` Private constructor, please use the factory method

Method Summary
`char[]`	`extendedValue()` This method creates a new array each time it is called - try not call it more than once.
`char`	`firstChar()`
`boolean`	`firstCharIsLetter()`
`int`	`getEndOffset()`
`int`	`getExtendedEndOffset()`
`HeaderTokenKind`	`getKind()`
`int`	`getStartOffset()`
`boolean`	`hasFollowingSpace()`
`boolean`	`isAttributeName()`
`boolean`	`isAttributeOrDirectiveName()`
`boolean`	`isDirectiveName()`
`boolean`	`isExtended()`
`boolean`	`isSpaced()`
`static BasicHeaderToken`	`makeToken(char[] data, HeaderTokenKind kind, int start, int end)` BasicHeaderToken factory method.
`void`	`setExtendedOffset(int endOffset)`
`java.lang.String`	`stringValue()`
`private char[]`	`subarray(int start, int end)`
`void`	`tagAsAttributeName()`
`void`	`tagAsDirectiveName()`
`void`	`tagAsFollowedBySpace()`
`void`	`tagAsSpaced()`
`void`	`tagAsStartedWithLetter()`
`java.lang.String`	`toString()`
`char[]`	`value()` This method creates a new array each time it is called - try not call it more than once.

Methods inherited from class java.lang.Object
`clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait`

Field Detail

kind

private HeaderTokenKind kind

headerText

private char[] headerText

startoffset

private int startoffset

endoffset

private int endoffset

extendedEndOffset

private int extendedEndOffset

bits

private byte bits

STARTED_WITH_LETTER

private static final byte STARTED_WITH_LETTER

See Also:: Constant Field Values

ATTRIBUTE_NAME

private static final byte ATTRIBUTE_NAME

See Also:: Constant Field Values

DIRECTIVE_NAME

private static final byte DIRECTIVE_NAME

See Also:: Constant Field Values

SPACED

private static final byte SPACED

See Also:: Constant Field Values

IS_EXTENDED

private static final byte IS_EXTENDED

See Also:: Constant Field Values

FOLLOWED_BY_SPACE

private static final byte FOLLOWED_BY_SPACE

See Also:: Constant Field Values

Constructor Detail