public class LookaheadCharInputReader extends Object implements CharInputReader
CharInputReader that wraps another CharInputReader and
collects a sequence of characters from the wrapped input, in order to analyze what the buffer contains
ahead of the current position.| Constructor and Description |
|---|
LookaheadCharInputReader(CharInputReader reader,
char newLine,
int whitespaceRangeStart)
Creates a lookahead input reader by wrapping a given
CharInputReader implementation |
| Modifier and Type | Method and Description |
|---|---|
long |
charCount()
Returns the number of characters returned by
CharInputReader.nextChar() at any given time. |
String |
currentParsedContent()
Returns a String with the input character sequence parsed to produce the current record.
|
int |
currentParsedContentLength()
Returns the length of the character sequence parsed to produce the current record.
|
void |
enableNormalizeLineEndings(boolean escaping)
Indicates to the input reader that the parser is running in "escape" mode and
new lines should be returned as-is to prevent modifying the content of the parsed value.
|
char |
getChar()
Returns the last character returned by the
CharInputReader.nextChar() method. |
char[] |
getLineSeparator()
Returns the line separator by this character input reader.
|
String |
getLookahead()
Returns the current lookahead value.
|
String |
getLookahead(char current)
Returns the lookahead value prepended with the current character
|
String |
getQuotedString(char quote,
char escape,
char escapeEscape,
int maxLength,
char stop1,
char stop2,
boolean keepQuotes,
boolean keepEscape,
boolean trimLeading,
boolean trimTrailing)
Attempts to collect a quoted
String from the current position until a closing quote or stop character is found on the input,
or a line ending is reached. |
String |
getString(char ch,
char stop,
boolean trim,
String nullValue,
int maxLength)
Attempts to collect a
String from the current position until a stop character is found on the input,
or a line ending is reached. |
int |
lastIndexOf(char ch)
Returns the last index of a given character in the current parsed content
|
long |
lineCount()
Returns the number of newlines read so far.
|
void |
lookahead(int numberOfCharacters)
Fills the lookahead buffer with a given number of characters that will be extracted from the wrapped
CharInputReader |
void |
markRecordStart()
Marks the start of a new record in the input, used internally to calculate the result of
CharInputReader.currentParsedContent() |
boolean |
matches(char[] sequence,
char wildcard)
Matches a sequence of characters against the current lookahead buffer.
|
boolean |
matches(char current,
char[] sequence,
char wildcard)
Matches a sequence of characters against the current lookahead buffer.
|
char |
nextChar()
Returns the next character in the input provided by the active
Reader. |
String |
readComment()
Collects the comment line found on the input.
|
void |
skipLines(long lineCount)
Skips characters in the input until the given number of lines is discarded.
|
boolean |
skipQuotedString(char quote,
char escape,
char stop1,
char stop2)
Attempts to skip a quoted
String from the current position until a stop character is found on the input,
or a line ending is reached. |
boolean |
skipString(char ch,
char stop)
Attempts to skip a
String from the current position until a stop character is found on the input,
or a line ending is reached. |
char |
skipWhitespace(char ch,
char stopChar1,
char stopChar2)
Skips characters from the current input position, until a non-whitespace character, or a stop character is found
|
void |
start(Reader reader)
Initializes the CharInputReader implementation with a
Reader which provides access to the input. |
void |
stop()
Stops the CharInputReader from reading characters from the
Reader provided in CharInputReader.start(Reader) and closes it. |
public LookaheadCharInputReader(CharInputReader reader, char newLine, int whitespaceRangeStart)
CharInputReader implementationreader - the input reader whose characters will read and stored in a limited internal buffer,
in order to allow a parser to query what the characters are available ahead of the current input position.newLine - the normalized character that represents a line ending. Used internally as a stop character.whitespaceRangeStart - starting range of characters considered to be whitespace.public boolean matches(char current,
char[] sequence,
char wildcard)
current - the last character used by the parser, which should match the first character in the lookahead buffersequence - the expected sequence of characters after the current character, that are expected appear in the current lookahead bufferwildcard - character used in the sequence as a wildcard (e.g. * or ?), meaning any character is acceptable in its place.true if the current character and the sequence characters that follows are present in the lookahead, otherwise falsepublic boolean matches(char[] sequence,
char wildcard)
sequence - the expected sequence of characters that are expected appear in the current lookahead bufferwildcard - character used in the sequence as a wildcard (e.g. * or ?), meaning any character is acceptable in its place.true if the given sequence of characters is present in the lookahead, otherwise falsepublic String getLookahead()
String if the lookahead buffer is empty.public String getLookahead(char current)
current - the current character obtained by the parserString formed by the given character followed by the lookahead value (if any).public void lookahead(int numberOfCharacters)
CharInputReadernumberOfCharacters - the number of characters to read from the wrapped CharInputReader, given in the constructor of this class.public void start(Reader reader)
CharInputReaderReader which provides access to the input.start in interface CharInputReaderreader - A Reader that provides access to the input.public void stop()
CharInputReaderReader provided in CharInputReader.start(Reader) and closes it.stop in interface CharInputReaderpublic char nextChar()
CharInputReaderReader.
If the input contains a sequence of newline characters (defined by Format.getLineSeparator()), this method will automatically converted them to the newline character specified in Format.getNormalizedNewline().
A subsequent call to this method will return the character after the newline sequence.
nextChar in interface CharInputnextChar in interface CharInputReaderpublic long charCount()
CharInputReaderCharInputReader.nextChar() at any given time.charCount in interface CharInputReaderCharInputReader.nextChar()public long lineCount()
CharInputReaderlineCount in interface CharInputReaderpublic void skipLines(long lineCount)
CharInputReaderskipLines in interface CharInputReaderlineCount - the number of lines to skip from the current location in the inputpublic void enableNormalizeLineEndings(boolean escaping)
CharInputReaderenableNormalizeLineEndings in interface CharInputReaderescaping - flag indicating that the parser is escaping values and line separators are to be returned as-is.public String readComment()
CharInputReaderreadComment in interface CharInputReaderpublic char[] getLineSeparator()
CharInputReaderFormat.getLineSeparator() configuration, or the line separator sequence identified automatically
when CommonParserSettings.isLineSeparatorDetectionEnabled() evaluates to true.getLineSeparator in interface CharInputReaderpublic final char getChar()
CharInputReaderCharInputReader.nextChar() method.getChar in interface CharInputgetChar in interface CharInputReaderCharInputReader.nextChar() method.'\0' if there are no more characters in the input or if the CharInputReader was stopped.public char skipWhitespace(char ch,
char stopChar1,
char stopChar2)
CharInputReaderskipWhitespace in interface CharInputReaderch - the current character of the inputstopChar1 - the first stop character (which can be a whitespace)stopChar2 - the second character (which can be a whitespace)public String currentParsedContent()
CharInputReadercurrentParsedContent in interface CharInputReaderpublic void markRecordStart()
CharInputReaderCharInputReader.currentParsedContent()markRecordStart in interface CharInputReaderpublic String getString(char ch, char stop, boolean trim, String nullValue, int maxLength)
CharInputReaderString from the current position until a stop character is found on the input,
or a line ending is reached. If the String can be obtained, the current position of the parser will be updated to
the last consumed character. If the internal buffer needs to be reloaded, this method will return null
and the current position of the buffer will remain unchanged.getString in interface CharInputReaderch - the current character to be considered. If equal to the stop character the nullValue will be returnedstop - the stop character that identifies the end of the content to be collectedtrim - flag indicating whether or not trailing whitespaces should be discardednullValue - value to return when the length of the content to be returned is 0.maxLength - the maximum length of the String to be returned. If the length exceeds this limit, null will be returnedString found on the input, or null if the buffer needs to reloaded or the maximum length has been exceeded.public String getQuotedString(char quote, char escape, char escapeEscape, int maxLength, char stop1, char stop2, boolean keepQuotes, boolean keepEscape, boolean trimLeading, boolean trimTrailing)
CharInputReaderString from the current position until a closing quote or stop character is found on the input,
or a line ending is reached. If the String can be obtained, the current position of the parser will be updated to
the last consumed character. If the internal buffer needs to be reloaded, this method will return null
and the current position of the buffer will remain unchanged.getQuotedString in interface CharInputReaderquote - the quote characterescape - the quote escape characterescapeEscape - the escape of the quote escape charactermaxLength - the maximum length of the String to be returned. If the length exceeds this limit, null will be returnedstop1 - the first stop character that identifies the end of the content to be collectedstop2 - the second stop character that identifies the end of the content to be collectedkeepQuotes - flag to indicate the quotes that wrap the resulting String should be kept.keepEscape - flag to indicate that escape sequences should be kepttrimLeading - flag to indicate leading whitespaces should be trimmedtrimTrailing - flag to indicate that trailing whitespaces should be trimmedString found on the input, or null if the buffer needs to reloaded or the maximum length has been exceeded.public int currentParsedContentLength()
CharInputReadercurrentParsedContentLength in interface CharInputReaderpublic boolean skipString(char ch,
char stop)
CharInputReaderString from the current position until a stop character is found on the input,
or a line ending is reached. If the String can be skipped, the current position of the parser will be updated to
the last consumed character. If the internal buffer needs to be reloaded, this method will return false
and the current position of the buffer will remain unchanged.skipString in interface CharInputReaderch - the current character to be considered. If equal to the stop character false will be returnedstop - the stop character that identifies the end of the content to be collectedtrue if an entire String value was found on the input and skipped, or false if the buffer needs to reloaded.public boolean skipQuotedString(char quote,
char escape,
char stop1,
char stop2)
CharInputReaderString from the current position until a stop character is found on the input,
or a line ending is reached. If the String can be skipped, the current position of the parser will be updated to
the last consumed character. If the internal buffer needs to be reloaded, this method will return false
and the current position of the buffer will remain unchanged.skipQuotedString in interface CharInputReaderquote - the quote characterescape - the quote escape characterstop1 - the first stop character that identifies the end of the content to be collectedstop2 - the second stop character that identifies the end of the content to be collectedtrue if an entire String value was found on the input and skipped, or false if the buffer needs to reloaded.public int lastIndexOf(char ch)
CharInputReaderlastIndexOf in interface CharInputReaderch - the character to look for-1 if not found.Copyright © 2019 Univocity Software Pty Ltd. All rights reserved.