org.neo4j.csv.reader

Interface CharSeeker

All Superinterfaces:

AutoCloseable, Closeable, SourceTraceability

All Known Implementing Classes:

BufferedCharSeeker

public interface CharSeeker
extends Closeable, SourceTraceability

Seeks for specific characters in a stream of characters, e.g. a CharReadable. Uses a Mark as keeper of position. Once a seek(Mark, int) has succeeded the characters specified by the mark can be extracted into a value of an arbitrary type. Typical usage is:

 CharSeeker seeker = ...
 Mark mark = new Mark();
 int[] delimiters = new int[] {'\t',','};

 while ( seeker.seek( mark, delimiters ) )
 {
     String value = seeker.extract( mark, Extractors.STRING );
     // ... somehow manage the value
     if ( mark.isEndOfLine() )
     {
         // ... end of line, put some logic to handle that here
     }
 }
 

Any Closeable resource that gets passed in will be closed in Closeable.close().

Author:

Mattias Persson

Nested Class Summary

Nested classes/interfaces inherited from interface org.neo4j.csv.reader.SourceTraceability

SourceTraceability.Adapter

Field Summary

Fields inherited from interface org.neo4j.csv.reader.SourceTraceability

EMPTY

Method Summary

Modifier and Type	Method and Description
<EXTRACTOR extends Extractor<?>> EXTRACTOR	extract(Mark mark, EXTRACTOR extractor) Extracts the value specified by the Mark, previously populated by a call to seek(Mark, int).
boolean	seek(Mark mark, int untilChar) Seeks the next occurrence of any of the characters in untilOneOfChars, or if end-of-line, or even end-of-file.
boolean	tryExtract(Mark mark, Extractor<?> extractor) Extracts the value specified by the Mark, previously populated by a call to seek(Mark, int).

Methods inherited from interface java.io.Closeable

close

Methods inherited from interface org.neo4j.csv.reader.SourceTraceability

lineNumber, position, sourceDescription

Method Detail

seek

boolean seek(Mark mark,
             int untilChar)
      throws IOException

Seeks the next occurrence of any of the characters in untilOneOfChars, or if end-of-line, or even end-of-file.

Parameters:

mark - the mutable Mark which will be updated with the findings, if any.

untilChar - array of characters to seek.

Returns:

false if the end was reached and hence no value found, otherwise true.

Throws:

IOException - in case of I/O error.

extract

<EXTRACTOR extends Extractor<?>> EXTRACTOR extract(Mark mark,
                                                   EXTRACTOR extractor)

Extracts the value specified by the Mark, previously populated by a call to seek(Mark, int).

Parameters:

mark - the Mark specifying which part of a bigger piece of data contains the found value.

extractor - Extractor capable of extracting the value.

Returns:

the supplied Extractor, which after the call carries the extracted value itself, where either Extractor.value() or a more specific accessor method can be called to access the value.

Throws:

IllegalStateException - if the extraction returns false.

tryExtract

boolean tryExtract(Mark mark,
                   Extractor<?> extractor)

Extracts the value specified by the Mark, previously populated by a call to seek(Mark, int).

Parameters:

mark - the Mark specifying which part of a bigger piece of data contains the found value.

extractor - Extractor capable of extracting the value.

Returns:

true if a value was extracted, otherwise false. Probably the only reason for returning false would be if the data to extract was empty.