Package org.codehaus.plexus.util

Class LineOrientedInterpolatingReader

java.lang.Object

java.io.Reader

java.io.FilterReader

org.codehaus.plexus.util.LineOrientedInterpolatingReader

All Implemented Interfaces:

Closeable, AutoCloseable, Readable

public class LineOrientedInterpolatingReader
extends FilterReader

A FilterReader which interpolates keyword values into a character stream. Keywords are recognized when enclosed between starting and ending delimiter strings. The keywords themselves, and their values, are fetched from a Map supplied to the constructor.

When a possible keyword token is recognized (by detecting the starting and ending token delimiters):

• if the enclosed string is found in the keyword Map, the delimiters and the keyword are effectively replaced by the keyword's value;
• if the enclosed string is found in the keyword Map, but its value has zero length, then the token (delimiters and keyword) is effectively removed from the character stream;
• if the enclosed string is not found in the keyword Map, then no substitution is made; the token text is passed through unaltered.

A token in the incoming character stream may be escaped by prepending an "escape sequence" which is specified to the constructor. An escaped token is passed through as written, with the escape sequence removed. This allows things which would look like tokens to be read literally rather than interpolated.

Author:

jdcasey Created on Feb 3, 2005

See Also:

InterpolationFilterReader

Field Summary

Fields

Modifier and Type	Field	Description
static String	DEFAULT_END_DELIM
static String	DEFAULT_ESCAPE_SEQ
static String	DEFAULT_START_DELIM

Fields inherited from class java.io.FilterReader

in

Fields inherited from class java.io.Reader

lock

Constructor Summary

Constructors

Constructor	Description
LineOrientedInterpolatingReader(Reader reader, Map<String,?> context)	Filters a Reader using the default escape sequence "\" and token delimiters "${", "}".
LineOrientedInterpolatingReader(Reader reader, Map<String,?> context, String startDelim, String endDelim)	Filters a Reader using the default escape sequence "\".
LineOrientedInterpolatingReader(Reader reader, Map<String,?> context, String startDelim, String endDelim, String escapeSeq)	Construct an interpolating Reader, specifying token delimiters and the escape sequence.

Method Summary

Modifier and Type	Method	Description
int	read()
int	read(char[] cbuf, int off, int len)
long	skip(long n)

Methods inherited from class java.io.FilterReader

close, mark, markSupported, ready, reset

Methods inherited from class java.io.Reader

nullReader, read, read, transferTo

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

DEFAULT_START_DELIM

public static final String DEFAULT_START_DELIM

See Also:

Constant Field Values

DEFAULT_END_DELIM

public static final String DEFAULT_END_DELIM

See Also:

Constant Field Values

DEFAULT_ESCAPE_SEQ

public static final String DEFAULT_ESCAPE_SEQ

See Also:

Constant Field Values

Constructor Detail

LineOrientedInterpolatingReader

public LineOrientedInterpolatingReader(Reader reader,
                                       Map<String,?> context,
                                       String startDelim,
                                       String endDelim,
                                       String escapeSeq)

Construct an interpolating Reader, specifying token delimiters and the escape sequence.

Parameters:

reader - the Reader to be filtered.

context - keyword/value pairs for interpolation.

startDelim - character sequence which (possibly) begins a token.

endDelim - character sequence which ends a token.

escapeSeq - escape sequence

LineOrientedInterpolatingReader

public LineOrientedInterpolatingReader(Reader reader,
                                       Map<String,?> context,
                                       String startDelim,
                                       String endDelim)

Filters a Reader using the default escape sequence "\".

Parameters:

reader - the Reader to be filtered.

context - keyword/value pairs for interpolation.

startDelim - the character sequence which (possibly) begins a token.

endDelim - the character sequence which ends a token.

LineOrientedInterpolatingReader

public LineOrientedInterpolatingReader(Reader reader,
                                       Map<String,?> context)

Filters a Reader using the default escape sequence "\" and token delimiters "${", "}".

Parameters:

reader - the Reader to be filtered.

context - keyword/value pairs for interpolation.

Method Detail

read

public int read()
         throws IOException

Overrides:

read in class FilterReader

Throws:

IOException

read

public int read(char[] cbuf,
                int off,
                int len)
         throws IOException

Overrides:

read in class FilterReader

Throws:

IOException

skip

public long skip(long n)
          throws IOException

Overrides:

skip in class FilterReader

Throws:

IOException