com.netphantom.eclipse

Class CodepageReader

java.lang.Object

com.netphantom.eclipse.CodepageReader

public class CodepageReader
extends Object

Universal codepage reader that supports reading any character set.

This reader is implementing buffering, so there is no need to add it.

An option for special case of having the codepage specified in the first line is also provided. First line normally looks like ";#CODEPAGE=" for e.g. text and translation tabled, but can be configured.

Support for Byte Order Mark (BOM) is included, see http://www.unicode.org/unicode/faq/utf_bom.html for more information.

The different BOM's are:

• 00 00 FE FF = UTF-32, big-endian
• FF FE 00 00 = UTF-32, little-endian
• FE FF = UTF-16, big-endian
• FF FE = UTF-16, little-endian
• EF BB BF = UTF-8

Windows (e.g. using Notepad) uses Unicode UTF-16, little-endian, encoding name UTF-16LE.

Unfortunately, this code is written for JDK 1.6, so the Closable interface cannot be implemented, for use with try-catch-resource.

Field Summary

Fields

Modifier and Type	Field and Description
static String	TEXTFILE_CODEPAGE_LINE_BEGINNING The default codepage line used for text and translation tables for codepage specification.

Constructor Summary

Constructors

Constructor and Description
CodepageReader(InputStream in, String codepageLineBeginning, boolean enableBOM, String defaultCodepage) Creates the reader from an input stream with default system codepage (e.g.

Method Summary

Modifier and Type	Method and Description
void	close() Closes the stream.
String	getEncoding() Gets the encoding.
boolean	hasStreamCodepage() Gets if the stream contained a BOM or a Codepage line.
int	read() Reads a single character.
int	read(char[] cbuf, int off, int len) Reads characters into a portion of an array.
String	readLine() Reads a line of text.
long	skip(long n) Skips characters.

Methods inherited from class java.lang.Object

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

Field Detail

TEXTFILE_CODEPAGE_LINE_BEGINNING

public static final String TEXTFILE_CODEPAGE_LINE_BEGINNING

The default codepage line used for text and translation tables for codepage specification.

See Also:

Constant Field Values

Constructor Detail

CodepageReader

public CodepageReader(InputStream in,
                      String codepageLineBeginning,
                      boolean enableBOM,
                      String defaultCodepage)
               throws IOException,
                      UnsupportedEncodingException

Creates the reader from an input stream with default system codepage (e.g. ANSI Cp1252 for Windows).

The beginning of the stream is read for 32 bytes blocking.

NOTE: If an IOException or UnsupportedEncodingException is thrown, the input stream is closed.

Parameters:

in - The input stream.

codepageLineBeginning - Code page line beginning specification, null for none. Note that this will not be used if a BOM is found.

enableBOM - Flag indicating BOM support should be used.

defaultCodepage - The default codepage, null for system default. This codepage can be Ansi, OEM or EBCDIC.

Throws:

IOException - For I/O errors.

UnsupportedEncodingException - If wrong encoding is specified.

Method Detail

getEncoding

public String getEncoding()

Gets the encoding.

Returns:

The encoding used, null for system default.

hasStreamCodepage

public boolean hasStreamCodepage()

Gets if the stream contained a BOM or a Codepage line.

Returns:

true if a BOM was encountered or a Codepage line.

read

public int read()
         throws IOException

Reads a single character.

Returns:

The character read, as an integer in the range 0 to 65535 (0x00-0xffff), or -1 if the end of the stream has been reached

Throws:

IOException - If an I/O error occurs

read

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

Reads characters into a portion of an array.

This method implements the general contract of the corresponding Reader.read(char[], int, int) read method of the Reader class. As an additional convenience, it attempts to read as many characters as possible by repeatedly invoking the read method of the underlying stream. This iterated read continues until one of the following conditions becomes true:

• The specified number of characters have been read,
• The read method of the underlying stream returns -1, indicating end-of-file, or
• The ready method of the underlying stream returns false, indicating that further input requests would block.

If the first read on the underlying stream returns -1 to indicate end-of-file then this method returns -1. Otherwise this method returns the number of characters actually read.

Subclasses of this class are encouraged, but not required, to attempt to read as many characters as possible in the same fashion.

Ordinarily this method takes characters from this stream's character buffer, filling it from the underlying stream as necessary. If, however, the buffer is empty, the mark is not valid, and the requested length is at least as large as the buffer, then this method will read characters directly from the underlying stream into the given array. Thus redundant BufferedReaders will not copy data unnecessarily.

Parameters:

cbuf - Destination buffer

off - Offset at which to start storing characters

len - Maximum number of characters to read

Returns:

The number of characters read, or -1 if the end of the stream has been reached

Throws:

IOException - If an I/O error occurs

readLine

public String readLine()
                throws IOException

Reads a line of text. A line is considered to be terminated by any one of a line feed ('\n'), a carriage return ('\r'), or a carriage return followed immediately by a linefeed.

Returns:

A String containing the contents of the line, not including any line-termination characters, or null if the end of the stream has been reached

Throws:

IOException - If an I/O error occurs

See Also:

Files.readAllLines(java.nio.file.Path, java.nio.charset.Charset)

skip

public long skip(long n)
          throws IOException

Skips characters.

Parameters:

n - The number of characters to skip

Returns:

The number of characters actually skipped

Throws:

IllegalArgumentException - If n is negative.

IOException - If an I/O error occurs

close

public void close()

Closes the stream.