Class UnicodeReader
- All Implemented Interfaces:
Closeable
,AutoCloseable
,Readable
- UTF-8
- UTF-16LE
- UTF-16BE
- UTF-32LE
- UTF-32BE
For optimum performance, it is recommended that you wrap all instances of
UnicodeReader
with a java.io.BufferedReader
.
This class is mostly ripped off from the workaround in the description of Java Bug 4508058.
- Version:
- 0.9
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Field Summary
FieldsModifier and TypeFieldDescriptionprivate static final int
The size of a BOM.private String
The encoding being used.private InputStreamReader
The input stream from which we're really reading. -
Constructor Summary
ConstructorsConstructorDescriptionUnicodeReader
(File file) This utility constructor is here because you will usually use aUnicodeReader
on files.UnicodeReader
(File file, String defaultEncoding) This utility constructor is here because you will usually use aUnicodeReader
on files.UnicodeReader
(File file, Charset defaultCharset) This utility constructor is here because you will usually use aUnicodeReader
on files.Creates a reader using the encoding specified by the BOM in the file; if there is no recognized BOM, then a system default encoding is used.UnicodeReader
(InputStream in, String defaultEncoding) Creates a reader using the encoding specified by the BOM in the file; if there is no recognized BOM, thendefaultEncoding
is used.UnicodeReader
(InputStream in, Charset defaultCharset) Creates a reader using the encoding specified by the BOM in the file; if there is no recognized BOM, thendefaultEncoding
is used.UnicodeReader
(String file) This utility constructor is here because you will usually use aUnicodeReader
on files. -
Method Summary
Modifier and TypeMethodDescriptionvoid
close()
Closes this reader.Returns the encoding being used to read this input stream (i.e., the encoding of the file).protected void
init
(InputStream in, String defaultEncoding) Read-ahead four bytes and check for BOM marks.int
read
(char[] cbuf, int off, int len) Read characters into a portion of an array.Methods inherited from class java.io.Reader
mark, markSupported, nullReader, read, read, read, ready, reset, skip, transferTo
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Field Details
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internalIn
The input stream from which we're really reading. -
encoding
The encoding being used. We keep our own instead of using the string returned byjava.io.InputStreamReader
since that class does not return user-friendly names. -
BOM_SIZE
private static final int BOM_SIZEThe size of a BOM.- See Also:
-
-
Constructor Details
-
UnicodeReader
This utility constructor is here because you will usually use aUnicodeReader
on files.Creates a reader using the encoding specified by the BOM in the file; if there is no recognized BOM, then a system default encoding is used.
- Parameters:
file
- The file from which you want to read.- Throws:
IOException
- If an error occurs when checking for/reading the BOM.SecurityException
- If a security manager exists and its checkRead method denies read access to the file.
-
UnicodeReader
This utility constructor is here because you will usually use aUnicodeReader
on files.Creates a reader using the encoding specified by the BOM in the file; if there is no recognized BOM, then a system default encoding is used.
- Parameters:
file
- The file from which you want to read.- Throws:
IOException
- If an error occurs when checking for/reading the BOM.SecurityException
- If a security manager exists and its checkRead method denies read access to the file.
-
UnicodeReader
This utility constructor is here because you will usually use aUnicodeReader
on files.Creates a reader using the encoding specified by the BOM in the file; if there is no recognized BOM, then a specified default encoding is used.
- Parameters:
file
- The file from which you want to read.defaultEncoding
- The encoding to use if no BOM is found. If this value isnull
, a system default is used.- Throws:
IOException
- If an error occurs when checking for/reading the BOM.SecurityException
- If a security manager exists and its checkRead method denies read access to the file.
-
UnicodeReader
This utility constructor is here because you will usually use aUnicodeReader
on files.Creates a reader using the encoding specified by the BOM in the file; if there is no recognized BOM, then a specified default encoding is used.
- Parameters:
file
- The file from which you want to read.defaultCharset
- The encoding to use if no BOM is found. If this value isnull
, a system default is used.- Throws:
IOException
- If an error occurs when checking for/reading the BOM.SecurityException
- If a security manager exists and its checkRead method denies read access to the file.
-
UnicodeReader
Creates a reader using the encoding specified by the BOM in the file; if there is no recognized BOM, then a system default encoding is used.- Parameters:
in
- The input stream from which to read.- Throws:
IOException
- If an error occurs when checking for/reading the BOM.
-
UnicodeReader
Creates a reader using the encoding specified by the BOM in the file; if there is no recognized BOM, thendefaultEncoding
is used.- Parameters:
in
- The input stream from which to read.defaultEncoding
- The encoding to use if no recognized BOM is found. If this value isnull
, a system default is used.- Throws:
IOException
- If an error occurs when checking for/reading the BOM.
-
UnicodeReader
Creates a reader using the encoding specified by the BOM in the file; if there is no recognized BOM, thendefaultEncoding
is used.- Parameters:
in
- The input stream from which to read.defaultCharset
- The encoding to use if no recognized BOM is found. If this value isnull
, a system default is used.- Throws:
IOException
- If an error occurs when checking for/reading the BOM.
-
-
Method Details
-
close
Closes this reader.- Specified by:
close
in interfaceAutoCloseable
- Specified by:
close
in interfaceCloseable
- Specified by:
close
in classReader
- Throws:
IOException
-
getEncoding
Returns the encoding being used to read this input stream (i.e., the encoding of the file). If a BOM was recognized, then the specific Unicode type is returned; otherwise, either the default encoding passed into the constructor or the system default is returned.- Returns:
- The encoding of the stream.
-
init
Read-ahead four bytes and check for BOM marks. Extra bytes are unread back to the stream, only BOM bytes are skipped.- Parameters:
defaultEncoding
- The encoding to use if no BOM was recognized. If this value isnull
, then a system default is used.- Throws:
IOException
- If an error occurs when trying to read a BOM.
-
read
Read characters into a portion of an array. This method will block until some input is available, an I/O error occurs, or the end of the stream is reached.- Specified by:
read
in classReader
- Parameters:
cbuf
- The buffer into which to read.off
- The offset at which to start storing characters.len
- The 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
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