Java IO.pdf - Nguyen Dang Binh

public OutputStreamWriter(OutputStream out)
public OutputStreamWriter(OutputStream out, String encoding) throws
UnsupportedEncodingException
Java I/O
The first constructor assumes that the text in the stream is to be written using the platform's
default encoding. The second constructor specifies an encoding. There's no easy way to
determine which encodings are supported, but the ones listed in Table B.4 in Appendix B, are
supported by most VMs. For example, this code attaches an OutputStreamWriter to
System.out with the default encoding:
OutputStreamWriter osw = new OutputStreamWriter(System.out);
The default encoding is normally ISO Latin-1, except on Macs, where it is MacRoman.
Whatever it is, you can find it in the system property file.encoding:
String defaultEncoding = System.getProperty("file.encoding");
On the other hand, if you want to write a file encoded in ISO 8859-7 (ASCII plus Greek) you
might do this:
FileOutputStream fos = new FileOutputStream("greek.txt");
OutputStreamWriter greekWriter = new OutputStreamWriter(fos, "8859_7");
The write() methods convert characters to bytes according to a specified character encoding
and write those bytes onto the underlying output stream:
public void write(int c) throws IOException
public void write(char[] text, int offset, int length) throws IOException
public void write(String s, int offset, int length) throws IOException
Once the Writer is constructed, writing the characters is easy. For example:
String arete = "\u03B1\u03C1\u03B5\u03C4\u03B7";
greekWriter.write(arete, 0, arete.length());
The String variable arete is the Unicode-escaped encoding of a?et?, the Greek word for
excellence. The second line writes this word in the ISO 8859-7 character set. In this encoding,
these five Unicode characters (10 bytes) become the five bytes 225, 241, 229, 244, 231, which
encode the word a?et? in ISO 8859-7. You don't have to worry about exactly how this
conversion is performed. You just have to construct the writer, write the string, and let Java
do the grunt work of figuring out which Unicode characters map to which externally encoded
characters.
Unicode is a fairly large character set; most other character sets don't have all the characters in
Unicode. Attempts to write characters that don't exist in a given set instead produce a
substitution character, generally a question mark.
The getEncoding() method returns a string containing the name of the encoding used by this
writer:
public String getEncoding()
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