com.ibm.jzos

Class TranscodingPrintStream

java.lang.Object

java.io.OutputStream

java.io.FilterOutputStream

java.io.PrintStream

com.ibm.jzos.TranscodingPrintStream

All Implemented Interfaces:

java.io.Closeable, java.io.Flushable, java.lang.Appendable, java.lang.AutoCloseable

public class TranscodingPrintStream
extends java.io.PrintStream

A subclass of PrintStream that sets an encoding on its OutputStreamWriter and also transcodes any write(byte[]) messages that are sent to it when it is treated as an OutputStream. This avoids the problem caused when an application wraps System.out or System.err in its own PrintWriter which would override and lose the PrintStream's encoding.

When both source and target codepages are single byte encodings, (e.g. ISO-8859-1, IBM-1047) a direct map can be used, and is the most efficient way to transcode. If one or both of the codepages are multi-byte (e.g. UTF-8) the CharsetEncoder and CharsetDecoder classes need to be used. For this case, the Transcoder class is used. It provides a protocol that accepts an array of source codepage encoded bytes, and writes the target codepage encoded bytes to a supplied output stream.

Constructor Summary

Constructors

Constructor and Description
TranscodingPrintStream(java.io.OutputStream out, boolean autoFlush, java.lang.String targetEncoding, boolean enable) Create a new transcoding print stream.
TranscodingPrintStream(java.io.OutputStream out, boolean autoFlush, java.lang.String sourceEncoding, java.lang.String targetEncoding, boolean enable) Create a new transcoding print stream.

Method Summary

Modifier and Type	Method and Description
void	flush() Overridden to flush the transcoder if one is being used.
byte[]	getTranslateTable() Answer the translate table in place.
boolean	isActive() Answer whether this PrintStream is actively transcoding.
void	write(byte[] buf, int off, int len) Override PrintStream.write(byte[], int, int) to transcode bytes from the default encoding to the target encoding.
void	write(int b) Override PrintStream.write(int b) to transcode bytes from the default encoding to the target encoding.

Methods inherited from class java.io.PrintStream

append, append, append, checkError, close, format, format, print, print, print, print, print, print, print, print, print, printf, printf, println, println, println, println, println, println, println, println, println, println

Methods inherited from class java.io.FilterOutputStream

write

Methods inherited from class java.lang.Object

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

Constructor Detail

TranscodingPrintStream

public TranscodingPrintStream(java.io.OutputStream out,
                              boolean autoFlush,
                              java.lang.String targetEncoding,
                              boolean enable)
                       throws java.io.UnsupportedEncodingException

Create a new transcoding print stream.

Parameters:

out - The output stream to which values and objects will be printed

autoFlush - A boolean; if true, the output buffer will be flushed whenever a byte array is written, one of the println methods is invoked, or a newline character or byte ('\n') is written

targetEncoding - The String naming the encoding to use, both for the internal OutputStreamWriter and for translating write(byte[]) IOStream messages sent to this object

Throws:

java.io.UnsupportedEncodingException

See Also:

PrintStream.PrintStream(java.io.OutputStream, boolean), PrintWriter.PrintWriter(java.io.OutputStream, boolean)

TranscodingPrintStream

public TranscodingPrintStream(java.io.OutputStream out,
                              boolean autoFlush,
                              java.lang.String sourceEncoding,
                              java.lang.String targetEncoding,
                              boolean enable)
                       throws java.io.UnsupportedEncodingException

Create a new transcoding print stream.

Parameters:

out - The output stream to which values and objects will be printed

autoFlush - A boolean; if true, the output buffer will be flushed whenever a byte array is written, one of the println methods is invoked, or a newline character or byte ('\n') is written

sourceEncoding - The String naming the encoding that is the source encoding for the transcoder. If null, the default will be used (the "file.encoding" System property)

targetEncoding - The String naming the encoding to use, both for the internal OutputStreamWriter and for translating write(byte[]) IOStream messages sent to this object

Throws:

java.io.UnsupportedEncodingException

See Also:

PrintStream.PrintStream(java.io.OutputStream, boolean), PrintWriter.PrintWriter(java.io.OutputStream, boolean)

Method Detail

write

public void write(int b)

Override PrintStream.write(int b) to transcode bytes from the default encoding to the target encoding.

Overrides:

write in class java.io.PrintStream

write

public void write(byte[] buf,
                  int off,
                  int len)

Override PrintStream.write(byte[], int, int) to transcode bytes from the default encoding to the target encoding.

Overrides:

write in class java.io.PrintStream

isActive

public boolean isActive()

Answer whether this PrintStream is actively transcoding. If false, the write() methods default to the superclass behavior.

getTranslateTable

public byte[] getTranslateTable()

Answer the translate table in place. Will return null if !isActive() or either encoding is multi-byte.

flush

public void flush()

Overridden to flush the transcoder if one is being used.

Specified by:

flush in interface java.io.Flushable

Overrides:

flush in class java.io.PrintStream