com.goldencode.p2j.util

Class StreamWrapper

java.lang.Object

com.goldencode.p2j.util.Stream

com.goldencode.p2j.util.StreamWrapper

All Implemented Interfaces:

Finalizable

public class StreamWrapper
extends Stream

A stream class which acts as a container which redirects any stream method call to the contained stream reference. This is needed to support shared streams, since such streams can be constructed/initialized in a different scope than they are defined. This can also be used to maintain a single reference which has an underlying stream implementation which can be changed without changing the reference itself.

This is a generic interface "redirector" (from this instance to the contained reference). Upon construction, the internal reference is null. Once an assign(com.goldencode.p2j.util.Stream) call has occurred, any other methods called on this class will succeed. They will be redirected to the contained reference. To obtain the reference directly, call the dereference() method.

After close() is called, the contained stream reference is null and subsequent usage will throw a NullPointerException.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
private static class	StreamWrapper.WorkArea Context-local data.

Nested classes/interfaces inherited from class com.goldencode.p2j.util.Stream

Stream.PrintMode

Field Summary

Fields

Modifier and Type	Field and Description
private boolean	inOk Status var for input.
private boolean	outOk Status var for output.
private Stream	stream The backing construct for the stream.
private static ContextLocal<StreamWrapper.WorkArea>	work Context-local data

Fields inherited from class com.goldencode.p2j.util.Stream

_convert, binary, convert, convertCached, CR, CRLF, DELIM, doneIn, doneOut, EOF, increment, internalCp, isWindows, LF, mapEntryProtermcap, MODE_EXPORT, MODE_PUT_CONTROL, MODE_PUT_NORMAL, MODE_PUT_UNFORMATTED, NEW_LINES, NEWLINE, NEWLINE_LEN, noMap, PAGED_DEFAULT, PIPE_BROKEN_MESSAGE, SET_PAGED_DEFAULT, sourceCharset, sourceCp, streamCp, targetCharset, targetCp, UNKNOWN_VALUE

Constructor Summary

Constructors

Constructor and Description
StreamWrapper() Default constructor.
StreamWrapper(java.lang.String name) Construct an instance associated with a specific legacy 4GL variable name.

Method Summary

Modifier and Type	Method and Description
void	advancePage() Inserts a page break if the stream is paged and if the next write position is not on the first line of a new page.
void	assign(Stream s) Assigns the internal stream reference to the given reference.
long	available() The number of bytes available to be immediately read without blocking.
protected void	cleanup(boolean in, boolean out) Perform common close preprocessing for all streams.
void	close() Closes the stream and releases OS resources associated with it.
void	closeIn() Closes the input stream and releases OS resources associated with it.
void	closeOut() Closes the output stream and releases OS resources associated with it.
Stream	dereference() Access the wrapped stream directly.
void	endOutput(boolean appendNewLine) Write the current output buffer to the stream.
(package private) static int	findRemoteStreamId(java.lang.String name) Finds a stream by its name.
void	flush() Flushes the stream.
long	getLen() The length of the stream in bytes.
integer	getNextLineNum() Gets the current page's next logical line number.
long	getPos() The 0-based offset into the stream at which the next read or write will occur.
static StreamWrapper	getRemoteStreamRef(java.lang.String name) Finds a stream by its name.
boolean	isIn() State of the input side of the stream.
boolean	isOut() State of the output side of the stream.
boolean	isSilent() Check if stream is in silent mode.
boolean	isTerm() Check if current stream is terminal.
(package private) boolean	needsPageBreak() Detects when a page break is needed.
int	peekCh() Peeks at the character from the current read position in the stream (reads a character from the current read position in the stream without incrementing stream read position.
void	putUnformatted(FieldEntry[] data) Output a list of fields with default formatting to the stream.
void	putWorker(FieldEntry[] data, int mode, char delim) Output a list of fields to the stream.
(package private) int	rawGetNextLineNum() Gets the current page's next line number.
(package private) int	rawGetPageNum() Gets the current page number.
(package private) int	rawGetPageSize() Gets the current page size in lines.
(package private) void	rawIncrementNextLineNum() Increments the current page's next line number.
(package private) void	rawIncrementPageNum() Increments the current page number.
(package private) void	rawResetNextLineNum() Resets the current page's next line number to 1.
(package private) void	rawSetPageSize(int sz) Sets the current page size in lines.
protected int	readBlockRemote(memptr var) Read a block of data from the stream with the block size equal to the size of the binary data array in the given memptr variable.
int	readByte() Read a single byte from the underlying stream.
byte[]	readBytes(int len) Read a chunk of bytes from the current read position in the stream to the offset calculated by given length or to the EOF, whichever comes first.
int	readCh() Read a character from the current read position in the stream.
java.lang.String	readLn() Read all characters from the current read position in the stream to the next line separator (as determined by the File.separator or to the EOF.
void	setControl(boolean mode) Sets the stream into control mode which ensures that subsequent characters written to the stream will not affect line/page counters.
void	setConvert(boolean convert) Sets the stream's character conversion mode.
void	setConvertSource(java.lang.String cp) Sets the stream's source codepage and activates character conversion mode.
void	setConvertTarget(java.lang.String cp) Sets the stream's target codepage and activates character conversion mode.
void	setDelimiter(char delim) Sets the stream's delimiter character for import/export of fields.
void	setDelimiter(java.lang.String delim) Sets the stream's delimiter character for import/export of fields.
void	setFont(int num) Sets the stream font number.
void	setLandscape() Set stream display mode to landscape
void	setLen(long len) Truncates or extends the stream to the specified length if this stream supports such an operation.
void	setLobDirectory(java.lang.String lobDir) Sets the stream's lob directory located as a subdirectory for opened current file stream directory.
void	setPortrait() Set stream display mode to portrait
void	setPos(long pos) Moves the current read/write position to the specified absolute 0-based offset.
void	setUnbuffered() Makes the stream UNBUFFERED.
void	write(byte[] data) Write the given byte array to the output stream.
void	write(byte[] data, int off, int len) Write the specified range of bytes from the given byte array to the output stream.
void	write(java.lang.String data) Write the given string to the output stream.
void	writeByte(byte b) Write the given byte to the output stream.
void	writeCh(char ch) Write the given character to the output stream.

Methods inherited from class com.goldencode.p2j.util.Stream

afterWrite, assignDatum, deleted, deregisterFooter, deregisterHeader, endOutput, export, finished, flushControlled, flushData, forcePageBreak, forcePageBreak, generateStringFormat, getAvailableLines, getControl, getConvert, getDelimiter, getDisplayMode, getEcho, getEffectivePageSize, getLength, getName, getPageNum, getPageSize, getPendingRowCount, getPosition, getPulseOnClose, getUnformatted, hasPageHeadersFooters, indexOfNewLine, isContiguous, isFileResource, isFreshPage, isKeepMessages, isNewLine, isSuppressFormFeed, isUnbuffered, isUnnamed, isValid, iterate, needsHeadersOutput, needsPageBreak, processFooters, processHeaders, processHeadersInt, processHeadersUncond, protectReads, protectWrites, pulseOutput, put, putControl, putField, putField, putField, putField, putField, putField, putField, putField, putField, putField, putField, putField, putField, putField, putField, putField, putField, putField, putField, putField, putField, putField, putField, putField, putField, putField, putField, putField, putField, putField, putLineEnd, putLineEnd, putNull, putNull, putSpace, putSpace, rawNextLineNum, rawPageSize, readBlock, readBlockWorker, readChar, readChar, readChunk, readField, readField, readField, readField, readFieldWorker, readLine, readLine, readLine, readLine, readLineCleanup, registerAdvanceListener, registerCloseListener, registerFlushListener, registerFooter, registerHeader, registerPageBreakListener, resetCurrentLine, retry, setAppend, setBinary, setContiguous, setConvertSource, setConvertTarget, setEcho, setFlushBeforePut, setFont, setKeepMessages, setLobDirectory, setMap, setName, setNoMap, setPageSize, setPageSize, setPageSize, setPendingRowCount, setPosition, setPosition, setPulseOnClose, setUnformatted, setUnnamed, skipField, skipLoneHyphenInput, startOutput, writeBlob, writeBlock, writeClob, writeControlled, writeControlledSpecial, writeField, writeField, writeField, writeField, writeField

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.goldencode.p2j.util.Finalizable

entry, initFailure, weight

Field Detail

stream

private Stream stream

The backing construct for the stream.

inOk

private boolean inOk

Status var for input.

outOk

private boolean outOk

Status var for output.

work

private static final ContextLocal<StreamWrapper.WorkArea> work

Context-local data

Constructor Detail

StreamWrapper

public StreamWrapper()

Default constructor.

StreamWrapper

public StreamWrapper(java.lang.String name)

Construct an instance associated with a specific legacy 4GL variable name.

Parameters:

name - The legacy variable name.

Method Detail

findRemoteStreamId

static int findRemoteStreamId(java.lang.String name)

Finds a stream by its name. The return value is an id of a remote stream.

Parameters:

name - Stream name.

Returns:

The remote stream id, -1 if no such stream exists.

getRemoteStreamRef

public static StreamWrapper getRemoteStreamRef(java.lang.String name)

Finds a stream by its name. The return value is the reference of the remote stream.

Parameters:

name - Stream name.

Returns:

The remote stream reference, or null if no such stream exists.

available

public long available()
               throws java.io.IOException

The number of bytes available to be immediately read without blocking.

Specified by:

available in class Stream

Returns:

The number of available bytes.

Throws:

java.io.IOException

getPos

public long getPos()
            throws java.lang.UnsupportedOperationException,
                   java.io.IOException

The 0-based offset into the stream at which the next read or write will occur. This does not work for "streams" that require sequential access.

Specified by:

getPos in class Stream

Returns:

The current position in the stream.

Throws:

java.lang.UnsupportedOperationException

java.io.IOException

setPos

public void setPos(long pos)
            throws java.lang.UnsupportedOperationException,
                   java.io.IOException

Moves the current read/write position to the specified absolute 0-based offset.

Specified by:

setPos in class Stream

Parameters:

pos - The new read/write position in the stream.

Throws:

java.lang.UnsupportedOperationException

java.io.IOException

getLen

public long getLen()
            throws java.lang.UnsupportedOperationException,
                   java.io.IOException

The length of the stream in bytes. This does not work for "streams" that require sequential access.

Specified by:

getLen in class Stream

Returns:

The length of the stream.

Throws:

java.lang.UnsupportedOperationException

java.io.IOException

setLen

public void setLen(long len)
            throws java.lang.UnsupportedOperationException,
                   java.io.IOException

Truncates or extends the stream to the specified length if this stream supports such an operation. If truncation is requested, all data located after this point in the file is discarded. If extending the file is requested, the values of the data in the extended portion of the file is undefined.

Specified by:

setLen in class Stream

Parameters:

len - The new length of the file.

Throws:

java.lang.UnsupportedOperationException

java.io.IOException

writeCh

public void writeCh(char ch)
             throws java.io.IOException

Write the given character to the output stream.

Specified by:

writeCh in class Stream

Parameters:

ch - The character to be written.

Throws:

java.io.IOException

writeByte

public void writeByte(byte b)
               throws java.io.IOException

Write the given byte to the output stream.

Specified by:

writeByte in class Stream

Parameters:

b - The byte to be written.

Throws:

java.io.IOException

write

public void write(java.lang.String data)
           throws java.io.IOException

Write the given string to the output stream.

Specified by:

write in class Stream

Parameters:

data - The data to be written.

Throws:

java.io.IOException

write

public void write(byte[] data)
           throws java.io.IOException

Write the given byte array to the output stream.

Specified by:

write in class Stream

Parameters:

data - The data to be written.

Throws:

java.io.IOException - If an I/O error occurs.

write

public void write(byte[] data,
                  int off,
                  int len)
           throws java.io.IOException

Write the specified range of bytes from the given byte array to the output stream.

Specified by:

write in class Stream

Parameters:

data - The data to be written.

off - Starting offset in data from which to read bytes to be written. Must be non-negative and < data.length.

len - Length of data to be written. Must be non-negative and <= (data.length - offset).

Throws:

java.io.IOException - If an I/O error occurs.

peekCh

public int peekCh()

Peeks at the character from the current read position in the stream (reads a character from the current read position in the stream without incrementing stream read position. The next peekCh() and readCh() will return the same value).

The underlying stream subclass determines the content of the result. Byte oriented streams such as pipes or files will return a byte while streams that generate keystrokes or characters may return a DBCS or Unicode character.

Specified by:

peekCh in class Stream

Returns:

The next character read from the stream, -1 on any failure and -2 upon an EOF.

readCh

public int readCh()

Read a character from the current read position in the stream.

The underlying stream subclass determines the content of the result. Byte oriented streams such as pipes or files will return a byte while streams that generate keystrokes or characters may return a DBCS or Unicode character.

Specified by:

readCh in class Stream

Returns:

The next character read from the stream, -1 on any failure and -2 upon an EOF.

readByte

public int readByte()

Read a single byte from the underlying stream.

Specified by:

readByte in class Stream

Returns:

A single byte from the stream, -1 on any failure and -2 upon an EOF.

readBytes

public byte[] readBytes(int len)
                 throws java.io.IOException

Read a chunk of bytes from the current read position in the stream to the offset calculated by given length or to the EOF, whichever comes first. The EOF character is not returned.

Overrides:

readBytes in class Stream

Parameters:

len - The number of bytes to read.

Returns:

The chunk read from the stream or null if there is nothing to read (the EOF has been reached). The length of the returned array will be the smaller of the len parameter or the actual bytes left before the EOF.

Throws:

java.io.IOException - If an I/O error occurs.

readLn

public java.lang.String readLn()
                        throws java.io.EOFException,
                               java.io.IOException,
                               java.lang.InterruptedException

Read all characters from the current read position in the stream to the next line separator (as determined by the File.separator or to the EOF. Any line separator character(s) and the EOF character are not returned.

Specified by:

readLn in class Stream

Returns:

The next line read from the stream.

Throws:

java.io.EOFException

java.io.IOException

java.lang.InterruptedException

closeIn

public void closeIn()

Closes the input stream and releases OS resources associated with it. Any output stream that is open is unaffected.

Specified by:

closeIn in class Stream

closeOut

public void closeOut()

Closes the output stream and releases OS resources associated with it. Any input stream that is open is unaffected.

Specified by:

closeOut in class Stream

endOutput

public void endOutput(boolean appendNewLine)
               throws ErrorConditionException,
                      StopConditionException

Write the current output buffer to the stream. This flushes all buffered output of the Stream.putField(int), Stream.putSpace(), Stream.putLineEnd() and Stream.writeField(int) methods to the stream. This method also resets the current delimiter to the default.

This method does nothing if the stream is in control mode.

Overrides:

endOutput in class Stream

Parameters:

appendNewLine - Automatically add new line at the end of output.

Throws:

ErrorConditionException - On any error during I/O.

StopConditionException - If any interruption occurs during I/O processing.

close

public void close()

Closes the stream and releases OS resources associated with it. After completion, further calls may not be made to use this instance, until an assign(com.goldencode.p2j.util.Stream) is used to "re-open" the stream. This is safe to call when no stream is open (it will do nothing in that case).

Specified by:

close in class Stream

assign

public void assign(Stream s)
            throws java.lang.UnsupportedOperationException

Assigns the internal stream reference to the given reference. This must be called before any other usage of this class.

Specified by:

assign in class Stream

Parameters:

s - The new internal stream reference to use for all operations.

Throws:

java.lang.UnsupportedOperationException

isTerm

public boolean isTerm()

Check if current stream is terminal.

Overrides:

isTerm in class Stream

Returns:

true if stream is terminal.

advancePage

public void advancePage()
                 throws ErrorConditionException

Inserts a page break if the stream is paged and if the next write position is not on the first line of a new page.

Overrides:

advancePage in class Stream

Throws:

ErrorConditionException

flush

public void flush()

Flushes the stream.

Overrides:

flush in class Stream

dereference

public Stream dereference()

Access the wrapped stream directly. This is useful for stream subclasses that implement their own APIs (beyond implementing the required Stream abstract methods).

Returns:

The stream upon which this instance operates. This may be null if no stream has yet been opened (assigned to this instance using assign(com.goldencode.p2j.util.Stream)).

isIn

public boolean isIn()

State of the input side of the stream.

Specified by:

isIn in class Stream

Returns:

true if the input side of the stream is active.

isOut

public boolean isOut()

State of the output side of the stream.

Specified by:

isOut in class Stream

Returns:

true if the output side of the stream is active.

isSilent

public boolean isSilent()

Check if stream is in silent mode.

Overrides:

isSilent in class Stream

Returns:

true if stream was explicitly closed by application.

putWorker

public void putWorker(FieldEntry[] data,
                      int mode,
                      char delim)
               throws ErrorConditionException

Output a list of fields to the stream.

Overrides:

putWorker in class Stream

Parameters:

data - The list of fields to be output.

mode - MODE_PUT_NORMAL, MODE_PUT_CONTROL, MODE_PUT_UNFORMATTED or MODE_EXPORT.

delim - The delimiter to use in EXPORT mode.

Throws:

ErrorConditionException - On any error during I/O.

putUnformatted

public void putUnformatted(FieldEntry[] data)
                    throws ErrorConditionException

Output a list of fields with default formatting to the stream.

Overrides:

putUnformatted in class Stream

Parameters:

data - The list of fields to be output.

Throws:

ErrorConditionException - On any error during I/O.

setDelimiter

public void setDelimiter(char delim)

Sets the stream's delimiter character for import/export of fields.

Overrides:

setDelimiter in class Stream

Parameters:

delim - The current delimiter char.

setDelimiter

public void setDelimiter(java.lang.String delim)

Sets the stream's delimiter character for import/export of fields.

Overrides:

setDelimiter in class Stream

Parameters:

delim - The current delimiter char (if this is not a single character, only the first character will be used). If null or an empty string, the delimiter is reset to the default of Stream.DELIM.

setControl

public void setControl(boolean mode)

Sets the stream into control mode which ensures that subsequent characters written to the stream will not affect line/page counters.

Warning: in Progress this is described as ensuring that the "position" (presumably the write position) will not be changed when this option is enabled. However, this really does not make any sense in the case where output characters are used for control purposes. No support is provided for this case.

Overrides:

setControl in class Stream

Parameters:

mode - If true, all output is emitted without modification of line/page counters.

setUnbuffered

public void setUnbuffered()

Makes the stream UNBUFFERED.

Overrides:

setUnbuffered in class Stream

setConvert

public void setConvert(boolean convert)

Sets the stream's character conversion mode.

Overrides:

setConvert in class Stream

Parameters:

convert - The new character conversion mode. true to enable character conversion, false to disable conversion.

setConvertSource

public void setConvertSource(java.lang.String cp)

Sets the stream's source codepage and activates character conversion mode.

Overrides:

setConvertSource in class Stream

Parameters:

cp - The source codepage for character conversion mode.

setConvertTarget

public void setConvertTarget(java.lang.String cp)

Sets the stream's target codepage and activates character conversion mode.

Overrides:

setConvertTarget in class Stream

Parameters:

cp - The target codepage for character conversion mode.

setLobDirectory

public void setLobDirectory(java.lang.String lobDir)

Sets the stream's lob directory located as a subdirectory for opened current file stream directory.

Overrides:

setLobDirectory in class Stream

Parameters:

lobDir - The name for subdirectory to store LOB files.

setFont

public void setFont(int num)

Sets the stream font number. The number denotes an index into the font table of the current environment. The method is part of the runtime support of the FONT option of the OUTPUT TO PRINTER statement (FWD extension to 4GL). This method is only implemented by the printer stream.

Overrides:

setFont in class Stream

Parameters:

num - Font number.

setLandscape

public void setLandscape()

Set stream display mode to landscape

Overrides:

setLandscape in class Stream

setPortrait

public void setPortrait()

Set stream display mode to portrait

Overrides:

setPortrait in class Stream

cleanup

protected void cleanup(boolean in,
                       boolean out)
                throws java.io.IOException

Perform common close preprocessing for all streams.

Overrides:

cleanup in class Stream

Parameters:

in - true if this was triggered during a call to closeIn() or close(). Input resources are to be cleaned up.

out - true if this was triggered during a call to closeOut() or close(). Output resources are to be cleaned up.

Throws:

java.io.IOException

needsPageBreak

boolean needsPageBreak()

Detects when a page break is needed.

Overrides:

needsPageBreak in class Stream

Returns:

true if a page break should be output.

rawGetPageSize

int rawGetPageSize()

Gets the current page size in lines.

Overrides:

rawGetPageSize in class Stream

Returns:

The number of lines per page.

rawSetPageSize

void rawSetPageSize(int sz)

Sets the current page size in lines.

Overrides:

rawSetPageSize in class Stream

Parameters:

sz - The number of lines per page.

rawGetPageNum

int rawGetPageNum()

Gets the current page number.

Overrides:

rawGetPageNum in class Stream

Returns:

The current page number.

rawIncrementPageNum

void rawIncrementPageNum()

Increments the current page number.

Overrides:

rawIncrementPageNum in class Stream

rawGetNextLineNum

int rawGetNextLineNum()

Gets the current page's next line number.

Overrides:

rawGetNextLineNum in class Stream

Returns:

The next line number.

getNextLineNum

public integer getNextLineNum()

Gets the current page's next logical line number.

Overrides:

getNextLineNum in class Stream

Returns:

The next line number.

rawIncrementNextLineNum

void rawIncrementNextLineNum()

Increments the current page's next line number.

Overrides:

rawIncrementNextLineNum in class Stream

rawResetNextLineNum

void rawResetNextLineNum()

Resets the current page's next line number to 1.

Overrides:

rawResetNextLineNum in class Stream

readBlockRemote

protected int readBlockRemote(memptr var)

Description copied from class: Stream

Read a block of data from the stream with the block size equal to the size of the binary data array in the given memptr variable. The data will be written into the memptr starting at the first byte in the array. The read data will be the smaller of the block size or the file size. Only an error or end of file condition will cause this read to terminate before the block size has been read.

Overrides:

readBlockRemote in class Stream

Parameters:

var - The variable to which the result is assigned.

Returns:

The number of the bytes read, -1 on any failure and -2 upon an EOF.