com.parctechnologies.eclipse

Class EXDROutputStream

java.lang.Object

java.io.OutputStream

java.io.FilterOutputStream

com.parctechnologies.eclipse.EXDROutputStream

All Implemented Interfaces:

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

public class EXDROutputStream
extends java.io.FilterOutputStream

A stream which can write EXDR format. An EXDROutputStream can be constructed from any instance of the OutputStream class and extends it to be able to write outgoing data in the EXDR (ECLiPSe eXternal Data Representation) format.

Use the method write(Object) to convert Java CompoundTerm objects and instances of other relevant Java classes into EXDR format so that data can be read in by ECLiPSe.

EXDROutputStream also uses a buffer: rather than writing to the underlying OutputStream byte-by-byte, EXDR data is written to the buffer and then copied to the OutputStream when a whole term has been completed.

Note that EXDROutputStream objects are often constructed using ToEclipseQueues.

See Also:

CompoundTerm, ToEclipseQueue

Constructor Summary

Constructors

Constructor and Description
EXDROutputStream(java.io.OutputStream s) Construct an EXDROutputStream which will write EXDR to a named OutputStream.
EXDROutputStream(java.io.OutputStream s, boolean compressStrings) Construct an EXDROutputStream which will write EXDR with optionally compressed strings to a named OutputStream.

Method Summary

Modifier and Type	Method and Description
void	enableCompression(boolean compress) Enable / disable string compression for subsequently written terms.
void	flush() Flushes the underlying OutputStream.
void	write(java.lang.Object o) Write an Object to the underlying stream in EXDR format.

Methods inherited from class java.io.FilterOutputStream

close, write, write, write

Methods inherited from class java.lang.Object

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

Constructor Detail

EXDROutputStream

public EXDROutputStream(java.io.OutputStream s)

Construct an EXDROutputStream which will write EXDR to a named OutputStream.

EXDROutputStream

public EXDROutputStream(java.io.OutputStream s,
                        boolean compressStrings)

Construct an EXDROutputStream which will write EXDR with optionally compressed strings to a named OutputStream.

Method Detail

write

public void write(java.lang.Object o)
           throws java.io.IOException

Write an Object to the underlying stream in EXDR format. The Object (or if it is a compound term, its arguments, nested however deep) can be of any of the following acceptable EXDR output types:

• null - this is interpreted as a variable in ECLiPSe.
• String objects.
• Anything implementing the CompoundTerm interface whose arguments are also instances of acceptable EXDR output types.
• Integer objects.
• Double or Float objects: these are interpreted as floats on the ECLiPSe side. Note that attempts to write Not-a-number (NaN) will raise an IllegalArgumentException.
• Any object implementing the Collection interface whose elements are all instances of acceptable EXDR output types. The collection is interpreted as an ECLiPSe list.

This is an atomic action, so that different threads writing to the same stream do not garble the data.

Throws:

java.lang.IllegalArgumentException - if the parameter is of an unrecognised class, or if Not-a-number (NaN)-valued Floats or Doubles are supplied.

java.io.IOException

flush

public void flush()
           throws java.io.IOException

Flushes the underlying OutputStream.

Specified by:

flush in interface java.io.Flushable

Overrides:

flush in class java.io.FilterOutputStream

Throws:

java.io.IOException

enableCompression

public void enableCompression(boolean compress)

Enable / disable string compression for subsequently written terms.