net.sf.scuba.tlv

Class TLVOutputStream

java.lang.Object

java.io.OutputStream

net.sf.scuba.tlv.TLVOutputStream

All Implemented Interfaces:

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

public class TLVOutputStream
extends java.io.OutputStream

An output-stream for constructing TLV structures which wraps an existing output-stream. Typical use is to first write a tag using writeTag(int), and then:

• either directly write a value using writeValue(byte[]) (which will cause the length and that value to be written),
• or use a series of lower-level output-stream write calls to write the value and terminate with a writeValueEnd() (which will cause the length and value to be computed and written).

Nested structures can be constructed by writing new tags during value construction.

Constructor Summary

Constructors

Constructor and Description
TLVOutputStream(java.io.OutputStream outputStream) Constructs a TLV output-stream by wrapping an existing output-stream.

Method Summary

Modifier and Type	Method and Description
void	close() Closes this output-stream and releases any system resources associated with this stream.
void	flush() Flushes the underlying output-stream.
void	write(byte[] bytes) Writes the specified bytes to this output-stream.
void	write(byte[] bytes, int offset, int length) Writes the specified number of bytes to this output-stream starting at the specified offset.
void	write(int b) Writes the specified byte to this output-stream.
void	writeLength(int length) Writes a length to the output-stream (if TLV state allows it).
void	writeTag(int tag) Writes a tag to the output-stream (if TLV state allows it).
void	writeValue(byte[] value) Writes a value at once.
void	writeValueEnd() Marks the end of the value written thus far.

Methods inherited from class java.lang.Object

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

Constructor Detail

TLVOutputStream

public TLVOutputStream(java.io.OutputStream outputStream)

Constructs a TLV output-stream by wrapping an existing output-stream.

Parameters:

outputStream - the existing output-stream

Method Detail

writeTag

public void writeTag(int tag)
              throws java.io.IOException

Writes a tag to the output-stream (if TLV state allows it).

Parameters:

tag - the tag to write

Throws:

java.io.IOException - on error writing to the underlying output-stream

writeLength

public void writeLength(int length)
                 throws java.io.IOException

Writes a length to the output-stream (if TLV state allows it).

Parameters:

length - the length to write

Throws:

java.io.IOException - on error writing to the underlying output-stream

writeValue

public void writeValue(byte[] value)
                throws java.io.IOException

Writes a value at once. If no tag was previously written, an exception is thrown. If no length was previously written, this method will write the length before writing value. If length was previously written, this method will check whether the length is consistent with value's length.

Parameters:

value - the value to write

Throws:

java.io.IOException - on error writing to the underlying output-stream

write

public void write(int b)
           throws java.io.IOException

Writes the specified byte to this output-stream. Note that this can only be used for writing value bytes and will throw an exception unless we have already written a tag.

Specified by:

write in class java.io.OutputStream

Parameters:

b - the byte to write

Throws:

java.io.IOException - on error writing to the underlying output-stream

write

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

Writes the specified bytes to this output-stream. Note that this can only be used for writing value bytes and will throw an exception unless we have already written a tag.

Overrides:

write in class java.io.OutputStream

Parameters:

bytes - the bytes to write

Throws:

java.io.IOException - on error writing to the underlying output-stream

write

public void write(byte[] bytes,
                  int offset,
                  int length)
           throws java.io.IOException

Writes the specified number of bytes to this output-stream starting at the specified offset. Note that this can only be used for writing value bytes and will throw an exception unless we have already written a tag.

Overrides:

write in class java.io.OutputStream

Parameters:

bytes - the bytes to write

offset - the offset

length - the number of bytes to write

Throws:

java.io.IOException - on error writing to the underlying output-stream

writeValueEnd

public void writeValueEnd()
                   throws java.io.IOException

Marks the end of the value written thus far. This will adjust the length and write the buffer to the underlying output-stream.

Throws:

java.io.IOException - on error writing to the underlying output-stream

flush

public void flush()
           throws java.io.IOException

Flushes the underlying output-stream. Note that this does not flush the value buffer if the current value has not been completed.

Specified by:

flush in interface java.io.Flushable

Overrides:

flush in class java.io.OutputStream

Throws:

java.io.IOException - on error writing to the underlying output-stream

close

public void close()
           throws java.io.IOException

Closes this output-stream and releases any system resources associated with this stream.

Specified by:

close in interface java.io.Closeable

Specified by:

close in interface java.lang.AutoCloseable

Overrides:

close in class java.io.OutputStream

Throws:

java.io.IOException - on error writing to the underlying output-stream