schemajic.decoder
Class DecodingStream

java.lang.Object
  schemajic.decoder.DecodingStream

public class DecodingStream
extends java.lang.Object

Decodes values of ASN.1 types represented in a conceptual Tag - Length - Value (TLV) format under the Distinguished Encoding Rules (DER) of ASN.1.

Version:

1.00 - 2006/02/10

Author:

support@phillipgriffin.com

Constructor Summary

DecodingStream(java.io.InputStream s)
Constructor for DecodingStream with input stream parameter.

Method Summary

DecodedTLV	decode() Decode a tag/length/value.
DecodedTLV	decode(TagList tags) Match each Tag in a TagList against the input stream.
int	getBytesRead() Returns the current stream of bytes that have been read.
DecodedTLV	peekNextTagLength() Peeks at the next TLV in the input stream.
void	readBytes(byte[] buffer) Read buffer.length raw bytes from the input stream into the buffer.
byte[]	readTLV() Reads a TLV from the input stream.

Methods inherited from class java.lang.Object

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

Constructor Detail

DecodingStream

public DecodingStream(java.io.InputStream s)

Constructor for DecodingStream with input stream parameter.

Parameters:

s - an input stream

Method Detail

decode

public DecodedTLV decode(TagList tags)
                  throws java.io.IOException

Match each Tag in a TagList against the input stream. Mark the stream in case the tags can't be matched - the stream will be reset and the tags that were read will be returned to the stream.

Parameters:

tags - a list of one or more tags (T)

Returns:

null or a DecodedTLV

Throws:

java.io.IOException

decode

public DecodedTLV decode()
                  throws java.io.IOException

Decode a tag/length/value. If the tag is primitive then the value bytes are read, otherwise only a tag/length is returned.

Returns:

null or a DecodedTLV

Throws:

java.io.IOException

peekNextTagLength

public DecodedTLV peekNextTagLength()
                             throws java.io.IOException

Peeks at the next TLV in the input stream.

Returns:

a new DecodedTLV

Throws:

java.io.IOException

readTLV

public byte[] readTLV()
               throws java.io.IOException

Reads a TLV from the input stream.

Returns:

the input stream storage buffer

Throws:

java.io.IOException

readBytes

public void readBytes(byte[] buffer)
               throws java.io.IOException

Read buffer.length raw bytes from the input stream into the buffer. This method facilitates the implementation of ASN.1 OpenType, where there is no tag present, and we want to read an entire tag/length/value without decoding the tag/length.

Parameters:

buffer - input stream storage

Throws:

java.io.IOException

getBytesRead

public int getBytesRead()

Returns the current stream of bytes that have been read.