com.objsys.asn1j.runtime

Class Asn1BerDecodeContext

java.lang.Object

com.objsys.asn1j.runtime.Asn1BerDecodeContext

public class Asn1BerDecodeContext
extends java.lang.Object

This class is mainly for internal use by the compiler to keep track of where nested constructed elements (SEQUENCE, SET, CHOICE, etc.) begin and end.

Field Summary

Fields

Modifier and Type	Field and Description
protected int	mDecBufByteCount This variable is used to keep track of the current byte count in the decode buffer.
protected Asn1BerDecodeBuffer	mDecodeBuffer This variable holds a reference to the BER decode buffer object that is being used to decode the entire message component.
protected int	mElemLength This variable holds the contructed element length for the context component.
protected boolean	mExplicitTagging This boolean flag variable indicates if explicit tagging is in effect for this element.
protected java.util.Vector	mTagHistory The tag history is a list of decoded tags.
protected Asn1Tag	mTagHolder This variable holds the current parsed tag for matching operations.

Constructor Summary

Constructors

Constructor and Description
Asn1BerDecodeContext(Asn1BerDecodeBuffer decodeBuffer, int elemLength) The constructor initializes all internal working varaibles.

Method Summary

Modifier and Type	Method and Description
void	addTag(Asn1Tag tag) This method adds a tag to the history.
boolean	expired() This method will determine if a decoding context is expired.
boolean	hasDecoded(Asn1Tag tag) This method checks to see whether a tag has been already decoded.
boolean	matchElemTag(Asn1Tag tag, IntHolder parsedLen, boolean advance) This method will attempt to match the next element tag in a constructed type with the expected value.
boolean	matchElemTag(short tagClass, short tagForm, int tagIDCode, IntHolder parsedLen, boolean advance) This method will attempt to match the next element tag in a constructed type with the expected value.

Methods inherited from class java.lang.Object

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

Field Detail

mDecodeBuffer

protected Asn1BerDecodeBuffer mDecodeBuffer

This variable holds a reference to the BER decode buffer object that is being used to decode the entire message component.

mDecBufByteCount

protected int mDecBufByteCount

This variable is used to keep track of the current byte count in the decode buffer.

mElemLength

protected int mElemLength

This variable holds the contructed element length for the context component.

mExplicitTagging

protected boolean mExplicitTagging

This boolean flag variable indicates if explicit tagging is in effect for this element.

mTagHolder

protected Asn1Tag mTagHolder

This variable holds the current parsed tag for matching operations.

mTagHistory

protected java.util.Vector mTagHistory

The tag history is a list of decoded tags. This is used when decoding SETs to ensure that duplicate elements are not encoded.

Constructor Detail

Asn1BerDecodeContext

public Asn1BerDecodeContext(Asn1BerDecodeBuffer decodeBuffer,
                            int elemLength)

The constructor initializes all internal working varaibles.

Parameters:

decodeBuffer - Reference to current decode buffer method.

elemLength - Length of the element being tracked.

Method Detail

expired

public final boolean expired()
                      throws Asn1Exception,
                             java.io.IOException

This method will determine if a decoding context is expired. A context is defined to be the wrapper in which a set of elements or a primitive data type resides..

Returns:

True if at the end of the context block

Throws:

java.io.IOException - for I/O exception

Asn1Exception

matchElemTag

public final boolean matchElemTag(short tagClass,
                                  short tagForm,
                                  int tagIDCode,
                                  IntHolder parsedLen,
                                  boolean advance)
                           throws Asn1Exception,
                                  java.io.IOException

This method will attempt to match the next element tag in a constructed type with the expected value. It will check to see if the context is expired and, if not, will match the given tag with the expected tag. The decode cursor is advanced if the boolean advance argument is true.

Parameters:

tagClass - Class value of tag to match

tagForm - Form value of tag to match

tagIDCode - ID code of tag to match

parsedLen - Holder object to receive parsed length value

advance - True if decode cursor to be advanced.

Returns:

True if at the end of the context block

Throws:

java.io.IOException - for I/O exception

Asn1Exception

matchElemTag

public final boolean matchElemTag(Asn1Tag tag,
                                  IntHolder parsedLen,
                                  boolean advance)
                           throws Asn1Exception,
                                  java.io.IOException

This method will attempt to match the next element tag in a constructed type with the expected value. It will check to see if the context is expired and, if not, will match the given tag with the expected tag. The decode cursor is advanced if the boolean advance argument is true.

Parameters:

tag - Tag object representing tag to be matched.

parsedLen - Holder object to receive parsed length value

advance - True if decode cursor to be advanced.

Returns:

True if at the end of the context block

Throws:

java.io.IOException - for I/O exception

Asn1Exception

addTag

public final void addTag(Asn1Tag tag)

This method adds a tag to the history.

Parameters:

tag - The tag to be added to the history.

hasDecoded

public final boolean hasDecoded(Asn1Tag tag)

This method checks to see whether a tag has been already decoded.

Parameters:

tag - The tag to be searched.

Returns:

True if the tag is in the history.