www.pudn.com > cryptix-asn1-0.1.11.zip > Any.java

/* $Id: Any.java,v 1.6 2001/05/26 07:10:24 raif Exp $ 
 * 
 * Copyright (C) 1997-2001 The Cryptix Foundation Limited. All rights reserved. 
 * 
 * Use, modification, copying and distribution of this software is subject to 
 * the terms and conditions of the Cryptix General Licence. You should have 
 * received a copy of the Cryptix General Licence along with this library; if 
 * not, you can download a copy from http://www.cryptix.org/ 
 */ 
package cryptix.asn1.lang; 
 
import cryptix.asn1.io.ASNReader; 
import cryptix.asn1.io.ASNWriter; 
import cryptix.asn1.io.BlankElementException; 
import cryptix.asn1.io.ElementNotFoundException; 
 
import org.apache.log4j.Category; 
 
import java.io.IOException; 
import java.io.EOFException; 
import java.util.ArrayList; 
 
/** 
 * The basic implementation of the ASN.1 ANY type.
 
 * 
 * The value of such type is a concrete instance of a valid ASN.1 type.
 
 * 
 * @version $Revision: 1.6 $ 
 * @author  Raif S. Naffah 
 */ 
public class Any extends Type implements IType { 
 
	// Constants and vars 
	// ....................................................................... 
 
	static Category cat = Category.getInstance(Any.class.getName()); 
 
	// Constructor(s) 
	// ....................................................................... 
 
	/** 
	 * Trivial constructor for a true ANY; ie. one with an unknown tag value 
	 * at the moment of construction. 
	 */ 
	public Any() { 
		super("", null); 
	} 
 
	public Any(String name) { 
		super(name, null); 
	} 
 
	public Any(String name, Tag tag) { 
		super(name, tag); 
	} 
 
	public Any(String name, Tag tag, Object value) { 
		super(name, tag); 
 
		if (value != null) 
			if (value instanceof IType) 
				value(value); 
//				setValue(((IType) value).getValue()); 
			else if (value instanceof ArrayList) 
				value(value); 
			else // should check if instance of byte[] 
//				throw new ClassCastException(); 
//            setValue((byte[]) value); 
            value(value); 
 
		if (this.value != null) 
			defaultValue(this.value); 
	} 
 
	// Class methods 
	// ....................................................................... 
 
	/** 
	 * Returns a new instance of this type with a trivial name and the 
	 * designated value. 
	 * 
	 * @param value a designated concrete value for the new instance. 
	 * @return a new instance with the designated value. 
	 */ 
	public static Any getInstance(IType value) { 
		return new Any("", null, value); 
	} 
 
	// Redefinition of methods in superclass Type 
	// ....................................................................... 
 
	/** 
	 * Decodes an instance of this object from an input stream. 
	 * 
	 * @param is the ASN.1 stream to read from. 
	 * @exception IOException if an exception occurs during the operation. 
	 */ 
	public void decode(ASNReader is) throws IOException { 
		String cn = this.getClass().getName(); 
		cat.debug("==> "+cn+".decode()"); 
 
		is.mark(Integer.MAX_VALUE); 
		try { 
			IType result = is.decodeAny(this.name()); 
			if (result == null) 
				throw new ElementNotFoundException(cn); 
			else { 
				result.name(this.name()); 
				this.value(result); 
			} 
		} catch (IOException x) { 
			cat.warn("Exception ("+String.valueOf(x)+") encountered while decoding a "+cn); 
			if (x instanceof ASNException || x instanceof EOFException) { 
				cat.warn("Resetting stream..."); 
				is.reset(); 
			} 
			throw x; 
		} 
 
		cat.debug("<== "+cn+".decode()"); 
	} 
 
	/** 
	 * Encodes an instance of this object to an output stream. 
	 * 
	 * @param os the ASN.1 stream to write to. 
	 * @exception IOException if an exception occurs during the operation. 
	 */ 
	public void encode(ASNWriter os) throws IOException { 
		String cn = this.getClass().getName(); 
		cat.debug("==> "+cn+".encode()"); 
 
//      Object val = this.getValue(); 
		IType val = (IType) this.value(); 
		if (val != null) 
//			os.encodeAny(this, val); 
			val.encode(os); 
		else { 
//			val = this.getDefaultValue(); 
			val = (IType) this.defaultValue(); 
			if (val != null) { 
				cat.warn("Encoding default value for "+cn); 
//				os.encodeAny(this, val); 
   			val.encode(os); 
			} else if (!this.isOptional()) 
				throw new BlankElementException(cn); 
//			else { 
//				cat.warn("Encoding a NULL for "+cn); 
//				new Null(this.name()).encode(os); 
//			} 
		} 
 
		cat.debug("<== "+cn+".encode()"); 
	} 
 
   // java.lang.Object overloaded methods 
   // ....................................................................... 
 
	/** 
	 * Returns a string representation of this instance. 
	 * 
	 * @return a string representation of this instance. 
	 */ 
	public String toString() { 
		StringBuffer sb = new StringBuffer("-- "); 
		if (value != null) 
			sb.append(String.valueOf(value)); 
		else 
			sb.append("N/A"); 
 
		return sb.toString(); 
	} 
}