www.pudn.com > cryptix-asn1-0.1.11.zip > ASNBoolean.java
/* $Id: ASNBoolean.java,v 1.5 2001/05/30 19:17:03 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.EOFException;
import java.io.IOException;
import java.math.BigInteger;
/**
* The basic implementation of an ASN.1 BOOLEAN type. The value of this type is
* a java.lang.Boolean. A convenience method to obtain this value as
* a java.lang.Boolean is supplied.
*
* @version $Revision: 1.5 $
* @author Raif S. Naffah
*/
public class ASNBoolean extends Type implements IType {
// Constants and vars
// .......................................................................
static Category cat = Category.getInstance(ASNBoolean.class.getName());
/**
* The constant TRUE.
*/
public static final ASNBoolean TRUE = new ASNBoolean("TRUE", Boolean.TRUE);
/**
* The constant FALSE.
*/
public static final ASNBoolean FALSE = new ASNBoolean("FALSE", Boolean.FALSE);
// Constructor(s)
//........................................................................
public ASNBoolean() {
super("", new Tag(Tag.BOOLEAN));
}
public ASNBoolean(String name) {
super(name, new Tag(Tag.BOOLEAN));
}
public ASNBoolean(String name, Tag tag) {
super(name, tag);
}
public ASNBoolean(String name, Object value) {
this(name, new Tag(Tag.BOOLEAN), value);
}
/**
* Constructs a new instance of a BOOLEAN type, given a designated Tag and a
* designated initial value.
*
* @param name the name of this instance.
* @param tag the designated Tag value.
* @param value the designated initial value. Allowed types are:
* java.lang.String, and this type.
* @exception ClassCastException if the designated value is not appropriate.
*/
public ASNBoolean(String name, Tag tag, Object value) {
super(name, tag);
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 initial value for the new instance.
* @return a new instance with the designated value.
* @exception ClassCastException if the designated value is not appropriate
* (see constructor with 3 arguments for suitable types of value).
*/
public static ASNBoolean getInstance(String value) {
return new ASNBoolean("", value);
}
/**
* Returns a new instance of this type with a trivial name and the
* designated value.
*
* @param value a designated initial value for the new instance.
* @return a new instance with the designated value.
* @exception ClassCastException if the designated value is not appropriate
* (see constructor with 3 arguments for suitable types of value).
*/
public static ASNBoolean getInstance(Boolean value) {
return new ASNBoolean("", value);
}
/**
* Returns a new instance of this type with a trivial name and the
* designated value.
*
* @param value a designated initial value for the new instance.
* @return a new instance with the designated value.
* @exception ClassCastException if the designated value is not appropriate
* (see constructor with 3 arguments for suitable types of value).
*/
public static ASNBoolean getInstance(boolean value) {
return new ASNBoolean("", new Boolean(value));
}
// Redefinition of methods in superclass Type
// .......................................................................
/**
* Decodes a BOOLEAN 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 {
Boolean result = is.decodeBoolean(this);
if (result == null)
throw new ElementNotFoundException(cn);
else
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 BOOLEAN 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.value();
if (val != null)
os.encodeBoolean(this, (Boolean) val);
else {
val = this.defaultValue();
if (val != null) {
cat.warn("Encoding default value for "+cn);
os.encodeBoolean(this, (Boolean) val);
} 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()");
}
/**
* Sets the current value of this instance to the designated one.
*
* @param value the designated value. Allowed types are:
* java.lang.String, and this type.
* @exception ClassCastException if the designated value is not appropriate.
*/
public void value(Object value) {
if (value == null)
return;
if (value instanceof String)
this.value = new Boolean((String) value);
else if (value instanceof Boolean)
this.value = (Boolean) value;
else if (value instanceof ASNBoolean)
this.value = ((ASNBoolean) value).booleanValue();
else
throw new ClassCastException();
}
// other instance methods
// .......................................................................
/**
* Convenience method to facilitate type casting.
*
* @return the current value as a java.lang.Boolean.
*/
public Boolean booleanValue() {
return (Boolean) this.value;
}
/**
* Returns true if the designated value is equal to the value of
* this instance.
*
* @param obj a value to compare with the value of this instance.
* @return true if this instance has an equal, non-null value to
* the designated one; false otherwise.
*/
protected boolean sameValue(Object obj) {
Boolean val = this.booleanValue();
return (val == null) ? false : val.equals(obj);
}
// 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(booleanValue()));
else
sb.append("N/A");
return sb.toString();
}
}