www.pudn.com > cryptix-asn1-0.1.11.zip > Tag.java
/* $Id: Tag.java,v 1.2 2001/05/24 19:25:52 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 java.io.Serializable; /** * The representation of an ASN.1 Tag.* * @version $Revision: 1.2 $ * @author Raif S. Naffah */ public class Tag implements Serializable { // Constants and variables // ....................................................................... /** * Constant values for Tag classes. */ public static final int UNIVERSAL = 0x00; public static final int APPLICATION = 0x40; public static final int CONTEXT = 0x80; public static final int PRIVATE = 0xC0; /** * Constant values for Tag values. */ public static final int BOOLEAN = 0x01; public static final int INTEGER = 0x02; public static final int BIT_STRING = 0x03; public static final int OCTET_STRING = 0x04; public static final int NULL = 0x05; public static final int OBJECT_IDENTIFIER = 0x06; public static final int REAL = 0x09; public static final int SEQUENCE = 0x10; // 16 public static final int SEQUENCE_OF = 0x10; public static final int SET = 0x11; // 17 public static final int SET_OF = 0x11; public static final int NUMERIC_STRING = 0x12; // 18 public static final int PRINTABLE_STRING = 0x13; // 19 public static final int T61_STRING = 0x14; // 20 public static final int VIDEOTEX_STRING = 0x15; // 21 public static final int IA5_STRING = 0x16; // 22 public static final int GRAPHIC_STRING = 0x19; // 25 public static final int ISO646_STRING = 0x1A; // 26 public static final int GENERAL_STRING = 0x1B; // 27 public static final int UNIVERSAL_STRING = 0x1C; // 28 public static final int BMP_STRING = 0x1E; // 30 public static final int UTC_TIME = 0x17; // 23 public static final int GENERALIZED_TIME = 0x18; // 24 int clazz; // the tag's class id int value; // the tag's actual value boolean explicit; // is it explicit or implicit? boolean constructed; // is it constructed? // Constructor(s) // ....................................................................... /** * Constructs an ASN.1 Tag instance. * * @param clazz the tag's class. * @param value the tag's value. * @param explicit whether this tag is explicit or implicit. Default is * explicit. * @param constructed Whether this tag is constructed or not. Default is not * constrcuted. */ public Tag(int clazz, int value, boolean explicit, boolean constructed) { super(); this.clazz = clazz; this.value = value; this.explicit = explicit; this.constructed = constructed; } /** * Convenience constructor. Constructs an ASN.1 Tag instance. The resulting * tag is of a non-constructed type. * * @param clazz the tag's class. * @param value the tag's value. * @param explicit whether this tag is explicit or implicit. Default is * explicit. */ public Tag(int clazz, int value, boolean explicit) { this(clazz, value, explicit, false); } /** * Convenience constructor. Constructs an ASN.1 Tag instance. The resulting * tag is explicit, of a non-constructed type. * * @param clazz the tag's class. * @param value the tag's value. */ public Tag(int clazz, int value) { this(clazz, value, true, false); } /** * Convenience constructor. Constructs an ASN.1 Tag instance. The resulting * tag is of class UNIVERSAL and is of a non-constructed type. * * @param value the tag's value. * @param explicit whether this tag is explicit or implicit. Default is * explicit. */ public Tag(int value, boolean explicit) { this(Tag.UNIVERSAL, value, explicit, false); } /** * Convenience constructor. Constructs an ASN.1 Tag instance. The resulting * tag is of class UNIVERSAL, is explicit, and is of a non-constructed type. * * @param value the tag's value. */ public Tag(int value) { this(Tag.UNIVERSAL, value, true, false); } /** * Private constructor for cloning purposes. * * @param that the tag to clone. */ private Tag(Tag that) { this(that.clazz, that.value, that.explicit, that.constructed); } // Cloneable interface methods // ....................................................................... /** * Returns a cloned instance of this. * * @return a cloned instance of this. */ public Object clone() { return new Tag(this); } // java.lang.Object overloaded methods // ....................................................................... /** * Tests for equality between this instance and a designated object. * * @param obj a designated object to test for equality with this instance. * @return true if the designated object is an instance of Tag, and has the * same class and value as this one. */ public boolean equals(Object obj) { if (!(obj instanceof Tag)) return false; Tag that = (Tag) obj; if (this.getClazz() != that.getClazz()) return false; return (this.getValue() == that.getValue()); } // Accessor methods // ....................................................................... /** * Returns the tag's class. * * @return the tag's class. */ public int getClazz() { return clazz; } /** * Returns the tag's class number. * * @return the tag's class number. */ public int getValue() { return value; } /** * Returns true if the tag is explicit, false otherwise. * * @return true if the tag is explicit, false otherwise. */ public boolean isExplicit() { return explicit; } /** * Returns true if the tag is constructed false otherwise. * * @return true if the tag is constructed false otherwise. */ public boolean isConstructed() { return constructed; } /** * Convenience method. Returns true if this tag is UNIVERSAL. * * @return true if this tag's class is UNIVERSAL; false otherwise. */ public boolean isUniversal() { return (clazz == Tag.UNIVERSAL); } // Visualisation methods // ....................................................................... /** * Returns a string representation of this instance. * * @return a string representation of this instance. */ public String toString() { StringBuffer result = new StringBuffer("
"); return result.toString(); } }