/* * Copyright (c) 1997, 2006, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation.  Oracle designates this * particular file as subject to the "Classpath" exception as provided * by Oracle in the LICENSE file that accompanied this code. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */  package com.sun.jmx.snmp;   /** * Represents an SNMP null value. * <p><b>This API is a Sun Microsystems internal API  and is subject * to change without notice.</b></p> */ public class SnmpNull extends SnmpValue {    private static final long serialVersionUID = 1783782515994279177L;     // CONSTRUCTORS    //-------------    /**     * Constructs a new <CODE>SnmpNull</CODE>.     */    public SnmpNull() {        tag = NullTag ;    }     /**     * Constructs a new <CODE>SnmpNull</CODE>.     * <BR>For mibgen private use only.     */    public SnmpNull(String dummy) {        this();    }     /**     * Constructs a new <CODE>SnmpNull</CODE> from the specified tag value.     * @param t The initialization value.     */    public SnmpNull(int t) {        tag = t ;    }     // PUBLIC METHODS    //---------------    /**     * Returns the tag value of this <CODE>SnmpNull</CODE>.     * @return The value.     */    public int getTag() {        return tag ;    }     /**     * Converts the <CODE>NULL</CODE> value to its ASN.1 <CODE>String</CODE> form.     * When the tag is not the universal one, it is preprended     * to the <CODE>String</CODE> form.     * @return The <CODE>String</CODE> representation of the value.     */    public String toString() {        String result = "" ;        if (tag != 5) {            result += "[" + tag + "] " ;        }        result += "NULL" ;        switch(tag) {        case errNoSuchObjectTag :            result += " (noSuchObject)" ;            break ;         case errNoSuchInstanceTag :            result += " (noSuchInstance)" ;            break ;         case errEndOfMibViewTag :            result += " (endOfMibView)" ;            break ;        }        return result ;    }     /**     * Converts the <CODE>NULL</CODE> value to its <CODE>SnmpOid</CODE> form.     * Normally, a <CODE>NULL</CODE> value cannot be used as an index value,     * this method triggers an exception.     * @return The OID representation of the value.     */    public SnmpOid toOid() {        throw new IllegalArgumentException() ;    }     /**     * Performs a clone action. This provides a workaround for the     * <CODE>SnmpValue</CODE> interface.     * @return The SnmpValue clone.     */    final synchronized public SnmpValue duplicate() {        return (SnmpValue) clone() ;    }     /**     * Clones the <CODE>SnmpNull</CODE> object, making a copy of its data.     * @return The object clone.     */    final synchronized public Object clone() {        SnmpNull  newclone = null ;        try {            newclone = (SnmpNull) super.clone() ;            newclone.tag = tag ;        } catch (CloneNotSupportedException e) {            throw new InternalError() ; // vm bug.        }        return newclone ;    }     /**     * Returns a textual description of the type object.     * @return ASN.1 textual description.     */    final public String getTypeName() {        return name ;    }     /**     * Checks if this <CODE>SnmpNull</CODE> object corresponds to a <CODE>noSuchObject</CODE> value.     * @return <CODE>true</CODE> if the tag equals {@link com.sun.jmx.snmp.SnmpDataTypeEnums#errNoSuchObjectTag},     * <CODE>false</CODE> otherwise.     */    public boolean isNoSuchObjectValue() {        return (tag == SnmpDataTypeEnums.errNoSuchObjectTag);    }     /**     * Checks if this <CODE>SnmpNull</CODE> object corresponds to a <CODE>noSuchInstance</CODE> value.     * @return <CODE>true</CODE> if the tag equals {@link com.sun.jmx.snmp.SnmpDataTypeEnums#errNoSuchInstanceTag},     * <CODE>false</CODE> otherwise.     */    public boolean isNoSuchInstanceValue() {        return (tag == SnmpDataTypeEnums.errNoSuchInstanceTag);    }     /**     * Checks if this <CODE>SnmpNull</CODE> object corresponds to an <CODE>endOfMibView</CODE> value.     * @return <CODE>true</CODE> if the tag equals {@link com.sun.jmx.snmp.SnmpDataTypeEnums#errEndOfMibViewTag},     * <CODE>false</CODE> otherwise.     */    public boolean isEndOfMibViewValue() {        return (tag == SnmpDataTypeEnums.errEndOfMibViewTag);    }     // VARIABLES    //----------    /**     * Name of the type.     */    final static String name = "Null" ;     /**     * This is the tag of the NULL value. By default, it is the universal tag value.     */    private int tag = 5 ;}