asn1dynamictype.java

来自「一个非常好的ssh客户端实现」· Java 代码 · 共 75 行

/******************************************************************************
 *
 * Copyright (c) 1999-2003 AppGate Network Security AB. All Rights Reserved.
 * 
 * This file contains Original Code and/or Modifications of Original Code as
 * defined in and that are subject to the MindTerm Public Source License,
 * Version 2.0, (the 'License'). You may not use this file except in compliance
 * with the License.
 * 
 * You should have received a copy of the MindTerm Public Source License
 * along with this software; see the file LICENSE.  If not, write to
 * AppGate Network Security AB, Otterhallegatan 2, SE-41118 Goteborg, SWEDEN
 *
 *****************************************************************************/

package com.mindbright.asn1;

import java.io.InputStream;
import java.io.OutputStream;
import java.io.IOException;

public abstract class ASN1DynamicType extends ASN1Object {

    protected ASN1Object value;

    protected ASN1DynamicType() {
	super(0);
    }

    public final void setValue(ASN1Object value) {
	this.value = value;
	this.tag   = value.getTag();
	setValue();
    }

    public final ASN1Object getValue() {
	return value;
    }

    public String getType() {
	if(value != null) {
	    return value.getType();
	}
	return "Unbound dynamic type";
    }

    public void setValue() {
	super.setValue();
	if(value != null) {
	    value.setValue();
	}
    }

    public int encodeValue(ASN1Encoder encoder, OutputStream out)
	throws IOException
    {
	if(value == null) {
	    throw new IOException("Value of " + getType() + " not set");
	}
	return value.encodeValue(encoder, out);
    }

    public void decodeValue(ASN1Decoder decoder, InputStream in,
			       int tag, int len)
	throws IOException
    {
	ASN1Object value = bindType(tag);
	setValue(value);
	decoder.decodeValue(in, (value.tag != 0) ? value.tag : tag , len, value);
    }

    protected abstract ASN1Object bindType(int tag) throws IOException;

}