Java tutorial
/** * Copyright 2013 Crypto Workshop Pty Ltd * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package org.cryptoworkshop.ximix.common.asn1.message; import org.bouncycastle.asn1.ASN1EncodableVector; import org.bouncycastle.asn1.ASN1Integer; import org.bouncycastle.asn1.ASN1Object; import org.bouncycastle.asn1.ASN1Primitive; import org.bouncycastle.asn1.ASN1Sequence; import org.bouncycastle.asn1.DEROctetString; import org.bouncycastle.asn1.DERSequence; /** * Carrier for a fragment of a transcript */ public class TranscriptTransferMessage extends ASN1Object { private final int stepNo; private final byte[] chunk; /** * Create a message for a particular step number with zero or more bytes of data. * * @param stepNo file name data belongs to. * @param chunk the data to be appended. */ public TranscriptTransferMessage(int stepNo, byte[] chunk) { this.stepNo = stepNo; this.chunk = chunk; } /** * Create an END OF TRANSFER message. * * @param stepNo step number we are signaling end of transfer for.. */ public TranscriptTransferMessage(int stepNo) { this.stepNo = stepNo; this.chunk = null; } private TranscriptTransferMessage(ASN1Sequence sequence) { this.stepNo = ASN1Integer.getInstance(sequence.getObjectAt(0)).getValue().intValue(); if (sequence.size() > 1) { this.chunk = DEROctetString.getInstance(sequence.getObjectAt(1)).getOctets(); } else { this.chunk = null; } } public static TranscriptTransferMessage getInstance(Object o) { if (o instanceof TranscriptTransferMessage) { return (TranscriptTransferMessage) o; } else if (o != null) { return new TranscriptTransferMessage(ASN1Sequence.getInstance(o)); } return null; } public int getStepNo() { return stepNo; } public boolean isEndOfTransfer() { return chunk == null; } public byte[] getChunk() { return chunk; } @Override public ASN1Primitive toASN1Primitive() { ASN1EncodableVector v = new ASN1EncodableVector(); v.add(new ASN1Integer(stepNo)); if (chunk != null) { v.add(new DEROctetString(chunk)); } return new DERSequence(v); } }