/**
* Copyright 2011-2012 Adrian Stabiszewski, as@nfctools.org
*
* 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.nfctools.ndefpush;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.util.ArrayList;
import java.util.Collection;
import java.util.List;
import org.nfctools.ndef.NdefContext;
import org.nfctools.ndef.NdefMessageEncoder;
import org.nfctools.ndef.Record;
/**
* Implementation of the NDEF Push Protocol.
*/
public class NdefPushProtocol {
public static final byte ACTION_IMMEDIATE = (byte)0x01;
public static final byte ACTION_BACKGROUND = (byte)0x02;
private static final byte VERSION = 1;
public static List<byte[]> parse(byte[] data) throws FormatException {
List<byte[]> messages = new ArrayList<byte[]>();
ByteArrayInputStream buffer = new ByteArrayInputStream(data);
DataInputStream input = new DataInputStream(buffer);
// Check version of protocol
try {
byte version = input.readByte();
if (version != VERSION) {
throw new FormatException("Got version " + version + ", expected " + VERSION);
}
int numMessages = input.readInt();
if (numMessages == 0) {
throw new FormatException("Error while parsing NdefMessage");
}
// Read actions and messages
byte[] actions = new byte[numMessages];
for (int i = 0; i < numMessages; i++) {
actions[i] = input.readByte();
int messageLength = input.readInt();
byte[] bytes = new byte[messageLength];
int readLength = input.read(bytes);
if (messageLength != readLength) {
throw new FormatException("Error while parsing NdefMessage");
}
messages.add(bytes);
}
}
catch (java.io.IOException e) {
throw new FormatException("Error while parsing NdefMessage", e);
}
return messages;
}
public static byte[] toByteArray(Collection<Record> records) {
ByteArrayOutputStream buffer = new ByteArrayOutputStream(1024);
DataOutputStream output = new DataOutputStream(buffer);
NdefMessageEncoder ndefMessageEncoder = NdefContext.getNdefMessageEncoder();
try {
byte[] bytes = ndefMessageEncoder.encode(records);
output.writeByte(VERSION);
output.writeInt(1);
output.writeByte(ACTION_IMMEDIATE);
output.writeInt(bytes.length);
output.write(bytes);
}
catch (java.io.IOException e) {
return null;
}
return buffer.toByteArray();
}
}