| /* |
| * Copyright (C) 2010 The Android Open Source Project |
| * |
| * 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 android.nfc; |
| |
| import android.net.Uri; |
| import android.os.Parcel; |
| import android.os.Parcelable; |
| import java.nio.BufferUnderflowException; |
| import java.nio.ByteBuffer; |
| import java.nio.charset.Charsets; |
| import java.util.ArrayList; |
| import java.util.Arrays; |
| import java.util.List; |
| |
| /** |
| * Represents an immutable NDEF Record. |
| * <p> |
| * NDEF (NFC Data Exchange Format) is a light-weight binary format, |
| * used to encapsulate typed data. It is specified by the NFC Forum, |
| * for transmission and storage with NFC, however it is transport agnostic. |
| * <p> |
| * NDEF defines messages and records. An NDEF Record contains |
| * typed data, such as MIME-type media, a URI, or a custom |
| * application payload. An NDEF Message is a container for |
| * one or more NDEF Records. |
| * <p> |
| * This class represents logical (complete) NDEF Records, and can not be |
| * used to represent chunked (partial) NDEF Records. However |
| * {@link NdefMessage#NdefMessage(byte[])} can be used to parse a message |
| * containing chunked records, and will return a message with unchunked |
| * (complete) records. |
| * <p> |
| * A logical NDEF Record always contains a 3-bit TNF (Type Name Field) |
| * that provides high level typing for the rest of the record. The |
| * remaining fields are variable length and not always present: |
| * <ul> |
| * <li><em>type</em>: detailed typing for the payload</li> |
| * <li><em>id</em>: identifier meta-data, not commonly used</li> |
| * <li><em>payload</em>: the actual payload</li> |
| * </ul> |
| * <p> |
| * Helpers such as {@link NdefRecord#createUri}, {@link NdefRecord#createMime} |
| * and {@link NdefRecord#createExternal} are included to create well-formatted |
| * NDEF Records with correctly set tnf, type, id and payload fields, please |
| * use these helpers whenever possible. |
| * <p> |
| * Use the constructor {@link #NdefRecord(short, byte[], byte[], byte[])} |
| * if you know what you are doing and what to set the fields individually. |
| * Only basic validation is performed with this constructor, so it is possible |
| * to create records that do not confirm to the strict NFC Forum |
| * specifications. |
| * <p> |
| * The binary representation of an NDEF Record includes additional flags to |
| * indicate location with an NDEF message, provide support for chunking of |
| * NDEF records, and to pack optional fields. This class does not expose |
| * those details. To write an NDEF Record as binary you must first put it |
| * into an @{link NdefMessage}, then call {@link NdefMessage#toByteArray()}. |
| * <p class="note"> |
| * {@link NdefMessage} and {@link NdefRecord} implementations are |
| * always available, even on Android devices that do not have NFC hardware. |
| * <p class="note"> |
| * {@link NdefRecord}s are intended to be immutable (and thread-safe), |
| * however they may contain mutable fields. So take care not to modify |
| * mutable fields passed into constructors, or modify mutable fields |
| * obtained by getter methods, unless such modification is explicitly |
| * marked as safe. |
| * |
| * @see NfcAdapter#ACTION_NDEF_DISCOVERED |
| * @see NdefMessage |
| */ |
| public final class NdefRecord implements Parcelable { |
| /** |
| * Indicates the record is empty.<p> |
| * Type, id and payload fields are empty in a {@literal TNF_EMPTY} record. |
| */ |
| public static final short TNF_EMPTY = 0x00; |
| |
| /** |
| * Indicates the type field contains a well-known RTD type name.<p> |
| * Use this tnf with RTD types such as {@link #RTD_TEXT}, {@link #RTD_URI}. |
| * <p> |
| * The RTD type name format is specified in NFCForum-TS-RTD_1.0. |
| * |
| * @see #RTD_URI |
| * @see #RTD_TEXT |
| * @see #RTD_SMART_POSTER |
| * @see #createUri |
| */ |
| public static final short TNF_WELL_KNOWN = 0x01; |
| |
| /** |
| * Indicates the type field contains a media-type BNF |
| * construct, defined by RFC 2046.<p> |
| * Use this with MIME type names such as {@literal "image/jpeg"}, or |
| * using the helper {@link #createMime}. |
| * |
| * @see #createMime |
| */ |
| public static final short TNF_MIME_MEDIA = 0x02; |
| |
| /** |
| * Indicates the type field contains an absolute-URI |
| * BNF construct defined by RFC 3986.<p> |
| * When creating new records prefer {@link #createUri}, |
| * since it offers more compact URI encoding |
| * ({@literal #RTD_URI} allows compression of common URI prefixes). |
| * |
| * @see #createUri |
| */ |
| public static final short TNF_ABSOLUTE_URI = 0x03; |
| |
| /** |
| * Indicates the type field contains an external type name.<p> |
| * Used to encode custom payloads. When creating new records |
| * use the helper {@link #createExternal}.<p> |
| * The external-type RTD format is specified in NFCForum-TS-RTD_1.0.<p> |
| * <p> |
| * Note this TNF should not be used with RTD_TEXT or RTD_URI constants. |
| * Those are well known RTD constants, not external RTD constants. |
| * |
| * @see #createExternal |
| */ |
| public static final short TNF_EXTERNAL_TYPE = 0x04; |
| |
| /** |
| * Indicates the payload type is unknown.<p> |
| * NFC Forum explains this should be treated similarly to the |
| * "application/octet-stream" MIME type. The payload |
| * type is not explicitly encoded within the record. |
| * <p> |
| * The type field is empty in an {@literal TNF_UNKNOWN} record. |
| */ |
| public static final short TNF_UNKNOWN = 0x05; |
| |
| /** |
| * Indicates the payload is an intermediate or final chunk of a chunked |
| * NDEF Record.<p> |
| * {@literal TNF_UNCHANGED} can not be used with this class |
| * since all {@link NdefRecord}s are already unchunked, however they |
| * may appear in the binary format. |
| */ |
| public static final short TNF_UNCHANGED = 0x06; |
| |
| /** |
| * Reserved TNF type. |
| * <p> |
| * The NFC Forum NDEF Specification v1.0 suggests for NDEF parsers to treat this |
| * value like TNF_UNKNOWN. |
| * @hide |
| */ |
| public static final short TNF_RESERVED = 0x07; |
| |
| /** |
| * RTD Text type. For use with {@literal TNF_WELL_KNOWN}. |
| * @see #TNF_WELL_KNOWN |
| */ |
| public static final byte[] RTD_TEXT = {0x54}; // "T" |
| |
| /** |
| * RTD URI type. For use with {@literal TNF_WELL_KNOWN}. |
| * @see #TNF_WELL_KNOWN |
| */ |
| public static final byte[] RTD_URI = {0x55}; // "U" |
| |
| /** |
| * RTD Smart Poster type. For use with {@literal TNF_WELL_KNOWN}. |
| * @see #TNF_WELL_KNOWN |
| */ |
| public static final byte[] RTD_SMART_POSTER = {0x53, 0x70}; // "Sp" |
| |
| /** |
| * RTD Alternative Carrier type. For use with {@literal TNF_WELL_KNOWN}. |
| * @see #TNF_WELL_KNOWN |
| */ |
| public static final byte[] RTD_ALTERNATIVE_CARRIER = {0x61, 0x63}; // "ac" |
| |
| /** |
| * RTD Handover Carrier type. For use with {@literal TNF_WELL_KNOWN}. |
| * @see #TNF_WELL_KNOWN |
| */ |
| public static final byte[] RTD_HANDOVER_CARRIER = {0x48, 0x63}; // "Hc" |
| |
| /** |
| * RTD Handover Request type. For use with {@literal TNF_WELL_KNOWN}. |
| * @see #TNF_WELL_KNOWN |
| */ |
| public static final byte[] RTD_HANDOVER_REQUEST = {0x48, 0x72}; // "Hr" |
| |
| /** |
| * RTD Handover Select type. For use with {@literal TNF_WELL_KNOWN}. |
| * @see #TNF_WELL_KNOWN |
| */ |
| public static final byte[] RTD_HANDOVER_SELECT = {0x48, 0x73}; // "Hs" |
| |
| /** |
| * RTD Android app type. For use with {@literal TNF_EXTERNAL}. |
| * <p> |
| * The payload of a record with type RTD_ANDROID_APP |
| * should be the package name identifying an application. |
| * Multiple RTD_ANDROID_APP records may be included |
| * in a single {@link NdefMessage}. |
| * <p> |
| * Use {@link #createApplicationRecord(String)} to create |
| * RTD_ANDROID_APP records. |
| * @hide |
| */ |
| public static final byte[] RTD_ANDROID_APP = "android.com:pkg".getBytes(); |
| |
| private static final byte FLAG_MB = (byte) 0x80; |
| private static final byte FLAG_ME = (byte) 0x40; |
| private static final byte FLAG_CF = (byte) 0x20; |
| private static final byte FLAG_SR = (byte) 0x10; |
| private static final byte FLAG_IL = (byte) 0x08; |
| |
| /** |
| * NFC Forum "URI Record Type Definition"<p> |
| * This is a mapping of "URI Identifier Codes" to URI string prefixes, |
| * per section 3.2.2 of the NFC Forum URI Record Type Definition document. |
| */ |
| private static final String[] URI_PREFIX_MAP = new String[] { |
| "", // 0x00 |
| "http://www.", // 0x01 |
| "https://www.", // 0x02 |
| "http://", // 0x03 |
| "https://", // 0x04 |
| "tel:", // 0x05 |
| "mailto:", // 0x06 |
| "ftp://anonymous:anonymous@", // 0x07 |
| "ftp://ftp.", // 0x08 |
| "ftps://", // 0x09 |
| "sftp://", // 0x0A |
| "smb://", // 0x0B |
| "nfs://", // 0x0C |
| "ftp://", // 0x0D |
| "dav://", // 0x0E |
| "news:", // 0x0F |
| "telnet://", // 0x10 |
| "imap:", // 0x11 |
| "rtsp://", // 0x12 |
| "urn:", // 0x13 |
| "pop:", // 0x14 |
| "sip:", // 0x15 |
| "sips:", // 0x16 |
| "tftp:", // 0x17 |
| "btspp://", // 0x18 |
| "btl2cap://", // 0x19 |
| "btgoep://", // 0x1A |
| "tcpobex://", // 0x1B |
| "irdaobex://", // 0x1C |
| "file://", // 0x1D |
| "urn:epc:id:", // 0x1E |
| "urn:epc:tag:", // 0x1F |
| "urn:epc:pat:", // 0x20 |
| "urn:epc:raw:", // 0x21 |
| "urn:epc:", // 0x22 |
| }; |
| |
| private static final int MAX_PAYLOAD_SIZE = 10 * (1 << 20); // 10 MB payload limit |
| |
| private static final byte[] EMPTY_BYTE_ARRAY = new byte[0]; |
| |
| private final short mTnf; |
| private final byte[] mType; |
| private final byte[] mId; |
| private final byte[] mPayload; |
| |
| /** |
| * Create a new Android Application Record (AAR). |
| * <p> |
| * This record indicates to other Android devices the package |
| * that should be used to handle the entire NDEF message. |
| * You can embed this record anywhere into your message |
| * to ensure that the intended package receives the message. |
| * <p> |
| * When an Android device dispatches an {@link NdefMessage} |
| * containing one or more Android application records, |
| * the applications contained in those records will be the |
| * preferred target for the {@link NfcAdapter#ACTION_NDEF_DISCOVERED} |
| * intent, in the order in which they appear in the message. |
| * This dispatch behavior was first added to Android in |
| * Ice Cream Sandwich. |
| * <p> |
| * If none of the applications have a are installed on the device, |
| * a Market link will be opened to the first application. |
| * <p> |
| * Note that Android application records do not overrule |
| * applications that have called |
| * {@link NfcAdapter#enableForegroundDispatch}. |
| * |
| * @param packageName Android package name |
| * @return Android application NDEF record |
| */ |
| public static NdefRecord createApplicationRecord(String packageName) { |
| if (packageName.length() == 0) { |
| throw new IllegalArgumentException("empty package name"); |
| } |
| return new NdefRecord(TNF_EXTERNAL_TYPE, RTD_ANDROID_APP, null, |
| packageName.getBytes(Charsets.UTF_8)); |
| } |
| |
| /** |
| * Create a new NDEF Record containing a URI.<p> |
| * Use this method to encode a URI (or URL) into an NDEF Record.<p> |
| * Uses the well known URI type representation: {@link #TNF_WELL_KNOWN} |
| * and {@link #RTD_URI}. This is the most efficient encoding |
| * of a URI into NDEF.<p> |
| * Reference specification: NFCForum-TS-RTD_URI_1.0 |
| * |
| * @param uri URI to encode. |
| * @return an NDEF Record containing the URI |
| * @throws IllegalArugmentException if a valid record cannot be created |
| */ |
| public static NdefRecord createUri(Uri uri) { |
| return createUri(uri.toString()); |
| } |
| |
| /** |
| * Create a new NDEF Record containing a URI.<p> |
| * Use this method to encode a URI (or URL) into an NDEF Record.<p> |
| * Uses the well known URI type representation: {@link #TNF_WELL_KNOWN} |
| * and {@link #RTD_URI}. This is the most efficient encoding |
| * of a URI into NDEF.<p> |
| * Reference specification: NFCForum-TS-RTD_URI_1.0 |
| * |
| * @param uriString string URI to encode. |
| * @return an NDEF Record containing the URI |
| * @throws IllegalArugmentException if a valid record cannot be created |
| */ |
| public static NdefRecord createUri(String uriString) { |
| if (uriString.length() == 0) { |
| throw new IllegalArgumentException("empty uriString"); |
| } |
| |
| byte prefix = 0; |
| for (int i = 1; i < URI_PREFIX_MAP.length; i++) { |
| if (uriString.startsWith(URI_PREFIX_MAP[i])) { |
| prefix = (byte) i; |
| uriString = uriString.substring(URI_PREFIX_MAP[i].length()); |
| break; |
| } |
| } |
| byte[] uriBytes = uriString.getBytes(Charsets.UTF_8); |
| byte[] recordBytes = new byte[uriBytes.length + 1]; |
| recordBytes[0] = prefix; |
| System.arraycopy(uriBytes, 0, recordBytes, 1, uriBytes.length); |
| return new NdefRecord(TNF_WELL_KNOWN, RTD_URI, null, recordBytes); |
| } |
| |
| /** |
| * Create a new NDEF Record containing MIME data.<p> |
| * Use this method to encode MIME-typed data into an NDEF Record, |
| * such as "text/plain", or "image/jpeg".<p> |
| * Expects US-ASCII characters in mimeType. The encoding of the |
| * mimeData depends on the mimeType.<p> |
| * For efficiency, This method might not make an internal copy of the |
| * mimeData byte array, so take care not |
| * to re-use the mimeData byte array while still using the returned |
| * NdefRecord. |
| * |
| * @param mimeType MIME type, expects US-ASCII characters only |
| * @param mimeData MIME data as bytes |
| * @return an NDEF Record containing the MIME-typed data |
| * @throws IllegalArugmentException if a valid record cannot be created |
| */ |
| public static NdefRecord createMime(String mimeType, byte[] mimeData) { |
| if (mimeType.length() == 0) { |
| throw new IllegalArgumentException("empty mimeType"); |
| } |
| |
| return new NdefRecord(TNF_MIME_MEDIA, mimeType.getBytes(Charsets.US_ASCII), null, |
| mimeData); |
| } |
| |
| /** |
| * Create a new NDEF Record containing external (application-specific) data.<p> |
| * Use this method to encode application specific data into an NDEF Record. |
| * The data is typed by a domain name (usually your Android package name) and |
| * a domain-specific type. This data is packaged into a "NFC Forum External |
| * Type" NDEF Record.<p> |
| * Both the domain and type used to construct an external record are case |
| * insensitive, and this implementation will encode all characters to lower |
| * case. Only a subset of ASCII characters are allowed for the domain |
| * and type. There are no restrictions on the payload data.<p> |
| * For efficiency, This method might not make an internal copy of the |
| * data byte array, so take care not |
| * to re-use the data byte array while still using the returned |
| * NdefRecord. |
| * |
| * Reference specification: NFCForum-TS-RTD_1.0 |
| * @param domain domain-name of issuing organization |
| * @param type domain-specific type of data |
| * @param data payload as bytes |
| * @throws IllegalArugmentException if a valid record cannot be created |
| */ |
| public static NdefRecord createExternal(String domain, String type, byte[] data) { |
| if (domain.length() == 0 || type.length() == 0) { |
| throw new IllegalArgumentException("empty domain or type"); |
| } |
| byte[] byteDomain = domain.getBytes(Charsets.US_ASCII); |
| ensureValidDomain(byteDomain); |
| toLowerCase(byteDomain); |
| byte[] byteType = type.getBytes(Charsets.US_ASCII); |
| ensureValidWkt(byteType); |
| toLowerCase(byteType); |
| |
| byte[] b = new byte[byteDomain.length + 1 + byteType.length]; |
| System.arraycopy(byteDomain, 0, b, 0, byteDomain.length); |
| b[byteDomain.length] = ':'; |
| System.arraycopy(byteType, 0, b, byteDomain.length + 1, byteType.length); |
| |
| return new NdefRecord(TNF_EXTERNAL_TYPE, b, null, data); |
| } |
| |
| /** |
| * Construct an NDEF Record from its component fields.<p> |
| * Recommend to use helpers such as {#createUri} or |
| * {{@link #createExternal} where possible, since they perform |
| * stricter validation that the record is correctly formatted |
| * as per NDEF specifications. However if you know what you are |
| * doing then this constructor offers the most flexibility.<p> |
| * An {@link NdefRecord} represents a logical (complete) |
| * record, and cannot represent NDEF Record chunks.<p> |
| * Basic validation of the tnf, type, id and payload is performed |
| * as per the following rules: |
| * <ul> |
| * <li>The tnf paramter must be a 3-bit value.</li> |
| * <li>Records with a tnf of {@link #TNF_EMPTY} cannot have a type, |
| * id or payload.</li> |
| * <li>Records with a tnf of {@link #TNF_UNKNOWN} or {@literal 0x07} |
| * cannot have a type.</li> |
| * <li>Records with a tnf of {@link #TNF_UNCHANGED} are not allowed |
| * since this class only represents complete (unchunked) records.</li> |
| * </ul> |
| * This minimal validation is specified by |
| * NFCForum-TS-NDEF_1.0 section 3.2.6 (Type Name Format).<p> |
| * If any of the above validation |
| * steps fail then {@link IllegalArgumentException} is thrown.<p> |
| * Deep inspection of the type, id and payload fields is not |
| * performed, so it is possible to create NDEF Records |
| * that conform to section 3.2.6 |
| * but fail other more strict NDEF specification requirements. For |
| * example, the payload may be invalid given the tnf and type. |
| * <p> |
| * To omit a type, id or payload field, set the parameter to an |
| * empty byte array or null. |
| * |
| * @param tnf a 3-bit TNF constant |
| * @param type byte array, containing zero to 255 bytes, or null |
| * @param id byte array, containing zero to 255 bytes, or null |
| * @param payload byte array, containing zero to (2 ** 32 - 1) bytes, |
| * or null |
| * @throws IllegalArugmentException if a valid record cannot be created |
| */ |
| public NdefRecord(short tnf, byte[] type, byte[] id, byte[] payload) { |
| /* convert nulls */ |
| if (type == null) type = EMPTY_BYTE_ARRAY; |
| if (id == null) id = EMPTY_BYTE_ARRAY; |
| if (payload == null) payload = EMPTY_BYTE_ARRAY; |
| |
| String message = validateTnf(tnf, type, id, payload); |
| if (message != null) { |
| throw new IllegalArgumentException(message); |
| } |
| |
| mTnf = tnf; |
| mType = type; |
| mId = id; |
| mPayload = payload; |
| } |
| |
| /** |
| * Construct an NDEF Record from raw bytes.<p> |
| * This method is deprecated, use {@link NdefMessage#NdefMessage(byte[])} |
| * instead. This is because it does not make sense to parse a record: |
| * the NDEF binary format is only defined for a message, and the |
| * record flags MB and ME do not make sense outside of the context of |
| * an entire message.<p> |
| * This implementation will attempt to parse a single record by ignoring |
| * the MB and ME flags, and otherwise following the rules of |
| * {@link NdefMessage#NdefMessage(byte[])}.<p> |
| * |
| * @param data raw bytes to parse |
| * @throws FormatException if the data cannot be parsed into a valid record |
| * @deprecated use {@link NdefMessage#NdefMessage(byte[])} instead. |
| */ |
| @Deprecated |
| public NdefRecord(byte[] data) throws FormatException { |
| ByteBuffer buffer = ByteBuffer.wrap(data); |
| NdefRecord[] rs = parse(buffer, true); |
| |
| if (buffer.remaining() > 0) { |
| throw new FormatException("data too long"); |
| } |
| |
| mTnf = rs[0].mTnf; |
| mType = rs[0].mType; |
| mId = rs[0].mId; |
| mPayload = rs[0].mPayload; |
| } |
| |
| /** |
| * Returns the 3-bit TNF. |
| * <p> |
| * TNF is the top-level type. |
| */ |
| public short getTnf() { |
| return mTnf; |
| } |
| |
| /** |
| * Returns the variable length Type field. |
| * <p> |
| * This should be used in conjunction with the TNF field to determine the |
| * payload format. |
| * <p> |
| * Returns an empty byte array if this record |
| * does not have a type field. |
| */ |
| public byte[] getType() { |
| return mType.clone(); |
| } |
| |
| /** |
| * Returns the variable length ID. |
| * <p> |
| * Returns an empty byte array if this record |
| * does not have an id field. |
| */ |
| public byte[] getId() { |
| return mId.clone(); |
| } |
| |
| /** |
| * Returns the variable length payload. |
| * <p> |
| * Returns an empty byte array if this record |
| * does not have a payload field. |
| */ |
| public byte[] getPayload() { |
| return mPayload.clone(); |
| } |
| |
| /** |
| * Return this NDEF Record as a byte array.<p> |
| * This method is deprecated, use {@link NdefMessage#toByteArray} |
| * instead. This is because the NDEF binary format is not defined for |
| * a record outside of the context of a message: the MB and ME flags |
| * cannot be set without knowing the location inside a message.<p> |
| * This implementation will attempt to serialize a single record by |
| * always setting the MB and ME flags (in other words, assume this |
| * is a single-record NDEF Message).<p> |
| * |
| * @deprecated use {@link NdefMessage#toByteArray()} instead |
| */ |
| @Deprecated |
| public byte[] toByteArray() { |
| ByteBuffer buffer = ByteBuffer.allocate(getByteLength()); |
| writeToByteBuffer(buffer, true, true); |
| return buffer.array(); |
| } |
| |
| /** |
| * Helper to return the NdefRecord as a URI. |
| * TODO: Consider making a member method instead of static |
| * TODO: Consider more validation that this is a URI record |
| * TODO: Make a public API |
| * @hide |
| */ |
| public static Uri parseWellKnownUriRecord(NdefRecord record) throws FormatException { |
| byte[] payload = record.getPayload(); |
| if (payload.length < 2) { |
| throw new FormatException("Payload is not a valid URI (missing prefix)"); |
| } |
| |
| /* |
| * payload[0] contains the URI Identifier Code, per the |
| * NFC Forum "URI Record Type Definition" section 3.2.2. |
| * |
| * payload[1]...payload[payload.length - 1] contains the rest of |
| * the URI. |
| */ |
| int prefixIndex = (payload[0] & 0xff); |
| if (prefixIndex < 0 || prefixIndex >= URI_PREFIX_MAP.length) { |
| throw new FormatException("Payload is not a valid URI (invalid prefix)"); |
| } |
| String prefix = URI_PREFIX_MAP[prefixIndex]; |
| byte[] fullUri = concat(prefix.getBytes(Charsets.UTF_8), |
| Arrays.copyOfRange(payload, 1, payload.length)); |
| return Uri.parse(new String(fullUri, Charsets.UTF_8)); |
| } |
| |
| private static byte[] concat(byte[]... arrays) { |
| int length = 0; |
| for (byte[] array : arrays) { |
| length += array.length; |
| } |
| byte[] result = new byte[length]; |
| int pos = 0; |
| for (byte[] array : arrays) { |
| System.arraycopy(array, 0, result, pos, array.length); |
| pos += array.length; |
| } |
| return result; |
| } |
| |
| /** |
| * Main parsing method.<p> |
| * Expects NdefMessage to begin immediately, allows trailing data.<p> |
| * Currently has strict validation of all fields as per NDEF 1.0 |
| * specification section 2.5. We will attempt to keep this as strict as |
| * possible to encourage well-formatted NDEF.<p> |
| * Always returns 1 or more NdefRecord's, or throws FormatException. |
| * |
| * @param buffer ByteBuffer to read from |
| * @param ignoreMbMe ignore MB and ME flags, and read only 1 complete record |
| * @return one or more records |
| * @throws FormatException on any parsing error |
| */ |
| static NdefRecord[] parse(ByteBuffer buffer, boolean ignoreMbMe) throws FormatException { |
| List<NdefRecord> records = new ArrayList<NdefRecord>(); |
| |
| try { |
| byte[] type = null; |
| byte[] id = null; |
| byte[] payload = null; |
| ArrayList<byte[]> chunks = new ArrayList<byte[]>(); |
| boolean inChunk = false; |
| short chunkTnf = -1; |
| boolean me = false; |
| |
| while (!me) { |
| byte flag = buffer.get(); |
| |
| boolean mb = (flag & NdefRecord.FLAG_MB) != 0; |
| me = (flag & NdefRecord.FLAG_ME) != 0; |
| boolean cf = (flag & NdefRecord.FLAG_CF) != 0; |
| boolean sr = (flag & NdefRecord.FLAG_SR) != 0; |
| boolean il = (flag & NdefRecord.FLAG_IL) != 0; |
| short tnf = (short)(flag & 0x07); |
| |
| if (!mb && records.size() == 0 && !inChunk && !ignoreMbMe) { |
| throw new FormatException("expected MB flag"); |
| } else if (mb && records.size() != 0 && !ignoreMbMe) { |
| throw new FormatException("unexpected MB flag"); |
| } else if (inChunk && il) { |
| throw new FormatException("unexpected IL flag in non-leading chunk"); |
| } else if (cf && me) { |
| throw new FormatException("unexpected ME flag in non-trailing chunk"); |
| } else if (inChunk && tnf != NdefRecord.TNF_UNCHANGED) { |
| throw new FormatException("expected TNF_UNCHANGED in non-leading chunk"); |
| } else if (!inChunk && tnf == NdefRecord.TNF_UNCHANGED) { |
| throw new FormatException("" + |
| "unexpected TNF_UNCHANGED in first chunk or unchunked record"); |
| } |
| |
| int typeLength = buffer.get() & 0xFF; |
| long payloadLength = sr ? (buffer.get() & 0xFF) : (buffer.getInt() & 0xFFFFFFFFL); |
| int idLength = il ? (buffer.get() & 0xFF) : 0; |
| |
| if (inChunk && typeLength != 0) { |
| throw new FormatException("expected zero-length type in non-leading chunk"); |
| } |
| |
| if (!inChunk) { |
| type = (typeLength > 0 ? new byte[typeLength] : EMPTY_BYTE_ARRAY); |
| id = (idLength > 0 ? new byte[idLength] : EMPTY_BYTE_ARRAY); |
| buffer.get(type); |
| buffer.get(id); |
| } |
| |
| ensureSanePayloadSize(payloadLength); |
| payload = (payloadLength > 0 ? new byte[(int)payloadLength] : EMPTY_BYTE_ARRAY); |
| buffer.get(payload); |
| |
| if (cf && !inChunk) { |
| // first chunk |
| chunks.clear(); |
| chunkTnf = tnf; |
| } |
| if (cf || inChunk) { |
| // any chunk |
| chunks.add(payload); |
| } |
| if (!cf && inChunk) { |
| // last chunk, flatten the payload |
| payloadLength = 0; |
| for (byte[] p : chunks) { |
| payloadLength += p.length; |
| } |
| ensureSanePayloadSize(payloadLength); |
| payload = new byte[(int)payloadLength]; |
| int i = 0; |
| for (byte[] p : chunks) { |
| System.arraycopy(p, 0, payload, i, p.length); |
| i += p.length; |
| } |
| tnf = chunkTnf; |
| } |
| if (cf) { |
| // more chunks to come |
| inChunk = true; |
| continue; |
| } else { |
| inChunk = false; |
| } |
| |
| String error = validateTnf(tnf, type, id, payload); |
| if (error != null) { |
| throw new FormatException(error); |
| } |
| records.add(new NdefRecord(tnf, type, id, payload)); |
| if (ignoreMbMe) { // for parsing a single NdefRecord |
| break; |
| } |
| } |
| } catch (BufferUnderflowException e) { |
| throw new FormatException("expected more data", e); |
| } |
| return records.toArray(new NdefRecord[records.size()]); |
| } |
| |
| private static void ensureSanePayloadSize(long size) throws FormatException { |
| if (size > MAX_PAYLOAD_SIZE) { |
| throw new FormatException( |
| "payload above max limit: " + size + " > " + MAX_PAYLOAD_SIZE); |
| } |
| } |
| |
| /** |
| * Perform simple validation that the tnf is valid.<p> |
| * Validates the requirements of NFCForum-TS-NDEF_1.0 section |
| * 3.2.6 (Type Name Format). This just validates that the tnf |
| * is valid, and that the relevant type, id and payload |
| * fields are present (or empty) for this tnf. It does not |
| * perform any deep inspection of the type, id and payload fields.<p> |
| * Also does not allow TNF_UNCHANGED since this class is only used |
| * to present logical (unchunked) records. |
| * |
| * @return null if valid, or a string error if invalid. |
| */ |
| static String validateTnf(short tnf, byte[] type, byte[] id, byte[] payload) { |
| switch (tnf) { |
| case TNF_EMPTY: |
| if (type.length != 0 || id.length != 0 || payload.length != 0) { |
| return "unexpected data in TNF_EMPTY record"; |
| } |
| return null; |
| case TNF_WELL_KNOWN: |
| case TNF_MIME_MEDIA: |
| case TNF_ABSOLUTE_URI: |
| case TNF_EXTERNAL_TYPE: |
| return null; |
| case TNF_UNKNOWN: |
| case TNF_RESERVED: |
| if (type.length != 0) { |
| return "unexpected type field in TNF_UNKNOWN or TNF_RESERVEd record"; |
| } |
| return null; |
| case TNF_UNCHANGED: |
| return "unexpected TNF_UNCHANGED in first chunk or logical record"; |
| default: |
| return String.format("unexpected tnf value: 0x%02x", tnf); |
| } |
| } |
| |
| /** |
| * Serialize record for network transmission.<p> |
| * Uses specified MB and ME flags.<p> |
| * Does not chunk records. |
| */ |
| void writeToByteBuffer(ByteBuffer buffer, boolean mb, boolean me) { |
| boolean sr = mPayload.length < 256; |
| boolean il = mId.length > 0; |
| |
| byte flags = (byte)((mb ? FLAG_MB : 0) | (me ? FLAG_ME : 0) | |
| (sr ? FLAG_SR : 0) | (il ? FLAG_IL : 0) | mTnf); |
| buffer.put(flags); |
| |
| buffer.put((byte)mType.length); |
| if (sr) { |
| buffer.put((byte)mPayload.length); |
| } else { |
| buffer.putInt(mPayload.length); |
| } |
| if (il) { |
| buffer.put((byte)mId.length); |
| } |
| |
| buffer.put(mType); |
| buffer.put(mId); |
| buffer.put(mPayload); |
| } |
| |
| /** |
| * Get byte length of serialized record. |
| */ |
| int getByteLength() { |
| int length = 3 + mType.length + mId.length + mPayload.length; |
| |
| boolean sr = mPayload.length < 256; |
| boolean il = mId.length > 0; |
| |
| if (!sr) length += 3; |
| if (il) length += 1; |
| |
| return length; |
| } |
| |
| @Override |
| public int describeContents() { |
| return 0; |
| } |
| |
| @Override |
| public void writeToParcel(Parcel dest, int flags) { |
| dest.writeInt(mTnf); |
| dest.writeInt(mType.length); |
| dest.writeByteArray(mType); |
| dest.writeInt(mId.length); |
| dest.writeByteArray(mId); |
| dest.writeInt(mPayload.length); |
| dest.writeByteArray(mPayload); |
| } |
| |
| public static final Parcelable.Creator<NdefRecord> CREATOR = |
| new Parcelable.Creator<NdefRecord>() { |
| @Override |
| public NdefRecord createFromParcel(Parcel in) { |
| short tnf = (short)in.readInt(); |
| int typeLength = in.readInt(); |
| byte[] type = new byte[typeLength]; |
| in.readByteArray(type); |
| int idLength = in.readInt(); |
| byte[] id = new byte[idLength]; |
| in.readByteArray(id); |
| int payloadLength = in.readInt(); |
| byte[] payload = new byte[payloadLength]; |
| in.readByteArray(payload); |
| |
| return new NdefRecord(tnf, type, id, payload); |
| } |
| @Override |
| public NdefRecord[] newArray(int size) { |
| return new NdefRecord[size]; |
| } |
| }; |
| |
| @Override |
| public int hashCode() { |
| final int prime = 31; |
| int result = 1; |
| result = prime * result + Arrays.hashCode(mId); |
| result = prime * result + Arrays.hashCode(mPayload); |
| result = prime * result + mTnf; |
| result = prime * result + Arrays.hashCode(mType); |
| return result; |
| } |
| |
| /** |
| * Returns true if the specified NDEF Record contains |
| * identical tnf, type, id and payload fields. |
| */ |
| @Override |
| public boolean equals(Object obj) { |
| if (this == obj) return true; |
| if (obj == null) return false; |
| if (getClass() != obj.getClass()) return false; |
| NdefRecord other = (NdefRecord) obj; |
| if (!Arrays.equals(mId, other.mId)) return false; |
| if (!Arrays.equals(mPayload, other.mPayload)) return false; |
| if (mTnf != other.mTnf) return false; |
| return Arrays.equals(mType, other.mType); |
| } |
| |
| @Override |
| public String toString() { |
| StringBuilder b = new StringBuilder(String.format("NdefRecord tnf=%X", mTnf)); |
| if (mType.length > 0) b.append(" type=").append(bytesToString(mType)); |
| if (mId.length > 0) b.append(" id=").append(bytesToString(mId)); |
| if (mPayload.length > 0) b.append(" payload=").append(bytesToString(mPayload)); |
| return b.toString(); |
| } |
| |
| private static StringBuilder bytesToString(byte[] bs) { |
| StringBuilder s = new StringBuilder(); |
| for (byte b : bs) { |
| s.append(String.format("%02X", b)); |
| } |
| return s; |
| } |
| |
| /** Ensure valid 'DNS-char' as per RFC2234 */ |
| private static void ensureValidDomain(byte[] bs) { |
| for (int i = 0; i < bs.length; i++) { |
| byte b = bs[i]; |
| if ((b >= 'A' && b <= 'Z') || |
| (b >= 'a' && b <= 'z') || |
| (b >= '0' && b <= '9') || |
| b == '.' || b == '-') { |
| continue; |
| } |
| throw new IllegalArgumentException("invalid character in domain"); |
| } |
| } |
| |
| /** Ensure valid 'WKT-char' as per RFC2234 */ |
| private static void ensureValidWkt(byte[] bs) { |
| for (int i = 0; i < bs.length; i++) { |
| byte b = bs[i]; |
| if ((b >= 'A' && b <= 'Z') || |
| (b >= 'a' && b <= 'z') || |
| (b >= '0' && b <= '9') || |
| b == '(' || b == ')' || b == '+' || b == ',' || b == '-' || |
| b == ':' || b == '=' || b == '@' || b == ';' || b == '$' || |
| b == '_' || b == '!' || b == '*' || b == '\'' || b == '.') { |
| continue; |
| } |
| throw new IllegalArgumentException("invalid character in type"); |
| } |
| } |
| |
| private static void toLowerCase(byte[] b) { |
| for (int i = 0; i < b.length; i++) { |
| if (b[i] >= 'A' && b[i] <= 'Z') { |
| b[i] += 0x20; |
| } |
| } |
| } |
| } |