下面列出了java.io.RandomAccessFile#readByte ( ) 实例代码，或者点击链接到github查看源代码，也可以在右侧发表评论。
/**
* Reads an .mca file from a {@code RandomAccessFile} into this object.
* This method does not perform any cleanups on the data.
* @param raf The {@code RandomAccessFile} to read from.
* @param loadFlags A logical or of {@link LoadFlags} constants indicating what data should be loaded
* @throws IOException If something went wrong during deserialization.
* */
public void deserialize(RandomAccessFile raf, long loadFlags) throws IOException {
chunks = new Chunk[1024];
for (int i = 0; i < 1024; i++) {
raf.seek(i * 4);
int offset = raf.read() << 16;
offset |= (raf.read() & 0xFF) << 8;
offset |= raf.read() & 0xFF;
if (raf.readByte() == 0) {
continue;
}
raf.seek(4096 + i * 4);
int timestamp = raf.readInt();
Chunk chunk = new Chunk(timestamp);
raf.seek(4096 * offset + 4); //+4: skip data size
chunk.deserialize(raf, loadFlags);
chunks[i] = chunk;
}
}
/**
* Reads chunk data from a RandomAccessFile. The RandomAccessFile must already be at the correct position.
* @param raf The RandomAccessFile to read the chunk data from.
* @param loadFlags A logical or of {@link LoadFlags} constants indicating what data should be loaded
* @throws IOException When something went wrong during reading.
*/
public void deserialize(RandomAccessFile raf, long loadFlags) throws IOException {
byte compressionTypeByte = raf.readByte();
CompressionType compressionType = CompressionType.getFromID(compressionTypeByte);
if (compressionType == null) {
throw new IOException("invalid compression type " + compressionTypeByte);
}
BufferedInputStream dis = new BufferedInputStream(compressionType.decompress(new FileInputStream(raf.getFD())));
NamedTag tag = new NBTDeserializer(false).fromStream(dis);
if (tag != null && tag.getTag() instanceof CompoundTag) {
data = (CompoundTag) tag.getTag();
initReferences(loadFlags);
} else {
throw new IOException("invalid data tag: " + (tag == null ? "null" : tag.getClass().getName()));
}
}
private void seekToLastLine(RandomAccessFile rReader) throws IOException {
long fileLength = rReader.length() - 1;
long filePointer = fileLength;
boolean posReached = false;
int readByte = 0;
while (filePointer != -1 && !posReached) {
rReader.seek(filePointer);
readByte = rReader.readByte();
if (readByte == 0xA) {
if (filePointer != fileLength) {
posReached = true;
rReader.seek(filePointer);
}
} else if (readByte == 0xD && filePointer != fileLength - 1) {
posReached = true;
rReader.seek(filePointer);
}
filePointer--;
}
}
public static boolean newLineExists(String log) throws IOException {
File file = new File(log );
RandomAccessFile fileHandler = new RandomAccessFile(file, "r");
long fileLength = fileHandler.length() - 1;
if (fileLength < 0) {
fileHandler.close();
return true;
}
fileHandler.seek(fileLength);
byte readByte = fileHandler.readByte();
fileHandler.close();
if (readByte == 0xA || readByte == 0xD) {
return true;
}
return false;
}
public void read(final RandomAccessFile file) throws IOException, InvalidTagException {
final byte[] buffer = new byte[3];
// lets scan for a non-zero byte;
long filePointer;
byte b;
do {
filePointer = file.getFilePointer();
b = file.readByte();
org.farng.mp3.id3.AbstractID3v2.incrementPaddingCounter();
} while (b == 0);
file.seek(filePointer);
org.farng.mp3.id3.AbstractID3v2.decrementPaddingCounter();
// read the 3 chracter identifier
file.read(buffer, 0, 3);
final String identifier = new String(buffer, 0, 3);
// is this a valid identifier?
if (isValidID3v2FrameIdentifier(identifier) == false) {
file.seek(file.getFilePointer() - 2);
throw new InvalidTagException(identifier + " is not a valid ID3v2.20 frame");
}
this.setBody(readBody(identifier, file));
}
public void read(final RandomAccessFile file) throws IOException, InvalidTagException {
final int size = readHeader(file);
if (size == 0) {
throw new InvalidTagException("Empty Frame");
}
dataStart = file.readInt();
dataLength = file.readInt();
indexPoints = (int) file.readShort();
bitsPerPoint = (int) file.readByte();
fraction = new short[indexPoints];
for (int i = 0; i < indexPoints; i++) {
if (bitsPerPoint == 8) {
fraction[i] = (short) file.readByte();
} else if (bitsPerPoint == 16) {
fraction[i] = file.readShort();
} else {
throw new InvalidTagException("ASPI bits per point wasn't 8 or 16");
}
}
}
public boolean seek(final RandomAccessFile file) throws IOException {
final byte[] buffer = new byte[3];
if (file.length() < 128) {
return false;
}
// Check for the empty byte before the TRACK
file.seek(file.length() - 3);
buffer[0] = file.readByte();
if (buffer[0] != 0) {
return false;
}
// If there's a tag, it's 128 bytes long and we'll find the tag
file.seek(file.length() - 128);
// read the TAG value
file.read(buffer, 0, 3);
final String tag = new String(buffer, 0, 3);
return tag.equals("TAG");
}
static void modify(File file) throws IOException {
long size = file.length();
if (size == 0) {
recreateZeroSizeFile(file);
return;
}
RandomAccessFile accessFile = new RandomAccessFile(file, "rwd");
accessFile.seek(size - 1);
byte lastByte = accessFile.readByte();
accessFile.seek(size - 1);
accessFile.write(lastByte);
accessFile.close();
}
static void modify(File file) throws IOException {
long size = file.length();
if (size == 0) {
recreateZeroSizeFile(file);
return;
}
RandomAccessFile accessFile = new RandomAccessFile(file, "rwd");
accessFile.seek(size - 1);
byte lastByte = accessFile.readByte();
accessFile.seek(size - 1);
accessFile.write(lastByte);
accessFile.close();
}
static void modify(File file) throws IOException {
long size = file.length();
if (size == 0) {
recreateZeroSizeFile(file);
return;
}
RandomAccessFile accessFile = new RandomAccessFile(file, "rwd");
accessFile.seek(size - 1);
byte lastByte = accessFile.readByte();
accessFile.seek(size - 1);
accessFile.write(lastByte);
accessFile.close();
}
static void modify(File file) throws IOException {
long size = file.length();
if (size == 0) {
recreateZeroSizeFile(file);
return;
}
RandomAccessFile accessFile = new RandomAccessFile(file, "rwd");
accessFile.seek(size - 1);
byte lastByte = accessFile.readByte();
accessFile.seek(size - 1);
accessFile.write(lastByte);
accessFile.close();
}
private static int nullTerminatorIndex(long offset, RandomAccessFile raf)
throws IOException {
raf.seek(offset);
int index = 0;
byte b;
do {
b = raf.readByte();
index++;
} while (b != 0);
return index;
}
protected void read(RandomAccessFile raf) throws IOException {
this._fhSize = raf.readShort();
this._pageSize = raf.readInt();
this._totalPageCount = raf.readLong();
this._firstFreePage = raf.readLong();
this._lastFreePage = raf.readLong();
this._pageHeaderSize = raf.readByte();
}
static void modify(File file) throws IOException {
long size = file.length();
if (size == 0) {
recreateZeroSizeFile(file);
return;
}
RandomAccessFile accessFile = new RandomAccessFile(file, "rwd");
accessFile.seek(size - 1);
byte lastByte = accessFile.readByte();
accessFile.seek(size - 1);
accessFile.write(lastByte);
accessFile.close();
}
/**
* Returns true if the first MP3 frame can be found for the MP3 file argument. It is recursive and called by
* seekMP3Frame. This is the first byte of music data and not the ID3 Tag Frame.
*
* @param file MP3 file to seek
* @param iterations recursive counter
*
* @return true if the first MP3 frame can be found
*
* @throws IOException on any I/O error
*/
private boolean seekNextMP3Frame(final RandomAccessFile file, final int iterations) throws IOException {
final boolean syncFound;
final byte[] buffer;
final byte first;
final byte second;
final long filePointer;
if (iterations == 0) {
syncFound = true;
} else {
try {
readFrameHeader(file);
} catch (TagException ex) {
return false;
}
final int size = getFrameSize();
if ((size <= 0) || (size > file.length())) {
return false;
}
buffer = new byte[size - 4];
file.read(buffer);
filePointer = file.getFilePointer();
first = file.readByte();
if (first == (byte) 0xFF) {
second = (byte) (file.readByte() & (byte) 0xE0);
if (second == (byte) 0xE0) {
file.seek(filePointer);
// recursively find the next frames
syncFound = seekNextMP3Frame(file, iterations - 1);
} else {
syncFound = false;
}
} else {
syncFound = false;
}
}
return syncFound;
}
public void read(final RandomAccessFile file) throws IOException, InvalidTagException {
byte b;
long filePointer;
final byte[] buffer = new byte[4];
// lets scan for a non-zero byte;
do {
filePointer = file.getFilePointer();
b = file.readByte();
org.farng.mp3.id3.AbstractID3v2.incrementPaddingCounter();
} while (b == 0);
file.seek(filePointer);
org.farng.mp3.id3.AbstractID3v2.decrementPaddingCounter();
// read the four character identifier
file.read(buffer, 0, 4);
final String identifier = new String(buffer, 0, 4);
// is this a valid identifier?
if (isValidID3v2FrameIdentifier(identifier) == false) {
file.seek(file.getFilePointer() - 3);
throw new InvalidTagException(identifier + " is not a valid ID3v2.30 frame");
}
filePointer = file.getFilePointer();
// skip the 4 byte size
file.skipBytes(4);
// read the flag bytes
file.read(buffer, 0, 2);
this.tagAlterPreservation = (buffer[0] & TagConstant.MASK_V23_TAG_ALTER_PRESERVATION) != 0;
this.fileAlterPreservation = (buffer[0] & TagConstant.MASK_V23_FILE_ALTER_PRESERVATION) != 0;
this.readOnly = (buffer[0] & TagConstant.MASK_V23_READ_ONLY) != 0;
this.compression = (buffer[1] & TagConstant.MASK_V23_COMPRESSION) != 0;
this.encryption = (buffer[1] & TagConstant.MASK_V23_ENCRYPTION) != 0;
this.groupingIdentity = (buffer[1] & TagConstant.MASK_V23_GROUPING_IDENTITY) != 0;
file.seek(filePointer);
this.setBody(readBody(identifier, file));
}
public Chunk readChunk(int x, int z) throws IOException {
int index = getChunkOffset(x, z);
if (index < 0 || index >= 4096) {
return null;
}
this.lastUsed = System.currentTimeMillis();
if (!this.isChunkGenerated(index)) {
return null;
}
Integer[] table = this.locationTable.get(index);
RandomAccessFile raf = this.getRandomAccessFile();
raf.seek(table[0] << 12);
int length = raf.readInt();
if (length <= 0 || length >= MAX_SECTOR_LENGTH) {
if (length >= MAX_SECTOR_LENGTH) {
table[0] = ++this.lastSector;
table[1] = 1;
this.locationTable.put(index, table);
MainLogger.getLogger().error("Corrupted chunk header detected");
}
return null;
}
byte compression = raf.readByte();
if (length > (table[1] << 12)) {
MainLogger.getLogger().error("Corrupted bigger chunk detected");
table[1] = length >> 12;
this.locationTable.put(index, table);
this.writeLocationIndex(index);
} else if (compression != COMPRESSION_ZLIB && compression != COMPRESSION_GZIP) {
MainLogger.getLogger().error("Invalid compression type");
return null;
}
byte[] data = new byte[length - 1];
raf.readFully(data);
Chunk chunk = this.unserializeChunk(data);
if (chunk != null) {
return chunk;
} else {
MainLogger.getLogger().error("Corrupted chunk detected");
return null;
}
}
public Chunk readChunk(int x, int z) throws IOException {
int index = getChunkOffset(x, z);
if (index < 0 || index >= 4096) {
return null;
}
this.lastUsed = System.currentTimeMillis();
if (!this.isChunkGenerated(index)) {
return null;
}
Integer[] table = this.locationTable.get(index);
RandomAccessFile raf = this.getRandomAccessFile();
raf.seek(table[0] << 12);
int length = raf.readInt();
if (length <= 0 || length >= MAX_SECTOR_LENGTH) {
if (length >= MAX_SECTOR_LENGTH) {
table[0] = ++this.lastSector;
table[1] = 1;
this.locationTable.put(index, table);
MainLogger.getLogger().error("Corrupted chunk header detected");
}
return null;
}
byte compression = raf.readByte();
if (length > (table[1] << 12)) {
MainLogger.getLogger().error("Corrupted bigger chunk detected");
table[1] = length >> 12;
this.locationTable.put(index, table);
this.writeLocationIndex(index);
} else if (compression != COMPRESSION_ZLIB && compression != COMPRESSION_GZIP) {
MainLogger.getLogger().error("Invalid compression type");
return null;
}
byte[] data = new byte[length - 1];
raf.readFully(data);
Chunk chunk = this.unserializeChunk(data);
if (chunk != null) {
return chunk;
} else {
MainLogger.getLogger().error("Corrupted chunk detected");
return null;
}
}
/**
* Records a short sample of AAC ADTS from the microphone to find out what the sampling rate really is
* On some phone indeed, no error will be reported if the sampling rate used differs from the
* one selected with setAudioSamplingRate
* @throws IOException
* @throws IllegalStateException
*/
@SuppressLint("InlinedApi")
private void testADTS() throws IllegalStateException, IOException {
setAudioEncoder(MediaRecorder.AudioEncoder.AAC);
try {
Field name = MediaRecorder.OutputFormat.class.getField("AAC_ADTS");
setOutputFormat(name.getInt(null));
}
catch (Exception ignore) {
setOutputFormat(6);
}
String key = PREF_PREFIX+"aac-"+mQuality.samplingRate;
if (mSettings!=null && mSettings.contains(key)) {
String[] s = mSettings.getString(key, "").split(",");
mQuality.samplingRate = Integer.valueOf(s[0]);
mConfig = Integer.valueOf(s[1]);
mChannel = Integer.valueOf(s[2]);
return;
}
final String TESTFILE = Environment.getExternalStorageDirectory().getPath()+"/spydroid-test.adts";
if (!Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)) {
throw new IllegalStateException("No external storage or external storage not ready !");
}
// The structure of an ADTS packet is described here: http://wiki.multimedia.cx/index.php?title=ADTS
// ADTS header is 7 or 9 bytes long
byte[] buffer = new byte[9];
mMediaRecorder = new MediaRecorder();
mMediaRecorder.setAudioSource(mAudioSource);
mMediaRecorder.setOutputFormat(mOutputFormat);
mMediaRecorder.setAudioEncoder(mAudioEncoder);
mMediaRecorder.setAudioChannels(1);
mMediaRecorder.setAudioSamplingRate(mQuality.samplingRate);
mMediaRecorder.setAudioEncodingBitRate(mQuality.bitRate);
mMediaRecorder.setOutputFile(TESTFILE);
mMediaRecorder.setMaxDuration(1000);
mMediaRecorder.prepare();
mMediaRecorder.start();
// We record for 1 sec
// TODO: use the MediaRecorder.OnInfoListener
try {
Thread.sleep(2000);
} catch (InterruptedException e) {}
mMediaRecorder.stop();
mMediaRecorder.release();
mMediaRecorder = null;
File file = new File(TESTFILE);
RandomAccessFile raf = new RandomAccessFile(file, "r");
// ADTS packets start with a sync word: 12bits set to 1
while (true) {
if ( (raf.readByte()&0xFF) == 0xFF ) {
buffer[0] = raf.readByte();
if ( (buffer[0]&0xF0) == 0xF0) break;
}
}
raf.read(buffer,1,5);
mSamplingRateIndex = (buffer[1]&0x3C)>>2 ;
mProfile = ( (buffer[1]&0xC0) >> 6 ) + 1 ;
mChannel = (buffer[1]&0x01) << 2 | (buffer[2]&0xC0) >> 6 ;
mQuality.samplingRate = AUDIO_SAMPLING_RATES[mSamplingRateIndex];
// 5 bits for the object type / 4 bits for the sampling rate / 4 bits for the channel / padding
mConfig = (mProfile & 0x1F) << 11 | (mSamplingRateIndex & 0x0F) << 7 | (mChannel & 0x0F) << 3;
Log.i(TAG,"MPEG VERSION: " + ( (buffer[0]&0x08) >> 3 ) );
Log.i(TAG,"PROTECTION: " + (buffer[0]&0x01) );
Log.i(TAG,"PROFILE: " + AUDIO_OBJECT_TYPES[ mProfile ] );
Log.i(TAG,"SAMPLING FREQUENCY: " + mQuality.samplingRate );
Log.i(TAG,"CHANNEL: " + mChannel );
raf.close();
if (mSettings!=null) {
Editor editor = mSettings.edit();
editor.putString(key, mQuality.samplingRate+","+mConfig+","+mChannel);
editor.commit();
}
if (!file.delete()) Log.e(TAG,"Temp file could not be erased");
}
public void read(final RandomAccessFile file) throws IOException, InvalidTagException {
long filePointer;
final byte[] buffer = new byte[4];
byte b;
// lets scan for a non-zero byte;
do {
filePointer = file.getFilePointer();
b = file.readByte();
org.farng.mp3.id3.AbstractID3v2.incrementPaddingCounter();
} while (b == 0);
file.seek(filePointer);
org.farng.mp3.id3.AbstractID3v2.decrementPaddingCounter();
// read the four character identifier
file.read(buffer, 0, 4);
final String identifier = new String(buffer, 0, 4);
// is this a valid identifier?
if (isValidID3v2FrameIdentifier(identifier) == false) {
file.seek(file.getFilePointer() - 3);
throw new InvalidTagException(identifier + " is not a valid ID3v2.40 frame");
}
filePointer = file.getFilePointer();
// skip the 4 byte size
file.skipBytes(4);
// read the flag bytes
file.read(buffer, 0, 2);
this.tagAlterPreservation = (buffer[0] & TagConstant.MASK_V24_TAG_ALTER_PRESERVATION) != 0;
this.fileAlterPreservation = (buffer[0] & TagConstant.MASK_V24_FILE_ALTER_PRESERVATION) != 0;
this.readOnly = (buffer[0] & TagConstant.MASK_V24_READ_ONLY) != 0;
this.groupingIdentity = (buffer[1] & TagConstant.MASK_V24_GROUPING_IDENTITY) != 0;
this.compression = (buffer[1] & TagConstant.MASK_V24_COMPRESSION) != 0;
this.encryption = (buffer[1] & TagConstant.MASK_V24_ENCRYPTION) != 0;
this.unsynchronization = (buffer[1] & TagConstant.MASK_V24_FRAME_UNSYNCHRONIZATION) != 0;
this.dataLengthIndicator = (buffer[1] & TagConstant.MASK_V24_DATA_LENGTH_INDICATOR) != 0;
file.seek(filePointer);
this.setBody(readBody(identifier, file));
}