下面列出了java.io.InputStream#skip ( ) 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。
protected void drain(InputStream dis, long bytesRead) throws IOException
{
long toSkip = totalSize() - bytesRead;
// InputStream.skip can return -1 if dis is inaccessible.
long skipped = dis.skip(toSkip);
if (skipped == -1)
return;
toSkip = toSkip - skipped;
while (toSkip > 0)
{
skipped = dis.skip(toSkip);
if (skipped == -1)
break;
toSkip = toSkip - skipped;
}
}
/**
* Parses a method entry.
*/
private void scanMethod(InputStream is)
throws IOException
{
/*
int accessFlags = readShort();
int nameIndex = readShort();
int descriptorIndex = readShort();
*/
is.skip(6);
int attributesCount = readShort(is);
for (int i = 0; i < attributesCount; i++) {
scanAttributeForAnnotation(is);
}
}
public static void skipLocalHeader(InputStream is)
throws IOException
{
int magic;
if ((magic = readInt(is)) != 0x04034b50) {
throw new IOException("invalid zip format "+ Integer.toHexString(magic));
}
is.skip(2 + 2 + 2 + 2 + 2 + 4 + 4 + 4);
int nameLen = readShort(is);
int extraLen = readShort(is);
is.skip(nameLen + extraLen);
}
public Collection<Location> retrieveLocations(String... macs) throws IOException {
Request request = createRequest(macs);
byte[] byteb = request.toByteArray();
byte[] bytes = combineBytes(APPLE_MAGIC_BYTES, byteb, (byte) byteb.length);
HttpsURLConnection connection = createConnection();
prepareConnection(connection, bytes.length);
OutputStream out = connection.getOutputStream();
out.write(bytes);
out.flush();
out.close();
InputStream in = connection.getInputStream();
in.skip(10);
Response response = wire.parseFrom(readStreamToEnd(in), Response.class);
in.close();
Collection<Location> locations = new ArrayList<Location>();
for (Response.ResponseWifi wifi : response.wifis) {
locations.add(fromResponseWifi(wifi));
}
return locations;
}
@Override
public void readFileAtURL(LocalFilesystemURL inputURL, long start, long end,
ReadFileCallback readFileCallback) throws IOException {
File file = new File(this.filesystemPathForURL(inputURL));
String contentType = FileHelper.getMimeTypeForExtension(file.getAbsolutePath());
if (end < 0) {
end = file.length();
}
long numBytesToRead = end - start;
InputStream rawInputStream = new FileInputStream(file);
try {
if (start > 0) {
rawInputStream.skip(start);
}
LimitedInputStream inputStream = new LimitedInputStream(rawInputStream, numBytesToRead);
readFileCallback.handleData(inputStream, contentType);
} finally {
rawInputStream.close();
}
}
/**
* Positions the given input stream to the entry that has a specified tag. Tag will be consumed.
*
* @param is the input stream of TIFF data positioned to the beginning of an IFD.
* @param length length of the available data in the given input stream.
* @param isLittleEndian whether the TIFF data is stored in little or big endian format
* @param tagToFind tag to find
* @return remaining length of the data on success, 0 on failure
*/
private static int moveToTiffEntryWithTag(
InputStream is, int length, boolean isLittleEndian, int tagToFind) throws IOException {
if (length < 14) {
return 0;
}
// read the number of entries and go through all of them
// each IFD entry has length of 12 bytes and is composed of
// {TAG [2], TYPE [2], COUNT [4], VALUE/OFFSET [4]}
int numEntries = StreamProcessor.readPackedInt(is, 2, isLittleEndian);
length -= 2;
while (numEntries-- > 0 && length >= 12) {
int tag = StreamProcessor.readPackedInt(is, 2, isLittleEndian);
length -= 2;
if (tag == tagToFind) {
return length;
}
is.skip(10);
length -= 10;
}
return 0;
}
public static void skipFully(InputStream is, long num_bytes) throws EOFException, IOException {
long num_skipped = 0;
while (num_skipped < num_bytes) {
long just_skipped = is.skip(num_bytes - num_skipped);
if (just_skipped > 0)
num_skipped += just_skipped;
else {
if (is.read() < 0)
throw new EOFException("Skipped only " + num_skipped + " bytes to end of file.");
else
++num_skipped;
}
}
}
@Override
@Nullable
@Guarded(by = STARTED)
public InputStream getLogFileStream(final String fileName, final long from, final long count) throws IOException {
log.debug("Retrieving log file: {}", fileName);
// checking for platform or normalized path-separator (on unix these are the same)
if (fileName.contains(File.pathSeparator) || fileName.contains("/")) {
log.warn("Cannot retrieve log files with path separators in their name");
return null;
}
File file = getLogFile(fileName);
if (file == null || !file.exists()) {
log.warn("Log file does not exist: {}", fileName);
return null;
}
long fromByte = from;
long bytesCount = count;
if (count < 0) {
bytesCount = Math.abs(count);
fromByte = Math.max(0, file.length() - bytesCount);
}
InputStream input = new BufferedInputStream(new FileInputStream(file));
if (fromByte == 0 && bytesCount >= file.length()) {
return input;
}
else {
input.skip(fromByte);
return ByteStreams.limit(input, bytesCount);
}
}
static public void process(final InputStream in, final Set<Entry<Long, byte[]>> snapshotData, final OutputStream out) throws IOException {
final byte[] bb = new byte[4096];
final Iterator<Entry<Long, byte[]>> bbs = snapshotData.iterator();
long curs = 0;
while (bbs.hasNext()) {
final Entry<Long, byte[]> e = bbs.next();
final long pos = e.getKey();
final byte[] buf = e.getValue();
final long blen = buf.length;
// transfer Input to Output until start of buffer
if (curs < pos) {
transfer(in, (pos-curs), bb, out);
curs = pos;
}
// transfer buffer
out.write(buf);
log.info("Write ByteBuffer at " + pos +", length: " + blen);
curs += blen;
// skip input over size of buffer
in.skip(blen);
}
// Now transfer remainder of stream
transfer(in, Long.MAX_VALUE, bb, out);
}
/**
* Skips exactly the specified number of bytes, throwing an exception if unsuccessful.
* @param in the stream to read from
* @param numBytes the number of bytes to skip
* @throws IOException if EOF is reached or no more bytes can be skipped
*/
private static void skipOrDie(InputStream in, long numBytes) throws IOException {
long numLeft = numBytes;
long numSkipped = 0;
while ((numSkipped = in.skip(numLeft)) > 0) {
numLeft -= numSkipped;
}
if (numLeft != 0) {
throw new IOException("Unable to skip");
}
}
private static void skipDefiniteLengthContents(InputStream in, int len)
throws IOException, BerDataValueFormatException {
long bytesRead = 0;
while (len > 0) {
int skipped = (int) in.skip(len);
if (skipped <= 0) {
throw new BerDataValueFormatException(
"Truncated definite-length contents: " + bytesRead + " bytes read"
+ ", " + len + " missing");
}
len -= skipped;
bytesRead += skipped;
}
}
private void skipElementValue(InputStream is)
throws IOException
{
int code = is.read();
switch (code) {
case 'B': case 'C': case 'D': case 'F': case 'I': case 'J':
case 'S': case 'Z': case 's':
is.skip(2);
return;
case 'e':
is.skip(4);
return;
case 'c':
is.skip(2);
return;
case '@':
scanAnnotation(is);
return;
case '[':
int len = readShort(is);
for (int i = 0; i < len; i++) {
skipElementValue(is);
}
return;
default:
throw new IllegalStateException("unknown code: " + (char) code);
}
}
@Test
public void testSkip() throws IOException {
RBinaryStream t = redisson.getBinaryStream("test");
t.set(new byte[] {1, 2, 3, 4, 5, 6});
InputStream is = t.getInputStream();
is.skip(3);
byte[] b = new byte[6];
is.read(b);
assertThat(b).isEqualTo(new byte[] {4, 5, 6, 0, 0, 0});
}
/**
* Skip the defined {@code n} number of bytes from the {@code InputStream}
* and validates success of the operation
* @param is {@link InputStream} to skip bytes from
* @param n {@code long} number bytes to skip
* @return actual number of bytes have been skipped
* @exception IllegalStateException in case of {@code InputStream} reading error
*/
public static long skipAvailableBytes(InputStream is, long n) throws IllegalStateException {
try {
long skipped = is.skip(n);
if (skipped != n) {
throw new IllegalStateException(String.format("The number of skipped bytes [%s] differs from the expected value [%s]! "
+ "The InputStream is too small, corrupted or not accessible!", skipped, n));
}
return skipped;
} catch (IOException e) {
throw new DSSException("Cannot read the InputStream!", e);
}
}
@Override
protected void setBody(BoxHttpRequest request) throws IOException {
InputStream inputStream = getInputStream();
//skip previous parts
if (!mIsAlreadyPositioned) {
long skipTo = ((long)mPartNumber) * mUploadSession.getPartSize();
inputStream.skip(skipTo);
}
//Write bytes to URLConnection of the request
URLConnection urlConnection = request.getUrlConnection();
urlConnection.setDoOutput(true);
OutputStream output = urlConnection.getOutputStream();
if(mListener != null) {
output = new ProgressOutputStream(output, mListener, getPartSize());
}
byte[] byteBuf = new byte[SdkUtils.BUFFER_SIZE];
long totalBytesRead = 0;
int bytesRead = 0;
try {
do {
if (Thread.currentThread().isInterrupted()){
throw new InterruptedException();
}
if (totalBytesRead + byteBuf.length > mCurrentChunkSize){
bytesRead = inputStream.read(byteBuf, 0, (int)(totalBytesRead + byteBuf.length - mCurrentChunkSize));
} else {
bytesRead = inputStream.read(byteBuf, 0, byteBuf.length);
}
if (bytesRead != -1) {
output.write(byteBuf, 0, bytesRead);
totalBytesRead += bytesRead;
}
} while (bytesRead != -1 && totalBytesRead < mCurrentChunkSize);
} catch (InterruptedException ie) {
throw new IOException(ie);
} finally {
output.close();
if (mFile != null || !mIsAlreadyPositioned){
inputStream.close();
}
}
}
public static int[] querySize(InputStream is) throws IOException {
int c1 = is.read();
int c2 = is.read();
int c3 = is.read();
int width = 0;
int height = 0;
if (c1 == 'G' && c2 == 'I' && c3 == 'F') { // GIF
is.skip(3);
width = readInt(is,2,false);
height = readInt(is,2,false);
} else if (c1 == 0xFF && c2 == 0xD8) { // JPG
while (c3 == 255) {
int marker = is.read();
int len = readInt(is,2,true);
if (marker == 192 || marker == 193 || marker == 194) {
is.skip(1);
width = readInt(is,2,true);
height = readInt(is,2,true);
break;
}
is.skip(len - 2);
c3 = is.read();
}
} else if (c1 == 137 && c2 == 80 && c3 == 78) { // PNG
is.skip(15);
width = readInt(is,2,true);
is.skip(2);
height = readInt(is,2,true);
} else if (c1 == 66 && c2 == 77) { // BMP
is.skip(15);
width = readInt(is,2,false);
is.skip(2);
height = readInt(is,2,false);
} else {
int c4 = is.read();
if ((c1 == 'M' && c2 == 'M' && c3 == 0 && c4 == 42)
|| (c1 == 'I' && c2 == 'I' && c3 == 42 && c4 == 0)) { //TIFF
boolean bigEndian = c1 == 'M';
int ifd = 0;
int entries;
ifd = readInt(is,4,bigEndian);
is.skip(ifd - 8);
entries = readInt(is,2,bigEndian);
for (int i = 1; i <= entries; i++) {
int tag = readInt(is,2,bigEndian);
int fieldType = readInt(is,2,bigEndian);
int valOffset;
if ((fieldType == 3 || fieldType == 8)) {
valOffset = readInt(is,2,bigEndian);
is.skip(2);
} else {
valOffset = readInt(is,4,bigEndian);
}
if (tag == 256) {
width = valOffset;
} else if (tag == 257) {
height = valOffset;
}
if (width != -1 && height != -1) {
break;
}
}
}
}
return new int[] {width, height};
}
public static void skipUnusedStream(InputStream is) throws IOException {
if (is.available() > 0) {
is.skip(is.available());
}
}
private synchronized void dispatchResponse(HttpResponse response,
HttpSocket httpSocket,
long contentOffset,
long contentLength,
boolean badRequest) {
printLog("----- dispatch http response -----");
InputStream inputStream = null;
OutputStream outputStream = null;
try {
outputStream = httpSocket.getOutputStream();
outputStream.write(response.getResponseHeader().getBytes());
//必须返回！！！
outputStream.write("\r\n".getBytes());
//无法处理的请求
if (badRequest) {
outputStream.flush();
printLog("----- return bad response -----");
return;
}
inputStream = response.getContentInputStream();
if (contentOffset > 0) {
if (inputStream.skip(contentOffset) > 0) {
printLog("----- input stream skip -----:" + contentOffset);
}
}
int bufferSize = 512 * 1024;
byte[] readBuffer = new byte[bufferSize];
long readTotalSize = 0;
long readSize = (bufferSize > contentLength) ? contentLength : bufferSize;
int readLen = inputStream.read(readBuffer, 0, (int) readSize);
printLog("----- send video data start -----:" + contentOffset);
while (readLen > 0 && readTotalSize < contentLength) {
outputStream.write(readBuffer, 0, readLen);
outputStream.flush();
readTotalSize += readLen;
readSize = (bufferSize > (contentLength - readTotalSize))
? (contentLength - readTotalSize)
: bufferSize;
readLen = inputStream.read(readBuffer, 0, (int) readSize);
printLog("----- send video data success -----:" + readTotalSize + "/" + contentLength);
}
printLog("----- send video data over -----:" + contentOffset);
outputStream.flush();
} catch (Exception e) {
printLog("----- send video data error -----:" + e.getMessage());
e.printStackTrace();
} finally {
try {if (inputStream != null)
inputStream.close();
if (outputStream != null)
outputStream.close();
}catch (IOException ignore){
}
}
}
public static void main(String[] args) throws Exception {
try
{
setUp();
for (int i = 0; i < 8; i++) {
ModelByteBuffer buff;
if(i % 2 == 0)
buff = new ModelByteBuffer(test_file);
else
buff = new ModelByteBuffer(test_byte_array);
if((i / 2) == 1)
buff.subbuffer(5);
if((i / 2) == 2)
buff.subbuffer(5,500);
if((i / 2) == 3)
buff.subbuffer(5,600,true);
long capacity = buff.capacity();
InputStream is = buff.getInputStream();
try
{
is.mark(1000);
int ret = is.available();
int a = is.read();
is.skip(75);
is.reset();
if(is.available() != ret)
throw new RuntimeException(
"is.available() returns incorrect value ("
+ is.available() + "!="+(ret)+") !");
int b = is.read();
if(a != b)
throw new RuntimeException(
"is doesn't return same value after reset ("
+ a + "!="+b+") !");
is.skip(15);
ret = is.available();
is.mark(1000);
is.reset();
if(is.available() != ret)
throw new RuntimeException(
"is.available() returns incorrect value ("
+ is.available() + "!="+(ret)+") !");
}
finally
{
is.close();
}
if(buff.capacity() != capacity)
throw new RuntimeException("Capacity variable should not change!");
}
}
finally
{
tearDown();
}
}
/**
* This method is an alternative for the <CODE>InputStream.skip()</CODE>
* -method that doesn't seem to work properly for big values of <CODE>size
* </CODE>.
*
* @param is
* the <CODE>InputStream</CODE>
* @param size
* the number of bytes to skip
* @throws IOException
*/
static public void skip(InputStream is, int size) throws IOException {
while (size > 0) {
size -= is.skip(size);
}
}