org.pdfbox.io
Class ByteArrayPushBackInputStream
java.io.PushbackInputStream
public class ByteArrayPushBackInputStream
PushBackInputStream for byte arrays.
The inheritance from PushBackInputStream is only to avoid the
introduction of an interface with all PushBackInputStream
methods. The parent PushBackInputStream is not used in any way and
all methods are overridden. (Thus when adding new methods to PushBackInputStream
override them in this class as well!)
unread() is limited to the number of bytes already read from this stream (i.e.
the current position in the array). This limitation usually poses no problem
to a parser, but allows for some optimization since only one array has to
be dealt with.
Note: This class is not thread safe. Clients must provide synchronization
if needed.
Note: Calling unread() after mark() will cause (part of) the unread data to be
read again after reset(). Thus do not call unread() between mark() and reset().
- Andreas Weiss (andreas.weiss@switzerland.org)
int | available() - Available bytes.
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boolean | isEOF() - A simple test to see if we are at the end of the stream.
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int | localRead(byte[] buffer, int off, int len) - Read a number of bytes.
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void | mark(int readlimit) - Save the state of this stream.
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boolean | markSupported() - Check if mark is supported.
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int | peek() - This will peek at the next byte.
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int | read() - Read a byte.
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int | read(byte[] buffer) - Read a number of bytes.
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int | read(byte[] buffer, int off, int len) - Read a number of bytes.
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void | reset() - Restore the state of this stream to the last saveState call.
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int | seek(int newpos) - Position the stream at a given index.
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int | size() - Totally available bytes in the underlying array.
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long | skip(long num) - Skips over and discards n bytes of data from this input stream.
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void | unread(byte[] buffer) - Pushes back a portion of an array of bytes by copying it to the
front of the pushback buffer.
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void | unread(byte[] buffer, int off, int len) - Pushes back a portion of an array of bytes by copying it to the
front of the pushback buffer.
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void | unread(int by) - Pushes back a byte.
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ByteArrayPushBackInputStream
public ByteArrayPushBackInputStream(byte[] input)
throws IOException
Constructor.
input
- Data to read from. Note that calls to unread() will
modify this array! If this is not desired, pass a copy.
available
public int available()
Available bytes.
isEOF
public boolean isEOF()
A simple test to see if we are at the end of the stream.
- isEOF in interface PushBackInputStream
- true if we are at the end of the stream.
localRead
public int localRead(byte[] buffer,
int off,
int len)
Read a number of bytes. Internal method that assumes off and len to be
valid.
buffer
- the buffer into which the data is read.off
- the start offset in array buffer at which the data is written.len
- the maximum number of bytes to read.
- the total number of bytes read into the buffer, or -1 if there
is no more data because the end of the stream has been reached.
InputStream.read(byte[], int, int)
mark
public void mark(int readlimit)
Save the state of this stream.
readlimit
- Has no effect.
markSupported
public boolean markSupported()
Check if mark is supported.
InputStream.markSupported()
peek
public int peek()
This will peek at the next byte.
- peek in interface PushBackInputStream
- The next byte on the stream, leaving it as available to read.
read
public int read()
Read a byte.
- Byte read or -1 if no more bytes are available.
read
public int read(byte[] buffer)
Read a number of bytes.
buffer
- the buffer into which the data is read.
- the total number of bytes read into the buffer, or -1 if there
is no more data because the end of the stream has been reached.
read
public int read(byte[] buffer,
int off,
int len)
Read a number of bytes.
buffer
- the buffer into which the data is read.off
- the start offset in array buffer at which the data is written.len
- the maximum number of bytes to read.
- the total number of bytes read into the buffer, or -1 if there
is no more data because the end of the stream has been reached.
InputStream.read(byte[], int, int)
reset
public void reset()
Restore the state of this stream to the last saveState call.
seek
public int seek(int newpos)
Position the stream at a given index. Positioning the stream
at position size() will cause the next call to read() to return -1.
newpos
- Position in the underlying array. A negative value will be
interpreted as 0, a value greater than size() as size().
size
public int size()
Totally available bytes in the underlying array.
skip
public long skip(long num)
Skips over and discards n bytes of data from this input stream.
The skip method may, for a variety of reasons, end up skipping over some
smaller number of bytes, possibly 0. This may result from any of a number
of conditions; reaching end of file before n bytes have been skipped is
only one possibility. The actual number of bytes skipped is returned.
If n is negative, no bytes are skipped.
num
- the number of bytes to be skipped.
- the actual number of bytes skipped.
unread
public void unread(byte[] buffer)
throws IOException
Pushes back a portion of an array of bytes by copying it to the
front of the pushback buffer. After this method returns, the next byte
to be read will have the value buffer[0], the byte after that will have
the value buffer[1], and so forth.
buffer
- the byte array to push back.
java.io.PushbackInputStream.unread(byte[])
unread
public void unread(byte[] buffer,
int off,
int len)
throws IOException
Pushes back a portion of an array of bytes by copying it to the
front of the pushback buffer. After this method returns, the next byte
to be read will have the value b[off], the byte after that will have
the value b[off+1], and so forth.
buffer
- the byte array to push back.off
- the start offset of the data.len
- the number of bytes to push back.
java.io.PushbackInputStream.unread(byte[], int, int)
unread
public void unread(int by)
throws IOException
Pushes back a byte.
After this method returns, the next byte to be read will have the value (byte)by.
by
- the int value whose low-order byte is to be pushed back.
java.io.PushbackInputStream.unread(int)