org.htmlparser.lexer

Class Stream

Implemented Interfaces:
Runnable

public class Stream
extends InputStream
implements Runnable

Provides for asynchronous fetching from a stream.

Field Summary

protected static int
BUFFER_SIZE
An initial buffer size.
protected static int
EOF
Return value when no more characters are left.
int
fills
The number of calls to fill.
byte[]
mBuffer
The bytes read so far.
protected int
mContentLength
The content length from the HTTP header.
protected InputStream
mIn
The underlying stream.
int
mLevel
The number of valid bytes in the buffer.
protected int
mMark
The bookmark.
protected int
mOffset
The offset of the next byte returned by read().
int
reallocations
The number of reallocations.
int
synchronous
The number of synchronous (blocking) fills.

Constructor Summary

Stream(InputStream in)
Construct a stream with no assumptions about the number of bytes available.
Stream(InputStream in, int bytes)
Construct a stream to read the given number of bytes.

Method Summary

int
available()
Returns the number of bytes that can be read (or skipped over) from this input stream without blocking by the next caller of a method for this input stream.
void
close()
Closes this input stream and releases any system resources associated with the stream.
protected boolean
fill(boolean force)
Fetch more bytes from the underlying stream.
void
mark(int readlimit)
Marks the current position in this input stream.
boolean
markSupported()
Tests if this input stream supports the mark and reset methods.
int
read()
Reads the next byte of data from the input stream.
void
reset()
Repositions this stream to the position at the time the mark method was last called on this input stream.
void
run()
Continually read the underlying stream untill exhausted.

Field Details

BUFFER_SIZE

protected static final int BUFFER_SIZE
An initial buffer size.
Field Value:
4096

EOF

protected static final int EOF
Return value when no more characters are left.
Field Value:
-1

fills

public int fills
The number of calls to fill. Note: to be removed.

mBuffer

public byte[] mBuffer
The bytes read so far.

mContentLength

protected int mContentLength
The content length from the HTTP header.

mIn

protected InputStream mIn
The underlying stream.

mLevel

public int mLevel
The number of valid bytes in the buffer.

mMark

protected int mMark
The bookmark.

mOffset

protected int mOffset
The offset of the next byte returned by read().

reallocations

public int reallocations
The number of reallocations. Note: to be removed.

synchronous

public int synchronous
The number of synchronous (blocking) fills. Note: to be removed.

Constructor Details

Stream

public Stream(InputStream in)
Construct a stream with no assumptions about the number of bytes available.
Parameters:
in - The input stream to use.

Stream

public Stream(InputStream in,
              int bytes)
Construct a stream to read the given number of bytes.
Parameters:
in - The input stream to use.
bytes - The maximum number of bytes to read. This should be set to the ContentLength from the HTTP header. A negative or zero value indicates an unknown number of bytes.

Method Details

available

public int available()
            throws IOException
Returns the number of bytes that can be read (or skipped over) from this input stream without blocking by the next caller of a method for this input stream. The next caller might be the same thread or or another thread.
Returns:
The number of bytes that can be read from this input stream without blocking.

close

public void close()
            throws IOException
Closes this input stream and releases any system resources associated with the stream.

fill

protected boolean fill(boolean force)
            throws IOException
Fetch more bytes from the underlying stream. Has no effect if the underlying stream has been drained.
Parameters:
force - If true, an attempt is made to read from the underlying stream, even if bytes are available, If false, a read of the underlying stream will not occur if there are already bytes available.
Returns:
true if not at the end of the input stream.

mark

public void mark(int readlimit)
Marks the current position in this input stream. A subsequent call to the reset method repositions this stream at the last marked position so that subsequent reads re-read the same bytes.

The readlimit arguments tells this input stream to allow that many bytes to be read before the mark position gets invalidated.

The general contract of mark is that, if the method markSupported returns true, the stream somehow remembers all the bytes read after the call to mark and stands ready to supply those same bytes again if and whenever the method reset is called. However, the stream is not required to remember any data at all if more than readlimit bytes are read from the stream before reset is called.

Parameters:
readlimit - Not used.

markSupported

public boolean markSupported()
Tests if this input stream supports the mark and reset methods. Whether or not mark and reset are supported is an invariant property of a particular input stream instance. The markSupported method of InputStream returns false.
Returns:
true.

read

public int read()
            throws IOException
Reads the next byte of data from the input stream. The value byte is returned as an int in the range 0 to 255. If no byte is available because the end of the stream has been reached, the value -1 is returned. This method blocks until input data is available, the end of the stream is detected, or an exception is thrown.
Returns:
The next byte of data, or -1 if the end of the stream is reached.

reset

public void reset()
            throws IOException
Repositions this stream to the position at the time the mark method was last called on this input stream.

The general contract of reset is:

  • If the method markSupported returns true, then:
    • If the method mark has not been called since the stream was created, or the number of bytes read from the stream since mark was last called is larger than the argument to mark at that last call, then an IOException might be thrown.
    • If such an IOException is not thrown, then the stream is reset to a state such that all the bytes read since the most recent call to mark (or since the start of the file, if mark has not been called) will be resupplied to subsequent callers of the read method, followed by any bytes that otherwise would have been the next input data as of the time of the call to reset.
  • If the method markSupported returns false, then:
    • The call to reset may throw an IOException.
    • If an IOException is not thrown, then the stream is reset to a fixed state that depends on the particular type of the input stream and how it was created. The bytes that will be supplied to subsequent callers of the read method depend on the particular type of the input stream.

  • run

    public void run()
    Continually read the underlying stream untill exhausted.

    HTML Parser is an open source library released under LGPL. SourceForge.net