InputStream

This abstract class is the superclass of all classes representing an input stream of bytes.

<p> Applications that need to define a subclass of <code>InputStream</code> must always provide a method that returns the next byte of input.

@author Arthur van Hoff

Members

Functions

available
int available()

Returns an estimate of the number of bytes that can be read (or skipped over) from this input stream without blocking by the next invocation of a method for this input stream. The next invocation might be the same thread or another thread. A single read or skip of this many bytes will not block, but may read or skip fewer bytes.

close
void close()

Closes this input stream and releases any system resources associated with the stream.

mark
void mark(int readlimit)

Marks the current position in this input stream. A subsequent call to the <code>reset</code> method repositions this stream at the last marked position so that subsequent reads re-read the same bytes.

markSupported
bool markSupported()

Tests if this input stream supports the <code>mark</code> and <code>reset</code> methods. Whether or not <code>mark</code> and <code>reset</code> are supported is an invariant property of a particular input stream instance. The <code>markSupported</code> method of <code>InputStream</code> returns <code>false</code>.

position
void position(int index)

set a new position

read
int read()

Reads the next byte of data from the input stream. The value byte is returned as an <code>int</code> in the range <code>0</code> to <code>255</code>. If no byte is available because the end of the stream has been reached, the value <code>-1</code> is returned. This method blocks until input data is available, the end of the stream is detected, or an exception is thrown.

read
int read(byte[] b)

Reads some number of bytes from the input stream and stores them into the buffer array <code>b</code>. The number of bytes actually read is returned as an integer. This method blocks until input data is available, end of file is detected, or an exception is thrown.

read
int read(byte[] b, int off, int len)

Reads up to <code>len</code> bytes of data from the input stream into an array of bytes. An attempt is made to read as many as <code>len</code> bytes, but a smaller number may be read. The number of bytes actually read is returned as an integer.

reset
void reset()

Repositions this stream to the position at the time the <code>mark</code> method was last called on this input stream.

skip
long skip(long n)

Skips over and discards <code>n</code> bytes of data from this input stream. The <code>skip</code> method may, for a variety of reasons, end up skipping over some smaller number of bytes, possibly <code>0</code>. This may result from any of a number of conditions; reaching end of file before <code>n</code> bytes have been skipped is only one possibility. The actual number of bytes skipped is returned. If {@code n} is negative, the {@code skip} method for class {@code InputStream} always returns 0, and no bytes are skipped. Subclasses may handle the negative value differently.

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