java.io
Class InputStream

java.lang.Object
  |
  +--java.io.InputStream

Direct Known Subclasses:

FileInputStream, FilterInputStream

public abstract class InputStream

extends Object

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

Constructor Summary

InputStream()
Default constructor.

Method Summary

int	available() Returns the number of bytes that can be read without blocking.
void	close() Closes this input stream and releases all system resources associated with it.
abstract int	read() Reads a single byte from this input stream.
int	read(byte[] bytes) Reads up to b.length bytes from this stream into b.
int	read(byte[] bytes, int ofs, int len) Reads up to len bytes from this stream into b starting at offset ofs.
long	skip(long n) Skips over and discards n bytes from the input stream.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, toString

Constructor Detail

InputStream

public InputStream()

Default constructor.

Method Detail

available

public int available()
              throws IOException

Returns the number of bytes that can be read without blocking. Returning 0 means that blocking might or might not occur. The method in this class always returns 0.

Returns:

number of bytes

IOException

close

public void close()
           throws IOException

Closes this input stream and releases all system resources associated with it.

IOException

read

public abstract int read()
                  throws IOException

Reads a single byte from this input stream. This abstract method shall be overloaded by subclasses.

Returns:

The next byte of data; -1 if the end of the stream is reached.

Throws:

IOException - if an I/O error occurs.

read

public int read(byte[] bytes)
         throws IOException

Reads up to b.length bytes from this stream into b. The method returns under the following conditions: 1. the array is completly filled, 2. there are no more bytes available, 3. a carriage return is read. If b was not completly filled, the remaining bytes of b still contain the values from before this method was called.

Parameters:

bytes - Array to be filled with data read.

Returns:

The number of bytes read; -1 if there are no more bytes to read.

Throws:

IOException - if an I/O error occurs.

read

public int read(byte[] bytes,
                int ofs,
                int len)
         throws IOException

Reads up to len bytes from this stream into b starting at offset ofs. The method returns under the following conditions: 1. len bytes have been read, 2. there are no more bytes available, 3. a carriage return is read.

Parameters:

bytes - Array to be filled with data read.

ofs - Offset into b where to start writing the read data.

len - Number of bytes to be read.

Returns:

The number of bytes read; -1 if there are no more bytes to read.

Throws:

IndexOutOfBoundsException - when either ofs or len are smaller than 0 or ofs+len exceed the array's length.

IOException - if an I/O error occurs.

skip

public long skip(long n)
          throws IOException

Skips over and discards n bytes from the input stream.

Parameters:

n - Number of bytes to overread.

Returns:

The number of bytes overread.

Throws:

IOException - if an I/O error occurs.