J2ME in a Nutshell

Name

InputStream

Synopsis

This is an abstract class that defines the methods used to read data from an input source in the form of a stream of bytes.

The no-argument read() method returns a single byte from the stream in the low-order 8 bits of an int, blocking until a byte is available to be read. If no more data is available from the stream, -1 is returned. There are also two other variants of read() that read a sequence of bytes into a buffer and return the number of bytes actually read, or -1 if end-of-file has been reached. These methods also block until data is available; however, they only guarantee to return a single byte--they do not block until the buffer is full. If you need this functionality, wrap the InputStream with a DataInputStream and use the readFully() method.

The available() method can be used to determine how much data is available to be read without blocking; this method is useful when the input source is a network connection which typically does not have all of its data immediately available. The skip() skips over a given number of bytes in the input stream; this method returns the number of bytes that it actually skipped, which may be fewer than the number requested if end-of-file was reached before or during the operation.

The mark() and reset() methods provide the capability for application code to mark a position in the input stream, which may be returned to later. The argument passed to the mark() method specifies the maximum number of bytes that application ...