Added in API level 8

Base64InputStream


open class Base64InputStream : FilterInputStream

An InputStream that does Base64 decoding on the data read through it.

Summary

Public constructors

An InputStream that performs Base64 decoding on the data read from the wrapped stream.

Public methods
open Int

open Unit

open Unit
mark(readlimit: Int)

open Boolean

open Int

open Int
read(b: ByteArray!, off: Int, len: Int)

open Unit

open Long
skip(n: Long)

Inherited functions
InputStream! nullInputStream()

Returns a new InputStream that reads no bytes. The returned stream is initially open. The stream is closed by calling the close() method. Subsequent calls to close() have no effect.

While the stream is open, the available(), read(), read(byte[]), read(byte[], int, int), readAllBytes(), readNBytes(byte[], int, int), readNBytes(int), skip(long), skipNBytes(long), and transferTo() methods all behave as if end of stream has been reached. After the stream has been closed, these methods all throw IOException.

The markSupported() method returns false. The mark() method does nothing, and the reset() method throws IOException.

ByteArray! readAllBytes()

Reads all remaining bytes from the input stream. This method blocks until all remaining bytes have been read and end of stream is detected, or an exception is thrown. This method does not close the input stream.

When this stream reaches end of stream, further invocations of this method will return an empty byte array.

Note that this method is intended for simple cases where it is convenient to read all bytes into a byte array. It is not intended for reading input streams with large amounts of data.

The behavior for the case where the input stream is asynchronously closed, or the thread interrupted during the read, is highly input stream specific, and therefore not specified.

If an I/O error occurs reading from the input stream, then it may do so after some, but not all, bytes have been read. Consequently the input stream may not be at end of stream and may be in an inconsistent state. It is strongly recommended that the stream be promptly closed if an I/O error occurs.

Int readNBytes(b: ByteArray!, off: Int, len: Int)

Reads the requested number of bytes from the input stream into the given byte array. This method blocks until len bytes of input data have been read, end of stream is detected, or an exception is thrown. The number of bytes actually read, possibly zero, is returned. This method does not close the input stream.

In the case where end of stream is reached before len bytes have been read, then the actual number of bytes read will be returned. When this stream reaches end of stream, further invocations of this method will return zero.

If len is zero, then no bytes are read and 0 is returned; otherwise, there is an attempt to read up to len bytes.

The first byte read is stored into element b[off], the next one in to b[off+1], and so on. The number of bytes read is, at most, equal to len. Let k be the number of bytes actually read; these bytes will be stored in elements b[off] through b[off+k-1], leaving elements b[off+k ] through b[off+len-1] unaffected.

The behavior for the case where the input stream is asynchronously closed, or the thread interrupted during the read, is highly input stream specific, and therefore not specified.

If an I/O error occurs reading from the input stream, then it may do so after some, but not all, bytes of b have been updated with data from the input stream. Consequently the input stream and b may be in an inconsistent state. It is strongly recommended that the stream be promptly closed if an I/O error occurs.

ByteArray! readNBytes(len: Int)

Reads up to a specified number of bytes from the input stream. This method blocks until the requested number of bytes has been read, end of stream is detected, or an exception is thrown. This method does not close the input stream.

The length of the returned array equals the number of bytes read from the stream. If len is zero, then no bytes are read and an empty byte array is returned. Otherwise, up to len bytes are read from the stream. Fewer than len bytes may be read if end of stream is encountered.

When this stream reaches end of stream, further invocations of this method will return an empty byte array.

Note that this method is intended for simple cases where it is convenient to read the specified number of bytes into a byte array. The total amount of memory allocated by this method is proportional to the number of bytes read from the stream which is bounded by len. Therefore, the method may be safely called with very large values of len provided sufficient memory is available.

The behavior for the case where the input stream is asynchronously closed, or the thread interrupted during the read, is highly input stream specific, and therefore not specified.

If an I/O error occurs reading from the input stream, then it may do so after some, but not all, bytes have been read. Consequently the input stream may not be at end of stream and may be in an inconsistent state. It is strongly recommended that the stream be promptly closed if an I/O error occurs.

Unit skipNBytes(n: Long)

Skips over and discards exactly n bytes of data from this input stream. If n is zero, then no bytes are skipped. If n is negative, then no bytes are skipped. Subclasses may handle the negative value differently.

This method blocks until the requested number of bytes has been skipped, end of file is reached, or an exception is thrown.

If end of stream is reached before the stream is at the desired position, then an EOFException is thrown.

If an I/O error occurs, then the input stream may be in an inconsistent state. It is strongly recommended that the stream be promptly closed if an I/O error occurs.

Long transferTo(out: OutputStream!)

Reads all bytes from this input stream and writes the bytes to the given output stream in the order that they are read. On return, this input stream will be at end of stream. This method does not close either stream.

This method may block indefinitely reading from the input stream, or writing to the output stream. The behavior for the case where the input and/or output stream is asynchronously closed, or the thread interrupted during the transfer, is highly input and output stream specific, and therefore not specified.

If an I/O error occurs reading from the input stream or writing to the output stream, then it may do so after some bytes have been read or written. Consequently the input stream may not be at end of stream and one, or both, streams may be in an inconsistent state. It is strongly recommended that both streams be promptly closed if an I/O error occurs.

Int read(b: ByteArray!)

Reads up to b.length bytes of data from this input stream into an array of bytes. This method blocks until some input is available.

This method simply performs the call read(b, 0, b.length) and returns the result. It is important that it does not do in.read(b) instead; certain subclasses of FilterInputStream depend on the implementation strategy actually used.

Inherited properties
InputStream! in

The input stream to be filtered.

Public constructors

Base64InputStream

Added in API level 8
Base64InputStream(
    in: InputStream!,
    flags: Int)

An InputStream that performs Base64 decoding on the data read from the wrapped stream.

Parameters
in InputStream!: the InputStream to read the source data from
flags Int: bit flags for controlling the decoder; see the constants in Base64

Public methods

available

Added in API level 8
open fun available(): Int
Return
Int an estimate of the number of bytes that can be read (or skipped over) from this input stream without blocking.
Exceptions
java.io.IOException if an I/O error occurs.

close

Added in API level 8
open fun close(): Unit
Exceptions
java.lang.Exception if this resource cannot be closed
java.io.IOException if an I/O error occurs.

mark

Added in API level 8
open fun mark(readlimit: Int): Unit
Parameters
readlimit Int: the maximum limit of bytes that can be read before the mark position becomes invalid.

markSupported

Added in API level 8
open fun markSupported(): Boolean
Return
Boolean true if this stream type supports the mark and reset method; false otherwise.

read

Added in API level 8
open fun read(): Int
Return
Int the next byte of data, or -1 if the end of the stream is reached.
Exceptions
java.io.IOException if an I/O error occurs.

read

Added in API level 8
open fun read(
    b: ByteArray!,
    off: Int,
    len: Int
): Int
Parameters
b ByteArray!: the buffer into which the data is read.
off Int: the start offset in the destination array b
len Int: the maximum number of bytes read.
Return
Int 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.
Exceptions
java.io.IOException If the first byte cannot be read for any reason other than end of file, or if the input stream has been closed, or if some other I/O error occurs.
java.lang.NullPointerException If b is null.
java.lang.IndexOutOfBoundsException If off is negative, len is negative, or len is greater than b.length - off

reset

Added in API level 8
open fun reset(): Unit
Exceptions
java.io.IOException if this stream has not been marked or if the mark has been invalidated.

skip

Added in API level 8
open fun skip(n: Long): Long
Parameters
n Long: the number of bytes to be skipped.
Return
Long the actual number of bytes skipped.
Exceptions
java.io.IOException if in.skip(n) throws an IOException.