Added in API level 1

Summary: Fields | Ctors | Methods | Inherited Methods

ByteArrayInputStream

public class ByteArrayInputStream
extends InputStream

java.lang.Object
↳	java.io.InputStream
	↳	java.io.ByteArrayInputStream

A ByteArrayInputStream contains an internal buffer that contains bytes that may be read from the stream. An internal counter keeps track of the next byte to be supplied by the read method.

Closing a ByteArrayInputStream has no effect. The methods in this class can be called after the stream has been closed without generating an IOException.

See also:

StringBufferInputStream

Summary

Fields
`protected byte[]`	`buf` An array of bytes that was provided by the creator of the stream.
`protected int`	`count` The index one greater than the last valid character in the input stream buffer.
`protected int`	`mark` The currently marked position in the stream.
`protected int`	`pos` The index of the next character to read from the input stream buffer.

Public constructors
`ByteArrayInputStream(byte[] buf)` Creates a `ByteArrayInputStream` so that it uses `buf` as its buffer array.
`ByteArrayInputStream(byte[] buf, int offset, int length)` Creates `ByteArrayInputStream` that uses `buf` as its buffer array.

Public methods
`int`	`available()` Returns the number of remaining bytes that can be read (or skipped over) from this input stream.
`void`	`close()` Closing a `ByteArrayInputStream` has no effect.
`void`	`mark(int readAheadLimit)` Set the current marked position in the stream.
`boolean`	`markSupported()` Tests if this `InputStream` supports mark/reset.
`int`	`read()` Reads the next byte of data from this input stream.
`int`	`read(byte[] b, int off, int len)` Reads up to `len` bytes of data into an array of bytes from this input stream.
`byte[]`	`readAllBytes()` Reads all remaining bytes from the input stream.
`int`	`readNBytes(byte[] b, int off, int len)` Reads the requested number of bytes from the input stream into the given byte array.
`void`	`reset()` Resets the buffer to the marked position.
`long`	`skip(long n)` Skips `n` bytes of input from this input stream.
`long`	`transferTo(OutputStream out)` Reads all bytes from this input stream and writes the bytes to the given output stream in the order that they are read.

Inherited methods

From class


        
          java.io.InputStream

`int`	`available()` Returns an estimate of the number of bytes that can be read (or skipped over) from this input stream without blocking, which may be 0, or 0 when end of stream is detected.
`void`	`close()` Closes this input stream and releases any system resources associated with the 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.
`static InputStream`	`nullInputStream()` Returns a new `InputStream` that reads no bytes.
`int`	`read(byte[] b)` Reads some number of bytes from the input stream and stores them into the buffer array `b`.
`abstract int`	`read()` Reads the next byte of data from the input stream.
`int`	`read(byte[] b, int off, int len)` Reads up to `len` bytes of data from the input stream into an array of bytes.
`byte[]`	`readAllBytes()` Reads all remaining bytes from the input stream.
`int`	`readNBytes(byte[] b, int off, int len)` Reads the requested number of bytes from the input stream into the given byte array.
`byte[]`	`readNBytes(int len)` Reads up to a specified number of bytes 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.
`long`	`skip(long n)` Skips over and discards `n` bytes of data from this input stream.
`void`	`skipNBytes(long n)` Skips over and discards exactly `n` bytes of data from this input stream.
`long`	`transferTo(OutputStream out)` Reads all bytes from this input stream and writes the bytes to the given output stream in the order that they are read.

From class


        
          java.lang.Object

`Object`	`clone()` Creates and returns a copy of this object.
`boolean`	`equals(Object obj)` Indicates whether some other object is "equal to" this one.
`void`	`finalize()` Called by the garbage collector on an object when garbage collection determines that there are no more references to the object.
`final Class<?>`	`getClass()` Returns the runtime class of this `Object`.
`int`	`hashCode()` Returns a hash code value for the object.
`final void`	`notify()` Wakes up a single thread that is waiting on this object's monitor.
`final void`	`notifyAll()` Wakes up all threads that are waiting on this object's monitor.
`String`	`toString()` Returns a string representation of the object.
`final void`	`wait(long timeoutMillis, int nanos)` Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.
`final void`	`wait(long timeoutMillis)` Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.
`final void`	`wait()` Causes the current thread to wait until it is awakened, typically by being notified or interrupted.

From interface


        
          java.io.Closeable


      close()

Closes this stream and releases any system resources associated with it.

From interface


        
          java.lang.AutoCloseable


      close()

Closes this resource, relinquishing any underlying resources.

Fields

buf

Added in API level 1

protected byte[] buf

An array of bytes that was provided by the creator of the stream. Elements buf[0] through buf[count-1] are the only bytes that can ever be read from the stream; element buf[pos] is the next byte to be read.

count

Added in API level 1

protected int count

The index one greater than the last valid character in the input stream buffer. This value should always be nonnegative and not larger than the length of buf. It is one greater than the position of the last byte within buf that can ever be read from the input stream buffer.

mark

Added in API level 1

protected int mark

The currently marked position in the stream. ByteArrayInputStream objects are marked at position zero by default when constructed. They may be marked at another position within the buffer by the mark() method. The current buffer position is set to this point by the reset() method.

If no mark has been set, then the value of mark is the offset passed to the constructor (or 0 if the offset was not supplied).

pos

Added in API level 1

protected int pos

The index of the next character to read from the input stream buffer. This value should always be nonnegative and not larger than the value of count. The next byte to be read from the input stream buffer will be buf[pos].

Public constructors

ByteArrayInputStream

Added in API level 1

public ByteArrayInputStream (byte[] buf)

Creates a ByteArrayInputStream so that it uses buf as its buffer array. The buffer array is not copied. The initial value of pos is 0 and the initial value of count is the length of buf.

Parameters
`buf`	`byte`: the input buffer.

ByteArrayInputStream

Added in API level 1

public ByteArrayInputStream (byte[] buf, 
                int offset, 
                int length)

Creates ByteArrayInputStream that uses buf as its buffer array. The initial value of pos is offset and the initial value of count is the minimum of offset+length and buf.length. The buffer array is not copied. The buffer's mark is set to the specified offset.

Parameters
`buf`	`byte`: the input buffer.
`offset`	`int`: the offset in the buffer of the first byte to read.
`length`	`int`: the maximum number of bytes to read from the buffer.

Public methods

available

Added in API level 1

public int available ()

Returns the number of remaining bytes that can be read (or skipped over) from this input stream.

The value returned is count - pos, which is the number of bytes remaining to be read from the input buffer.

Returns
`int`	the number of remaining bytes that can be read (or skipped over) from this input stream without blocking.

close

Added in API level 1

public void close ()

Closing a ByteArrayInputStream has no effect. The methods in this class can be called after the stream has been closed without generating an IOException.

Throws
`IOException`

mark

Added in API level 1

public void mark (int readAheadLimit)

Set the current marked position in the stream. ByteArrayInputStream objects are marked at position zero by default when constructed. They may be marked at another position within the buffer by this method.

If no mark has been set, then the value of the mark is the offset passed to the constructor (or 0 if the offset was not supplied).

Note: The readAheadLimit for this class has no meaning.

Parameters
`readAheadLimit`	`int`: the maximum limit of bytes that can be read before the mark position becomes invalid.

markSupported

Added in API level 1

public boolean markSupported ()

Tests if this InputStream supports mark/reset. The markSupported method of ByteArrayInputStream always returns true.

Returns
`boolean`	`true` if this stream instance supports the mark and reset methods; `false` otherwise.

read

Added in API level 1

public int read ()

Reads the next byte of data from this 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 read method cannot block.

Returns
`int`	the next byte of data, or `-1` if the end of the stream has been reached.

read

Added in API level 1

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

Reads up to len bytes of data into an array of bytes from this input stream. If pos equals count, then -1 is returned to indicate end of file. Otherwise, the number k of bytes read is equal to the smaller of len and count-pos. If k is positive, then bytes buf[pos] through buf[pos+k-1] are copied into b[off] through b[off+k-1] in the manner performed by System.arraycopy. The value k is added into pos and k is returned.

This read method cannot block.

Parameters
`b`	`byte`: 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.

Returns
`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.

Throws
`NullPointerException`	If `b` is `null`.
`IndexOutOfBoundsException`	If `off` is negative, `len` is negative, or `len` is greater than `b.length - off`

readAllBytes

Added in API level 33

public byte[] 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.

Returns
`byte[]`	a byte array containing the bytes read from this input stream

readNBytes

Added in API level 33

public int readNBytes (byte[] b, 
                int off, 
                int len)

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.

Parameters
`b`	`byte`: the byte array into which the data is read
`off`	`int`: the start offset in `b` at which the data is written
`len`	`int`: the maximum number of bytes to read

Returns
`int`	the actual number of bytes read into the buffer

reset

Added in API level 1

public void reset ()

Resets the buffer to the marked position. The marked position is 0 unless another position was marked or an offset was specified in the constructor.

skip

Added in API level 1

public long skip (long n)

Skips n bytes of input from this input stream. Fewer bytes might be skipped if the end of the input stream is reached. The actual number k of bytes to be skipped is equal to the smaller of n and count-pos. The value k is added into pos and k is returned.

Parameters
`n`	`long`: the number of bytes to be skipped.

Returns
`long`	the actual number of bytes skipped.

transferTo

Added in API level 33

public long transferTo (OutputStream out)

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.

Parameters
`out`	`OutputStream`: the output stream, non-null

Returns
`long`	the number of bytes transferred

Throws
`IOException`