Class UByteArrayInputStream

java.lang.Object
java.io.InputStream
cl.netswitch.lib.util.UByteArrayInputStream
All Implemented Interfaces:
Closeable, AutoCloseable
public final class UByteArrayInputStream extends InputStream
Unsynchronized InputStream in which data is read from a byte array. An internal counter keeps track of the next byte to be supplied by the read method.

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

  • Constructor Summary

    Constructors
    Constructor
    Description
    UByteArrayInputStream(byte[] buffer)
    Creates a UByteArrayInputStream so that it uses buffer as its buffer array.
    UByteArrayInputStream(byte[] buffer, int offset, int length)
    Creates a UByteArrayInputStream that uses buffer as its buffer array.

  • Method Summary

    Modifier and Type
    Method
    Description
    int
    available()
    Returns the number of remaining bytes that can be read (or skipped over) from this input stream.
    void
    close()
    Closing a UByteArrayInputStream 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[] array, int offset, int length)
    Reads up to length 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[] array, int offset, int length)
    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 output)
    Reads all bytes from this input stream and writes the bytes to the given output stream in the order that they are read.

    Methods inherited from class InputStream

    nullInputStream, read, readNBytes, skipNBytes

    Methods inherited from class Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

  • Constructor Details

    • UByteArrayInputStream

      public UByteArrayInputStream(byte[] buffer)
      Creates a UByteArrayInputStream so that it uses buffer as its buffer array. The buffer array is not copied. The initial value of position is 0 and the initial value of count is the length of buffer.
      Parameters:
      buffer - the input buffer.

    • UByteArrayInputStream

      public UByteArrayInputStream(byte[] buffer, int offset, int length)
      Creates a UByteArrayInputStream that uses buffer as its buffer array. The initial value of position is offset and the initial value of count is the minimum of offset+length and buffer.length. The buffer array is not copied. The buffer's mark is set to the specified offset.
      Parameters:
      buffer - the input buffer.
      offset - the offset in the buffer of the first byte to read.
      length - the maximum number of bytes to read from the buffer.

  • Method Details

    • read

      public int read() throws IOException
      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.

      Specified by:
      read in class InputStream
      Returns:
      the next byte of data, or -1 if the end of the stream has been reached.
      Throws:
      IOException

    • read

      public int read(byte[] array, int offset, int length) throws IOException
      Reads up to length bytes of data into an array of bytes from this input stream. If position equals count, then -1 is returned to indicate end of file. Otherwise, the number k of bytes read is equal to the smaller of length and count-position. If k is positive, then bytes buffer[position] through buffer[pos+k-1] are copied into array[offset] through array[offset+k-1] in the manner performed by System.arraycopy. The value k is added into position and k is returned.

      Unlike the overridden method of InputStream, this method returns -1 instead of zero if the end of the stream has been reached and len == 0.

      This read method cannot block.

      Overrides:
      read in class InputStream
      Parameters:
      array - the buffer into which the data is read.
      offset - the start offset in the destination array array
      length - the maximum number of bytes read.
      Returns:
      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 buf is null.
      IndexOutOfBoundsException - If offset is negative, length is negative, or length is greater than array.length - offset
      IOException

    • readAllBytes

      public byte[] readAllBytes() throws IOException
      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.

      Overrides:
      readAllBytes in class InputStream
      Returns:
      a byte array containing the bytes read from this input stream
      Throws:
      IOException - if an I/O error occurs
      OutOfMemoryError - if an array of the required size cannot be allocated.

    • readNBytes

      public int readNBytes(byte[] array, int offset, int length) throws IOException
      Reads the requested number of bytes from the input stream into the given byte array. This method blocks until length 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 length 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 length is zero, then no bytes are read and 0 is returned; otherwise, there is an attempt to read up to length bytes.

      The first byte read is stored into element array[offset], the next one in to array[offset+1], and so on. The number of bytes read is, at most, equal to length. Let k be the number of bytes actually read; these bytes will be stored in elements array[offset] through array[offset+k-1], leaving elements array[offset+k ] through array[offset+length-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 buf have been updated with data from the input stream. Consequently the input stream and buf may be in an inconsistent state. It is strongly recommended that the stream be promptly closed if an I/O error occurs.

      Overrides:
      readNBytes in class InputStream
      Parameters:
      array - the byte array into which the data is read
      offset - the start offset in array at which the data is written
      length - the maximum number of bytes to read
      Returns:
      the actual number of bytes read into the buffer
      Throws:
      IOException - if an I/O error occurs
      NullPointerException - if array is null
      IndexOutOfBoundsException - If offset is negative, length is negative, or length is greater than buf.length - offset

    • transferTo

      public long transferTo(OutputStream output) throws IOException
      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.

      Overrides:
      transferTo in class InputStream
      Parameters:
      output - the output stream, non-null
      Returns:
      the number of bytes transferred
      Throws:
      IOException - if an I/O error occurs when reading or writing
      NullPointerException - if output is null

    • skip

      public long skip(long n) throws IOException
      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 - position. The value k is added into position and k is returned.
      Overrides:
      skip in class InputStream
      Parameters:
      n - the number of bytes to be skipped.
      Returns:
      the actual number of bytes skipped.
      Throws:
      IOException

    • available

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

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

      Overrides:
      available in class InputStream
      Returns:
      the number of remaining bytes that can be read (or skipped over) from this input stream without blocking.
      Throws:
      IOException

    • markSupported

      public boolean markSupported()
      Tests if this InputStream supports mark/reset. The markSupported method of UByteArrayInputStream always returns true.
      Overrides:
      markSupported in class InputStream

    • mark

      public void mark(int readAheadLimit)
      Set the current marked position in the stream. UByteArrayInputStream 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.

      Overrides:
      mark in class InputStream

    • reset

      public void reset() throws IOException
      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.
      Overrides:
      reset in class InputStream
      Throws:
      IOException

    • close

      public void close() throws IOException
      Closing a UByteArrayInputStream has no effect. The methods in this class can be called after the stream has been closed without generating an IOException.
      Specified by:
      close in interface AutoCloseable
      Specified by:
      close in interface Closeable
      Overrides:
      close in class InputStream
      Throws:
      IOException