DataInputStream.read

Reads up to <code>len</code> bytes of data from the contained input stream into an array of bytes. An attempt is made to read as many as <code>len</code> bytes, but a smaller number may be read, possibly zero. The number of bytes actually read is returned as an integer.

<p> This method blocks until input data is available, end of file is detected, or an exception is thrown.

<p> If <code>len</code> is zero, then no bytes are read and <code>0</code> is returned; otherwise, there is an attempt to read at least one byte. If no byte is available because the stream is at end of file, the value <code>-1</code> is returned; otherwise, at least one byte is read and stored into <code>b</code>.

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

<p> In every case, elements <code>b[0]</code> through <code>boff</code> and elements <code>b[off+len]</code> through <code>b[b.length-1]</code> are unaffected.

@param b the buffer into which the data is read. @param off the start offset inputStream the destination array <code>b</code> @param len the maximum number of bytes read. @return the total number of bytes read into the buffer, or <code>-1</code> if there is no more data because the end of the stream has been reached. @exception NullPointerException If <code>b</code> is <code>null</code>. @exception IndexOutOfBoundsException If <code>off</code> is negative, <code>len</code> is negative, or <code>len</code> is greater than <code>b.length - off</code> @exception IOException if the first byte cannot be read for any reason other than end of file, the stream has been closed and the underlying input stream does not support reading after close, or another I/O error occurs. @see java.io.FilterInputStream#inputStream @see java.io.InputStream#read(byte[], int, int)

  1. int read(byte[] b)
  2. int read(byte[] b, int off, int len)
    class DataInputStream
    override final
    int
    read
    (
    byte[] b
    ,
    int off
    ,
    int len
    )

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