Module java.base
Package java.io

Class SequenceInputStream

  • All Implemented Interfaces:
    Closeable,AutoCloseable
    public classSequenceInputStreamextendsInputStream
    ASequenceInputStream represents the logical concatenation of other input streams. It starts out with an ordered collection of input streams and reads from the first one until end of file is reached, whereupon it reads from the second one, and so on, until end of file is reached on the last of the contained input streams.
    Since:
    1.0

    • Constructor Detail

      • SequenceInputStream

        public SequenceInputStream​(Enumeration<? extendsInputStream> e)
        Initializes a newly createdSequenceInputStream by remembering the argument, which must be anEnumeration that produces objects whose run-time type isInputStream. The input streams that are produced by the enumeration will be read, in order, to provide the bytes to be read from thisSequenceInputStream. After each input stream from the enumeration is exhausted, it is closed by calling itsclose method.
        Parameters:
        e - an enumeration of input streams.
        See Also:
        Enumeration

      • SequenceInputStream

        public SequenceInputStream​(InputStream s1,InputStream s2)
        Initializes a newly createdSequenceInputStream by remembering the two arguments, which will be read in order, firsts1 and thens2, to provide the bytes to be read from thisSequenceInputStream.
        Parameters:
        s1 - the first input stream to read.
        s2 - the second input stream to read.

    • Method Detail

      • available

        public int available()              throwsIOException
        Returns an estimate of the number of bytes that can be read (or skipped over) from the current underlying input stream without blocking by the next invocation of a method for the current underlying input stream. The next invocation might be the same thread or another thread. A single read or skip of this many bytes will not block, but may read or skip fewer bytes.

        This method simply callsavailable of the current underlying input stream and returns the result.

        Overrides:
        available in class InputStream
        Returns:
        an estimate of the number of bytes that can be read (or skipped over) from the current underlying input stream without blocking or0 if this input stream has been closed by invoking itsclose() method
        Throws:
        IOException - if an I/O error occurs.
        Since:
        1.1

      • read

        public int read()         throwsIOException
        Reads the next byte of data from this input stream. The byte is returned as anint in the range0 to255. If no byte is available because the end of the stream has been reached, the value-1 is returned. This method blocks until input data is available, the end of the stream is detected, or an exception is thrown.

        This method tries to read one character from the current substream. If it reaches the end of the stream, it calls theclose method of the current substream and begins reading from the next substream.

        Specified by:
        read in class InputStream
        Returns:
        the next byte of data, or-1 if the end of the stream is reached.
        Throws:
        IOException - if an I/O error occurs.

      • read

        public int read​(byte[] b,                int off,                int len)         throwsIOException
        Reads up tolen bytes of data from this input stream into an array of bytes. Iflen is not zero, the method blocks until at least 1 byte of input is available; otherwise, no bytes are read and0 is returned.

        Theread method ofSequenceInputStream tries to read the data from the current substream. If it fails to read any characters because the substream has reached the end of the stream, it calls theclose method of the current substream and begins reading from the next substream.

        Overrides:
        read in class InputStream
        Parameters:
        b - the buffer into which the data is read.
        off - the start offset in arrayb at which the data is written.
        len - the maximum number of bytes read.
        Returns:
        int the number of bytes read.
        Throws:
        NullPointerException - Ifb isnull.
        IndexOutOfBoundsException - Ifoff is negative,len is negative, orlen is greater thanb.length - off
        IOException - if an I/O error occurs.
        See Also:
        InputStream.read()

      • close

        public void close()           throwsIOException
        Closes this input stream and releases any system resources associated with the stream. A closedSequenceInputStream cannot perform input operations and cannot be reopened.

        If this stream was created from an enumeration, all remaining elements are requested from the enumeration and closed before theclose method returns.

        Specified by:
        close in interface AutoCloseable
        Specified by:
        close in interface Closeable
        Overrides:
        close in class InputStream
        Throws:
        IOException - if an I/O error occurs.