public class SequenceInputStream extends InputStream
SequenceInputStream 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.| Constructor and Description | 
|---|
| SequenceInputStream(Enumeration<? extends InputStream> e)Initializes a newly created  SequenceInputStreamby remembering the argument, which must be anEnumerationthat produces objects whose run-time type isInputStream. | 
| SequenceInputStream(InputStream s1,
                   InputStream s2)Initializes a newly created  SequenceInputStreamby remembering the two arguments, which will be read
 in order, firsts1and thens2, to provide the bytes to be read from thisSequenceInputStream. | 
| Modifier and Type | Method and Description | 
|---|---|
| int | available()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. | 
| void | close()Closes this input stream and releases any system resources associated with the stream. | 
| int | read()Reads the next byte of data from this input stream. | 
| int | read(byte[] b,
    int off,
    int len)Reads up to  lenbytes of data from this input stream into an array of bytes. | 
mark, markSupported, read, reset, skippublic SequenceInputStream(Enumeration<? extends InputStream> e)
SequenceInputStream by remembering the argument, which must be an
 Enumeration that produces objects whose run-time type is InputStream. The input streams
 that are produced by the enumeration will be read, in order, to provide the bytes to be read from this
 SequenceInputStream. After each input stream from the enumeration is exhausted, it is closed by
 calling its close method.e - an enumeration of input streams.Enumerationpublic SequenceInputStream(InputStream s1, InputStream s2)
SequenceInputStream by remembering the two arguments, which will be read
 in order, first s1 and then s2, to provide the bytes to be read from this
 SequenceInputStream.s1 - the first input stream to read.s2 - the second input stream to read.public int available()
              throws IOException
 This method simply calls available of the current underlying input stream and returns the result.
available in class InputStream0 if this input stream has been closed by invoking its
         close() methodIOException - if an I/O error occurs.public void close()
           throws IOException
SequenceInputStream 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 the close method returns.
close in interface Closeableclose in interface AutoCloseableclose in class InputStreamIOException - if an I/O error occurs.public int read()
         throws IOException
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 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
 the close method of the current substream and begins reading from the next substream.
read in class InputStream-1 if the end of the stream is reached.IOException - if an I/O error occurs.public int read(@Nullable byte[] b, int off, int len) throws IOException
len bytes of data from this input stream into an array of bytes. If len is
 not zero, the method blocks until at least 1 byte of input is available; otherwise, no bytes are read and
 0 is returned.
 
 The read method of SequenceInputStream 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
 the close method of the current substream and begins reading from the next substream.
read in class InputStreamb - the buffer into which the data is read.off - the start offset in array b at which the data is written.len - the maximum number of bytes read.NullPointerException - If b is null.IndexOutOfBoundsException - If off is negative, len is negative, or len is greater than
                b.length - offIOException - if an I/O error occurs.InputStream.read()