Class SequenceInputStream
java.lang.Object
java.io.InputStream
java.io.SequenceInputStream
- All Implemented Interfaces:
Closeable
,AutoCloseable
A
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.- Since:
- 1.0
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Constructor Summary
ConstructorDescriptionInitializes 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
.SequenceInputStream
(Enumeration<? extends InputStream> e) Initializes a newly createdSequenceInputStream
by remembering the argument, which must be anEnumeration
that produces objects whose run-time type isInputStream
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Method Summary
Modifier and TypeMethodDescriptionint
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 the input stream.int
read
(byte[] b, int off, int len) Reads up tolen
bytes of data from this input stream into an array of bytes.Methods declared in class java.io.InputStream
mark, markSupported, nullInputStream, read, readAllBytes, readNBytes, readNBytes, reset, skip, skipNBytes, transferTo
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Constructor Details
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SequenceInputStream
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:
-
SequenceInputStream
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.
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Method Details
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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. 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 calls
available
of the current underlying input stream and returns the result.- Overrides:
available
in classInputStream
- Returns:
- an estimate of the number of bytes that can be read (or
skipped over) from the current underlying input stream
without blocking or
0
if this input stream has been closed by invoking itsclose()
method - Throws:
IOException
- if an I/O error occurs.- Since:
- 1.1
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read
Reads the next byte of data from the input stream. The value 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 byte 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.- Specified by:
read
in classInputStream
- Returns:
- the next byte of data, or
-1
if the end of the stream is reached. - Throws:
IOException
- if an I/O error occurs.
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read
Reads up tolen
bytes of data from this input stream into an array of bytes. If the end of the last contained stream has been reached then-1
is returned. Otherwise, iflen
is not zero, the method blocks until at least 1 byte of input is available; iflen
is zero, no bytes are read and0
is returned.The
read
method ofSequenceInputStream
tries to read the data from the current substream. If it fails to read any bytes 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 classInputStream
- 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:
- the total number of bytes read into the buffer, or
-1
if there is no more data because the end of the last contained stream has been reached. - Throws:
NullPointerException
- if the end of the last contained stream has not been reached andb
isnull
.IndexOutOfBoundsException
- if the end of the last contained stream has not been reached andoff
is negative,len
is negative, orlen
is greater thanb.length - off
IOException
- if an I/O error occurs.- See Also:
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close
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 the
close
method returns.- Specified by:
close
in interfaceAutoCloseable
- Specified by:
close
in interfaceCloseable
- Overrides:
close
in classInputStream
- Throws:
IOException
- if an I/O error occurs.
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