SequenceInputStream (Java SE 15 & JDK 15) (original) (raw)
All Implemented Interfaces:
[Closeable](Closeable.html "interface in java.io")
, [AutoCloseable](../lang/AutoCloseable.html "interface in java.lang")
public class SequenceInputStream extends InputStream
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
Constructor Summary
Constructors
Constructor | Description |
---|---|
SequenceInputStream(InputStream s1,InputStream s2) | Initializes a newly created 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. |
SequenceInputStream(Enumeration<? extends InputStream> e) | Initializes a newly created SequenceInputStream by remembering the argument, which must be an Enumeration that produces objects whose run-time type is InputStream. |
Method Summary
Modifier and Type | Method | 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 len bytes of data from this input stream into an array of bytes. |
Methods declared in class java.io.InputStream
[mark](InputStream.html#mark%28int%29), [markSupported](InputStream.html#markSupported%28%29), [nullInputStream](InputStream.html#nullInputStream%28%29), [read](InputStream.html#read%28byte%5B%5D%29), [readAllBytes](InputStream.html#readAllBytes%28%29), [readNBytes](InputStream.html#readNBytes%28byte%5B%5D,int,int%29), [readNBytes](InputStream.html#readNBytes%28int%29), [reset](InputStream.html#reset%28%29), [skip](InputStream.html#skip%28long%29), [skipNBytes](InputStream.html#skipNBytes%28long%29), [transferTo](InputStream.html#transferTo%28java.io.OutputStream%29)
Methods declared in class java.lang.Object
[clone](../lang/Object.html#clone%28%29), [equals](../lang/Object.html#equals%28java.lang.Object%29), [finalize](../lang/Object.html#finalize%28%29), [getClass](../lang/Object.html#getClass%28%29), [hashCode](../lang/Object.html#hashCode%28%29), [notify](../lang/Object.html#notify%28%29), [notifyAll](../lang/Object.html#notifyAll%28%29), [toString](../lang/Object.html#toString%28%29), [wait](../lang/Object.html#wait%28%29), [wait](../lang/Object.html#wait%28long%29), [wait](../lang/Object.html#wait%28long,int%29)
Constructor Details
SequenceInputStream
Initializes a newly created
SequenceInputStream
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:
EnumerationSequenceInputStream
Initializes a newly created
SequenceInputStream
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 Details
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 callsavailable
of the current underlying input stream and returns the result.
Overrides:
[available](InputStream.html#available%28%29)
in class[InputStream](InputStream.html "class in java.io")
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 its close() method
Throws:
[IOException](IOException.html "class in java.io")
- if an I/O error occurs.
Since:
1.1read
Reads the next byte of data from this input stream. The byte is returned as an
int
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](InputStream.html#read%28%29)
in class[InputStream](InputStream.html "class in java.io")
Returns:
the next byte of data, or-1
if the end of the stream is reached.
Throws:
[IOException](IOException.html "class in java.io")
- if an I/O error occurs.read
public int read(byte[] b, int off, int len) throws IOException
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](InputStream.html#read%28byte%5B%5D,int,int%29)
in class[InputStream](InputStream.html "class in java.io")
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](../lang/NullPointerException.html "class in java.lang")
- Ifb
isnull
.
[IndexOutOfBoundsException](../lang/IndexOutOfBoundsException.html "class in java.lang")
- Ifoff
is negative,len
is negative, orlen
is greater thanb.length - off
[IOException](IOException.html "class in java.io")
- if an I/O error occurs.
See Also:
InputStream.read()close
Closes this input stream and releases any system resources associated with the stream. A closed
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 theclose
method returns.
Specified by:
[close](../lang/AutoCloseable.html#close%28%29)
in interface[AutoCloseable](../lang/AutoCloseable.html "interface in java.lang")
Specified by:
[close](Closeable.html#close%28%29)
in interface[Closeable](Closeable.html "interface in java.io")
Overrides:
[close](InputStream.html#close%28%29)
in class[InputStream](InputStream.html "class in java.io")
Throws:
[IOException](IOException.html "class in java.io")
- if an I/O error occurs.