Class ByteSource.ConcatenatedByteSource
- Enclosing class:
ByteSource
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Nested Class Summary
Nested classes/interfaces inherited from class com.google.common.io.ByteSource
ByteSource.AsCharSource
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Field Summary
Fields -
Constructor Summary
Constructors -
Method Summary
Modifier and TypeMethodDescriptionboolean
isEmpty()
Returns whether the source has zero bytes.Opens a newInputStream
for reading from this source.long
size()
Returns the size of this source in bytes, even if doing so requires opening and traversing an entire stream.Returns the size of this source in bytes, if the size can be easily determined without actually opening the data stream.toString()
Methods inherited from class com.google.common.io.ByteSource
asCharSource, concat, concat, concat, contentEquals, copyTo, copyTo, empty, hash, openBufferedStream, read, read, slice, wrap
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Field Details
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sources
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Constructor Details
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ConcatenatedByteSource
ConcatenatedByteSource(Iterable<? extends ByteSource> sources)
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Method Details
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openStream
Description copied from class:ByteSource
Opens a newInputStream
for reading from this source. This method returns a new, independent stream each time it is called.The caller is responsible for ensuring that the returned stream is closed.
- Specified by:
openStream
in classByteSource
- Throws:
IOException
- if an I/O error occurs while opening the stream
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isEmpty
Description copied from class:ByteSource
Returns whether the source has zero bytes. The default implementation first checksByteSource.sizeIfKnown()
, returning true if it's known to be zero and false if it's known to be non-zero. If the size is not known, it falls back to opening a stream and checking for EOF.Note that, in cases where
sizeIfKnown
returns zero, it is possible that bytes are actually available for reading. (For example, some special files may return a size of 0 despite actually having content when read.) This means that a source may returntrue
fromisEmpty()
despite having readable content.- Overrides:
isEmpty
in classByteSource
- Throws:
IOException
- if an I/O error occurs
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sizeIfKnown
Description copied from class:ByteSource
Returns the size of this source in bytes, if the size can be easily determined without actually opening the data stream.The default implementation returns
Optional.absent()
. Some sources, such as a file, may return a non-absent value. Note that in such cases, it is possible that this method will return a different number of bytes than would be returned by reading all of the bytes (for example, some special files may return a size of 0 despite actually having content when read).Additionally, for mutable sources such as files, a subsequent read may return a different number of bytes if the contents are changed.
- Overrides:
sizeIfKnown
in classByteSource
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size
Description copied from class:ByteSource
Returns the size of this source in bytes, even if doing so requires opening and traversing an entire stream. To avoid a potentially expensive operation, seeByteSource.sizeIfKnown()
.The default implementation calls
ByteSource.sizeIfKnown()
and returns the value if present. If absent, it will fall back to a heavyweight operation that will open a stream, read (orskip
, if possible) to the end of the stream and return the total number of bytes that were read.Note that for some sources that implement
ByteSource.sizeIfKnown()
to provide a more efficient implementation, it is possible that this method will return a different number of bytes than would be returned by reading all of the bytes (for example, some special files may return a size of 0 despite actually having content when read).In either case, for mutable sources such as files, a subsequent read may return a different number of bytes if the contents are changed.
- Overrides:
size
in classByteSource
- Throws:
IOException
- if an I/O error occurs while reading the size of this source
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toString
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