Class ByteSource.ConcatenatedByteSource
- java.lang.Object
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- com.google.common.io.ByteSource
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- com.google.common.io.ByteSource.ConcatenatedByteSource
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- Enclosing class:
- ByteSource
private static final class ByteSource.ConcatenatedByteSource extends ByteSource
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Field Summary
Fields Modifier and Type Field Description (package private) java.lang.Iterable<? extends ByteSource>
sources
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Constructor Summary
Constructors Constructor Description ConcatenatedByteSource(java.lang.Iterable<? extends ByteSource> sources)
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description boolean
isEmpty()
Returns whether the source has zero bytes.java.io.InputStream
openStream()
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.Optional<java.lang.Long>
sizeIfKnown()
Returns the size of this source in bytes, if the size can be easily determined without actually opening the data stream.java.lang.String
toString()
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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 Detail
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sources
final java.lang.Iterable<? extends ByteSource> sources
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Constructor Detail
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ConcatenatedByteSource
ConcatenatedByteSource(java.lang.Iterable<? extends ByteSource> sources)
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Method Detail
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openStream
public java.io.InputStream openStream() throws java.io.IOException
Description copied from class:ByteSource
Opens a newInputStream
for reading from this source. This method should return 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:
java.io.IOException
- if an I/O error occurs in the process of opening the stream
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isEmpty
public boolean isEmpty() throws java.io.IOException
Description copied from class:ByteSource
Returns whether the source has zero bytes. The default implementation returns true ifByteSource.sizeIfKnown()
returns zero, falling back to opening a stream and checking for EOF if the size is not known.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:
java.io.IOException
- if an I/O error occurs
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sizeIfKnown
public Optional<java.lang.Long> 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
public long size() throws java.io.IOException
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:
java.io.IOException
- if an I/O error occurs in the process of reading the size of this source
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toString
public java.lang.String toString()
- Overrides:
toString
in classjava.lang.Object
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