Class ByteSource.SlicedByteSource
- java.lang.Object
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- com.google.common.io.ByteSource
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- com.google.common.io.ByteSource.SlicedByteSource
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- Enclosing class:
- ByteSource
private final class ByteSource.SlicedByteSource extends ByteSource
A view of a subsection of the containing byte source.
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Constructor Summary
Constructors Constructor Description SlicedByteSource(long offset, long length)
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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
openBufferedStream()
Opens a new bufferedInputStream
for reading from this source.java.io.InputStream
openStream()
Opens a newInputStream
for reading from this source.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.ByteSource
slice(long offset, long length)
Returns a view of a slice of this byte source that is at mostlength
bytes long starting at the givenoffset
.private java.io.InputStream
sliceStream(java.io.InputStream in)
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, read, read, size, wrap
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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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openBufferedStream
public java.io.InputStream openBufferedStream() throws java.io.IOException
Description copied from class:ByteSource
Opens a new bufferedInputStream
for reading from this source. The returned stream is not required to be aBufferedInputStream
in order to allow implementations to simply delegate toByteSource.openStream()
when the stream returned by that method does not benefit from additional buffering (for example, aByteArrayInputStream
). 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.
- Overrides:
openBufferedStream
in classByteSource
- Throws:
java.io.IOException
- if an I/O error occurs in the process of opening the stream
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sliceStream
private java.io.InputStream sliceStream(java.io.InputStream in) throws java.io.IOException
- Throws:
java.io.IOException
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slice
public ByteSource slice(long offset, long length)
Description copied from class:ByteSource
Returns a view of a slice of this byte source that is at mostlength
bytes long starting at the givenoffset
. Ifoffset
is greater than the size of this source, the returned source will be empty. Ifoffset + length
is greater than the size of this source, the returned source will contain the slice starting atoffset
and ending at the end of this source.- Overrides:
slice
in classByteSource
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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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toString
public java.lang.String toString()
- Overrides:
toString
in classjava.lang.Object
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