Package com.itextpdf.io.source
Class WindowRandomAccessSource
- java.lang.Object
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- com.itextpdf.io.source.WindowRandomAccessSource
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- All Implemented Interfaces:
IRandomAccessSource
public class WindowRandomAccessSource extends java.lang.Object implements IRandomAccessSource
A RandomAccessSource that wraps another RandomAccessSource and provides a window of it at a specific offset and over a specific length. Position 0 becomes the offset position in the underlying source.
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Field Summary
Fields Modifier and Type Field Description private long
length
The lengthprivate long
offset
The amount to offset the source byprivate IRandomAccessSource
source
The source
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Constructor Summary
Constructors Constructor Description WindowRandomAccessSource(IRandomAccessSource source, long offset)
Constructs a new OffsetRandomAccessSource that extends to the end of the underlying sourceWindowRandomAccessSource(IRandomAccessSource source, long offset, long length)
Constructs a new OffsetRandomAccessSource with an explicit length
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description void
close()
Closes this source.int
get(long position)
Gets a byte at the specified positionint
get(long position, byte[] bytes, int off, int len)
Read an array of bytes of specified length from the specified position of source to the buffer applying the offset.long
length()
Gets the length of the source
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Field Detail
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source
private final IRandomAccessSource source
The source
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offset
private final long offset
The amount to offset the source by
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length
private final long length
The length
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Constructor Detail
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WindowRandomAccessSource
public WindowRandomAccessSource(IRandomAccessSource source, long offset)
Constructs a new OffsetRandomAccessSource that extends to the end of the underlying source- Parameters:
source
- the sourceoffset
- the amount of the offset to use
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WindowRandomAccessSource
public WindowRandomAccessSource(IRandomAccessSource source, long offset, long length)
Constructs a new OffsetRandomAccessSource with an explicit length- Parameters:
source
- the sourceoffset
- the amount of the offset to uselength
- the number of bytes to be included in this RAS
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Method Detail
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get
public int get(long position) throws java.io.IOException
Gets a byte at the specified position Note that the position will be adjusted to read from the corrected location in the underlying source- Specified by:
get
in interfaceIRandomAccessSource
- Parameters:
position
- byte position- Returns:
- the byte, or -1 if EOF is reached
- Throws:
java.io.IOException
- in case of any reading error.
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get
public int get(long position, byte[] bytes, int off, int len) throws java.io.IOException
Read an array of bytes of specified length from the specified position of source to the buffer applying the offset. If the number of bytes requested cannot be read, all the possible bytes will be read to the buffer, and the number of actually read bytes will be returned. Note that the position will be adjusted to read from the corrected location in the underlying source- Specified by:
get
in interfaceIRandomAccessSource
- Parameters:
position
- the position in the RandomAccessSource to read frombytes
- output bufferoff
- offset into the output buffer where results will be placedlen
- the number of bytes to read- Returns:
- the number of bytes actually read, or -1 if the file is at EOF
- Throws:
java.io.IOException
- in case of any I/O error.
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length
public long length()
Gets the length of the source Note that the length will be adjusted to read from the corrected location in the underlying source- Specified by:
length
in interfaceIRandomAccessSource
- Returns:
- the length of this source
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close
public void close() throws java.io.IOException
Closes this source. The underlying data structure or source (if any) will also be closed- Specified by:
close
in interfaceIRandomAccessSource
- Throws:
java.io.IOException
- in case of any reading error.
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