MappedByteBuffer

A direct byte buffer whose content is a memory-mapped region of a file.

Mapped byte buffers are created via the {@link java.nio.channels.FileChannel#map FileChannel.map} method. This class extends the {@link ByteBuffer} class with operations that are specific to memory-mapped file regions.

A mapped byte buffer and the file mapping that it represents remain valid until the buffer itself is garbage-collected.

The content of a mapped byte buffer can change at any time, for example if the content of the corresponding region of the mapped file is changed by this program or another. Whether or not such changes occur, and when they occur, is operating-system dependent and therefore unspecified.

<a name="inaccess"></a> All or part of a mapped byte buffer may become inaccessible at any time, for example if the mapped file is truncated. An attempt to access an inaccessible region of a mapped byte buffer will not change the buffer's content and will cause an unspecified exception to be thrown either at the time of the access or at some later time. It is therefore strongly recommended that appropriate precautions be taken to avoid the manipulation of a mapped file by this program, or by a concurrently running program, except to read or write the file's content.

Mapped byte buffers otherwise behave no differently than ordinary direct byte buffers.

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abstract

class MappedByteBuffer : ByteBuffer {

this(int mark, int pos, int lim, int cap, FileDescriptor fd);

this(int mark, int pos, int lim, int cap);

}

Constructors

this this(int mark, int pos, int lim, int cap, FileDescriptor fd): Undocumented in source.
this this(int mark, int pos, int lim, int cap): Undocumented in source.

Inherited Members

From ByteBuffer

hb byte[] hb;: Undocumented in source.
offset int offset;: Undocumented in source.
bigEndian bool bigEndian;: Undocumented in source.
order ByteOrder order(): Retrieves this buffer's byte order.
order ByteBuffer order(ByteOrder bo): Modifies this buffer's byte order.
allocateDirect deprecated ByteBuffer allocateDirect(int capacity): Allocates a new direct byte buffer.
allocate deprecated ByteBuffer allocate(size_t capacity): Allocates a new byte buffer.
wrap deprecated ByteBuffer wrap(byte[] array, int offset, int length): Wraps a byte array into a buffer.
wrap deprecated ByteBuffer wrap(byte[] array): Wraps a byte array into a buffer.
slice ByteBuffer slice(): Creates a new byte buffer whose content is a shared subsequence of this buffer's content.
duplicate ByteBuffer duplicate(): Creates a new byte buffer that shares this buffer's content.
asReadOnlyBuffer ByteBuffer asReadOnlyBuffer(): Creates a new, read-only byte buffer that shares this buffer's content.
get byte get(): Relative get method. Reads the byte at this buffer's current position, and then increments the position.
put ByteBuffer put(byte b): Relative put method  (optional operation).
get byte get(int index): Absolute get method. Reads the byte at the given index.
put ByteBuffer put(int index, byte b): Absolute put method  (optional operation).
get ByteBuffer get(byte[] dst, int offset, int length): Relative bulk get method.
get ByteBuffer get(byte[] dst): Relative bulk get method.
put ByteBuffer put(ByteBuffer src): Relative bulk put method  (optional operation).
put ByteBuffer put(byte[] src, int offset, int length): Relative bulk put method  (optional operation).
put ByteBuffer put(byte[] src): Relative bulk put method  (optional operation).
put ByteBuffer put(string src): Undocumented in source. Be warned that the author may not have intended to support it.
getShort short getShort(): Relative get method for reading a short value.
putShort ByteBuffer putShort(short value): Relative put method for writing a short value  (optional operation).
getShort short getShort(int index): Absolute get method for reading a short value.
putShort ByteBuffer putShort(int index, short value): Absolute put method for writing a short value  (optional operation).
getInt int getInt(): Relative get method for reading an int value.
putInt ByteBuffer putInt(int value): Relative put method for writing an int value  (optional operation).
getInt int getInt(int index): Absolute get method for reading an int value.
putInt ByteBuffer putInt(int index, int value): Absolute put method for writing an int value  (optional operation).
getLong long getLong(): Relative get method for reading a long value.
putLong ByteBuffer putLong(long value): Relative put method for writing a long value  (optional operation).
getLong long getLong(int index): Absolute get method for reading a long value.
putLong ByteBuffer putLong(int index, long value): Absolute put method for writing a long value  (optional operation).
hasArray bool hasArray(): Tells whether or not this buffer is backed by an accessible byte array.
array byte[] array(): Returns the byte array that backs this buffer  (optional operation).
arrayOffset int arrayOffset(): Returns the offset within this buffer's backing array of the first element of the buffer  (optional operation).
compact ByteBuffer compact(): Compacts this buffer  (optional operation).
get T get(): Relative get method for reading an int value.
get T get(int index): Absolute get method for reading an int value.
put ByteBuffer put(T value): Relative put method for writing a short value  (optional operation).
put ByteBuffer put(int index, T value): Absolute put method for writing a short value  (optional operation).
ix int ix(int i): Undocumented in source. Be warned that the author may not have intended to support it.
byteOffset size_t byteOffset(size_t i): Undocumented in source. Be warned that the author may not have intended to support it.
getString string getString(size_t offset, size_t len): Undocumented in source. Be warned that the author may not have intended to support it.
getRemaining byte[] getRemaining(): Undocumented in source. Be warned that the author may not have intended to support it.
toString string toString(): Returns a string summarizing the state of this buffer.

Detailed Description

@author Mark Reinhold @author JSR-51 Expert Group

MappedByteBuffer

Constructors

Inherited Members

From ByteBuffer

Detailed Description

Meta

Source