## org.apache.lucene.store
Class IndexOutput

    java.lang.Object
      org.apache.lucene.store.IndexOutput

Direct Known Subclasses:
  BufferedIndexOutput, ChecksumIndexOutput, DbIndexOutput, JEIndexOutput, RAMOutputStream

    public abstract class IndexOutput

extends Object

Abstract base class for output to a file in a Directory. A random-access output stream. Used for all Lucene index output operations.

See Also:
  `Directory`, `IndexInput`

Constructor Summary
`IndexOutput()`

Method Summary
`abstract void` `close()` Closes this stream to further operations.
`void` `copyBytes(IndexInput input, long numBytes)` Copy numBytes bytes from input to ourself.
`abstract void` `flush()` Forces any buffered output to be written.
`abstract long` `getFilePointer()` Returns the current position in this file, where the next write will occur.
`abstract long` `length()` The number of bytes in the file.
`abstract void` `seek(long pos)` Sets current position in this file, where the next write will occur.
`void` `setLength(long length)` Set the file length.
`abstract void` `writeByte(byte b)` Writes a single byte.
`void` `writeBytes(byte[] b, int length)` Writes an array of bytes.
`abstract void` `writeBytes(byte[] b, int offset, int length)` Writes an array of bytes.
`void` `writeChars(char[] s, int start, int length)` Deprecated. -- please pre-convert to utf8 bytes instead or use `writeString(java.lang.String)`
`void` `writeChars(String s, int start, int length)` Deprecated. -- please pre-convert to utf8 bytes instead or use `writeString(java.lang.String)`
`void` `writeInt(int i)` Writes an int as four bytes.
`void` `writeLong(long i)` Writes a long as eight bytes.
`void` `writeString(String s)` Writes a string.
`void` `writeVInt(int i)` Writes an int in a variable-length format.
`void` `writeVLong(long i)` Writes an long in a variable-length format.

Methods inherited from class java.lang.Object
`clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

Constructor Detail

### IndexOutput

    public IndexOutput()

Method Detail

### writeByte

    public abstract void writeByte(byte b)
                            throws IOException

  Writes a single byte.

  Throws:
    `IOException`
  See Also:
    `IndexInput.readByte()`

### writeBytes

    public void writeBytes(byte[] b,
                           int length)
                    throws IOException

  Writes an array of bytes.

  Parameters:
    `b` - the bytes to write
    `length` - the number of bytes to write
  Throws:
    `IOException`
  See Also:
    `IndexInput.readBytes(byte[],int,int)`

### writeBytes

    public abstract void writeBytes(byte[] b,
                                    int offset,
                                    int length)
                             throws IOException

  Writes an array of bytes.

  Parameters:
    `b` - the bytes to write
    `offset` - the offset in the byte array
    `length` - the number of bytes to write
  Throws:
    `IOException`
  See Also:
    `IndexInput.readBytes(byte[],int,int)`

### writeInt

    public void writeInt(int i)
                  throws IOException

  Writes an int as four bytes.

  Throws:
    `IOException`
  See Also:
    `IndexInput.readInt()`

### writeVInt

    public void writeVInt(int i)
                   throws IOException

  Writes an int in a variable-length format. Writes between one and five bytes. Smaller values take fewer bytes. Negative numbers are not supported.

  Throws:
    `IOException`
  See Also:
    `IndexInput.readVInt()`

### writeLong

    public void writeLong(long i)
                   throws IOException

  Writes a long as eight bytes.

  Throws:
    `IOException`
  See Also:
    `IndexInput.readLong()`

### writeVLong

    public void writeVLong(long i)
                    throws IOException

  Writes an long in a variable-length format. Writes between one and five bytes. Smaller values take fewer bytes. Negative numbers are not supported.

  Throws:
    `IOException`
  See Also:
    `IndexInput.readVLong()`

### writeString

    public void writeString(String s)
                     throws IOException

  Writes a string.

  Throws:
    `IOException`
  See Also:
    `IndexInput.readString()`

### writeChars

    public void writeChars(String s,
                           int start,
                           int length)
                    throws IOException

  Deprecated. -- please pre-convert to utf8 bytes instead or use `writeString(java.lang.String)`

  Writes a sub sequence of characters from s as the old format (modified UTF-8 encoded bytes).

  Parameters:
    `s` - the source of the characters
    `start` - the first character in the sequence
    `length` - the number of characters in the sequence
  Throws:
    `IOException`

### writeChars

    public void writeChars(char[] s,
                           int start,
                           int length)
                    throws IOException

  Deprecated. -- please pre-convert to utf8 bytes instead or use `writeString(java.lang.String)`

  Writes a sub sequence of characters from char[] as the old format (modified UTF-8 encoded bytes).

  Parameters:
    `s` - the source of the characters
    `start` - the first character in the sequence
    `length` - the number of characters in the sequence
  Throws:
    `IOException`

### copyBytes

    public void copyBytes(IndexInput input,
                          long numBytes)
                   throws IOException

  Copy numBytes bytes from input to ourself.

  Throws:
    `IOException`

### flush

    public abstract void flush()
                        throws IOException

  Forces any buffered output to be written.

  Throws:
    `IOException`

### close

    public abstract void close()
                        throws IOException

  Closes this stream to further operations.

  Throws:
    `IOException`

### getFilePointer

    public abstract long getFilePointer()

  Returns the current position in this file, where the next write will occur.

  See Also:
    `seek(long)`

### seek

    public abstract void seek(long pos)
                       throws IOException

  Sets current position in this file, where the next write will occur.

  Throws:
    `IOException`
  See Also:
    `getFilePointer()`

### length

    public abstract long length()
                         throws IOException

  The number of bytes in the file.

  Throws:
    `IOException`

### setLength

    public void setLength(long length)
                   throws IOException

  Set the file length. By default, this method does nothing (it's optional for a Directory to implement it). But, certain Directory implementations (for example @see FSDirectory) can use this to inform the underlying IO system to pre-allocate the file to the specified size. If the length is longer than the current file length, the bytes added to the file are undefined. Otherwise the file is truncated.

  Parameters:
    `length` - file length
  Throws:
    `IOException`

Copyright © 2000-2009 Apache Software Foundation. All Rights Reserved.