java.lang.Object
- org.apache.lucene.store.DataOutput

Direct Known Subclasses:

ByteArrayDataOutput, IndexOutput, OutputStreamDataOutput, PagedBytes.PagedBytesDataOutput
```
public abstract class DataOutput
extends Object
```
Abstract base class for performing write operations of Lucene's low-level data types.

Constructor Summary

Constructors
Constructor Description

DataOutput()

Method Summary

All Methods Instance Methods Abstract Methods Concrete Methods Deprecated Methods
Modifier and Type	Method	Description
`void`	`copyBytes(DataInput input, long numBytes)`	Copy numBytes bytes from input to ourself.
`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`	`writeShort(short i)`	Writes a short as two bytes.
`void`	`writeString(String s)`	Writes a string.
`void`	`writeStringStringMap(Map<String,String> map)`
`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
  - DataOutput
```
public DataOutput()
```
- Method Detail
  - writeByte
```
public abstract void writeByte(byte b)
                        throws IOException
```
    Writes a single byte.
    
    Throws:
    
    IOException
    
    See Also:
    
    DataInput.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:
    
    DataInput.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:
    
    DataInput.readBytes(byte[],int,int)
  - writeInt
```
public void writeInt(int i)
              throws IOException
```
    Writes an int as four bytes.
    
    Throws:
    
    IOException
    
    See Also:
    
    DataInput.readInt()
  - writeShort
```
public void writeShort(short i)
                throws IOException
```
    Writes a short as two bytes.
    
    Throws:
    
    IOException
    
    See Also:
    
    DataInput.readShort()
  - writeVInt
```
public final 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 supported, but should be avoided.
    
    Throws:
    
    IOException
    
    See Also:
    
    DataInput.readVInt()
  - writeLong
```
public void writeLong(long i)
               throws IOException
```
    Writes a long as eight bytes.
    
    Throws:
    
    IOException
    
    See Also:
    
    DataInput.readLong()
  - writeVLong
```
public final void writeVLong(long i)
                      throws IOException
```
    Writes an long in a variable-length format. Writes between one and nine bytes. Smaller values take fewer bytes. Negative numbers are not supported.
    
    Throws:
    
    IOException
    
    See Also:
    
    DataInput.readVLong()
  - writeString
```
public void writeString(String s)
                 throws IOException
```
    Writes a string.
    
    Throws:
    
    IOException
    
    See Also:
    
    DataInput.readString()
  - copyBytes
```
public void copyBytes(DataInput input,
                      long numBytes)
               throws IOException
```
    Copy numBytes bytes from input to ourself.
    
    Throws:
    
    IOException
  - writeChars
```
@Deprecated
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
```
@Deprecated
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
  - writeStringStringMap
```
public void writeStringStringMap(Map<String,String> map)
                          throws IOException
```
    Throws:
    
    IOException

Class DataOutput

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

DataOutput

Method Detail

writeByte

writeBytes

writeBytes

writeInt

writeShort

writeVInt

writeLong

writeVLong

writeString

copyBytes

writeChars

writeChars

writeStringStringMap