Module java.base
Package java.io

# Interface ObjectOutput

All Superinterfaces:
  `AutoCloseable`, `DataOutput`

All Known Implementing Classes:
  `ObjectOutputStream`

public interface ObjectOutput extends DataOutput, AutoCloseable
ObjectOutput extends the DataOutput interface to include writing of objects. DataOutput includes methods for output of primitive types, ObjectOutput extends that interface to include objects, arrays, and Strings.

Since:
  1.1
See Also:
  - `InputStream`
  - `ObjectOutputStream`
  - `ObjectInputStream`

## Method Summary

Modifier and Type
Method
Description
`void`
`close()`
Closes the stream.
`void`
`flush()`
Flushes the stream.
`void`
`write(byte[] b)`
Writes an array of bytes.
`void`
`write(byte[] b, int off, int len)`
Writes a sub array of bytes.
`void`
`write(int b)`
Writes a byte.
`void`
`writeObject(Object obj)`
Write an object to the underlying storage or stream.

### Methods declared in interface java.io.DataOutput

`writeBoolean, writeByte, writeBytes, writeChar, writeChars, writeDouble, writeFloat, writeInt, writeLong, writeShort, writeUTF`

## Method Details

### writeObject

void writeObject(Object obj) throws IOException
Write an object to the underlying storage or stream. The class that implements this interface defines how the object is written.

Parameters:
  `obj` - the object to be written
Throws:
  `IOException` - Any of the usual Input/Output related exceptions.

### write

void write(int b) throws IOException
Writes a byte. This method will block until the byte is actually written.

Specified by:
  `write` in interface `DataOutput`
Parameters:
  `b` - the byte
Throws:
  `IOException` - If an I/O error has occurred.

### write

void write(byte[] b) throws IOException
Writes an array of bytes. This method will block until the bytes are actually written.

Specified by:
  `write` in interface `DataOutput`
Parameters:
  `b` - the data to be written
Throws:
  `IOException` - If an I/O error has occurred.

### write

void write(byte[] b, int off, int len) throws IOException
Writes a sub array of bytes.

Specified by:
  `write` in interface `DataOutput`
Parameters:
  `b` - the data to be written
  `off` - the start offset in the data
  `len` - the number of bytes that are written
Throws:
  `IOException` - If an I/O error has occurred.

### flush

void flush() throws IOException
Flushes the stream. This will write any buffered output bytes.

Throws:
  `IOException` - If an I/O error has occurred.

### close

void close() throws IOException
Closes the stream. This method must be called to release any resources associated with the stream.

Specified by:
  `close` in interface `AutoCloseable`
Throws:
  `IOException` - If an I/O error has occurred.