ObjectInput (Java SE 11 & JDK 11 )
Keywords: java.io.ObjectInput interface

Module java.base
Package java.io

## Interface ObjectInput

- All Superinterfaces:
    `AutoCloseable`, `DataInput`
  All Known Implementing Classes:
    `ObjectInputStream`

      public interface ObjectInput
      extends DataInput, AutoCloseable

  ObjectInput extends the DataInput interface to include the reading of objects. DataInput includes methods for the input of primitive types, ObjectInput extends that interface to include objects, arrays, and Strings.
  Since:
    1.1
  See Also:
    `InputStream`, `ObjectOutputStream`, `ObjectInputStream`

- - ### Method Summary

    All Methods Instance Methods Abstract Methods
    Modifier and Type | Method | Description
    --- | --- | ---
    `int` | `available()` | Returns the number of bytes that can be read without blocking.
    `void` | `close()` | Closes the input stream.
    `int` | `read()` | Reads a byte of data.
    `int` | `read​(byte[] b)` | Reads into an array of bytes.
    `int` | `read​(byte[] b, int off, int len)` | Reads into an array of bytes.
    `Object` | `readObject()` | Read and return an object.
    `long` | `skip​(long n)` | Skips n bytes of input.

    - ### Methods declared in interface java.io.DataInput

      `readBoolean, readByte, readChar, readDouble, readFloat, readFully, readFully, readInt, readLine, readLong, readShort, readUnsignedByte, readUnsignedShort, readUTF, skipBytes`

- - ### Method Detail

    - #### readObject

          Object readObject()
                     throws ClassNotFoundException,
                            IOException

      Read and return an object. The class that implements this interface defines where the object is "read" from.
      Returns:
        the object read from the stream
      Throws:
        `ClassNotFoundException` - If the class of a serialized object cannot be found.
        `IOException` - If any of the usual Input/Output related exceptions occur.

    - #### read

          int read()
            throws IOException

      Reads a byte of data. This method will block if no input is available.
      Returns:
        the byte read, or -1 if the end of the stream is reached.
      Throws:
        `IOException` - If an I/O error has occurred.

    - #### read

          int read​(byte[] b)
            throws IOException

      Reads into an array of bytes. This method will block until some input is available.
      Parameters:
        `b` - the buffer into which the data is read
      Returns:
        the actual number of bytes read, -1 is returned when the end of the stream is reached.
      Throws:
        `IOException` - If an I/O error has occurred.

    - #### read

          int read​(byte[] b,
                   int off,
                   int len)
            throws IOException

      Reads into an array of bytes. This method will block until some input is available.
      Parameters:
        `b` - the buffer into which the data is read
        `off` - the start offset of the data
        `len` - the maximum number of bytes read
      Returns:
        the actual number of bytes read, -1 is returned when the end of the stream is reached.
      Throws:
        `IOException` - If an I/O error has occurred.

    - #### skip

          long skip​(long n)
             throws IOException

      Skips n bytes of input.
      Parameters:
        `n` - the number of bytes to be skipped
      Returns:
        the actual number of bytes skipped.
      Throws:
        `IOException` - If an I/O error has occurred.

    - #### available

          int available()
                 throws IOException

      Returns the number of bytes that can be read without blocking.
      Returns:
        the number of available bytes.
      Throws:
        `IOException` - If an I/O error has occurred.

    - #### close

          void close()
              throws IOException

      Closes the input stream. 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.