# ObjectOutput Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels) # ObjectOutput ``` interface ObjectOutput : AutoCloseable, DataOutput ``` |----------------------------------------------------------------------------------------------| | [java.io.ObjectOutput](https://developer.android.com/reference/kotlin/java/io/ObjectOutput#) | |---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| | Known Direct Subclasses [ObjectOutputStream](https://developer.android.com/reference/kotlin/java/io/ObjectOutputStream) |-------------------------------------------------------------------------------------------------|--------------------------------------------------------------------------------------------------| | [ObjectOutputStream](https://developer.android.com/reference/kotlin/java/io/ObjectOutputStream) | An ObjectOutputStream writes primitive data types and graphs of Java objects to an OutputStream. | | 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. ## Summary | Public methods || |--------------------------------------------------------------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| | abstract[Unit](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-unit/index.html) | [close](https://developer.android.com/reference/kotlin/java/io/ObjectOutput#close())`()` Closes the stream. | | abstract[Unit](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-unit/index.html) | [flush](https://developer.android.com/reference/kotlin/java/io/ObjectOutput#flush())`()` Flushes the stream. | | abstract[Unit](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-unit/index.html) | [write](https://developer.android.com/reference/kotlin/java/io/ObjectOutput#write(kotlin.ByteArray))`(`b:` `[ByteArray](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-byte-array/index.html)!`)` Writes an array of bytes. | | abstract[Unit](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-unit/index.html) | [write](https://developer.android.com/reference/kotlin/java/io/ObjectOutput#write(kotlin.ByteArray,%20kotlin.Int,%20kotlin.Int))`(`b:` `[ByteArray](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-byte-array/index.html)!`, `off:` `[Int](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html)`, `len:` `[Int](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html)`)` Writes a sub array of bytes. | | abstract[Unit](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-unit/index.html) | [write](https://developer.android.com/reference/kotlin/java/io/ObjectOutput#write(kotlin.Int))`(`b:` `[Int](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html)`)` Writes a byte. | | abstract[Unit](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-unit/index.html) | [writeObject](https://developer.android.com/reference/kotlin/java/io/ObjectOutput#writeObject(kotlin.Any))`(`obj:` `[Any](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-any/index.html)!`)` Write an object to the underlying storage or stream. | | Inherited functions || |---|---| | From class[DataOutput](https://developer.android.com/reference/kotlin/java/io/DataOutput) |------------------------------------------------------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| | [Unit](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-unit/index.html) | [writeBoolean](https://developer.android.com/reference/kotlin/java/io/DataOutput#writeBoolean(kotlin.Boolean))`(`v:` `[Boolean](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-boolean/index.html)`)`
Writes a`boolean`value to this output stream. If the argument`v`is`true`, the value`(byte)1`is written; if`v`is`false`, the value`(byte)0`is written. The byte written by this method may be read by the`readBoolean`method of interface`DataInput`, which will then return a`boolean`equal to`v`.
| | [Unit](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-unit/index.html) | [writeByte](https://developer.android.com/reference/kotlin/java/io/DataOutput#writeByte(kotlin.Int))`(`v:` `[Int](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html)`)`
Writes to the output stream the eight low- order bits of the argument`v`. The 24 high-order bits of`v`are ignored. (This means that`writeByte`does exactly the same thing as`write`for an integer argument.) The byte written by this method may be read by the`readByte`method of interface`DataInput`, which will then return a`byte`equal to`(byte)v`.
| | [Unit](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-unit/index.html) | [writeBytes](https://developer.android.com/reference/kotlin/java/io/DataOutput#writeBytes(kotlin.String))`(`s:` `[String](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-string/index.html)!`)`
Writes a string to the output stream. For every character in the string`s`, taken in order, one byte is written to the output stream. If`s`is`null`, a`NullPointerException`is thrown. If`s.length`is zero, then no bytes are written. Otherwise, the character`s[0]`is written first, then`s[1]`, and so on; the last character written is`s[s.length-1]`. For each character, one byte is written, the low-order byte, in exactly the manner of the`writeByte`method . The high-order eight bits of each character in the string are ignored.
| | [Unit](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-unit/index.html) | [writeChar](https://developer.android.com/reference/kotlin/java/io/DataOutput#writeChar(kotlin.Int))`(`v:` `[Int](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html)`)`
Writes a`char`value, which is comprised of two bytes, to the output stream. The byte values to be written, in the order shown, are: ```kotlin (byte)(0xff & (v >> 8)) (byte)(0xff & v) ```
The bytes written by this method may be read by the`readChar`method of interface`DataInput`, which will then return a`char`equal to`(char)v`.
| | [Unit](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-unit/index.html) | [writeChars](https://developer.android.com/reference/kotlin/java/io/DataOutput#writeChars(kotlin.String))`(`s:` `[String](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-string/index.html)!`)`
Writes every character in the string`s`, to the output stream, in order, two bytes per character. If`s`is`null`, a`NullPointerException`is thrown. If`s.length`is zero, then no characters are written. Otherwise, the character`s[0]`is written first, then`s[1]`, and so on; the last character written is`s[s.length-1]`. For each character, two bytes are actually written, high-order byte first, in exactly the manner of the`writeChar`method.
| | [Unit](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-unit/index.html) | [writeDouble](https://developer.android.com/reference/kotlin/java/io/DataOutput#writeDouble(kotlin.Double))`(`v:` `[Double](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-double/index.html)`)`
Writes a`double`value, which is comprised of eight bytes, to the output stream. It does this as if it first converts this`double`value to a`long`in exactly the manner of the`Double.doubleToLongBits`method and then writes the`long`value in exactly the manner of the`writeLong`method. The bytes written by this method may be read by the`readDouble`method of interface`DataInput`, which will then return a`double`equal to`v`.
| | [Unit](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-unit/index.html) | [writeFloat](https://developer.android.com/reference/kotlin/java/io/DataOutput#writeFloat(kotlin.Float))`(`v:` `[Float](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-float/index.html)`)`
Writes a`float`value, which is comprised of four bytes, to the output stream. It does this as if it first converts this`float`value to an`int`in exactly the manner of the`Float.floatToIntBits`method and then writes the`int`value in exactly the manner of the`writeInt`method. The bytes written by this method may be read by the`readFloat`method of interface`DataInput`, which will then return a`float`equal to`v`.
| | [Unit](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-unit/index.html) | [writeInt](https://developer.android.com/reference/kotlin/java/io/DataOutput#writeInt(kotlin.Int))`(`v:` `[Int](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html)`)`
Writes an`int`value, which is comprised of four bytes, to the output stream. The byte values to be written, in the order shown, are: ```kotlin (byte)(0xff & (v >> 24)) (byte)(0xff & (v >> 16)) (byte)(0xff & (v >> 8)) (byte)(0xff & v) ```
The bytes written by this method may be read by the`readInt`method of interface`DataInput`, which will then return an`int`equal to`v`.
| | [Unit](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-unit/index.html) | [writeLong](https://developer.android.com/reference/kotlin/java/io/DataOutput#writeLong(kotlin.Long))`(`v:` `[Long](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-long/index.html)`)`
Writes a`long`value, which is comprised of eight bytes, to the output stream. The byte values to be written, in the order shown, are: ```kotlin (byte)(0xff & (v >> 56)) (byte)(0xff & (v >> 48)) (byte)(0xff & (v >> 40)) (byte)(0xff & (v >> 32)) (byte)(0xff & (v >> 24)) (byte)(0xff & (v >> 16)) (byte)(0xff & (v >> 8)) (byte)(0xff & v) ```
The bytes written by this method may be read by the`readLong`method of interface`DataInput`, which will then return a`long`equal to`v`.
| | [Unit](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-unit/index.html) | [writeShort](https://developer.android.com/reference/kotlin/java/io/DataOutput#writeShort(kotlin.Int))`(`v:` `[Int](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html)`)`
Writes two bytes to the output stream to represent the value of the argument. The byte values to be written, in the order shown, are: ```kotlin (byte)(0xff & (v >> 8)) (byte)(0xff & v) ```
The bytes written by this method may be read by the`readShort`method of interface`DataInput`, which will then return a`short`equal to`(short)v`.
| | [Unit](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-unit/index.html) | [writeUTF](https://developer.android.com/reference/kotlin/java/io/DataOutput#writeUTF(kotlin.String))`(`s:` `[String](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-string/index.html)!`)`
Writes two bytes of length information to the output stream, followed by the[modified UTF-8](https://developer.android.com/reference/kotlin/java/io/DataInput#modified-utf-8)representation of every character in the string`s`. If`s`is`null`, a`NullPointerException`is thrown. Each character in the string`s`is converted to a group of one, two, or three bytes, depending on the value of the character. If a character`c`is in the range`\u0001`through`\u007f`, it is represented by one byte: ```kotlin (byte)c ``` If a character`c`is`\u0000`or is in the range`\u0080`through`\u07ff`, then it is represented by two bytes, to be written in the order shown: ```kotlin (byte)(0xc0 | (0x1f & (c >> 6))) (byte)(0x80 | (0x3f & c)) ``` If a character`c`is in the range`\u0800`through`uffff`, then it is represented by three bytes, to be written in the order shown: ```kotlin (byte)(0xe0 | (0x0f & (c >> 12))) (byte)(0x80 | (0x3f & (c >> 6))) (byte)(0x80 | (0x3f & c)) ``` First, the total number of bytes needed to represent all the characters of`s`is calculated. If this number is larger than`65535`, then a`UTFDataFormatException`is thrown. Otherwise, this length is written to the output stream in exactly the manner of the`writeShort`method; after this, the one-, two-, or three-byte representation of each character in the string`s`is written. The bytes written by this method may be read by the`readUTF`method of interface`DataInput`, which will then return a`String`equal to`s`.
| || ## Public methods ### close Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels) ``` abstract fun close(): Unit ``` Closes the stream. This method must be called to release any resources associated with the stream. | Exceptions || |-----------------------|-----------------------------------| | `java.lang.Exception` | if this resource cannot be closed | | `java.io.IOException` | If an I/O error has occurred. | ### flush Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels) ``` abstract fun flush(): Unit ``` Flushes the stream. This will write any buffered output bytes. | Exceptions || |-----------------------|-------------------------------| | `java.io.IOException` | If an I/O error has occurred. | ### write Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels) ``` abstract fun write(b: ByteArray!): Unit ``` Writes an array of bytes. This method will block until the bytes are actually written. | Parameters || |-----|-----------------------------------------------------------------------------------------------------------------| | `b` | [ByteArray](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-byte-array/index.html)!:the data to be written | | Exceptions || |-----------------------|-------------------------------| | `java.io.IOException` | if an I/O error occurs. | | `java.io.IOException` | If an I/O error has occurred. | ### write Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels) ``` abstract fun write(     b: ByteArray!,     off: Int,     len: Int ): Unit ``` Writes a sub array of bytes. | Parameters || |-------|-----------------------------------------------------------------------------------------------------------------| | `b` | [ByteArray](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-byte-array/index.html)!:the data to be written | | `off` | [Int](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html):the start offset in the data | | `len` | [Int](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html):the number of bytes that are written | | Exceptions || |-----------------------|-------------------------------| | `java.io.IOException` | if an I/O error occurs. | | `java.io.IOException` | If an I/O error has occurred. | ### write Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels) ``` abstract fun write(b: Int): Unit ``` Writes a byte. This method will block until the byte is actually written. | Parameters || |-----|-------------------------------------------------------------------------------------| | `b` | [Int](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html):the byte | | Exceptions || |-----------------------|-------------------------------| | `java.io.IOException` | if an I/O error occurs. | | `java.io.IOException` | If an I/O error has occurred. | ### writeObject Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels) ``` abstract fun writeObject(obj: Any!): Unit ``` Write an object to the underlying storage or stream. The class that implements this interface defines how the object is written. | Parameters || |-------|------------------------------------------------------------------------------------------------------| | `obj` | [Any](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-any/index.html)!:the object to be written | | Exceptions || |-----------------------|---------------------------------------------------| | `java.io.IOException` | Any of the usual Input/Output related exceptions. |