# OutputStreamWriter
Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels)
# OutputStreamWriter
```
open class OutputStreamWriter : Writer
```
|---|---|----------------------------------------------------------------------------------------------------------|
| [kotlin.Any](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-any/index.html) |||
| ↳ | [java.io.Writer](https://developer.android.com/reference/kotlin/java/io/Writer) ||
| | ↳ | [java.io.OutputStreamWriter](https://developer.android.com/reference/kotlin/java/io/OutputStreamWriter#) |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| Known Direct Subclasses [FileWriter](https://developer.android.com/reference/kotlin/java/io/FileWriter) |---------------------------------------------------------------------------------|-------------------------------------------------------------| | [FileWriter](https://developer.android.com/reference/kotlin/java/io/FileWriter) | Writes text to character files using a default buffer size. | |
An OutputStreamWriter is a bridge from character streams to byte streams: Characters written to it are encoded into bytes using a specified . The charset that it uses may be specified by name or may be given explicitly, or the platform's default charset may be accepted.
Each invocation of a write() method causes the encoding converter to be invoked on the given character(s). The resulting bytes are accumulated in a buffer before being written to the underlying output stream. Note that the characters passed to the write() methods are not buffered.
For top efficiency, consider wrapping an OutputStreamWriter within a BufferedWriter so as to avoid frequent converter invocations. For example:
```kotlin
Writer out
= new BufferedWriter(new OutputStreamWriter(System.out));
```
A*surrogate pair* is a character represented by a sequence of two`char`values: A*high* surrogate in the range '\\uD800' to '\\uDBFF' followed by a*low*surrogate in the range '\\uDC00' to '\\uDFFF'.
A*malformed surrogate element*is a high surrogate that is not followed by a low surrogate or a low surrogate that is not preceded by a high surrogate.
This class always replaces malformed surrogate elements and unmappable character sequences with the charset's default*substitution sequence* . The[java.nio.charset.CharsetEncoder](https://developer.android.com/reference/kotlin/java/nio/charset/CharsetEncoder.html#)class should be used when more control over the encoding process is required.
## Summary
| Public constructors ||
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|---|
| [OutputStreamWriter](https://developer.android.com/reference/kotlin/java/io/OutputStreamWriter#OutputStreamWriter(java.io.OutputStream))`(`out:` `[OutputStream](https://developer.android.com/reference/kotlin/java/io/OutputStream)!`)` Creates an OutputStreamWriter that uses the default character encoding. |
| [OutputStreamWriter](https://developer.android.com/reference/kotlin/java/io/OutputStreamWriter#OutputStreamWriter(java.io.OutputStream,%20kotlin.String))`(`out:` `[OutputStream](https://developer.android.com/reference/kotlin/java/io/OutputStream)!`, `charsetName:` `[String](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-string/index.html)!`)` Creates an OutputStreamWriter that uses the named charset. |
| [OutputStreamWriter](https://developer.android.com/reference/kotlin/java/io/OutputStreamWriter#OutputStreamWriter(java.io.OutputStream,%20java.nio.charset.Charset))`(`out:` `[OutputStream](https://developer.android.com/reference/kotlin/java/io/OutputStream)!`, `cs:` `[Charset](https://developer.android.com/reference/kotlin/java/nio/charset/Charset.html#)!`)` Creates an OutputStreamWriter that uses the given charset. |
| [OutputStreamWriter](https://developer.android.com/reference/kotlin/java/io/OutputStreamWriter#OutputStreamWriter(java.io.OutputStream,%20java.nio.charset.CharsetEncoder))`(`out:` `[OutputStream](https://developer.android.com/reference/kotlin/java/io/OutputStream)!`, `enc:` `[CharsetEncoder](https://developer.android.com/reference/kotlin/java/nio/charset/CharsetEncoder.html#)!`)` Creates an OutputStreamWriter that uses the given charset encoder. |
| Public methods ||
|---------------------------------------------------------------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| open[Writer](https://developer.android.com/reference/kotlin/java/io/Writer) | [append](https://developer.android.com/reference/kotlin/java/io/OutputStreamWriter#append(kotlin.CharSequence))`(`csq:` `[CharSequence](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-char-sequence/index.html)?`)`
|
| open[Writer](https://developer.android.com/reference/kotlin/java/io/Writer) | [append](https://developer.android.com/reference/kotlin/java/io/OutputStreamWriter#append(kotlin.CharSequence,%20kotlin.Int,%20kotlin.Int))`(`csq:` `[CharSequence](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-char-sequence/index.html)?`, `start:` `[Int](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html)`, `end:` `[Int](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html)`)`
|
| open[Unit](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-unit/index.html) | [close](https://developer.android.com/reference/kotlin/java/io/OutputStreamWriter#close())`()`
|
| open[Unit](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-unit/index.html) | [flush](https://developer.android.com/reference/kotlin/java/io/OutputStreamWriter#flush())`()` Flushes the stream. |
| open[String](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-string/index.html)! | [getEncoding](https://developer.android.com/reference/kotlin/java/io/OutputStreamWriter#getEncoding())`()` Returns the name of the character encoding being used by this stream. |
| open[Unit](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-unit/index.html) | [write](https://developer.android.com/reference/kotlin/java/io/OutputStreamWriter#write(kotlin.CharArray,%20kotlin.Int,%20kotlin.Int))`(`cbuf:` `[CharArray](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-char-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 portion of an array of characters. |
| open[Unit](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-unit/index.html) | [write](https://developer.android.com/reference/kotlin/java/io/OutputStreamWriter#write(kotlin.Int))`(`c:` `[Int](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html)`)` Writes a single character. |
| open[Unit](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-unit/index.html) | [write](https://developer.android.com/reference/kotlin/java/io/OutputStreamWriter#write(kotlin.String,%20kotlin.Int,%20kotlin.Int))`(`str:` `[String](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-string/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 portion of a string. |
| Inherited functions ||
|---|---|
| From class[Writer](https://developer.android.com/reference/kotlin/java/io/Writer) |------------------------------------------------------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| | [Writer](https://developer.android.com/reference/kotlin/java/io/Writer) | [append](https://developer.android.com/reference/kotlin/java/io/Writer#append(kotlin.Char))`(`c:` `[Char](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-char/index.html)`)`
Appends the specified character to this writer. An invocation of this method of the form`out.append(c)`behaves in exactly the same way as the invocation ```kotlin out.write(c) ```
| | [Writer](https://developer.android.com/reference/kotlin/java/io/Writer)! | [nullWriter](https://developer.android.com/reference/kotlin/java/io/Writer#nullWriter())`()`
Returns a new`Writer`which discards all characters. The returned stream is initially open. The stream is closed by calling the`close()`method. Subsequent calls to`close()`have no effect. While the stream is open, the`append(char)`,`append(CharSequence)`,`append(CharSequence, int, int)`,`flush()`,`write(int)`,`write(char[])`, and`write(char[], int, int)`methods do nothing. After the stream has been closed, these methods all throw`IOException`. The[object](https://developer.android.com/reference/kotlin/java/io/Writer#lock:kotlin.Any)used to synchronize operations on the returned`Writer`is not specified.
| | [Unit](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-unit/index.html) | [write](https://developer.android.com/reference/kotlin/java/io/Writer#write(kotlin.CharArray))`(`cbuf:` `[CharArray](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-char-array/index.html)!`)`
Writes an array of characters.
| | [Unit](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-unit/index.html) | [write](https://developer.android.com/reference/kotlin/java/io/Writer#write(kotlin.String))`(`str:` `[String](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-string/index.html)!`)`
Writes a string.
| ||
| Inherited properties ||
|---|---|
| From class[Writer](https://developer.android.com/reference/kotlin/java/io/Writer) |-----------------------------------------------------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| | [Any](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-any/index.html)! | [lock](https://developer.android.com/reference/kotlin/java/io/Writer#lock:kotlin.Any)
The object used to synchronize operations on this stream. For efficiency, a character-stream object may use an object other than itself to protect critical sections. A subclass should therefore use the object in this field rather than`this`or a synchronized method.
| ||
## Public constructors
### OutputStreamWriter
Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels)
```
OutputStreamWriter(out: OutputStream!)
```
Creates an OutputStreamWriter that uses the default character encoding.
| Parameters ||
|-------|------------------------------------------------------------------------------------------------------|
| `out` | [OutputStream](https://developer.android.com/reference/kotlin/java/io/OutputStream)!:An OutputStream |
### OutputStreamWriter
Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels)
```
OutputStreamWriter(
out: OutputStream!,
charsetName: String!)
```
Creates an OutputStreamWriter that uses the named charset.
| Parameters ||
|---------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| `out` | [OutputStream](https://developer.android.com/reference/kotlin/java/io/OutputStream)!:An OutputStream |
| `charsetName` | [String](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-string/index.html)!:The name of a supported[charset](https://developer.android.com/reference/kotlin/java/nio/charset/Charset.html#) |
| Exceptions ||
|----------------------------------------|----------------------------------------|
| `java.io.UnsupportedEncodingException` | If the named encoding is not supported |
### OutputStreamWriter
Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels)
```
OutputStreamWriter(
out: OutputStream!,
cs: Charset!)
```
Creates an OutputStreamWriter that uses the given charset.
| Parameters ||
|-------|------------------------------------------------------------------------------------------------------|
| `out` | [OutputStream](https://developer.android.com/reference/kotlin/java/io/OutputStream)!:An OutputStream |
| `cs` | [Charset](https://developer.android.com/reference/kotlin/java/nio/charset/Charset.html#)!:A charset |
### OutputStreamWriter
Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels)
```
OutputStreamWriter(
out: OutputStream!,
enc: CharsetEncoder!)
```
Creates an OutputStreamWriter that uses the given charset encoder.
| Parameters ||
|-------|---------------------------------------------------------------------------------------------------------------------------|
| `out` | [OutputStream](https://developer.android.com/reference/kotlin/java/io/OutputStream)!:An OutputStream |
| `enc` | [CharsetEncoder](https://developer.android.com/reference/kotlin/java/nio/charset/CharsetEncoder.html#)!:A charset encoder |
## Public methods
### append
Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels)
```
open fun append(csq: CharSequence?): Writer
```
| Parameters ||
|-------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| `csq` | [CharSequence](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-char-sequence/index.html)?:The character sequence to append. If`csq`is`null`, then the four characters`"null"`are appended to this writer. |
| Return ||
|-------------------------------------------------------------------------|-------------|
| [Writer](https://developer.android.com/reference/kotlin/java/io/Writer) | This writer |
| Exceptions ||
|-----------------------|------------------------|
| `java.io.IOException` | If an I/O error occurs |
### append
Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels)
```
open fun append(
csq: CharSequence?,
start: Int,
end: Int
): Writer
```
| Parameters ||
|---------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| `csq` | [CharSequence](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-char-sequence/index.html)?:The character sequence from which a subsequence will be appended. If`csq`is`null`, then characters will be appended as if`csq`contained the four characters`"null"`. |
| `start` | [Int](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html):The index of the first character in the subsequence |
| `end` | [Int](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html):The index of the character following the last character in the subsequence |
| Return ||
|-------------------------------------------------------------------------|-------------|
| [Writer](https://developer.android.com/reference/kotlin/java/io/Writer) | This writer |
| Exceptions ||
|---------------------------------------|------------------------------------------------------------------------------------------------|
| `java.lang.IndexOutOfBoundsException` | If`start`or`end`are negative,`start`is greater than`end`, or`end`is greater than`csq.length()` |
| `java.io.IOException` | If an I/O error occurs |
### close
Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels)
```
open fun close(): Unit
```
| Exceptions ||
|-----------------------|-----------------------------------|
| `java.lang.Exception` | if this resource cannot be closed |
| `java.io.IOException` | If an I/O error occurs |
### flush
Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels)
```
open fun flush(): Unit
```
Flushes the stream.
| Exceptions ||
|-----------------------|------------------------|
| `java.io.IOException` | If an I/O error occurs |
### getEncoding
Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels)
```
open fun getEncoding(): String!
```
Returns the name of the character encoding being used by this stream.
If the encoding has an historical name then that name is returned; otherwise the encoding's canonical name is returned.
If this instance was created with the[OutputStreamWriter(java.io.OutputStream,java.lang.String)](https://developer.android.com/reference/kotlin/java/io/OutputStreamWriter#OutputStreamWriter(java.io.OutputStream,%20kotlin.String))constructor then the returned name, being unique for the encoding, may differ from the name passed to the constructor. This method may return`null`if the stream has been closed.
| Return ||
|-----------------------------------------------------------------------------------|--------------------------------------------------------------------------------------|
| [String](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-string/index.html)! | The historical name of this encoding, or possibly`null`if the stream has been closed |
**See Also**
- [java.nio.charset.Charset](https://developer.android.com/reference/kotlin/java/nio/charset/Charset.html#)
### write
Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels)
```
open fun write(
cbuf: CharArray!,
off: Int,
len: Int
): Unit
```
Writes a portion of an array of characters.
| Parameters ||
|--------|--------------------------------------------------------------------------------------------------------------------------|
| `cbuf` | [CharArray](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-char-array/index.html)!:Buffer of characters |
| `off` | [Int](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html):Offset from which to start writing characters |
| `len` | [Int](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html):Number of characters to write |
| Exceptions ||
|---------------------------------------|----------------------------------------------------------------------------------------------------------------|
| `java.lang.IndexOutOfBoundsException` | If`off`is negative, or`len`is negative, or`off + len`is negative or greater than the length of the given array |
| `java.io.IOException` | If an I/O error occurs |
### write
Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels)
```
open fun write(c: Int): Unit
```
Writes a single character.
| Parameters ||
|-----|---------------------------------------------------------------------------------------------------------------------|
| `c` | [Int](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html):int specifying a character to be written |
| Exceptions ||
|-----------------------|------------------------|
| `java.io.IOException` | If an I/O error occurs |
### write
Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element.html#ApiLevels)
```
open fun write(
str: String!,
off: Int,
len: Int
): Unit
```
Writes a portion of a string.
| Parameters ||
|-------|--------------------------------------------------------------------------------------------------------------------------|
| `str` | [String](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-string/index.html)!:A String |
| `off` | [Int](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html):Offset from which to start writing characters |
| `len` | [Int](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-int/index.html):Number of characters to write |
| Exceptions ||
|---------------------------------------|-----------------------------------------------------------------------------------------------------------------|
| `java.lang.IndexOutOfBoundsException` | If`off`is negative, or`len`is negative, or`off + len`is negative or greater than the length of the given string |
| `java.io.IOException` | If an I/O error occurs |