# PipedReader
Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)
Summary:[Inherited Fields](https://developer.android.com/reference/java/io/PipedReader#inhfields)\|[Ctors](https://developer.android.com/reference/java/io/PipedReader#pubctors)\|[Methods](https://developer.android.com/reference/java/io/PipedReader#pubmethods)\|[Inherited Methods](https://developer.android.com/reference/java/io/PipedReader#inhmethods)
# PipedReader
`
public
class
PipedReader
`
`
``
extends `[Reader](https://developer.android.com/reference/java/io/Reader)`
``
`
|---|---|---------------------|
| [java.lang.Object](https://developer.android.com/reference/java/lang/Object) |||
| ↳ | [java.io.Reader](https://developer.android.com/reference/java/io/Reader) ||
| | ↳ | java.io.PipedReader |
*** ** * ** ***
Piped character-input streams.
## Summary
| ### Inherited fields |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| From class[java.io.Reader](https://developer.android.com/reference/java/io/Reader) |---------------------------------------------------------------------------------|-------------------------------------------------------------------------------------------------------------------------------| | ` protected `[Object](https://developer.android.com/reference/java/lang/Object) | [lock](https://developer.android.com/reference/java/io/Reader#lock) The object used to synchronize operations on this stream. | |
| ### Public constructors ||
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|---|
| ` `[PipedReader](https://developer.android.com/reference/java/io/PipedReader#PipedReader())`() ` Creates a`PipedReader`so that it is not yet[connected](https://developer.android.com/reference/java/io/PipedReader#connect(java.io.PipedWriter)). |
| ` `[PipedReader](https://developer.android.com/reference/java/io/PipedReader#PipedReader(int))`(int pipeSize) ` Creates a`PipedReader`so that it is not yet[connected](https://developer.android.com/reference/java/io/PipedReader#connect(java.io.PipedWriter))and uses the specified pipe size for the pipe's buffer. |
| ` `[PipedReader](https://developer.android.com/reference/java/io/PipedReader#PipedReader(java.io.PipedWriter))`(`[PipedWriter](https://developer.android.com/reference/java/io/PipedWriter)` src) ` Creates a`PipedReader`so that it is connected to the piped writer`src`. |
| ` `[PipedReader](https://developer.android.com/reference/java/io/PipedReader#PipedReader(java.io.PipedWriter,%20int))`(`[PipedWriter](https://developer.android.com/reference/java/io/PipedWriter)` src, int pipeSize) ` Creates a`PipedReader`so that it is connected to the piped writer`src`and uses the specified pipe size for the pipe's buffer. |
| ### Public methods ||
|------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| ` void` | ` `[close](https://developer.android.com/reference/java/io/PipedReader#close())`() ` Closes this piped stream and releases any system resources associated with the stream. |
| ` void` | ` `[connect](https://developer.android.com/reference/java/io/PipedReader#connect(java.io.PipedWriter))`(`[PipedWriter](https://developer.android.com/reference/java/io/PipedWriter)` src) ` Causes this piped reader to be connected to the piped writer`src`. |
| ` int` | ` `[read](https://developer.android.com/reference/java/io/PipedReader#read())`() ` Reads the next character of data from this piped stream. |
| ` int` | ` `[read](https://developer.android.com/reference/java/io/PipedReader#read(char[],%20int,%20int))`(char[] cbuf, int off, int len) ` Reads up to`len`characters of data from this piped stream into an array of characters. |
| ` boolean` | ` `[ready](https://developer.android.com/reference/java/io/PipedReader#ready())`() ` Tell whether this stream is ready to be read. |
| ### Inherited methods |
|-----------------------|---|
| From class` `[java.io.Reader](https://developer.android.com/reference/java/io/Reader)` ` |----------------------------------------------------------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| | ` abstract void` | ` `[close](https://developer.android.com/reference/java/io/Reader#close())`() ` Closes the stream and releases any system resources associated with it. | | ` void` | ` `[mark](https://developer.android.com/reference/java/io/Reader#mark(int))`(int readAheadLimit) ` Marks the present position in the stream. | | ` boolean` | ` `[markSupported](https://developer.android.com/reference/java/io/Reader#markSupported())`() ` Tells whether this stream supports the mark() operation. | | ` static `[Reader](https://developer.android.com/reference/java/io/Reader) | ` `[nullReader](https://developer.android.com/reference/java/io/Reader#nullReader())`() ` Returns a new`Reader`that reads no characters. | | ` int` | ` `[read](https://developer.android.com/reference/java/io/Reader#read())`() ` Reads a single character. | | ` abstract int` | ` `[read](https://developer.android.com/reference/java/io/Reader#read(char[],%20int,%20int))`(char[] cbuf, int off, int len) ` Reads characters into a portion of an array. | | ` int` | ` `[read](https://developer.android.com/reference/java/io/Reader#read(char[]))`(char[] cbuf) ` Reads characters into an array. | | ` int` | ` `[read](https://developer.android.com/reference/java/io/Reader#read(java.nio.CharBuffer))`(`[CharBuffer](https://developer.android.com/reference/java/nio/CharBuffer)` target) ` Attempts to read characters into the specified character buffer. | | ` boolean` | ` `[ready](https://developer.android.com/reference/java/io/Reader#ready())`() ` Tells whether this stream is ready to be read. | | ` void` | ` `[reset](https://developer.android.com/reference/java/io/Reader#reset())`() ` Resets the stream. | | ` long` | ` `[skip](https://developer.android.com/reference/java/io/Reader#skip(long))`(long n) ` Skips characters. | | ` long` | ` `[transferTo](https://developer.android.com/reference/java/io/Reader#transferTo(java.io.Writer))`(`[Writer](https://developer.android.com/reference/java/io/Writer)` out) ` Reads all characters from this reader and writes the characters to the given writer in the order that they are read. | ||
| From class` `[java.lang.Object](https://developer.android.com/reference/java/lang/Object)` ` |--------------------------------------------------------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| | ` `[Object](https://developer.android.com/reference/java/lang/Object) | ` `[clone](https://developer.android.com/reference/java/lang/Object#clone())`() ` Creates and returns a copy of this object. | | ` boolean` | ` `[equals](https://developer.android.com/reference/java/lang/Object#equals(java.lang.Object))`(`[Object](https://developer.android.com/reference/java/lang/Object)` obj) ` Indicates whether some other object is "equal to" this one. | | ` void` | ` `[finalize](https://developer.android.com/reference/java/lang/Object#finalize())`() ` Called by the garbage collector on an object when garbage collection determines that there are no more references to the object. | | ` final `[Class](https://developer.android.com/reference/java/lang/Class)`` | ` `[getClass](https://developer.android.com/reference/java/lang/Object#getClass())`() ` Returns the runtime class of this`Object`. | | ` int` | ` `[hashCode](https://developer.android.com/reference/java/lang/Object#hashCode())`() ` Returns a hash code value for the object. | | ` final void` | ` `[notify](https://developer.android.com/reference/java/lang/Object#notify())`() ` Wakes up a single thread that is waiting on this object's monitor. | | ` final void` | ` `[notifyAll](https://developer.android.com/reference/java/lang/Object#notifyAll())`() ` Wakes up all threads that are waiting on this object's monitor. | | ` `[String](https://developer.android.com/reference/java/lang/String) | ` `[toString](https://developer.android.com/reference/java/lang/Object#toString())`() ` Returns a string representation of the object. | | ` final void` | ` `[wait](https://developer.android.com/reference/java/lang/Object#wait(long,%20int))`(long timeoutMillis, int nanos) ` Causes the current thread to wait until it is awakened, typically by being*notified* or*interrupted*, or until a certain amount of real time has elapsed. | | ` final void` | ` `[wait](https://developer.android.com/reference/java/lang/Object#wait(long))`(long timeoutMillis) ` Causes the current thread to wait until it is awakened, typically by being*notified* or*interrupted*, or until a certain amount of real time has elapsed. | | ` final void` | ` `[wait](https://developer.android.com/reference/java/lang/Object#wait())`() ` Causes the current thread to wait until it is awakened, typically by being*notified* or*interrupted*. | ||
| From interface` `[java.io.Closeable](https://developer.android.com/reference/java/io/Closeable)` ` |------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------| | ` abstract void` | ` `[close](https://developer.android.com/reference/java/io/Closeable#close())`() ` Closes this stream and releases any system resources associated with it. | ||
| From interface` `[java.lang.Readable](https://developer.android.com/reference/java/lang/Readable)` ` |-----------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| | ` abstract int` | ` `[read](https://developer.android.com/reference/java/lang/Readable#read(java.nio.CharBuffer))`(`[CharBuffer](https://developer.android.com/reference/java/nio/CharBuffer)` cb) ` Attempts to read characters into the specified character buffer. | ||
| From interface` `[java.lang.AutoCloseable](https://developer.android.com/reference/java/lang/AutoCloseable)` ` |------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------| | ` abstract void` | ` `[close](https://developer.android.com/reference/java/lang/AutoCloseable#close())`() ` Closes this resource, relinquishing any underlying resources. | ||
## Public constructors
### PipedReader
Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)
```
public PipedReader ()
```
Creates a`PipedReader`so that it is not yet[connected](https://developer.android.com/reference/java/io/PipedReader#connect(java.io.PipedWriter)). It must be[connected](https://developer.android.com/reference/java/io/PipedWriter#connect(java.io.PipedReader))to a`PipedWriter`before being used.
### PipedReader
Added in[API level 9](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)
```
public PipedReader (int pipeSize)
```
Creates a`PipedReader`so that it is not yet[connected](https://developer.android.com/reference/java/io/PipedReader#connect(java.io.PipedWriter))and uses the specified pipe size for the pipe's buffer. It must be[connected](https://developer.android.com/reference/java/io/PipedWriter#connect(java.io.PipedReader))to a`PipedWriter`before being used.
| Parameters ||
|------------|----------------------------------------------|
| `pipeSize` | `int`: the size of the pipe's buffer.
|
| Throws ||
|--------------------------------------------------------------------------------------------------------|--------------------|
| [IllegalArgumentException](https://developer.android.com/reference/java/lang/IllegalArgumentException) | if`pipeSize <= 0`. |
### PipedReader
Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)
```
public PipedReader (PipedWriter src)
```
Creates a`PipedReader`so that it is connected to the piped writer`src`. Data written to`src`will then be available as input from this stream.
| Parameters ||
|-------|-------------------------------------------------|
| `src` | `PipedWriter`: the stream to connect to.
|
| Throws ||
|----------------------------------------------------------------------------|-------------------------|
| [IOException](https://developer.android.com/reference/java/io/IOException) | if an I/O error occurs. |
### PipedReader
Added in[API level 9](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)
```
public PipedReader (PipedWriter src,
int pipeSize)
```
Creates a`PipedReader`so that it is connected to the piped writer`src`and uses the specified pipe size for the pipe's buffer. Data written to`src`will then be available as input from this stream.
| Parameters ||
|------------|-------------------------------------------------|
| `src` | `PipedWriter`: the stream to connect to.
|
| `pipeSize` | `int`: the size of the pipe's buffer.
|
| Throws ||
|--------------------------------------------------------------------------------------------------------|-------------------------|
| [IOException](https://developer.android.com/reference/java/io/IOException) | if an I/O error occurs. |
| [IllegalArgumentException](https://developer.android.com/reference/java/lang/IllegalArgumentException) | if`pipeSize <= 0`. |
## Public methods
### close
Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)
```
public void close ()
```
Closes this piped stream and releases any system resources associated with the stream.
| Throws ||
|----------------------------------------------------------------------------|-------------------------|
| [IOException](https://developer.android.com/reference/java/io/IOException) | if an I/O error occurs. |
### connect
Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)
```
public void connect (PipedWriter src)
```
Causes this piped reader to be connected to the piped writer`src`. If this object is already connected to some other piped writer, an`IOException`is thrown.
If`src`is an unconnected piped writer and`snk`is an unconnected piped reader, they may be connected by either the call:
snk.connect(src)
or the call:
src.connect(snk)
The two calls have the same effect.
| Parameters ||
|-------|-------------------------------------------------------|
| `src` | `PipedWriter`: The piped writer to connect to.
|
| Throws ||
|----------------------------------------------------------------------------|-------------------------|
| [IOException](https://developer.android.com/reference/java/io/IOException) | if an I/O error occurs. |
### read
Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)
```
public int read ()
```
Reads the next character of data from this piped stream. If no character is available because the end of the stream has been reached, the value`-1`is returned. This method blocks until input data is available, the end of the stream is detected, or an exception is thrown.
| Returns ||
|-------|-------------------------------------------------------------------------------|
| `int` | the next character of data, or`-1`if the end of the stream is reached.
|
| Throws ||
|----------------------------------------------------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| [IOException](https://developer.android.com/reference/java/io/IOException) | if the pipe is[`broken`](https://developer.android.com/reference/java/io/PipedInputStream#BROKEN),[unconnected](https://developer.android.com/reference/java/io/PipedReader#connect(java.io.PipedWriter)), closed, or an I/O error occurs. |
### read
Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)
```
public int read (char[] cbuf,
int off,
int len)
```
Reads up to`len`characters of data from this piped stream into an array of characters. Less than`len`characters will be read if the end of the data stream is reached or if`len`exceeds the pipe's buffer size. This method blocks until at least one character of input is available.
| Parameters ||
|--------|--------------------------------------------------------|
| `cbuf` | `char`: the buffer into which the data is read.
|
| `off` | `int`: the start offset of the data.
|
| `len` | `int`: the maximum number of characters read.
|
| Returns ||
|-------|--------------------------------------------------------------------------------------------------------------------------------------------|
| `int` | the total number of characters read into the buffer, or`-1`if there is no more data because the end of the stream has been reached.
|
| Throws ||
|----------------------------------------------------------------------------------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| [IOException](https://developer.android.com/reference/java/io/IOException) | if the pipe is[`broken`](https://developer.android.com/reference/java/io/PipedInputStream#BROKEN),[unconnected](https://developer.android.com/reference/java/io/PipedReader#connect(java.io.PipedWriter)), closed, or an I/O error occurs. |
| [IndexOutOfBoundsException](https://developer.android.com/reference/java/lang/IndexOutOfBoundsException) | |
### ready
Added in[API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)
```
public boolean ready ()
```
Tell whether this stream is ready to be read. A piped character stream is ready if the circular buffer is not empty.
| Returns ||
|-----------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| `boolean` | True if the next read() is guaranteed not to block for input, false otherwise. Note that returning false does not guarantee that the next read will block.
|
| Throws ||
|----------------------------------------------------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| [IOException](https://developer.android.com/reference/java/io/IOException) | if the pipe is[`broken`](https://developer.android.com/reference/java/io/PipedInputStream#BROKEN),[unconnected](https://developer.android.com/reference/java/io/PipedReader#connect(java.io.PipedWriter)), or closed. |