Added in [API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) Summary: [Constants](https://developer.android.com/reference/java/io/PipedInputStream#constants) \| [Fields](https://developer.android.com/reference/java/io/PipedInputStream#lfields) \| [Ctors](https://developer.android.com/reference/java/io/PipedInputStream#pubctors) \| [Methods](https://developer.android.com/reference/java/io/PipedInputStream#pubmethods) \| [Protected Methods](https://developer.android.com/reference/java/io/PipedInputStream#promethods) \| [Inherited Methods](https://developer.android.com/reference/java/io/PipedInputStream#inhmethods)
# PipedInputStream
` public class PipedInputStream `
` ` ` extends https://developer.android.com/reference/java/io/InputStream ` ` `
|---|---|---|
| [java.lang.Object](https://developer.android.com/reference/java/lang/Object) |||
| ↳ | [java.io.InputStream](https://developer.android.com/reference/java/io/InputStream) ||
| | ↳ | java.io.PipedInputStream |
*** ** * ** ***
A piped input stream should be connected to a piped output stream; the piped input stream then provides whatever data bytes are written to the piped output stream. Typically, data is read from a `PipedInputStream` object by one thread and data is written to the corresponding `PipedOutputStream` by some other thread. Attempting to use both objects from a single thread is not recommended, as it may deadlock the thread. The piped input stream contains a buffer, decoupling read operations from write operations, within limits. A pipe is said to be *broken* if a thread that was providing data bytes to the connected piped output stream is no longer alive.
**See also:**
- `https://developer.android.com/reference/java/io/PipedOutputStream`
## Summary
| ### Constants ||
|---|---|
| `int` | `https://developer.android.com/reference/java/io/PipedInputStream#PIPE_SIZE` The default size of the pipe's circular input buffer. |
| ### Fields ||
|---|---|
| ` protected byte[]` | `https://developer.android.com/reference/java/io/PipedInputStream#buffer` The circular buffer into which incoming data is placed. |
| ` protected int` | `https://developer.android.com/reference/java/io/PipedInputStream#in` The index of the position in the circular buffer at which the next byte of data will be stored when received from the connected piped output stream. |
| ` protected int` | `https://developer.android.com/reference/java/io/PipedInputStream#out` The index of the position in the circular buffer at which the next byte of data will be read by this piped input stream. |
| ### Public constructors ||
|---|---|
| ` https://developer.android.com/reference/java/io/PipedInputStream#PipedInputStream()() ` Creates a `PipedInputStream` so that it is not yet [connected](https://developer.android.com/reference/java/io/PipedInputStream#connect(java.io.PipedOutputStream)). |
| ` https://developer.android.com/reference/java/io/PipedInputStream#PipedInputStream(int)(int pipeSize) ` Creates a `PipedInputStream` so that it is not yet [connected](https://developer.android.com/reference/java/io/PipedInputStream#connect(java.io.PipedOutputStream)) and uses the specified pipe size for the pipe's buffer. |
| ` https://developer.android.com/reference/java/io/PipedInputStream#PipedInputStream(java.io.PipedOutputStream)(https://developer.android.com/reference/java/io/PipedOutputStream src) ` Creates a `PipedInputStream` so that it is connected to the piped output stream `src`. |
| ` https://developer.android.com/reference/java/io/PipedInputStream#PipedInputStream(java.io.PipedOutputStream,%20int)(https://developer.android.com/reference/java/io/PipedOutputStream src, int pipeSize) ` Creates a `PipedInputStream` so that it is connected to the piped output stream `src` and uses the specified pipe size for the pipe's buffer. |
| ### Public methods ||
|---|---|
| ` int` | ` https://developer.android.com/reference/java/io/PipedInputStream#available()() ` Returns the number of bytes that can be read from this input stream without blocking. |
| ` void` | ` https://developer.android.com/reference/java/io/PipedInputStream#close()() ` Closes this piped input stream and releases any system resources associated with the stream. |
| ` void` | ` https://developer.android.com/reference/java/io/PipedInputStream#connect(java.io.PipedOutputStream)(https://developer.android.com/reference/java/io/PipedOutputStream src) ` Causes this piped input stream to be connected to the piped output stream `src`. |
| ` int` | ` https://developer.android.com/reference/java/io/PipedInputStream#read()() ` Reads the next byte of data from this piped input stream. |
| ` int` | ` https://developer.android.com/reference/java/io/PipedInputStream#read(byte[],%20int,%20int)(byte[] b, int off, int len) ` Reads up to `len` bytes of data from this piped input stream into an array of bytes. |
| ### Protected methods ||
|---|---|
| ` void` | ` https://developer.android.com/reference/java/io/PipedInputStream#receive(int)(int b) ` Receives a byte of data. |
### Inherited methods
From class ` https://developer.android.com/reference/java/io/InputStream ` ` int` ` https://developer.android.com/reference/java/io/InputStream#available()() `
Returns an estimate of the number of bytes that can be read (or skipped over) from this input stream without blocking, which may be 0, or 0 when end of stream is detected.
` void` ` https://developer.android.com/reference/java/io/InputStream#close()() `
Closes this input stream and releases any system resources associated with the stream.
` void` ` https://developer.android.com/reference/java/io/InputStream#mark(int)(int readlimit) `
Marks the current position in this input stream.
` boolean` ` https://developer.android.com/reference/java/io/InputStream#markSupported()() `
Tests if this input stream supports the `mark` and `reset` methods.
` static https://developer.android.com/reference/java/io/InputStream` ` https://developer.android.com/reference/java/io/InputStream#nullInputStream()() `
Returns a new `InputStream` that reads no bytes.
` int` ` https://developer.android.com/reference/java/io/InputStream#read(byte[])(byte[] b) `
Reads some number of bytes from the input stream and stores them into the buffer array `b`.
` abstract int` ` https://developer.android.com/reference/java/io/InputStream#read()() `
Reads the next byte of data from the input stream.
` int` ` https://developer.android.com/reference/java/io/InputStream#read(byte[],%20int,%20int)(byte[] b, int off, int len) `
Reads up to `len` bytes of data from the input stream into an array of bytes.
` byte[]` ` https://developer.android.com/reference/java/io/InputStream#readAllBytes()() `
Reads all remaining bytes from the input stream.
` int` ` https://developer.android.com/reference/java/io/InputStream#readNBytes(byte[],%20int,%20int)(byte[] b, int off, int len) `
Reads the requested number of bytes from the input stream into the given byte array.
` byte[]` ` https://developer.android.com/reference/java/io/InputStream#readNBytes(int)(int len) `
Reads up to a specified number of bytes from the input stream.
` void` ` https://developer.android.com/reference/java/io/InputStream#reset()() `
Repositions this stream to the position at the time the `mark` method was last called on this input stream.
` long` ` https://developer.android.com/reference/java/io/InputStream#skip(long)(long n) `
Skips over and discards `n` bytes of data from this input stream.
` void` ` https://developer.android.com/reference/java/io/InputStream#skipNBytes(long)(long n) `
Skips over and discards exactly `n` bytes of data from this input stream.
` long` ` https://developer.android.com/reference/java/io/InputStream#transferTo(java.io.OutputStream)(https://developer.android.com/reference/java/io/OutputStream out) `
Reads all bytes from this input stream and writes the bytes to the given output stream in the order that they are read.
From class ` https://developer.android.com/reference/java/lang/Object ` ` https://developer.android.com/reference/java/lang/Object` ` https://developer.android.com/reference/java/lang/Object#clone()() `
Creates and returns a copy of this object.
` boolean` ` https://developer.android.com/reference/java/lang/Object#equals(java.lang.Object)(https://developer.android.com/reference/java/lang/Object obj) `
Indicates whether some other object is "equal to" this one.
` void` ` 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 https://developer.android.com/reference/java/lang/Class` ` https://developer.android.com/reference/java/lang/Object#getClass()() `
Returns the runtime class of this `Object`.
` int` ` https://developer.android.com/reference/java/lang/Object#hashCode()() `
Returns a hash code value for the object.
` final void` ` https://developer.android.com/reference/java/lang/Object#notify()() `
Wakes up a single thread that is waiting on this object's monitor.
` final void` ` https://developer.android.com/reference/java/lang/Object#notifyAll()() `
Wakes up all threads that are waiting on this object's monitor.
` https://developer.android.com/reference/java/lang/String` ` https://developer.android.com/reference/java/lang/Object#toString()() `
Returns a string representation of the object.
` final void` ` 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` ` 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` ` 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 ` https://developer.android.com/reference/java/io/Closeable ` ` abstract void` ` https://developer.android.com/reference/java/io/Closeable#close()() `
Closes this stream and releases any system resources associated with it.
From interface ` https://developer.android.com/reference/java/lang/AutoCloseable ` ` abstract void` ` https://developer.android.com/reference/java/lang/AutoCloseable#close()() `
Closes this resource, relinquishing any underlying resources.
## Constants
### PIPE_SIZE
Added in [API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)
```
protected static final int PIPE_SIZE
```
The default size of the pipe's circular input buffer.
Constant Value: 1024 (0x00000400)
## Fields
### buffer
Added in [API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)
```
protected byte[] buffer
```
The circular buffer into which incoming data is placed.
### in
Added in [API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)
```
protected int in
```
The index of the position in the circular buffer at which the next byte of data will be stored when received from the connected piped output stream. `in<0` implies the buffer is empty, `in==out` implies the buffer is full
### out
Added in [API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)
```
protected int out
```
The index of the position in the circular buffer at which the next byte of data will be read by this piped input stream.
## Public constructors
### PipedInputStream
Added in [API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)
```
public PipedInputStream ()
```
Creates a `PipedInputStream` so that it is not yet [connected](https://developer.android.com/reference/java/io/PipedInputStream#connect(java.io.PipedOutputStream)). It must be [connected](https://developer.android.com/reference/java/io/PipedOutputStream#connect(java.io.PipedInputStream)) to a `PipedOutputStream` before being used.
### PipedInputStream
Added in [API level 9](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)
```
public PipedInputStream (int pipeSize)
```
Creates a `PipedInputStream` so that it is not yet [connected](https://developer.android.com/reference/java/io/PipedInputStream#connect(java.io.PipedOutputStream)) and uses the specified pipe size for the pipe's buffer. It must be [connected](https://developer.android.com/reference/java/io/PipedOutputStream#connect(java.io.PipedInputStream)) to a `PipedOutputStream` before being used.
| Parameters ||
|---|---|
| `pipeSize` | `int`: the size of the pipe's buffer.
|
| Throws ||
|---|---|
| `https://developer.android.com/reference/java/lang/IllegalArgumentException` | if `pipeSize <= 0`. |
### PipedInputStream
Added in [API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)
```
public PipedInputStream (PipedOutputStream src)
```
Creates a `PipedInputStream` so that it is connected to the piped output stream `src`. Data bytes written to `src` will then be available as input from this stream.
| Parameters ||
|---|---|
| `src` | `PipedOutputStream`: the stream to connect to.
|
| Throws ||
|---|---|
| `https://developer.android.com/reference/java/io/IOException` | if an I/O error occurs. |
### PipedInputStream
Added in [API level 9](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)
```
public PipedInputStream (PipedOutputStream src,
int pipeSize)
```
Creates a `PipedInputStream` so that it is connected to the piped output stream `src` and uses the specified pipe size for the pipe's buffer. Data bytes written to `src` will then be available as input from this stream.
| Parameters ||
|---|---|
| `src` | `PipedOutputStream`: the stream to connect to.
|
| `pipeSize` | `int`: the size of the pipe's buffer.
|
| Throws ||
|---|---|
| `https://developer.android.com/reference/java/io/IOException` | if an I/O error occurs. |
| `https://developer.android.com/reference/java/lang/IllegalArgumentException` | if `pipeSize <= 0`. |
## Public methods
### available
Added in [API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)
```
public int available ()
```
Returns the number of bytes that can be read from this input stream without blocking.
| Returns ||
|---|---|
| `int` | the number of bytes that can be read from this input stream without blocking, or `0` if this input stream has been closed by invoking its `https://developer.android.com/reference/java/io/PipedInputStream#close()` method, or if the pipe is `https://developer.android.com/reference/java/io/PipedInputStream#connect(java.io.PipedOutputStream)`, or [`broken`](https://developer.android.com/reference/java/io/PipedInputStream#BROKEN).
|
| Throws ||
|---|---|
| `https://developer.android.com/reference/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#ApiLevels)
```
public void close ()
```
Closes this piped input stream and releases any system resources associated with the stream.
| Throws ||
|---|---|
| `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 (PipedOutputStream src)
```
Causes this piped input stream to be connected to the piped output stream `src`. If this object is already connected to some other piped output stream, an `IOException` is thrown.
If `src` is an unconnected piped output stream and `snk` is an unconnected piped input stream, 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` | `PipedOutputStream`: The piped output stream to connect to.
|
| Throws ||
|---|---|
| `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 byte of data from this piped input stream. The value byte is returned as an `int` in the range `0` to `255`. This method blocks until input data is available, the end of the stream is detected, or an exception is thrown.
| Returns ||
|---|---|
| `int` | the next byte of data, or `-1` if the end of the stream is reached.
|
| Throws ||
|---|---|
| `https://developer.android.com/reference/java/io/IOException` | if the pipe is `https://developer.android.com/reference/java/io/PipedInputStream#connect(java.io.PipedOutputStream)`, [`broken`](https://developer.android.com/reference/java/io/PipedInputStream#BROKEN), closed, or 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 (byte[] b,
int off,
int len)
```
Reads up to `len` bytes of data from this piped input stream into an array of bytes. Less than `len` bytes will be read if the end of the data stream is reached or if `len` exceeds the pipe's buffer size. If `len ` is zero, then no bytes are read and 0 is returned; otherwise, the method blocks until at least 1 byte of input is available, end of the stream has been detected, or an exception is thrown.
| Parameters ||
|---|---|
| `b` | `byte`: the buffer into which the data is read.
|
| `off` | `int`: the start offset in the destination array `b`
|
| `len` | `int`: the maximum number of bytes read.
|
| Returns ||
|---|---|
| `int` | the total number of bytes read into the buffer, or `-1` if there is no more data because the end of the stream has been reached.
|
| Throws ||
|---|---|
| `https://developer.android.com/reference/java/io/IOException` | if the pipe is [`broken`](https://developer.android.com/reference/java/io/PipedInputStream#BROKEN), `https://developer.android.com/reference/java/io/PipedInputStream#connect(java.io.PipedOutputStream)`, closed, or if an I/O error occurs. |
| `https://developer.android.com/reference/java/lang/IndexOutOfBoundsException` | If `off` is negative, `len` is negative, or `len` is greater than `b.length - off` |
| `https://developer.android.com/reference/java/lang/NullPointerException` | If `b` is `null`. |
## Protected methods
### receive
Added in [API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)
```
protected void receive (int b)
```
Receives a byte of data. This method will block if no input is available.
| Parameters ||
|---|---|
| `b` | `int`: the byte being received
|
| Throws ||
|---|---|
| `https://developer.android.com/reference/java/io/IOException` | If the pipe is [`broken`](https://developer.android.com/reference/java/io/PipedInputStream#BROKEN), `https://developer.android.com/reference/java/io/PipedInputStream#connect(java.io.PipedOutputStream)`, closed, or if an I/O error occurs. |