Package org.eclipse.net4j.util.io

# Klasse DelegatingInputStream

java.lang.Object
java.io.InputStream
org.eclipse.net4j.util.io.DelegatingInputStream

Alle implementierten Schnittstellen:
  `Closeable`, `AutoCloseable`

Bekannte direkte Unterklassen:
  `XORInputStream`

public class DelegatingInputStream extends InputStream
A `DelegatingInputStream` contains some other input stream, which it uses as its basic source of data, possibly transforming the data along the way or providing additional functionality. The class `DelegatingInputStream` itself simply overrides all (see note below) methods of `InputStream` with versions that pass all requests to the contained input stream. Subclasses of `DelegatingInputStream` may further override some of these methods and may also provide additional methods and fields.

Note: The only difference to `FilterInputStream` is that `DelegatingInputStream` does not override `InputStream.read(byte[])` or `InputStream.read(byte[], int, int)` but rather exposes the original implementations of `InputStream` which call `read()` instead of their delegate counterparts.

Autor:
  Eike Stepper

## Feldübersicht

Felder
Modifizierer und Typ
Feld
Beschreibung
`protected InputStream`
`in`
The input stream to be filtered.

## Konstruktorübersicht

Konstruktoren
Modifizierer
Konstruktor
Beschreibung
`protected`
`DelegatingInputStream(InputStream in)`
Creates a `DelegatingInputStream` by assigning the argument `in` to the field `this.in` so as to remember it for later use.

## Methodenübersicht

Modifizierer und Typ
Methode
Beschreibung
`int`
`available()`
Returns the number of bytes that can be read from this input stream without blocking.
`void`
`close()`
Closes this input stream and releases any system resources associated with the stream.
`InputStream`
`getDelegate()`
`void`
`mark(int readlimit)`
Marks the current position in this input stream.
`boolean`
`markSupported()`
Tests if this input stream supports the `mark` and `reset` methods.
`int`
`read()`
Reads the next byte of data from this input stream.
`void`
`reset()`
Repositions this stream to the position at the time the `mark` method was last called on this input stream.
`long`
`skip(long n)`
Skips over and discards `n` bytes of data from the input stream.

### Von Klasse geerbte Methoden java.io.InputStream

`nullInputStream, read, read, readAllBytes, readNBytes, readNBytes, skipNBytes, transferTo`

### Von Klasse geerbte Methoden java.lang.Object

`clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

## Felddetails

### in

protected volatile InputStream in
The input stream to be filtered.

## Konstruktordetails

### DelegatingInputStream

protected DelegatingInputStream(InputStream in)
Creates a `DelegatingInputStream` by assigning the argument `in` to the field `this.in` so as to remember it for later use.

Parameter:
  `in` - the underlying input stream, or `null` if this instance is to be created without an underlying stream.

## Methodendetails

### getDelegate

public InputStream getDelegate()

### read

public int read() throws IOException
Reads the next byte of data from this input stream. The value byte is returned as an `int` in the range `0` to `255`. If no byte 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.

This method simply performs `in.read()` and returns the result.

Angegeben von:
  `read` in Klasse `InputStream`
Gibt zurück:
  the next byte of data, or `-1` if the end of the stream is reached.
Löst aus:
  `IOException` - if an I/O error occurs.
Siehe auch:
  - `in`

### skip

public long skip(long n) throws IOException
Skips over and discards `n` bytes of data from the input stream. The `skip` method may, for a variety of reasons, end up skipping over some smaller number of bytes, possibly `0`. The actual number of bytes skipped is returned.

This method simply performs `in.skip(n)`.

Setzt außer Kraft:
  `skip` in Klasse `InputStream`
Parameter:
  `n` - the number of bytes to be skipped.
Gibt zurück:
  the actual number of bytes skipped.
Löst aus:
  `IOException` - if an I/O error occurs.

### available

public int available() throws IOException
Returns the number of bytes that can be read from this input stream without blocking.

This method simply performs `in.available()` and returns the result.

Setzt außer Kraft:
  `available` in Klasse `InputStream`
Gibt zurück:
  the number of bytes that can be read from the input stream without blocking.
Löst aus:
  `IOException` - if an I/O error occurs.
Siehe auch:
  - `in`

### close

public void close() throws IOException
Closes this input stream and releases any system resources associated with the stream. This method simply performs `in.close()`.

Angegeben von:
  `close` in Schnittstelle `AutoCloseable`
Angegeben von:
  `close` in Schnittstelle `Closeable`
Setzt außer Kraft:
  `close` in Klasse `InputStream`
Löst aus:
  `IOException` - if an I/O error occurs.
Siehe auch:
  - `in`

### mark

public void mark(int readlimit)
Marks the current position in this input stream. A subsequent call to the `reset` method repositions this stream at the last marked position so that subsequent reads re-read the same bytes.

The `readlimit` argument tells this input stream to allow that many bytes to be read before the mark position gets invalidated.

This method simply performs `in.mark(readlimit)`.

Setzt außer Kraft:
  `mark` in Klasse `InputStream`
Parameter:
  `readlimit` - the maximum limit of bytes that can be read before the mark position becomes invalid.
Siehe auch:
  - `in`
  - `reset()`

### reset

public void reset() throws IOException
Repositions this stream to the position at the time the `mark` method was last called on this input stream.

This method simply performs `in.reset()`.

Stream marks are intended to be used in situations where you need to read ahead a little to see what's in the stream. Often this is most easily done by invoking some general parser. If the stream is of the type handled by the parse, it just chugs along happily. If the stream is not of that type, the parser should toss an exception when it fails. If this happens within readlimit bytes, it allows the outer code to reset the stream and try another parser.

Setzt außer Kraft:
  `reset` in Klasse `InputStream`
Löst aus:
  `IOException` - if the stream has not been marked or if the mark has been invalidated.
Siehe auch:
  - `in`
  - `mark(int)`

### markSupported

public boolean markSupported()
Tests if this input stream supports the `mark` and `reset` methods. This method simply performs `in.markSupported()`.

Setzt außer Kraft:
  `markSupported` in Klasse `InputStream`
Gibt zurück:
  `true` if this stream type supports the `mark` and `reset` method; `false` otherwise.
Siehe auch:
  - `in`
  - `InputStream.mark(int)`
  - `InputStream.reset()`