BufferedInputStream (Java Platform SE 7 ) (original) (raw)

java.lang.Object
- java.io.InputStream
- - java.io.FilterInputStream
    - - java.io.BufferedInputStream
All Implemented Interfaces:
Closeable, AutoCloseable

public class BufferedInputStream
extends FilterInputStream
A BufferedInputStream adds functionality to another input stream-namely, the ability to buffer the input and to support the mark and reset methods. When the BufferedInputStream is created, an internal buffer array is created. As bytes from the stream are read or skipped, the internal buffer is refilled as necessary from the contained input stream, many bytes at a time. The mark operation remembers a point in the input stream and the reset operation causes all the bytes read since the most recent mark operation to be reread before new bytes are taken from the contained input stream.
Since:
JDK1.0

Field Summary

Fields

Modifier and Type	Field and Description
protected byte[]	buf The internal buffer array where the data is stored.
protected int	count The index one greater than the index of the last valid byte in the buffer.
protected int	marklimit The maximum read ahead allowed after a call to themark method before subsequent calls to thereset method fail.
protected int	markpos The value of the pos field at the time the lastmark method was called.
protected int	pos The current position in the buffer.

   * ### Fields inherited from class java.io.[FilterInputStream](../../java/io/FilterInputStream.html "class in java.io")  
   `[in](../../java/io/FilterInputStream.html#in)`

Constructor Summary

Constructors

Constructor and Description
BufferedInputStream(InputStream in) Creates a BufferedInputStream and saves its argument, the input streamin, for later use.
BufferedInputStream(InputStream in, int size) Creates a BufferedInputStream with the specified buffer size, and saves its argument, the input streamin, for later use.

Method Summary

Methods

Modifier and Type	Method and Description
int	available() Returns an estimate of the number of bytes that can be read (or skipped over) from this input stream without blocking by the next invocation of a method for this input stream.
void	close() Closes this input stream and releases any system resources associated with the stream.
void	mark(int readlimit) See the general contract of the mark method of InputStream.
boolean	markSupported() Tests if this input stream supports the mark and reset methods.
int	read() See the general contract of the read method of InputStream.
int	read(byte[] b, int off, int len) Reads bytes from this byte-input stream into the specified byte array, starting at the given offset.
void	reset() See the general contract of the reset method of InputStream.
long	skip(long n) See the general contract of the skip method of InputStream.

   * ### Methods inherited from class java.io.[FilterInputStream](../../java/io/FilterInputStream.html "class in java.io")  
   `[read](../../java/io/FilterInputStream.html#read%28byte[]%29)`  
   * ### Methods inherited from class java.lang.[Object](../../java/lang/Object.html "class in java.lang")  
   `[clone](../../java/lang/Object.html#clone%28%29), [equals](../../java/lang/Object.html#equals%28java.lang.Object%29), [finalize](../../java/lang/Object.html#finalize%28%29), [getClass](../../java/lang/Object.html#getClass%28%29), [hashCode](../../java/lang/Object.html#hashCode%28%29), [notify](../../java/lang/Object.html#notify%28%29), [notifyAll](../../java/lang/Object.html#notifyAll%28%29), [toString](../../java/lang/Object.html#toString%28%29), [wait](../../java/lang/Object.html#wait%28%29), [wait](../../java/lang/Object.html#wait%28long%29), [wait](../../java/lang/Object.html#wait%28long,%20int%29)`

Field Detail

 * #### buf  
 protected volatile byte[] buf  
 The internal buffer array where the data is stored. When necessary, it may be replaced by another array of a different size.  
 * #### count  
 protected int count  
 The index one greater than the index of the last valid byte in the buffer. This value is always in the range `0` through `buf.length`; elements `buf[0]` through `buf[count-1]`contain buffered input data obtained from the underlying input stream.  
 * #### pos  
 protected int pos  
 The current position in the buffer. This is the index of the next character to be read from the `buf` array.  
  This value is always in the range `0` through `count`. If it is less than `count`, then `buf[pos]` is the next byte to be supplied as input; if it is equal to `count`, then the next `read` or `skip` operation will require more bytes to be read from the contained input stream.  
 See Also:  
 [buf](../../java/io/BufferedInputStream.html#buf)  
 * #### markpos  
 protected int markpos  
 The value of the `pos` field at the time the last`mark` method was called.  
  This value is always in the range `-1` through `pos`. If there is no marked position in the input stream, this field is `-1`. If there is a marked position in the input stream, then `buf[markpos]` is the first byte to be supplied as input after a `reset` operation. If`markpos` is not `-1`, then all bytes from positions `buf[markpos]` through `buf[pos-1]` must remain in the buffer array (though they may be moved to another place in the buffer array, with suitable adjustments to the values of `count`, `pos`, and `markpos`); they may not be discarded unless and until the difference between `pos` and `markpos` exceeds `marklimit`.  
 See Also:  
 [mark(int)](../../java/io/BufferedInputStream.html#mark%28int%29), [pos](../../java/io/BufferedInputStream.html#pos)  
 * #### marklimit  
 protected int marklimit  
 The maximum read ahead allowed after a call to the`mark` method before subsequent calls to the`reset` method fail. Whenever the difference between `pos` and `markpos` exceeds `marklimit`, then the mark may be dropped by setting`markpos` to `-1`.  
 See Also:  
 [mark(int)](../../java/io/BufferedInputStream.html#mark%28int%29), [reset()](../../java/io/BufferedInputStream.html#reset%28%29)

Constructor Detail

* #### BufferedInputStream  
public BufferedInputStream([InputStream](../../java/io/InputStream.html "class in java.io") in)  
Creates a `BufferedInputStream` and saves its argument, the input stream`in`, for later use. An internal buffer array is created and stored in `buf`.  
Parameters:  
`in` \- the underlying input stream.  
* #### BufferedInputStream  
public BufferedInputStream([InputStream](../../java/io/InputStream.html "class in java.io") in,  
                   int size)  
Creates a `BufferedInputStream` with the specified buffer size, and saves its argument, the input stream`in`, for later use. An internal buffer array of length `size` is created and stored in `buf`.  
Parameters:  
`in` \- the underlying input stream.  
`size` \- the buffer size.  
Throws:  
`[IllegalArgumentException](../../java/lang/IllegalArgumentException.html "class in java.lang")` \- if size <= 0.

Method Detail

* #### read  
public int read()  
         throws [IOException](../../java/io/IOException.html "class in java.io")  
See the general contract of the `read` method of `InputStream`.  
**Overrides:**  
`[read](../../java/io/FilterInputStream.html#read%28%29)` in class `[FilterInputStream](../../java/io/FilterInputStream.html "class in java.io")`  
Returns:  
the next byte of data, or `-1` if the end of the stream is reached.  
Throws:  
`[IOException](../../java/io/IOException.html "class in java.io")` \- if this input stream has been closed by invoking its [close()](../../java/io/BufferedInputStream.html#close%28%29) method, or an I/O error occurs.  
See Also:  
[FilterInputStream.in](../../java/io/FilterInputStream.html#in)  
* #### read  
public int read(byte[] b,  
       int off,  
       int len)  
         throws [IOException](../../java/io/IOException.html "class in java.io")  
Reads bytes from this byte-input stream into the specified byte array, starting at the given offset.  
 This method implements the general contract of the corresponding`[read](../../java/io/InputStream.html#read%28byte[],%20int,%20int%29)` method of the `[InputStream](../../java/io/InputStream.html "class in java.io")` class. As an additional convenience, it attempts to read as many bytes as possible by repeatedly invoking the `read` method of the underlying stream. This iterated `read` continues until one of the following conditions becomes true:  
         * The specified number of bytes have been read,  
         * The `read` method of the underlying stream returns`-1`, indicating end-of-file, or  
         * The `available` method of the underlying stream returns zero, indicating that further input requests would block.  
 If the first `read` on the underlying stream returns`-1` to indicate end-of-file then this method returns`-1`. Otherwise this method returns the number of bytes actually read.  
 Subclasses of this class are encouraged, but not required, to attempt to read as many bytes as possible in the same fashion.  
**Overrides:**  
`[read](../../java/io/FilterInputStream.html#read%28byte[],%20int,%20int%29)` in class `[FilterInputStream](../../java/io/FilterInputStream.html "class in java.io")`  
Parameters:  
`b` \- destination buffer.  
`off` \- offset at which to start storing bytes.  
`len` \- maximum number of bytes to read.  
Returns:  
the number of bytes read, or `-1` if the end of the stream has been reached.  
Throws:  
`[IOException](../../java/io/IOException.html "class in java.io")` \- if this input stream has been closed by invoking its [close()](../../java/io/BufferedInputStream.html#close%28%29) method, or an I/O error occurs.  
See Also:  
[FilterInputStream.in](../../java/io/FilterInputStream.html#in)  
* #### skip  
public long skip(long n)  
          throws [IOException](../../java/io/IOException.html "class in java.io")  
See the general contract of the `skip` method of `InputStream`.  
**Overrides:**  
`[skip](../../java/io/FilterInputStream.html#skip%28long%29)` in class `[FilterInputStream](../../java/io/FilterInputStream.html "class in java.io")`  
Parameters:  
`n` \- the number of bytes to be skipped.  
Returns:  
the actual number of bytes skipped.  
Throws:  
`[IOException](../../java/io/IOException.html "class in java.io")` \- if the stream does not support seek, or if this input stream has been closed by invoking its [close()](../../java/io/BufferedInputStream.html#close%28%29) method, or an I/O error occurs.  
* #### available  
public int available()  
              throws [IOException](../../java/io/IOException.html "class in java.io")  
Returns an estimate of the number of bytes that can be read (or skipped over) from this input stream without blocking by the next invocation of a method for this input stream. The next invocation might be the same thread or another thread. A single read or skip of this many bytes will not block, but may read or skip fewer bytes.  
 This method returns the sum of the number of bytes remaining to be read in the buffer (`count - pos`) and the result of calling the[in](../../java/io/FilterInputStream.html#in).available().  
**Overrides:**  
`[available](../../java/io/FilterInputStream.html#available%28%29)` in class `[FilterInputStream](../../java/io/FilterInputStream.html "class in java.io")`  
Returns:  
an estimate of the number of bytes that can be read (or skipped over) from this input stream without blocking.  
Throws:  
`[IOException](../../java/io/IOException.html "class in java.io")` \- if this input stream has been closed by invoking its [close()](../../java/io/BufferedInputStream.html#close%28%29) method, or an I/O error occurs.  
* #### mark  
public void mark(int readlimit)  
See the general contract of the `mark` method of `InputStream`.  
**Overrides:**  
`[mark](../../java/io/FilterInputStream.html#mark%28int%29)` in class `[FilterInputStream](../../java/io/FilterInputStream.html "class in java.io")`  
Parameters:  
`readlimit` \- the maximum limit of bytes that can be read before the mark position becomes invalid.  
See Also:  
[reset()](../../java/io/BufferedInputStream.html#reset%28%29)  
* #### reset  
public void reset()  
           throws [IOException](../../java/io/IOException.html "class in java.io")  
See the general contract of the `reset` method of `InputStream`.  
 If `markpos` is `-1` (no mark has been set or the mark has been invalidated), an `IOException` is thrown. Otherwise, `pos` is set equal to `markpos`.  
**Overrides:**  
`[reset](../../java/io/FilterInputStream.html#reset%28%29)` in class `[FilterInputStream](../../java/io/FilterInputStream.html "class in java.io")`  
Throws:  
`[IOException](../../java/io/IOException.html "class in java.io")` \- if this stream has not been marked or, if the mark has been invalidated, or the stream has been closed by invoking its [close()](../../java/io/BufferedInputStream.html#close%28%29) method, or an I/O error occurs.  
See Also:  
[mark(int)](../../java/io/BufferedInputStream.html#mark%28int%29)  
* #### markSupported  
public boolean markSupported()  
Tests if this input stream supports the `mark` and `reset` methods. The `markSupported` method of `BufferedInputStream` returns`true`.  
**Overrides:**  
`[markSupported](../../java/io/FilterInputStream.html#markSupported%28%29)` in class `[FilterInputStream](../../java/io/FilterInputStream.html "class in java.io")`  
Returns:  
a `boolean` indicating if this stream type supports the `mark` and `reset` methods.  
See Also:  
[InputStream.mark(int)](../../java/io/InputStream.html#mark%28int%29), [InputStream.reset()](../../java/io/InputStream.html#reset%28%29)  
* #### close  
public void close()  
           throws [IOException](../../java/io/IOException.html "class in java.io")  
Closes this input stream and releases any system resources associated with the stream. Once the stream has been closed, further read(), available(), reset(), or skip() invocations will throw an IOException. Closing a previously closed stream has no effect.  
**Specified by:**  
`[close](../../java/io/Closeable.html#close%28%29)` in interface `[Closeable](../../java/io/Closeable.html "interface in java.io")`  
**Specified by:**  
`[close](../../java/lang/AutoCloseable.html#close%28%29)` in interface `[AutoCloseable](../../java/lang/AutoCloseable.html "interface in java.lang")`  
**Overrides:**  
`[close](../../java/io/FilterInputStream.html#close%28%29)` in class `[FilterInputStream](../../java/io/FilterInputStream.html "class in java.io")`  
Throws:  
`[IOException](../../java/io/IOException.html "class in java.io")` \- if an I/O error occurs.  
See Also:  
[FilterInputStream.in](../../java/io/FilterInputStream.html#in)

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BufferedInputStream (Java Platform SE 7 ) (original) (raw)

Field Summary

Constructor Summary

Method Summary

Field Detail

Constructor Detail

Method Detail