public class

MeteredStream

extends FilterInputStream
java.lang.Object
   ↳ java.io.InputStream
     ↳ java.io.FilterInputStream
       ↳ sun.net.www.MeteredStream
Known Direct Subclasses

Summary

Fields
protected boolean closed
protected int count
protected int expected
protected int markLimit
protected int markedCount
protected ProgressSource pi
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Inherited Fields
From class java.io.FilterInputStream
Public Constructors
MeteredStream(InputStream is, ProgressSource pi, int expected)
Public Methods
synchronized 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 caller of a method for this input stream.
void close()
Closes this input stream and releases any system resources associated with the stream.
synchronized 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.
synchronized int read()
Reads the next byte of data from this input stream.
synchronized int read(byte[] b, int off, int len)
Reads up to len bytes of data from this input stream into an array of bytes.
synchronized void reset()
Repositions this stream to the position at the time the mark method was last called on this input stream.
synchronized long skip(long n)
Skips over and discards n bytes of data from this input stream.

This method simply performs in.skip(n).

Protected Methods
void finalize()
Called by the garbage collector on an object when garbage collection determines that there are no more references to the object.
[Expand]
Inherited Methods
From class java.io.FilterInputStream
From class java.io.InputStream
From class java.lang.Object
From interface java.io.Closeable

Fields

protected boolean closed

protected int count

protected int expected

protected int markLimit

protected int markedCount

protected ProgressSource pi

Public Constructors

public MeteredStream (InputStream is, ProgressSource pi, int expected)

Public Methods

public synchronized 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 caller of a method for this input stream. The next caller 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 result of in.available().

Returns
  • an estimate of the number of bytes that can be read (or skipped over) from this input stream without blocking.
Throws
IOException

public void close ()

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

Throws
IOException

public synchronized 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).

Parameters
readLimit the maximum limit of bytes that can be read before the mark position becomes invalid.

public boolean markSupported ()

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

Returns
  • true if this stream type supports the mark and reset method; false otherwise.

public synchronized int read ()

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.

Returns
  • the next byte of data, or -1 if the end of the stream is reached.
Throws
IOException

public synchronized int read (byte[] b, int off, int len)

Reads up to len bytes of data from this input stream into an array of bytes. If len is not zero, the method blocks until some input is available; otherwise, no bytes are read and 0 is returned.

This method simply performs in.read(b, off, len) and returns the result.

Parameters
b the buffer into which the data is read.
off the start offset in the destination array b
len the maximum number of bytes read.
Returns
  • 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
IOException

public synchronized void reset ()

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.

Throws
IOException

public synchronized long skip (long n)

Skips over and discards n bytes of data from this input stream. The skip method may, for a variety of reasons, end up skipping over some smaller number of bytes, possibly 0. This may result from any of a number of conditions; reaching end of file before n bytes have been skipped is only one possibility. The actual number of bytes skipped is returned. If n is negative, no bytes are skipped.

The skip method of this class creates a byte array and then repeatedly reads into it until n bytes have been read or the end of the stream has been reached. Subclasses are encouraged to provide a more efficient implementation of this method. For instance, the implementation may depend on the ability to seek.

This method simply performs in.skip(n).

Parameters
n the number of bytes to be skipped.
Returns
  • the actual number of bytes skipped.
Throws
IOException

Protected Methods

protected void finalize ()

Called by the garbage collector on an object when garbage collection determines that there are no more references to the object. A subclass overrides the finalize method to dispose of system resources or to perform other cleanup.

The general contract of finalize is that it is invoked if and when the JavaTM virtual machine has determined that there is no longer any means by which this object can be accessed by any thread that has not yet died, except as a result of an action taken by the finalization of some other object or class which is ready to be finalized. The finalize method may take any action, including making this object available again to other threads; the usual purpose of finalize, however, is to perform cleanup actions before the object is irrevocably discarded. For example, the finalize method for an object that represents an input/output connection might perform explicit I/O transactions to break the connection before the object is permanently discarded.

The finalize method of class Object performs no special action; it simply returns normally. Subclasses of Object may override this definition.

The Java programming language does not guarantee which thread will invoke the finalize method for any given object. It is guaranteed, however, that the thread that invokes finalize will not be holding any user-visible synchronization locks when finalize is invoked. If an uncaught exception is thrown by the finalize method, the exception is ignored and finalization of that object terminates.

After the finalize method has been invoked for an object, no further action is taken until the Java virtual machine has again determined that there is no longer any means by which this object can be accessed by any thread that has not yet died, including possible actions by other objects or classes which are ready to be finalized, at which point the object may be discarded.

The finalize method is never invoked more than once by a Java virtual machine for any given object.

Any exception thrown by the finalize method causes the finalization of this object to be halted, but is otherwise ignored.

Throws
Throwable