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Added in API level 1

AssetManager.AssetInputStream

public final class AssetManager.AssetInputStream
extends InputStream

java.lang.Object
   ↳ java.io.InputStream
     ↳ android.content.res.AssetManager.AssetInputStream


Summary

Public methods

final int available()

Returns an estimated number of bytes that can be read or skipped without blocking for more input.

final void close()

Closes this stream.

final void mark(int readlimit)

Sets a mark position in this InputStream.

final boolean markSupported()

Indicates whether this stream supports the mark() and reset() methods.

final int read(byte[] b)

Equivalent to read(buffer, 0, buffer.length).

final int read()

Reads a single byte from this stream and returns it as an integer in the range from 0 to 255.

final int read(byte[] b, int off, int len)

Reads up to byteCount bytes from this stream and stores them in the byte array buffer starting at byteOffset.

final void reset()

Resets this stream to the last marked location.

final long skip(long n)

Skips at most byteCount bytes in this stream.

Protected methods

void finalize()

Invoked when the garbage collector has detected that this instance is no longer reachable.

Inherited methods

From class java.io.InputStream
From class java.lang.Object
From interface java.io.Closeable
From interface java.lang.AutoCloseable

Public methods

available

Added in API level 1
int available ()

Returns an estimated number of bytes that can be read or skipped without blocking for more input.

Note that this method provides such a weak guarantee that it is not very useful in practice.

Firstly, the guarantee is "without blocking for more input" rather than "without blocking": a read may still block waiting for I/O to complete — the guarantee is merely that it won't have to wait indefinitely for data to be written. The result of this method should not be used as a license to do I/O on a thread that shouldn't be blocked.

Secondly, the result is a conservative estimate and may be significantly smaller than the actual number of bytes available. In particular, an implementation that always returns 0 would be correct. In general, callers should only use this method if they'd be satisfied with treating the result as a boolean yes or no answer to the question "is there definitely data ready?".

Thirdly, the fact that a given number of bytes is "available" does not guarantee that a read or skip will actually read or skip that many bytes: they may read or skip fewer.

It is particularly important to realize that you must not use this method to size a container and assume that you can read the entirety of the stream without needing to resize the container. Such callers should probably write everything they read to a ByteArrayOutputStream and convert that to a byte array. Alternatively, if you're reading from a file, length() returns the current length of the file (though assuming the file's length can't change may be incorrect, reading a file is inherently racy).

The default implementation of this method in InputStream always returns 0. Subclasses should override this method if they are able to indicate the number of bytes available.

Returns
int the estimated number of bytes available
Throws
IOException

close

Added in API level 1
void close ()

Closes this stream. Concrete implementations of this class should free any resources during close. This implementation does nothing.

Throws
IOException

mark

Added in API level 1
void mark (int readlimit)

Sets a mark position in this InputStream. The parameter readlimit indicates how many bytes can be read before the mark is invalidated. Sending reset() will reposition the stream back to the marked position provided readLimit has not been surpassed.

This default implementation does nothing and concrete subclasses must provide their own implementation.

Parameters
readlimit int: the number of bytes that can be read from this stream before the mark is invalidated.

markSupported

Added in API level 1
boolean markSupported ()

Indicates whether this stream supports the mark() and reset() methods. The default implementation returns false.

Returns
boolean always false.

read

Added in API level 1
int read (byte[] b)

Equivalent to read(buffer, 0, buffer.length).

Parameters
b byte
Returns
int
Throws
IOException

read

Added in API level 1
int read ()

Reads a single byte from this stream and returns it as an integer in the range from 0 to 255. Returns -1 if the end of the stream has been reached. Blocks until one byte has been read, the end of the source stream is detected or an exception is thrown.

Returns
int
Throws
IOException

read

Added in API level 1
int read (byte[] b, 
                int off, 
                int len)

Reads up to byteCount bytes from this stream and stores them in the byte array buffer starting at byteOffset. Returns the number of bytes actually read or -1 if the end of the stream has been reached.

Parameters
b byte
off int
len int
Returns
int
Throws
IOException

reset

Added in API level 1
void reset ()

Resets this stream to the last marked location. Throws an IOException if the number of bytes read since the mark has been set is greater than the limit provided to mark, or if no mark has been set.

This implementation always throws an IOException and concrete subclasses should provide the proper implementation.

Throws
IOException

skip

Added in API level 1
long skip (long n)

Skips at most byteCount bytes in this stream. The number of actual bytes skipped may be anywhere between 0 and byteCount. If byteCount is negative, this method does nothing and returns 0, but some subclasses may throw.

Note the "at most" in the description of this method: this method may choose to skip fewer bytes than requested. Callers should always check the return value.

This default implementation reads bytes into a temporary buffer. Concrete subclasses should provide their own implementation.

Parameters
n long
Returns
long the number of bytes actually skipped.
Throws
IOException

Protected methods

finalize

Added in API level 1
void finalize ()

Invoked when the garbage collector has detected that this instance is no longer reachable. The default implementation does nothing, but this method can be overridden to free resources.

Note that objects that override finalize are significantly more expensive than objects that don't. Finalizers may be run a long time after the object is no longer reachable, depending on memory pressure, so it's a bad idea to rely on them for cleanup. Note also that finalizers are run on a single VM-wide finalizer thread, so doing blocking work in a finalizer is a bad idea. A finalizer is usually only necessary for a class that has a native peer and needs to call a native method to destroy that peer. Even then, it's better to provide an explicit close method (and implement Closeable), and insist that callers manually dispose of instances. This works well for something like files, but less well for something like a BigInteger where typical calling code would have to deal with lots of temporaries. Unfortunately, code that creates lots of temporaries is the worst kind of code from the point of view of the single finalizer thread.

If you must use finalizers, consider at least providing your own ReferenceQueue and having your own thread process that queue.

Unlike constructors, finalizers are not automatically chained. You are responsible for calling super.finalize() yourself.

Uncaught exceptions thrown by finalizers are ignored and do not terminate the finalizer thread. See Effective Java Item 7, "Avoid finalizers" for more.

Throws
Throwable
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