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javax.imageio.stream
public class: MemoryCacheImageInputStream [javadoc | source]

java.lang.Object
   javax.imageio.stream.ImageInputStreamImpl
      javax.imageio.stream.MemoryCacheImageInputStream

All Implemented Interfaces:
    ImageInputStream

An implementation of ImageInputStream that gets its input from a regular InputStream. A memory buffer is used to cache at least the data between the discard position and the current read position.

In general, it is preferable to use a FileCacheImageInputStream when reading from a regular InputStream. This class is provided for cases where it is not possible to create a writable temporary file.

Fields inherited from javax.imageio.stream.ImageInputStreamImpl:
byteBuf,  byteOrder,  streamPos,  bitOffset,  flushedPos

Constructor:

public MemoryCacheImageInputStream(InputStream stream) { if (stream == null) { throw new IllegalArgumentException("stream == null!"); } this.stream = stream; disposerRecord = new StreamDisposerRecord(cache); if (getClass() == MemoryCacheImageInputStream.class) { disposerReferent = new Object(); Disposer.addRecord(disposerReferent, disposerRecord); } else { disposerReferent = new StreamFinalizer(this); } } Constructs a MemoryCacheImageInputStream that will read from a given InputStream. Parameters: stream - an InputStream to read from. Throws: IllegalArgumentException - if stream is null. exception: IllegalArgumentException - if stream is null.

Method from javax.imageio.stream.MemoryCacheImageInputStream Summary:
close,   finalize,   flushBefore,   isCached,   isCachedFile,   isCachedMemory,   read,   read

Methods from javax.imageio.stream.ImageInputStreamImpl:

checkClosed,   close,   finalize,   flush,   flushBefore,   getBitOffset,   getByteOrder,   getFlushedPosition,   getStreamPosition,   isCached,   isCachedFile,   isCachedMemory,   length,   mark,   read,   read,   read,   readBit,   readBits,   readBoolean,   readByte,   readBytes,   readChar,   readDouble,   readFloat,   readFully,   readFully,   readFully,   readFully,   readFully,   readFully,   readFully,   readFully,   readInt,   readLine,   readLong,   readShort,   readUTF,   readUnsignedByte,   readUnsignedInt,   readUnsignedShort,   reset,   seek,   setBitOffset,   setByteOrder,   skipBytes,   skipBytes

Methods from java.lang.Object:
clone,   equals,   finalize,   getClass,   hashCode,   notify,   notifyAll,   toString,   wait,   wait,   wait

Method from javax.imageio.stream.MemoryCacheImageInputStream Detail:
public void close() throws IOException { super.close(); disposerRecord.dispose(); // this resets the MemoryCache stream = null; cache = null; } Closes this MemoryCacheImageInputStream, freeing the cache. The source InputStream is not closed.
protected void finalize() throws Throwable { // Empty finalizer: for performance reasons we instead use the // Disposer mechanism for ensuring that the underlying // MemoryCache is reset prior to garbage collection } {@inheritDoc}
public void flushBefore(long pos) throws IOException { super.flushBefore(pos); // this will call checkClosed() for us cache.disposeBefore(pos); }
public boolean isCached() { return true; } Returns true since this ImageInputStream caches data in order to allow seeking backwards.
public boolean isCachedFile() { return false; } Returns false since this ImageInputStream does not maintain a file cache.
public boolean isCachedMemory() { return true; } Returns true since this ImageInputStream maintains a main memory cache.
public int read() throws IOException { checkClosed(); bitOffset = 0; long pos = cache.loadFromStream(stream, streamPos+1); if (pos >= streamPos+1) { return cache.read(streamPos++); } else { return -1; } }
public int read(byte[] b, int off, int len) throws IOException { checkClosed(); if (b == null) { throw new NullPointerException("b == null!"); } if (off < 0 || len < 0 || off + len > b.length || off + len < 0) { throw new IndexOutOfBoundsException ("off < 0 || len < 0 || off+len > b.length || off+len < 0!"); } bitOffset = 0; if (len == 0) { return 0; } long pos = cache.loadFromStream(stream, streamPos+len); len = (int)(pos - streamPos); // In case stream ended early if (len > 0) { cache.read(b, off, len, streamPos); streamPos += len; return len; } else { return -1; } }