diff options
| -rw-r--r-- | src/java/org/apache/poi/poifs/filesystem/POIFSStream.java | 98 |
1 files changed, 30 insertions, 68 deletions
diff --git a/src/java/org/apache/poi/poifs/filesystem/POIFSStream.java b/src/java/org/apache/poi/poifs/filesystem/POIFSStream.java index d1b83afc04..2b1b5621ab 100644 --- a/src/java/org/apache/poi/poifs/filesystem/POIFSStream.java +++ b/src/java/org/apache/poi/poifs/filesystem/POIFSStream.java @@ -32,28 +32,29 @@ import org.apache.poi.poifs.storage.HeaderBlock; /** * This handles reading and writing a stream within a - * {@link POIFSFileSystem}. It can supply an iterator - * to read blocks, and way to write out to existing and - * new blocks. + * {@link POIFSFileSystem}. It can supply an iterator + * to read blocks, and way to write out to existing and + * new blocks. * Most users will want a higher level version of this, - * which deals with properties to track which stream - * this is. + * which deals with properties to track which stream + * this is. * This only works on big block streams, it doesn't - * handle small block ones. + * handle small block ones. * This uses the new NIO code - * <p> + * * TODO Implement a streaming write method, and append */ -public class POIFSStream implements Iterable<ByteBuffer> { +public class POIFSStream implements Iterable<ByteBuffer> +{ private final BlockStore blockStore; private int startBlock; private OutputStream outStream; /** * Constructor for an existing stream. It's up to you - * to know how to get the start block (eg from a - * {@link HeaderBlock} or a {@link Property}) + * to know how to get the start block (eg from a + * {@link HeaderBlock} or a {@link Property}) */ public POIFSStream(BlockStore blockStore, int startBlock) { this.blockStore = blockStore; @@ -62,7 +63,7 @@ public class POIFSStream implements Iterable<ByteBuffer> { /** * Constructor for a new stream. A start block won't - * be allocated until you begin writing to it. + * be allocated until you begin writing to it. */ public POIFSStream(BlockStore blockStore) { this.blockStore = blockStore; @@ -72,7 +73,7 @@ public class POIFSStream implements Iterable<ByteBuffer> { /** * What block does this stream start at? * Will be {@link POIFSConstants#END_OF_CHAIN} for a - * new stream that hasn't been written to yet. + * new stream that hasn't been written to yet. */ public int getStartBlock() { return startBlock; @@ -80,14 +81,14 @@ public class POIFSStream implements Iterable<ByteBuffer> { /** * Returns an iterator that'll supply one {@link ByteBuffer} - * per block in the stream. + * per block in the stream. */ public Iterator<ByteBuffer> iterator() { return getBlockIterator(); } Iterator<ByteBuffer> getBlockIterator() { - if (startBlock == POIFSConstants.END_OF_CHAIN) { + if(startBlock == POIFSConstants.END_OF_CHAIN) { throw new IllegalStateException( "Can't read from a new stream before it has been written to" ); @@ -95,20 +96,11 @@ public class POIFSStream implements Iterable<ByteBuffer> { return new StreamBlockByteBufferIterator(startBlock); } - Iterator<Integer> getBlockOffsetIterator() { - if (startBlock == POIFSConstants.END_OF_CHAIN) { - throw new IllegalStateException( - "Can't read from a new stream before it has been written to" - ); - } - return new StreamBlockOffsetIterator(startBlock); - } - /** * Updates the contents of the stream to the new - * set of bytes. + * set of bytes. * Note - if this is property based, you'll still - * need to update the size in the property yourself + * need to update the size in the property yourself */ void updateContents(byte[] contents) throws IOException { OutputStream os = getOutputStream(); @@ -134,10 +126,9 @@ public class POIFSStream implements Iterable<ByteBuffer> { ChainLoopDetector loopDetector = blockStore.getChainLoopDetector(); free(loopDetector); } - private void free(ChainLoopDetector loopDetector) { int nextBlock = startBlock; - while (nextBlock != POIFSConstants.END_OF_CHAIN) { + while(nextBlock != POIFSConstants.END_OF_CHAIN) { int thisBlock = nextBlock; loopDetector.claim(thisBlock); nextBlock = blockStore.getNextBlock(thisBlock); @@ -149,15 +140,15 @@ public class POIFSStream implements Iterable<ByteBuffer> { /** * Class that handles a streaming read of one stream */ - private class StreamBlockOffsetIterator implements Iterator<Integer> { + private class StreamBlockByteBufferIterator implements Iterator<ByteBuffer> { private final ChainLoopDetector loopDetector; private int nextBlock; - StreamBlockOffsetIterator(int firstBlock) { + StreamBlockByteBufferIterator(int firstBlock) { this.nextBlock = firstBlock; try { this.loopDetector = blockStore.getChainLoopDetector(); - } catch (IOException e) { + } catch(IOException e) { throw new RuntimeException(e); } } @@ -166,44 +157,17 @@ public class POIFSStream implements Iterable<ByteBuffer> { return nextBlock != POIFSConstants.END_OF_CHAIN; } - public Integer next() { - if (!hasNext()) { - throw new NoSuchElementException("Can't read past the end of the stream"); - } - - loopDetector.claim(nextBlock); - int currentBlock = nextBlock; - nextBlock = blockStore.getNextBlock(nextBlock); - return currentBlock; - } - - public void remove() { - throw new UnsupportedOperationException(); - } - } - - /** - * Class that handles a streaming read of one stream - */ - private class StreamBlockByteBufferIterator implements Iterator<ByteBuffer> { - private final StreamBlockOffsetIterator offsetIterator; - - StreamBlockByteBufferIterator(int firstBlock) { - offsetIterator = new StreamBlockOffsetIterator(firstBlock); - } - - public boolean hasNext() { - return offsetIterator.hasNext(); - } - public ByteBuffer next() { if (!hasNext()) { throw new NoSuchElementException("Can't read past the end of the stream"); } try { - return blockStore.getBlockAt(offsetIterator.next()); - } catch (IOException e) { + loopDetector.claim(nextBlock); + ByteBuffer data = blockStore.getBlockAt(nextBlock); + nextBlock = blockStore.getNextBlock(nextBlock); + return data; + } catch(IOException e) { throw new RuntimeException(e); } } @@ -213,7 +177,6 @@ public class POIFSStream implements Iterable<ByteBuffer> { } } - protected class StreamBlockByteBuffer extends OutputStream { byte[] oneByte = new byte[1]; ByteBuffer buffer; @@ -235,7 +198,7 @@ public class POIFSStream implements Iterable<ByteBuffer> { // Allocate a block if needed, otherwise figure // out what the next block will be - if (thisBlock == POIFSConstants.END_OF_CHAIN) { + if(thisBlock == POIFSConstants.END_OF_CHAIN) { thisBlock = blockStore.getFreeBlock(); loopDetector.claim(thisBlock); @@ -243,14 +206,14 @@ public class POIFSStream implements Iterable<ByteBuffer> { nextBlock = POIFSConstants.END_OF_CHAIN; // Mark the previous block as carrying on to us if needed - if (prevBlock != POIFSConstants.END_OF_CHAIN) { + if(prevBlock != POIFSConstants.END_OF_CHAIN) { blockStore.setNextBlock(prevBlock, thisBlock); } blockStore.setNextBlock(thisBlock, POIFSConstants.END_OF_CHAIN); // If we've just written the first block on a // new stream, save the start block offset - if (startBlock == POIFSConstants.END_OF_CHAIN) { + if(startBlock == POIFSConstants.END_OF_CHAIN) { startBlock = thisBlock; } } else { @@ -269,7 +232,7 @@ public class POIFSStream implements Iterable<ByteBuffer> { @Override public void write(int b) throws IOException { - oneByte[0] = (byte) (b & 0xFF); + oneByte[0] = (byte)(b & 0xFF); write(oneByte); } @@ -303,4 +266,3 @@ public class POIFSStream implements Iterable<ByteBuffer> { } } } - |