Java Code Examples for java.io.FileInputStream#getChannel()

public static void loadSql(Context context, Uri uri) {
    try {
        final String databaseName = new Configuration.Builder(context).create().getDatabaseName();

        final File currentDB = context.getDatabasePath(databaseName);
        final File replacement = new File(uri.getPath());
        if (currentDB.canWrite()) {
            final FileInputStream srcStream = new FileInputStream(replacement);
            final FileChannel src = srcStream.getChannel();
            final FileOutputStream destStream = new FileOutputStream(currentDB);
            final FileChannel dst = destStream.getChannel();
            dst.transferFrom(src, 0, src.size());
            src.close();
            srcStream.close();
            dst.close();
            destStream.close();
        } else {
            throw new RuntimeException("Couldn't write to " + currentDB);
        }
    } catch (final Exception e) {
        throw new RuntimeException(e);
    }
}
 

/**
 * Moved this code into it's own method so moveTo could use it when the move is across file systems
 */
private void copyAction(File srcFile, File destFile)
        throws FileNotFoundException, IOException {
    FileInputStream istream = new FileInputStream(srcFile);
    FileOutputStream ostream = new FileOutputStream(destFile);
    FileChannel input = istream.getChannel();
    FileChannel output = ostream.getChannel();

    try {
        input.transferTo(0, input.size(), output);
    } finally {
        istream.close();
        ostream.close();
        input.close();
        output.close();
    }
}
 

private static void copyAction(File srcFile, File destFile)
        throws FileNotFoundException, IOException {
    FileInputStream istream = new FileInputStream(srcFile);
    FileOutputStream ostream = new FileOutputStream(destFile);
    FileChannel input = istream.getChannel();
    FileChannel output = ostream.getChannel();

    try {
        input.transferTo(0, input.size(), output);
    } finally {
        istream.close();
        ostream.close();
        input.close();
        output.close();
    }
}
 

/**
 * Read a datavec schema and record set
 * from the given arrow file.
 * @param input the input to read
 * @return the associated datavec schema and record
 */
public static Pair<Schema,ArrowWritableRecordBatch> readFromFile(FileInputStream input) throws IOException {
    BufferAllocator allocator = new RootAllocator(Long.MAX_VALUE);
    Schema retSchema = null;
    ArrowWritableRecordBatch ret = null;
    SeekableReadChannel channel = new SeekableReadChannel(input.getChannel());
    ArrowFileReader reader = new ArrowFileReader(channel, allocator);
    reader.loadNextBatch();
    retSchema = toDatavecSchema(reader.getVectorSchemaRoot().getSchema());
    //load the batch
    VectorUnloader unloader = new VectorUnloader(reader.getVectorSchemaRoot());
    VectorLoader vectorLoader = new VectorLoader(reader.getVectorSchemaRoot());
    ArrowRecordBatch recordBatch = unloader.getRecordBatch();

    vectorLoader.load(recordBatch);
    ret = asDataVecBatch(recordBatch,retSchema,reader.getVectorSchemaRoot());
    ret.setUnloader(unloader);

    return Pair.of(retSchema,ret);

}
 

/**
 * Copy a single file using NIO.
 * @throws IOException
 */
private static void nioCopy(FileOutputStream fos, FileInputStream fis)
    throws IOException {
  FileChannel outChannel = fos.getChannel();
  FileChannel inChannel = fis.getChannel();
  long length = inChannel.size();
  long offset = 0;
  while(true) {
    long remaining = length - offset;
    
    long toTransfer = remaining < MAX_TRANSFER_SIZE ? remaining : MAX_TRANSFER_SIZE;
    long transferredBytes = inChannel.transferTo(offset, toTransfer, outChannel);
    offset += transferredBytes;
    length = inChannel.size();
    if(offset >= length) {
      break;
    }
  }
}
 

/**
 * Load the block.
 *
 * mmap and mlock the block, and then verify its checksum.
 *
 * @param length         The current length of the block.
 * @param blockIn        The block input stream.  Should be positioned at the
 *                       start.  The caller must close this.
 * @param metaIn         The meta file input stream.  Should be positioned at
 *                       the start.  The caller must close this.
 * @param blockFileName  The block file name, for logging purposes.
 *
 * @return               The Mappable block.
 */
public static MappableBlock load(long length,
    FileInputStream blockIn, FileInputStream metaIn,
    String blockFileName) throws IOException {
  MappableBlock mappableBlock = null;
  MappedByteBuffer mmap = null;
  FileChannel blockChannel = null;
  try {
    blockChannel = blockIn.getChannel();
    if (blockChannel == null) {
      throw new IOException("Block InputStream has no FileChannel.");
    }
    mmap = blockChannel.map(MapMode.READ_ONLY, 0, length);
    NativeIO.POSIX.getCacheManipulator().mlock(blockFileName, mmap, length);
    verifyChecksum(length, metaIn, blockChannel, blockFileName);
    mappableBlock = new MappableBlock(mmap, length);
  } finally {
    IOUtils.closeQuietly(blockChannel);
    if (mappableBlock == null) {
      if (mmap != null) {
        NativeIO.POSIX.munmap(mmap); // unmapping also unlocks
      }
    }
  }
  return mappableBlock;
}
 

/**
 * Moved this code into it's own method so moveTo could use it when the move is across file systems
 */
private void copyAction(File srcFile, File destFile)
        throws FileNotFoundException, IOException {
    FileInputStream istream = new FileInputStream(srcFile);
    FileOutputStream ostream = new FileOutputStream(destFile);
    FileChannel input = istream.getChannel();
    FileChannel output = ostream.getChannel();

    try {
        input.transferTo(0, input.size(), output);
    } finally {
        istream.close();
        ostream.close();
        input.close();
        output.close();
    }
}
 

@Override
protected ReadableByteChannel open(LocalResourceId resourceId) throws IOException {
  LOG.debug("opening file {}", resourceId);
  @SuppressWarnings("resource") // The caller is responsible for closing the channel.
  FileInputStream inputStream = new FileInputStream(resourceId.getPath().toFile());
  // Use this method for creating the channel (rather than new FileChannel) so that we get
  // regular FileNotFoundException. Closing the underyling channel will close the inputStream.
  return inputStream.getChannel();
}
 

/**
 * 从文件流里面拷贝数据
 *
 * @param in     输入流
 * @param out    输出流
 * @param start  输入位置
 * @param length 长度
 * @throws IOException
 */
protected static void copy(final FileInputStream in, final FileOutputStream out, final long start,
        final long length) throws IOException {
    if (in == null || out == null) {
        return;
    }
    FileChannel fci = in.getChannel();
    FileChannel fco = out.getChannel();
    try {
        fci.transferTo(start, length, fco);
        fco.force(false);
    } finally {
        Close.close(fci).close(fco);
    }
}
 

/**
 * @param file
 *            can be null if not known
 */
private ResettableInputStream(FileInputStream fis, File file) throws IOException {
    super(fis);
    this.file = file;
    this.fis = fis;
    this.fileChannel = fis.getChannel();
    this.markPos = fileChannel.position();
}
 

/**
 * @param file can be null if not known
 */
private ResettableInputStream(FileInputStream fis, File file) throws IOException {
    super(fis);
    this.file = file;
    this.fis = fis;
    this.fileChannel = fis.getChannel();
    this.markPos = fileChannel.position();
}
 

@Override
public synchronized Channel write(File file) {
	try {
		FileInputStream stream = new FileInputStream(file);
		FileChannel fileChannel = stream.getChannel();
		output.append(fileChannel);
		stream.close();
	} catch (IOException e) {
		throw U.rte(e);
	}

	return this;
}
 

public Page handle(URL url) {
      long size = 0;
String content = "";
String modified = "Not exist";
if (file != null && file.exists()) {
	try {
		FileInputStream fis = new FileInputStream(file);
		FileChannel channel = fis.getChannel();
		size = channel.size();
		ByteBuffer bb;
		if (size <= SHOW_LOG_LENGTH) {
			bb = ByteBuffer.allocate((int) size);
			channel.read(bb, 0);
		} else {
			int pos = (int) (size - SHOW_LOG_LENGTH);
			bb = ByteBuffer.allocate(SHOW_LOG_LENGTH);
			channel.read(bb, pos);
		}
		bb.flip();
		content = new String(bb.array()).replace("<", "&lt;")
				.replace(">", "&gt;").replace("\n", "<br/><br/>");
		modified = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss")
				.format(new Date(file.lastModified()));
	} catch (IOException e) {
	}
}
Level level = LogManager.getRootLogger().getLevel();
      List<List<String>> rows = new ArrayList<List<String>>();
      List<String> row = new ArrayList<String>();
      row.add(content);
      rows.add(row);
      return new Page("Log", "Log",  new String[] {(file == null ? "" : file.getName()) + ", " + size + " bytes, " + modified + ", " + level}, rows);
  }
 

/**
 * 以指定编码读入本地文件，以指定编码方式输出，NIO
 * 
 * @param filePath
 *            文件路径
 * @param inCharsetName
 *            编码名称，读入
 * @param outCharsetName
 *            编码名称，输出
 * @throws FileNotFoundException
 * @throws IOException
 * @return
 */
public static byte[] readWithNIO(String filePath, String inCharsetName,
		String outCharsetName) throws FileNotFoundException, IOException {
	if (filePath == null) {
		return null;
	}
	FileInputStream fis = new FileInputStream(new File(filePath));
	FileChannel fc = fis.getChannel();
	ByteBuffer byteBuffer = ByteBuffer.allocate(fis.available());
	ByteBuffer buffer = ByteBuffer.allocate(BUFFER_SIZE);

	while (true) {
		int count = fc.read(buffer);
		if (count == -1) {
			break;
		}
		buffer.flip();
		byteBuffer.put(buffer);
		buffer.clear();
	}
	fc.close();
	fis.close();
	byteBuffer.flip();
	Charset inCharset = Charset.forName(inCharsetName);
	Charset outCharset = Charset.forName(outCharsetName);
	CharsetDecoder decoder = inCharset.newDecoder();
	CharsetEncoder encoder = outCharset.newEncoder();
	CharBuffer charBuffer = decoder.decode(byteBuffer);
	ByteBuffer resultBuffer = encoder.encode(charBuffer);
	int size = resultBuffer.limit();
	byte[] data = new byte[size];
	resultBuffer.get(data, 0, size);
	return data;
}
 

/** Memory-map the model file in Assets. */
private MappedByteBuffer loadModelFile(Activity activity) throws IOException {
    AssetFileDescriptor fileDescriptor = activity.getAssets().openFd(getModelPath());
    FileInputStream inputStream = new FileInputStream(fileDescriptor.getFileDescriptor());
    FileChannel fileChannel = inputStream.getChannel();
    long startOffset = fileDescriptor.getStartOffset();
    long declaredLength = fileDescriptor.getDeclaredLength();
    return fileChannel.map(FileChannel.MapMode.READ_ONLY, startOffset, declaredLength);
}
 

public void testStream() throws FileNotFoundException, IOException {
	File f = File.createTempFile( ByteBufferInputStreamTest.class.getName(), "tmp" );
	f.deleteOnExit();
	final int l = 100000;
	long seed = System.currentTimeMillis();
	if ( DEBUG ) System.err.println( "Seed: " + seed );
	Random random = new Random( seed );

	for( int n = 1; n < 4; n++ ) {
		final FileOutputStream fos = new FileOutputStream( f );
		for( int i = 0; i < l * n; i++ ) fos.write( random.nextInt() & 0xFF );
		fos.close();

		ByteBufferInputStream bis = ByteBufferInputStream.map( new FileInputStream( f ).getChannel(), MapMode.READ_ONLY );

		FileInputStream test = new FileInputStream( f );
		FileChannel fc = test.getChannel();
		int a1, a2, off, len, pos;
		byte b1[] = new byte[ 32768 ];
		byte b2[] = new byte[ 32768 ];

		for( int k = 0; k < l / 10; k++ ) {

			switch ( random.nextInt( 6 ) ) {

			case 0:
				if ( DEBUG ) System.err.println( "read()" );
				a1 = bis.read();
				a2 = test.read();
				assertEquals( a2, a1 );
				break;

			case 1:
				off = random.nextInt( b1.length );
				len = random.nextInt( b1.length - off + 1 );
				a1 = bis.read( b1, off, len );
				a2 = test.read( b2, off, len );
				if ( DEBUG ) System.err.println( "read(b, " + off + ", " + len + ")" );

				assertEquals( a2, a1 );

				for ( int i = off; i < off + len; i++ )
					assertEquals( b2[ i ], b1[ i ] );
				break;

			case 2:
				if ( DEBUG ) System.err.println( "available()" );
				assertEquals( test.available(), bis.available() );
				break;

			case 3:
				pos = (int)bis.position();
				if ( DEBUG ) System.err.println( "position()=" + pos );
				assertEquals( (int)fc.position(), pos );
				break;

			case 4:
				pos = random.nextInt( l * n );
				bis.position( pos );
				if ( DEBUG ) System.err.println( "position(" + pos + ")" );
				( test = new FileInputStream( f ) ).skip( pos );
				fc = test.getChannel();
				break;

			case 5:
				pos = random.nextInt( (int)( l * n - bis.position() + 1 ) );
				if ( DEBUG ) System.err.println( "skip(" + pos + ")" );
				a1 = (int)bis.skip( pos );
				a2 = (int)test.skip( pos );
				assertEquals( a2, a1 );
				break;
			}
		}
		
		test.close();
	}
}
 

public GFSnapshotImporter(File in) throws IOException, ClassNotFoundException {
  pdx = new ExportedRegistry();

  // read header and pdx registry
  long entryPosition;
  
  FileInputStream fis = new FileInputStream(in);
  FileChannel fc = fis.getChannel();
  DataInputStream tmp = new DataInputStream(fis);
  try {
    // read the snapshot file header
    version = tmp.readByte();
    if (version == SNAP_VER_1) {
      throw new IOException(LocalizedStrings.Snapshot_UNSUPPORTED_SNAPSHOT_VERSION_0.toLocalizedString(SNAP_VER_1) + ": " + in);
      
    } else if (version == SNAP_VER_2) {
      // read format
      byte[] format = new byte[3];
      tmp.readFully(format);
      if (!Arrays.equals(format, SNAP_FMT)) {
        throw new IOException(LocalizedStrings.Snapshot_UNRECOGNIZED_FILE_TYPE_0.toLocalizedString(Arrays.toString(format)) + ": " + in);
      }
      
      // read pdx location
      long registryPosition = tmp.readLong();
      
      // read region
      region = tmp.readUTF();
      entryPosition = fc.position();
      
      // read pdx
      if (registryPosition != -1) {
        fc.position(registryPosition);
        pdx.fromData(tmp);
      }
    } else {
      throw new IOException(LocalizedStrings.Snapshot_UNRECOGNIZED_FILE_VERSION_0.toLocalizedString(version) + ": " + in);
    }
  } finally {
    tmp.close();
  }
  
  // check compatibility with the existing pdx types so we don't have to 
  // do any translation...preexisting types or concurrent put ops may cause
  // this check to fail
  checkPdxTypeCompatibility();
  checkPdxEnumCompatibility();
  
  // open new stream with buffering for reading entries
  dis = new DataInputStream(new BufferedInputStream(new FileInputStream(in)));
  dis.skip(entryPosition);
}
 

@Test
public void T_convert_1() throws IOException{
  byte[] mdsFile = createTestData();
  InputStream in = new ByteArrayInputStream( mdsFile );
  MDSReader reader = new MDSReader();
  Configuration config = new Configuration();
  reader.setNewStream( in , mdsFile.length , config );
  MDSArrowReader arrowReader = new MDSArrowReader( reader , config );
  File testFile = new File( "target/TestConvertArrowFormatTool_T_convert_1.mds" );
  if( testFile.exists() ){
    testFile.delete();
  }
  FileOutputStream out = new FileOutputStream( testFile );
  ConvertArrowFormatTool.convert( arrowReader , out , config );

  FileInputStream arrowIn = new FileInputStream( testFile ); 
  ArrowFileReader ar = new ArrowFileReader( arrowIn.getChannel() , new RootAllocator( Integer.MAX_VALUE ) );
  VectorSchemaRoot root  = ar.getVectorSchemaRoot();
  ArrowBlock rbBlock = ar.getRecordBlocks().get(0);
  ar.loadRecordBatch(rbBlock);
  List<FieldVector> fieldVectorList = root.getFieldVectors();
  Map<String,FieldVector> vectorMap = new HashMap<String,FieldVector>();
  for( FieldVector v : fieldVectorList ){
    vectorMap.put( v.getField().getName() , v );
  }

  assertTrue( vectorMap.containsKey( "col1" ) );
  assertTrue( vectorMap.containsKey( "col2" ) );
  assertTrue( vectorMap.containsKey( "col3" ) );

  BigIntVector col1 = (BigIntVector)( vectorMap.get( "col1" ) );
  VarCharVector col2 = (VarCharVector)( vectorMap.get( "col2" ) );
  VarCharVector col3 = (VarCharVector)( vectorMap.get( "col3" ) );


  assertEquals( col1.get(0) , 100L );
  assertEquals( col1.get(1) , 200L );
  assertEquals( col1.get(2) , 300L );

  assertEquals( col2.getObject(0).toString() , "aaa" );
  assertTrue( col2.isNull(1) );
  assertTrue( col2.isNull(2) );

  assertTrue( col3.isNull(0) );
  assertEquals( col3.getObject(1).toString() , "BBB" );
  assertEquals( col3.getObject(2).toString() , "CCC" );

  testFile.delete();
  ar.close();
}
 

@Test
public void testFileChannel() throws Exception {
    File source = File.createTempFile("source", null);
    source.deleteOnExit();
    File sink = File.createTempFile("sink", null);
    sink.deleteOnExit();

    FileOutputStream fos = new FileOutputStream(source);
    FileChannel sourceChannel = fos.getChannel();
    sourceChannel.write(ByteBuffer.wrap(
        "Use the source, Luke!".getBytes()));
    sourceChannel.close();

    FileInputStream fis = new FileInputStream(source);
    sourceChannel = fis.getChannel();

    RandomAccessFile raf = new RandomAccessFile(sink, "rw");
    FileChannel sinkChannel = raf.getChannel();
    long oldSinkPosition = sinkChannel.position();
    long oldSourcePosition = sourceChannel.position();

    long bytesWritten = sinkChannel.transferFrom(sourceChannel, 0, 10);
    if (bytesWritten != 10)
        throw new RuntimeException("Transfer failed");

    if (sourceChannel.position() == oldSourcePosition)
        throw new RuntimeException("Source position didn't change");

    if (sinkChannel.position() != oldSinkPosition)
        throw new RuntimeException("Sink position changed");

    if (sinkChannel.size() != 10)
        throw new RuntimeException("Unexpected sink size");

    bytesWritten = sinkChannel.transferFrom(sourceChannel, 1000, 10);

    if (bytesWritten > 0)
        throw new RuntimeException("Wrote past file size");

    sourceChannel.close();
    sinkChannel.close();

    source.delete();
    sink.delete();
}
 

/**
 * 快速复制文件（采用nio操作）
 * 
 * @param is
 *            数据来源
 * @param os
 *            数据目标
 * @throws IOException
 */
public static void copyFileFast(FileInputStream is, FileOutputStream os)
        throws IOException {
    FileChannel in = is.getChannel();
    FileChannel out = os.getChannel();
    in.transferTo(0, in.size(), out);
}