Add DataHandle implementation for FileLocations

This is a redesigned version of SCIFIO's old FileHandle class.

It delegates to java.io.RandomAccessFile for the bulk of its
implementation.

Author: ctrueden

src/main/java/org/scijava/io/FileHandle.java

@@ -0,0 +1,285 @@
+/*
+ * #%L
+ * SciJava Common shared library for SciJava software.
+ * %%
+ * Copyright (C) 2009 - 2015 Board of Regents of the University of
+ * Wisconsin-Madison, Broad Institute of MIT and Harvard, and Max Planck
+ * Institute of Molecular Cell Biology and Genetics.
+ * %%
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ * 
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ * 
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ * #L%
+ */
+
+package org.scijava.io;
+
+import java.io.IOException;
+import java.io.RandomAccessFile;
+
+import org.scijava.plugin.Plugin;
+
+/**
+ * {@link DataHandle} for a {@link FileLocation}.
+ * 
+ * @author Curtis Rueden
+ */
+@Plugin(type = DataHandle.class)
+public class FileHandle extends AbstractDataHandle<FileLocation> {
+
+	// -- Fields --
+
+	/** The {@link RandomAccessFile} backing this file handle. */
+	private RandomAccessFile raf;
+
+	/** The mode of the {@link RandomAccessFile}. */
+	private String mode = "rw";
+
+	// -- FileHandle methods --
+
+	/** Gets the random access file object backing this FileHandle. */
+	public RandomAccessFile getRandomAccessFile() throws IOException {
+		return raf();
+	}
+
+	public String getMode() {
+		return mode;
+	}
+
+	public void setMode(final String mode) {
+		if (raf != null) {
+			throw new IllegalStateException("File already initialized");
+		}
+		this.mode = mode;
+	}
+
+	// -- DataHandle methods --
+
+	@Override
+	public long offset() throws IOException {
+		return raf().getFilePointer();
+	}
+
+	@Override
+	public long length() throws IOException {
+		return raf().length();
+	}
+
+	@Override
+	public int read() throws IOException {
+		return raf().read();
+	}
+
+	@Override
+	public int read(final byte[] b) throws IOException {
+		return raf().read(b);
+	}
+
+	@Override
+	public int read(final byte[] b, final int off, final int len)
+		throws IOException
+	{
+		return raf().read(b, off, len);
+	}
+
+	@Override
+	public void seek(final long pos) throws IOException {
+		raf().seek(pos);
+	}
+
+	// -- DataInput methods --
+
+	@Override
+	public boolean readBoolean() throws IOException {
+		return raf().readBoolean();
+	}
+
+	@Override
+	public byte readByte() throws IOException {
+		return raf().readByte();
+	}
+
+	@Override
+	public char readChar() throws IOException {
+		return raf().readChar();
+	}
+
+	@Override
+	public double readDouble() throws IOException {
+		return raf().readDouble();
+	}
+
+	@Override
+	public float readFloat() throws IOException {
+		return raf().readFloat();
+	}
+
+	@Override
+	public void readFully(final byte[] b) throws IOException {
+		raf().readFully(b);
+	}
+
+	@Override
+	public void readFully(final byte[] b, final int off, final int len)
+		throws IOException
+	{
+		raf().readFully(b, off, len);
+	}
+
+	@Override
+	public int readInt() throws IOException {
+		return raf().readInt();
+	}
+
+	@Override
+	public String readLine() throws IOException {
+		return raf().readLine();
+	}
+
+	@Override
+	public long readLong() throws IOException {
+		return raf().readLong();
+	}
+
+	@Override
+	public short readShort() throws IOException {
+		return raf().readShort();
+	}
+
+	@Override
+	public int readUnsignedByte() throws IOException {
+		return raf().readUnsignedByte();
+	}
+
+	@Override
+	public int readUnsignedShort() throws IOException {
+		return raf().readUnsignedShort();
+	}
+
+	@Override
+	public String readUTF() throws IOException {
+		return raf().readUTF();
+	}
+
+	@Override
+	public int skipBytes(final int n) throws IOException {
+		return raf().skipBytes(n);
+	}
+
+	// -- DataOutput methods --
+
+	@Override
+	public void write(final byte[] b) throws IOException {
+		raf().write(b);
+	}
+
+	@Override
+	public void write(final byte[] b, final int off, final int len)
+		throws IOException
+	{
+		raf().write(b, off, len);
+	}
+
+	@Override
+	public void write(final int b) throws IOException {
+		raf().write(b);
+	}
+
+	@Override
+	public void writeBoolean(final boolean v) throws IOException {
+		raf().writeBoolean(v);
+	}
+
+	@Override
+	public void writeByte(final int v) throws IOException {
+		raf().writeByte(v);
+	}
+
+	@Override
+	public void writeBytes(final String s) throws IOException {
+		raf().writeBytes(s);
+	}
+
+	@Override
+	public void writeChar(final int v) throws IOException {
+		raf().writeChar(v);
+	}
+
+	@Override
+	public void writeChars(final String s) throws IOException {
+		raf().writeChars(s);
+	}
+
+	@Override
+	public void writeDouble(final double v) throws IOException {
+		raf().writeDouble(v);
+	}
+
+	@Override
+	public void writeFloat(final float v) throws IOException {
+		raf().writeFloat(v);
+	}
+
+	@Override
+	public void writeInt(final int v) throws IOException {
+		raf().writeInt(v);
+	}
+
+	@Override
+	public void writeLong(final long v) throws IOException {
+		raf().writeLong(v);
+	}
+
+	@Override
+	public void writeShort(final int v) throws IOException {
+		raf().writeShort(v);
+	}
+
+	@Override
+	public void writeUTF(final String str) throws IOException {
+		raf().writeUTF(str);
+	}
+
+	// -- Closeable methods --
+
+	@Override
+	public void close() throws IOException {
+		raf().close();
+	}
+
+	// -- Typed methods --
+
+	@Override
+	public Class<FileLocation> getType() {
+		return FileLocation.class;
+	}
+
+	// -- Helper methods --
+
+	private RandomAccessFile raf() throws IOException {
+		if (raf == null) initRAF();
+		return raf;
+	}
+
+	private synchronized void initRAF() throws IOException {
+		raf = new RandomAccessFile(get().getFile(), getMode());
+	}
+
+}