1 files changed, 132 insertions, 0 deletions
diff --git a/src/main/java/org/pdfbox/io/RandomAccessFileInputStream.java b/src/main/java/org/pdfbox/io/RandomAccessFileInputStream.java
new file mode 100644
index 0000000..6589bcb
--- /dev/null
+++ b/src/main/java/org/pdfbox/io/RandomAccessFileInputStream.java
@@ -0,0 +1,132 @@
+/**
+ * Copyright (c) 2003, www.pdfbox.org
+ * All rights reserved.
+ *
+ * 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.
+ * 3. Neither the name of pdfbox; nor the names of its
+ *    contributors may be used to endorse or promote products derived from this
+ *    software without specific prior written permission.
+ *
+ * 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 REGENTS 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.
+ *
+ * http://www.pdfbox.org
+ *
+ */
+package org.pdfbox.io;
+
+import java.io.InputStream;
+import java.io.IOException;
+import java.io.RandomAccessFile;
+
+/**
+ * This class allows a section of a RandomAccessFile to be accessed as an
+ * input stream.
+ *
+ * @author Ben Litchfield (ben@csh.rit.edu)
+ * @version $Revision: 1.3 $
+ */
+public class RandomAccessFileInputStream extends InputStream
+{
+    private RandomAccessFile file;
+    private long currentPosition;
+    private long endPosition;
+
+    /**
+     * Constructor.
+     *
+     * @param raFile The file to read the data from.
+     * @param startPosition The position in the file that this stream starts.
+     * @param length The length of the input stream.
+     */
+    public RandomAccessFileInputStream( RandomAccessFile raFile, long startPosition, long length )
+    {
+        file = raFile;
+        currentPosition = startPosition;
+        endPosition = currentPosition+length;
+    }
+    /**
+     * @see InputStream#available()
+     */
+    public int available()
+    {
+        return (int)(endPosition - currentPosition);
+    }
+    /**
+     * @see InputStream#close()
+     */
+    public void close()
+    {
+        //do nothing because we want to leave the random access file open.
+    }
+    /**
+     * @see InputStream#read()
+     */
+    public int read() throws IOException
+    {
+        synchronized(file)
+        {
+            int retval = -1;
+            if( currentPosition < endPosition )
+            {
+                file.seek( currentPosition );
+                currentPosition++;
+                retval = file.read();
+            }
+            return retval;
+        }
+    }
+    /**
+     * @see InputStream#read( byte[], int, int )
+     */
+    public int read( byte[] b, int offset, int length ) throws IOException
+    {
+        //only allow a read of the amount available.
+        if( length > available() )
+        {
+            length = available();
+        }
+        int amountRead = -1;
+        //only read if there are bytes actually available, otherwise
+        //return -1 if the EOF has been reached.
+        if( available() > 0 )
+        {
+            synchronized(file)
+            {
+                file.seek( currentPosition );
+                amountRead = file.read( b, offset, length );
+            }
+        }
+        //update the current cursor position.
+        if( amountRead > 0 )
+        {
+            currentPosition += amountRead;
+        }
+        return amountRead;
+    }
+
+    /**
+     * @see InputStream#skip( long )
+     */
+    public long skip( long amountToSkip )
+    {
+        long amountSkipped = Math.min( amountToSkip, available() );
+        currentPosition+= amountSkipped;
+        return amountSkipped;
+    }
+}
+\ No newline at end of file