managedmemorydatasource.java

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            Object[] array = readers.keySet().toArray();
            for (int i = 0; i < array.length; i++) {
                Instream stream = (Instream) array[i];
                if (null != stream) {
                    try {
                        stream.close();
                    } catch (Exception e) {
                    }
                }
            }
            readers.clear();

            try {
                diskCacheFile.delete();

                ret = true;
            } catch (Exception e) {

                // Give it our best shot.
                diskCacheFile.deleteOnExit();
            }
        }


        return ret;
    }

    // inner classes cannot have static declarations...

    /** Field is_log           */
    protected static Log is_log =
        LogFactory.getLog(Instream.class.getName());

    /**
     * Inner class to handle getting an input stream to this data source
     *  Handles creating an input stream to the source.
     */
    private class Instream extends java.io.InputStream {

        /** bytes read. */
        protected long bread = 0;

        /** The real stream. */
        java.io.FileInputStream fin = null;

        /** The position in the list were we are reading from. */
        int currentIndex =
                0;

        /** the buffer we are currently reading from. */
        byte[] currentBuf = null;

        /** The current position in there. */
        int currentBufPos = 0;

        /** The read stream has been closed. */
        boolean readClosed = false;

        /**
         * Constructor Instream.
         *
         * @throws java.io.IOException if the Instream could not be created or
         *              if the data source has been deleted
         */
        protected Instream() throws java.io.IOException {

            if (deleted) {
                throw new java.io.IOException(
                        Messages.getMessage("resourceDeleted"));
            }

            readers.put(this, null);
        }

        /**
         * Query for the number of bytes available for reading.
         *
         * @return the number of bytes left
         *
         * @throws java.io.IOException if this stream is not in a state that
         *              supports reading
         */
        public int available() throws java.io.IOException {

            if (deleted) {
                throw new java.io.IOException(
                        Messages.getMessage("resourceDeleted"));
            }

            if (readClosed) {
                throw new java.io.IOException(
                        Messages.getMessage("streamClosed"));
            }

            int ret = new Long(Math.min(Integer.MAX_VALUE, totalsz - bread)).intValue();

            if (debugEnabled) {
                is_log.debug("available() = " + ret + ".");
            }

            return ret;
        }

        /**
         * Read a byte from the stream.
         *
         * @return byte read or -1 if no more data.
         *
         * @throws java.io.IOException
         */
        public int read() throws java.io.IOException {

            synchronized (ManagedMemoryDataSource.this) {
                byte[] retb = new byte[1];
                int br = read(retb, 0, 1);

                if (br == -1) {
                    return -1;
                }
                return 0xFF & retb[0];
            }
        }

        /**
         * Not supported.
         *
         * @return
         */
        public boolean markSupported() {

            if (debugEnabled) {
                is_log.debug("markSupported() = " + false + ".");
            }

            return false;
        }

        /**
         * Not supported.
         *
         * @param readlimit
         */
        public void mark(int readlimit) {

            if (debugEnabled) {
                is_log.debug("mark()");
            }
        }

        /**
         * Not supported.
         *
         * @throws java.io.IOException
         */
        public void reset() throws java.io.IOException {

            if (debugEnabled) {
                is_log.debug("reset()");
            }

            throw new java.io.IOException(Messages.getMessage("noResetMark"));
        }

        public long skip(long skipped) throws java.io.IOException {

            if (debugEnabled) {
                is_log.debug("skip(" + skipped + ").");
            }

            if (deleted) {
                throw new java.io.IOException(
                        Messages.getMessage("resourceDeleted"));
            }

            if (readClosed) {
                throw new java.io.IOException(
                        Messages.getMessage("streamClosed"));
            }

            if (skipped < 1) {
                return 0;    // nothing to skip.
            }

            synchronized (ManagedMemoryDataSource.this) {
                skipped = Math.min(skipped,
                        totalsz
                        - bread);    // only skip what we've read.

                if (skipped == 0) {
                    return 0;
                }

                java.util.List ml = memorybuflist;    // hold the memory list.
                int bwritten = 0;

                if (ml != null) {
                    if (null == currentBuf) {    // get the buffer we need to read from.
                        currentBuf = (byte[]) ml.get(currentIndex);
                        currentBufPos = 0;    // start reading from the begining.
                    }

                    do {
                        long bcopy = Math.min(currentBuf.length
                                - currentBufPos,
                                skipped - bwritten);

                        bwritten += bcopy;
                        currentBufPos += bcopy;

                        if (bwritten < skipped) {
                            currentBuf = (byte[]) ml.get(++currentIndex);
                            currentBufPos = 0;
                        }
                    } while (bwritten < skipped);
                }

                if (null != fin) {
                    fin.skip(skipped);
                }

                bread += skipped;
            }

            if (debugEnabled) {
                is_log.debug("skipped " + skipped + ".");
            }

            return skipped;
        }

        public int read(byte[] b, int off, int len) throws java.io.IOException {

            if (debugEnabled) {
                is_log.debug(this.hashCode() + " read(" + off + ", " + len
                        + ")");
            }

            if (deleted) {
                throw new java.io.IOException(
                        Messages.getMessage("resourceDeleted"));
            }

            if (readClosed) {
                throw new java.io.IOException(
                        Messages.getMessage("streamClosed"));
            }

            if (b == null) {
                throw new InternalException(Messages.getMessage("nullInput"));
            }

            if (off < 0) {
                throw new IndexOutOfBoundsException(
                        Messages.getMessage("negOffset", "" + off));
            }

            if (len < 0) {
                throw new IndexOutOfBoundsException(
                        Messages.getMessage("length", "" + len));
            }

            if (len + off > b.length) {
                throw new IndexOutOfBoundsException(
                        Messages.getMessage("writeBeyond"));
            }

            if (len == 0) {
                return 0;
            }

            int bwritten = 0;

            synchronized (ManagedMemoryDataSource.this) {
                if (bread == totalsz) {
                    return -1;
                }

                java.util.List ml = memorybuflist;
                
                long longlen = len;
                longlen = Math.min(
                        longlen,
                        totalsz
                        - bread);    // Only return the number of bytes in the data store that is left.
                len = new Long(longlen).intValue();
                
                if (debugEnabled) {
                    is_log.debug("len = " + len);
                }

                if (ml != null) {
                    if (null == currentBuf) {    // Get the buffer we need to read from.
                        currentBuf = (byte[]) ml.get(currentIndex);
                        currentBufPos = 0;    // New buffer start from the begining.
                    }

                    do {

                        // The bytes to copy, the minimum of the bytes left in this buffer or bytes remaining.
                        int bcopy = Math.min(currentBuf.length - currentBufPos,
                                len - bwritten);

                        // Copy the data.
                        System.arraycopy(currentBuf, currentBufPos, b,
                                off + bwritten, bcopy);

                        bwritten += bcopy;
                        currentBufPos += bcopy;

                        if (bwritten < len) {    // Get the next buffer.
                            currentBuf = (byte[]) ml.get(++currentIndex);
                            currentBufPos = 0;
                        }
                    } while (bwritten < len);
                }

                if ((bwritten == 0) && (null != diskCacheFile)) {
                    if (debugEnabled) {
                        is_log.debug(Messages.getMessage("reading", "" + len));
                    }

                    if (null == fin) {           // we are now reading from disk.
                        if (debugEnabled) {
                            is_log.debug(
                                    Messages.getMessage(
                                            "openBread",
                                            diskCacheFile.getCanonicalPath()));
                        }

                        if (debugEnabled) {
                            is_log.debug(Messages.getMessage("openBread",
                                    "" + bread));
                        }

                        fin = new java.io.FileInputStream(diskCacheFile);

                        if (bread > 0) {
                            fin.skip(bread);     // Skip what we've read so far.
                        }
                    }

                    if (cachediskstream != null) {
                        if (debugEnabled) {
                            is_log.debug(Messages.getMessage("flushing"));
                        }

                        cachediskstream.flush();
                    }

                    if (debugEnabled) {
                        is_log.debug(Messages.getMessage("flushing"));
                        is_log.debug("len=" + len);
                        is_log.debug("off=" + off);
                        is_log.debug("b.length=" + b.length);
                    }

                    bwritten = fin.read(b, off, len);
                }

                if (bwritten > 0) {
                    bread += bwritten;
                }
            }

            if (debugEnabled) {
                is_log.debug(this.hashCode()
                        + Messages.getMessage("read", "" + bwritten));
            }

            return bwritten;
        }

        /**
         * close the stream.
         *
         * @throws java.io.IOException
         */
        public synchronized void close() throws java.io.IOException {

            if (debugEnabled) {
                is_log.debug("close()");
            }

            if (!readClosed) {
                readers.remove(this);

                readClosed = true;

                if (fin != null) {
                    fin.close();
                }

                fin = null;
            }
        }

        protected void finalize() throws Throwable {
            close();
        }
    }                                          // endof innerclass Instream

    // Used to test.

    /**
     * Method main
     *
     * @param arg
     */
    public static void main(String arg[]) {    // test

        try {
            String readFile = arg[0];
            String writeFile = arg[1];
            java.io.FileInputStream ss =
                    new java.io.FileInputStream(readFile);
            ManagedMemoryDataSource ms =
                    new ManagedMemoryDataSource(ss, 1024 * 1024, "foo/data", true);
            javax.activation.DataHandler dh =
                    new javax.activation.DataHandler(ms);
            java.io.InputStream is = dh.getInputStream();
            java.io.FileOutputStream fo =
                    new java.io.FileOutputStream(writeFile);
            byte[] buf = new byte[512];
            int read = 0;

            do {
                read = is.read(buf);

                if (read > 0) {
                    fo.write(buf, 0, read);
                }
            } while (read > -1);

            fo.close();
            is.close();
        } catch (java.lang.Exception e) {
            log.error(Messages.getMessage("exception00"), e);
        }
    }

    /**
     * get the filename of the content if it is cached to disk.
     * @return file object pointing to file, or null for memory-stored content
     */
    public File getDiskCacheFile() {
        return diskCacheFile;
    }
}