saajdatasource.java

来自「开源的axis2框架的源码。用于开发WEBSERVER」· Java 代码 · 共 640 行 · 第 1/2 页

        if (closed) {
            throw new java.io.IOException("streamClosed");
        }

        int byteswritten = 0;
        if (memorybuflist != null) {    // Can write to memory.
            do {
                if (null == currentMemoryBuf) {
                    currentMemoryBuf = new byte[READ_CHUNK_SZ];
                    currentMemoryBufSz = 0;

                    memorybuflist.add(currentMemoryBuf);
                }

                // bytes to write is the min. between the remaining bytes and what is left in this buffer.
                int bytes2write = Math.min((length - byteswritten),
                                           (currentMemoryBuf.length
                                                   - currentMemoryBufSz));

                // copy the data.
                System.arraycopy(data, byteswritten, currentMemoryBuf,
                                 currentMemoryBufSz, bytes2write);

                byteswritten += bytes2write;
                currentMemoryBufSz += bytes2write;

                if (byteswritten
                        < length) {    // only get more if we really need it.
                    currentMemoryBuf = new byte[READ_CHUNK_SZ];
                    currentMemoryBufSz = 0;
                    memorybuflist.add(currentMemoryBuf);    // add it to the chain.
                }
            } while (byteswritten < length);
        }
        totalsz += length;
    }

    /**
     * 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;
    }

    public InputStream getInputStream() throws IOException {
        return new SAAJInputStream();    // Return the memory held stream.
    }

    public OutputStream getOutputStream() throws IOException {
        //TODO: Method implementation
        return null;
    }

    public String getContentType() {
        return contentType;
    }

    public String getName() {
        String ret = null;
        try {
            flushToDisk();
            if (diskCacheFile != null) {
                ret = diskCacheFile.getAbsolutePath();
            }
        } catch (Exception e) {
            diskCacheFile = null;
        }
        return ret;
    }


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

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

        /** The real stream. */
        private FileInputStream fileIS;

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

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

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

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

        /**
         * Constructor Instream.
         *
         * @throws java.io.IOException if the Instream could not be created or if the data source
         *                             has been deleted
         */
        protected SAAJInputStream() throws java.io.IOException {
            if (deleted) {
                throw new java.io.IOException("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("resourceDeleted");
            }
            if (readClosed) {
                throw new java.io.IOException("streamClosed");
            }
            return new Long(Math.min(Integer.MAX_VALUE, totalsz - bread)).intValue();
        }

        /**
         * 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 (SAAJDataSource.this) {
                byte[] retb = new byte[1];
                int br = read(retb, 0, 1);
                if (br == -1) {
                    return -1;
                }
                return 0xFF & retb[0];
            }
        }

        /** Not supported. */
        public boolean markSupported() {
            return false;
        }

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

        /**
         * Not supported.
         *
         * @throws java.io.IOException
         */
        public void reset() throws IOException {
            throw new IOException("noResetMark");
        }

        public long skip(long skipped) throws IOException {

            if (deleted) {
                throw new IOException("resourceDeleted");
            }

            if (readClosed) {
                throw new IOException("streamClosed");
            }

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

            synchronized (SAAJDataSource.this) {
                skipped = Math.min(skipped, totalsz - bread);    // only skip what we've read.
                if (skipped == 0) {
                    return 0;
                }
                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 != fileIS) {
                    fileIS.skip(skipped);
                }

                bread += skipped;
            }
            return skipped;
        }

        public int read(byte[] b, int off, int len) throws IOException {
            if (deleted) {
                throw new IOException("resourceDeleted");
            }

            if (readClosed) {
                throw new IOException("streamClosed");
            }

            if (b == null) {
                throw new RuntimeException("nullInput");
            }

            if (off < 0) {
                throw new IndexOutOfBoundsException("negOffset " + off);
            }

            if (len < 0) {
                throw new IndexOutOfBoundsException("length " + len);
            }

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

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

            int bwritten = 0;

            synchronized (SAAJDataSource.this) {
                if (bread == totalsz) {
                    return -1;
                }
                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 (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 (null == fileIS) {           // we are now reading from disk.
                        fileIS = new java.io.FileInputStream(diskCacheFile);

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

                    if (cachediskstream != null) {
                        cachediskstream.flush();
                    }
                    bwritten = fileIS.read(b, off, len);
                }

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

        /**
         * close the stream.
         *
         * @throws IOException
         */
        public synchronized void close() throws IOException {
            if (!readClosed) {
                readers.remove(this);
                readClosed = true;
                if (fileIS != null) {
                    fileIS.close();
                }

                fileIS = null;
            }
        }

        protected void finalize() throws Throwable {
            super.finalize();
            close();
        }
    }
}