Example usage for java.io RandomAccessFile RandomAccessFile

Introduction

In this page you can find the example usage for java.io RandomAccessFile RandomAccessFile.

Prototype

public RandomAccessFile(File file, String mode) throws FileNotFoundException 

Source Link

Document

Creates a random access file stream to read from, and optionally to write to, the file specified by the File argument.

Usage

From source file:com.slytechs.capture.FileFactory.java

public FormatType formatType(final File file) throws IOException {

    try {//  www .  j  a  v a2 s .  com
        new PcapFileCapture(file, FileMode.ReadOnlyNoMap, null).close();

        if (logger.isTraceEnabled()) {
            logger.trace(file.getName() + ", type=" + FormatType.Pcap);
        }

        return FormatType.Pcap;
    } catch (final Exception e) {
    }

    try {
        new SnoopFileCapture(file, FileMode.ReadOnlyNoMap, null).close();

        if (logger.isTraceEnabled()) {
            logger.trace(file.getName() + ", type=" + FormatType.Pcap);
        }

        return FormatType.Snoop;
    } catch (final Exception e) {
    }

    /*
     * Now try InputCapture which may also yield a known format
     */
    ReadableByteChannel channel = new RandomAccessFile(file, "r").getChannel();
    FormatType type = formatType(channel);
    channel.close();

    if (logger.isTraceEnabled()) {
        logger.trace(file.getName() + ", type=" + FormatType.Pcap);
    }

    return type;
}

---

From source file:dbseer.comp.process.live.LogTailer.java

@Override
public void run() {
    RandomAccessFile reader = null;
    try {/*from w w  w.j  av a 2 s .c o m*/
        long last = 0; // The last time the file was checked for changes
        long position = 0; // position within the file
        // Open the file
        while (run && reader == null) {
            try {
                reader = new RandomAccessFile(file, RAF_MODE);
            } catch (FileNotFoundException e) {
                listener.fileNotFound();
            }

            if (reader == null) {
                try {
                    Thread.sleep(delayMillis);
                } catch (InterruptedException e) {
                }
            } else {
                // The current position in the file
                //               position = (startOffset > file.length()) ? file.length() : startOffset;
                if (startOffset == -1) {
                    position = file.length();
                } else {
                    position = startOffset;
                }
                last = System.currentTimeMillis();
                reader.seek(position);
            }
        }

        while (run) {

            boolean newer = FileUtils.isFileNewer(file, last); // IO-279, must be done first

            // Check the file length to see if it was rotated
            long length = file.length();

            if (length < position) {

                // File was rotated
                listener.fileRotated();

                // Reopen the reader after rotation
                try {
                    // Ensure that the old file is closed iff we re-open it successfully
                    RandomAccessFile save = reader;
                    reader = new RandomAccessFile(file, RAF_MODE);
                    position = 0;
                    // close old file explicitly rather than relying on GC picking up previous RAF
                    IOUtils.closeQuietly(save);
                } catch (FileNotFoundException e) {
                    // in this case we continue to use the previous reader and position values
                    listener.fileNotFound();
                }
                continue;
            } else {

                // File was not rotated

                // See if the file needs to be read again
                if (length > position) {

                    // The file has more content than it did last time
                    position = readLines(reader);
                    last = System.currentTimeMillis();

                } else if (newer) {

                    /*
                     * This can happen if the file is truncated or overwritten with the exact same length of
                     * information. In cases like this, the file position needs to be reset
                     */
                    if (resetFilePositionIfOverwrittenWithTheSameLength) {
                        position = 0;
                        reader.seek(position); // cannot be null here

                        // Now we can read new lines
                        position = readLines(reader);
                        last = System.currentTimeMillis();
                    }
                } else {
                    Thread.sleep(DEFAULT_DELAY_MILLIS);
                }
            }
        }

    } catch (Exception e) {

        listener.handle(e);

    } finally {
        IOUtils.closeQuietly(reader);
    }
}

---

From source file:bobs.is.compress.sevenzip.SevenZOutputFile.java

/**
 * Opens file to write a 7z archive to./*from  www  .  jav a  2 s . co m*/
 *
 * @param filename name of the file to write to
 * @throws IOException if opening the file fails
 */
public SevenZOutputFile(final File filename) throws IOException {
    file = new RandomAccessFile(filename, "rw");
    file.seek(SevenZFile.SIGNATURE_HEADER_SIZE);
}

---

From source file:com.owncloud.android.oc_framework.network.webdav.FileRequestEntity.java

@Override
public void writeRequest(final OutputStream out) throws IOException {
    //byte[] tmp = new byte[4096];
    ByteBuffer tmp = ByteBuffer.allocate(4096);
    int readResult = 0;

    // TODO(bprzybylski): each mem allocation can throw OutOfMemoryError we need to handle it
    //                    globally in some fashionable manner
    RandomAccessFile raf = new RandomAccessFile(mFile, "r");
    FileChannel channel = raf.getChannel();
    Iterator<OnDatatransferProgressListener> it = null;
    long transferred = 0;
    long size = mFile.length();
    if (size == 0)
        size = -1;/*from  w  w w . ja  v  a2s . c om*/
    try {
        while ((readResult = channel.read(tmp)) >= 0) {
            out.write(tmp.array(), 0, readResult);
            tmp.clear();
            transferred += readResult;
            synchronized (mDataTransferListeners) {
                it = mDataTransferListeners.iterator();
                while (it.hasNext()) {
                    it.next().onTransferProgress(readResult, transferred, size, mFile.getName());
                }
            }
        }

    } catch (IOException io) {
        Log.e("FileRequestException", io.getMessage());
        throw new RuntimeException(
                "Ugly solution to workaround the default policy of retries when the server falls while uploading ; temporal fix; really",
                io);

    } finally {
        channel.close();
        raf.close();
    }
}

---

From source file:eu.alefzero.webdav.FileRequestEntity.java

@Override
public void writeRequest(final OutputStream out) throws IOException {
    //byte[] tmp = new byte[4096];
    ByteBuffer tmp = ByteBuffer.allocate(4096);
    int readResult = 0;

    // TODO(bprzybylski): each mem allocation can throw OutOfMemoryError we need to handle it
    //                    globally in some fashionable manner
    RandomAccessFile raf = new RandomAccessFile(mFile, "r");
    FileChannel channel = raf.getChannel();
    Iterator<OnDatatransferProgressListener> it = null;
    long transferred = 0;
    long size = mFile.length();
    if (size == 0)
        size = -1;//from  w  w  w  .ja  v  a  2s . c  o m
    try {
        while ((readResult = channel.read(tmp)) >= 0) {
            out.write(tmp.array(), 0, readResult);
            tmp.clear();
            transferred += readResult;
            synchronized (mDataTransferListeners) {
                it = mDataTransferListeners.iterator();
                while (it.hasNext()) {
                    it.next().onTransferProgress(readResult, transferred, size, mFile.getName());
                }
            }
        }

    } catch (IOException io) {
        Log_OC.e("FileRequestException", io.getMessage());
        throw new RuntimeException(
                "Ugly solution to workaround the default policy of retries when the server falls while uploading ; temporal fix; really",
                io);

    } finally {
        channel.close();
        raf.close();
    }
}

---

From source file:com.haulmont.cuba.core.sys.LogControlImpl.java

@Override
public String getTail(String fileName) throws LogControlException {
    // security check, supported only valid file names
    fileName = FilenameUtils.getName(fileName);

    StringBuilder sb = new StringBuilder();
    RandomAccessFile randomAccessFile = null;
    try {//w w w.  java2 s .  co  m
        File logFile = new File(logDir, fileName);
        if (!logFile.exists())
            throw new LogFileNotFoundException(fileName);

        randomAccessFile = new RandomAccessFile(logFile, "r");
        long lengthFile = randomAccessFile.length();
        if (lengthFile >= LOG_TAIL_AMOUNT_BYTES) {
            randomAccessFile.seek(lengthFile - LOG_TAIL_AMOUNT_BYTES);
            skipFirstLine(randomAccessFile);
        }
        while (randomAccessFile.read() != -1) {
            randomAccessFile.seek(randomAccessFile.getFilePointer() - 1);
            String line = readUtf8Line(randomAccessFile);
            if (line != null) {
                sb.append(line).append("\n");
            }
        }
    } catch (IOException e) {
        log.error("Error reading log file", e);
        throw new LogControlException("Error reading log file: " + fileName);
    } finally {
        if (randomAccessFile != null) {
            try {
                randomAccessFile.close();
            } catch (IOException ignored) {
            }
        }
    }
    return sb.toString();
}

---

From source file:com.sc.l45.weblogviewer.reader.ReversedLinesFileReaderLineSeparator.java

/**
 * Creates a ReversedLinesFileReader with the given block size and encoding.
 *
 * @param file/*from  w  w w .ja v a2s  .  c  o m*/
 *            the file to be read
 * @param blockSize
 *            size of the internal buffer (for ideal performance this should
 *            match with the block size of the underlying file system).
 * @param encoding
 *            the encoding of the file
 * @throws IOException  if an I/O error occurs
 * @since 2.3
 */
public ReversedLinesFileReaderLineSeparator(final File file, final int blockSize, final Charset encoding)
        throws IOException {
    this.blockSize = blockSize;
    this.encoding = encoding;

    randomAccessFile = new RandomAccessFile(file, "r");
    totalByteLength = randomAccessFile.length();
    int lastBlockLength = (int) (totalByteLength % blockSize);
    if (lastBlockLength > 0) {
        totalBlockCount = totalByteLength / blockSize + 1;
    } else {
        totalBlockCount = totalByteLength / blockSize;
        if (totalByteLength > 0) {
            lastBlockLength = blockSize;
        }
    }
    currentFilePart = new FilePart(totalBlockCount, lastBlockLength, null);

    // --- check & prepare encoding ---
    Charset charset = Charsets.toCharset(encoding);
    CharsetEncoder charsetEncoder = charset.newEncoder();
    float maxBytesPerChar = charsetEncoder.maxBytesPerChar();
    if (maxBytesPerChar == 1f) {
        // all one byte encodings are no problem
        byteDecrement = 1;
    } else if (charset == Charset.forName("UTF-8")) {
        // UTF-8 works fine out of the box, for multibyte sequences a second UTF-8 byte can never be a newline byte
        // http://en.wikipedia.org/wiki/UTF-8
        byteDecrement = 1;
    } else if (charset == Charset.forName("Shift_JIS")) {
        // Same as for UTF-8
        // http://www.herongyang.com/Unicode/JIS-Shift-JIS-Encoding.html
        byteDecrement = 1;
    } else if (charset == Charset.forName("UTF-16BE") || charset == Charset.forName("UTF-16LE")) {
        // UTF-16 new line sequences are not allowed as second tuple of four byte sequences,
        // however byte order has to be specified
        byteDecrement = 2;
    } else if (charset == Charset.forName("UTF-16")) {
        throw new UnsupportedEncodingException(
                "For UTF-16, you need to specify the byte order (use UTF-16BE or UTF-16LE)");
    } else {
        throw new UnsupportedEncodingException(
                "Encoding " + encoding + " is not supported yet (feel free to submit a patch)");
    }
    // NOTE: The new line sequences are matched in the order given, so it is important that \r\n is BEFORE \n
    newLineSequences = new byte[][] { "\r\n".getBytes(encoding), "\n".getBytes(encoding),
            "\r".getBytes(encoding) };

    avoidNewlineSplitBufferSize = newLineSequences[0].length;
}

---

From source file:com.adaptris.core.fs.enhanced.FileSorterCase.java

private void ensureSize(long size, File f) throws IOException {
    RandomAccessFile rf = new RandomAccessFile(f, "rw");
    rf.setLength(size);/*from   w  w  w .j  a v a2 s  .c  om*/
    rf.close();
}

---

From source file:test.other.T_DaoTest.java

public void test2() throws SQLException, IOException {
    System.out.println(System.nanoTime() / 1000000);
    ResultSet rs = conn.createStatement().executeQuery("select content from fc_Post where id = 15");
    rs.next();//from   w  w w  .j a v  a 2 s .c o  m
    String text = rs.getString(1);
    System.out.println(text.length());
    System.out.println(System.nanoTime() / 1000000);
    @SuppressWarnings("resource")
    FileChannel rwChannel = new RandomAccessFile("textfile.txt", "rw").getChannel();
    ByteBuffer wrBuf = rwChannel.map(FileChannel.MapMode.READ_WRITE, 0, text.length() + 10);
    int lg = text.length() / 1000000;
    int pos = 0;
    byte[] buf = new byte[text.length() / 1000000];
    System.out.println(System.nanoTime() / 1000000);
    for (int i = 0; i < 1000000; i++) {
        System.arraycopy(text.getBytes(), pos, buf, 0, lg);
        wrBuf.put(buf);
        pos += lg;
    }
    System.out.println(System.nanoTime() / 1000000);
    rwChannel.close();
}

---

From source file:com.taobao.common.tfs.impl.GcWorker.java

private void doGc(SegmentInfoContainer segmentInfoContainer, File[] fileList) {
    for (File file : fileList) {
        if (file.length() == 0) {
            log.info("expired gc file is empty, unlink. " + file.getAbsolutePath());
            file.delete();//from w w  w. j  a v a 2  s.  c om
            continue;
        }

        String fileName = file.getAbsolutePath();
        log.info("do gc filename " + fileName);

        int serverIdIndex = fileName.lastIndexOf('!');
        if (serverIdIndex == -1) {
            log.error("file name is invalid, no server id: " + fileName);
            // unlink ?
            continue;
        }

        FileLock fileLock = null;
        try {
            FileChannel fileChannel = (new RandomAccessFile(file, "rw")).getChannel();
            fileLock = fileChannel.tryLock();
            if (fileLock == null) {
                log.warn("file: " + fileName + " is busy, maybe another gc worker is working over it");
                continue;
            }

            long serverId = Long.parseLong(fileName.substring(serverIdIndex + 1));
            segmentInfoContainer.loadFile(fileName);
            Collection<SegmentInfo> segmentInfos = segmentInfoContainer.getSegmentInfos();

            for (SegmentInfo segmentInfo : segmentInfos) {
                if (tfsManager.unlinkFile(segmentInfo.getBlockId(), segmentInfo.getFileId(), serverId)) {
                    log.info("gc success. blockId: " + segmentInfo.getBlockId() + " fileId: "
                            + segmentInfo.getFileId() + " serverId: " + serverId);
                } else {
                    log.error("gc fail. blockId: " + segmentInfo.getFileId() + " fileId: "
                            + segmentInfo.getFileId() + " serverId: " + serverId);
                }
            }
        } catch (Exception e) {
            log.warn("", e);
        } finally {
            try {
                if (fileLock != null) {
                    fileLock.release();
                }
                segmentInfoContainer.cleanUp();
                // delete anyway
                file.delete();
            } catch (Exception e) {
                log.warn("filelock realse fail.", e);
            }
        }
    }
}

---

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