Example usage for java.io RandomAccessFile seek

List of usage examples for java.io RandomAccessFile seek

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Introduction

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

Prototype

public void seek(long pos) throws IOException

Source Link

Document

Sets the file-pointer offset, measured from the beginning of this file, at which the next read or write occurs.

Usage

From source file:org.red5.io.flv.FLVReader.java

public static long getDuration(File flvFile) {
    RandomAccessFile flv = null;
    try {/*from   w w w  .j  a  va2 s  .co  m*/
        flv = new RandomAccessFile(flvFile, "r");
        long flvLength = flv.length();
        if (flvLength < 13) {
            return 0;
        }
        flv.seek(flvLength - 4);
        byte[] buf = new byte[4];
        flv.read(buf);
        long lastTagSize = 0;
        for (int i = 0; i < 4; i++) {
            lastTagSize += (buf[i] & 0x0ff) << ((3 - i) * 8);
        }
        if (lastTagSize == 0) {
            return 0;
        }
        flv.seek(flvLength - lastTagSize);
        flv.read(buf);
        long duration = 0;
        for (int i = 0; i < 3; i++) {
            duration += (buf[i] & 0x0ff) << ((2 - i) * 8);
        }
        duration += (buf[3] & 0x0ff) << 24; // extension byte
        return duration;
    } catch (IOException e) {
        return 0;
    } finally {
        try {
            if (flv != null) {
                flv.close();
            }
        } catch (IOException e) {
        }
        flv = null;
    }
}

From source file:org.apache.hadoop.hdfs.TestRaidDfs.java

public static void corruptBlock(Path file, Block blockNum, int numDataNodes, boolean delete,
        MiniDFSCluster cluster) throws IOException {
    long id = blockNum.getBlockId();

    // Now deliberately remove/truncate data blocks from the block.
    int numDeleted = 0;
    int numCorrupted = 0;
    for (int i = 0; i < numDataNodes; i++) {
        File[] dirs = getDataNodeDirs(i, cluster);

        for (int j = 0; j < dirs.length; j++) {
            File[] blocks = dirs[j].listFiles();
            assertTrue("Blocks do not exist in data-dir", (blocks != null) && (blocks.length >= 0));
            for (int idx = 0; idx < blocks.length; idx++) {
                LOG.info("block file: " + blocks[idx]);
                if (blocks[idx].getName().startsWith("blk_" + id) && !blocks[idx].getName().endsWith(".meta")) {
                    if (delete) {
                        blocks[idx].delete();
                        LOG.info("Deleted block " + blocks[idx]);
                        numDeleted++;/*from w  w  w  .  java  2 s.  co m*/
                    } else {
                        // Corrupt
                        File f = blocks[idx];
                        long seekPos = f.length() / 2;
                        RandomAccessFile raf = new RandomAccessFile(f, "rw");
                        raf.seek(seekPos);
                        int data = raf.readInt();
                        raf.seek(seekPos);
                        raf.writeInt(data + 1);
                        LOG.info("Corrupted block " + blocks[idx]);
                        numCorrupted++;
                    }
                }
            }
        }
    }
    assertTrue("Nothing corrupted or deleted", (numCorrupted + numDeleted) > 0);
}

From source file:com.github.nlloyd.hornofmongo.MongoScope.java

public static Object fuzzFile(Context cx, Scriptable thisObj, Object[] args, Function funObj) {
    if (args.length != 2)
        Context.throwAsScriptRuntimeEx(new MongoScriptException("fuzzFile takes 2 arguments"));
    File fileToFuzz;/*from  w w  w .  j a va  2  s . c  om*/
    try {
        fileToFuzz = resolveFilePath((MongoScope) thisObj, Context.toString(args[0])).getCanonicalFile();
    } catch (IOException e) {
        Context.throwAsScriptRuntimeEx(new MongoScriptException(e));
        return null;
    }
    RandomAccessFile fuzzFile = null;
    try {
        fuzzFile = new RandomAccessFile(fileToFuzz, "rw");
        long fuzzPosition = Double.valueOf(Context.toNumber(args[1])).longValue();
        fuzzFile.seek(fuzzPosition);
        int byteToFuzz = fuzzFile.readByte();
        byteToFuzz = ~byteToFuzz;
        fuzzFile.seek(fuzzPosition);
        fuzzFile.write(byteToFuzz);
        fuzzFile.close();
    } catch (FileNotFoundException e) {
        Context.throwAsScriptRuntimeEx(e);
    } catch (IOException e) {
        Context.throwAsScriptRuntimeEx(e);
    } finally {
        if (fuzzFile != null) {
            try {
                fuzzFile.close();
            } catch (IOException e) {
            }
        }
    }

    return Undefined.instance;
}

From source file:net.naijatek.myalumni.util.utilities.FileUtil.java

public static String[] getLastLines(final File file, final int linesToReturn, final String logType)
        throws IOException, FileNotFoundException {

    final int AVERAGE_CHARS_PER_LINE = 250;
    final int BYTES_PER_CHAR = 2;

    RandomAccessFile randomAccessFile = null;
    StringBuffer buffer = new StringBuffer(linesToReturn * AVERAGE_CHARS_PER_LINE);
    int lineTotal = 0;
    try {/* ww w.  j av  a2s.  c  o  m*/
        randomAccessFile = new RandomAccessFile(file, "r");
        long byteTotal = randomAccessFile.length();
        long byteEstimateToRead = linesToReturn * AVERAGE_CHARS_PER_LINE * BYTES_PER_CHAR;

        long offset = byteTotal - byteEstimateToRead;
        if (offset < 0) {
            offset = 0;
        }

        randomAccessFile.seek(offset);
        //log.debug("SKIP IS ::" + offset);

        String line = null;
        String lineUTF8 = null;
        while ((line = randomAccessFile.readLine()) != null) {
            lineUTF8 = new String(line.getBytes("ISO8859_1"), "UTF-8");
            lineTotal++;
            buffer.append(lineUTF8).append("\n");
        }
    } finally {
        if (randomAccessFile != null) {
            try {
                randomAccessFile.close();
            } catch (IOException ex) {
            }
        }
    }

    //String[] resultLines = new String[linesToReturn];
    ArrayList<String> resultLines = new ArrayList<String>();
    BufferedReader in = null;
    try {
        in = new BufferedReader(new StringReader(buffer.toString()));

        int start = lineTotal /* + 2 */ - linesToReturn; // Ex : 55 - 10 = 45 ~ offset
        if (start < 0) {
            start = 0; // not start line
        }
        for (int i = 0; i < start; i++) {
            in.readLine(); // loop until the offset. Ex: loop 0, 1 ~~ 2 lines
        }

        int i = 0;
        String line = null;
        while ((line = in.readLine()) != null) {
            if (logType.equalsIgnoreCase("ALL")) {
                //resultLines[i] = line;
                resultLines.add(line);
                i++;
            } else if (line.indexOf(logType) > -1) {
                //resultLines[i] = line;
                resultLines.add(line);
                i++;
            }
        }
    } catch (IOException ie) {
        logger.error("Error" + ie);
        throw ie;
    } finally {
        if (in != null) {
            try {
                in.close();
            } catch (IOException ex) {
            }
        }
    }

    String[] resultLines1 = new String[resultLines.size()];
    String tmp = new String();
    for (int i = 0; i < resultLines.size(); i++) {
        tmp = (String) resultLines.get(i);
        resultLines1[i] = tmp;
    }

    return resultLines1;
}

From source file:com.liferay.lms.servlet.SCORMFileServerServlet.java

/**
 * Copy the given byte range of the given input to the given output.
 * @param input The input to copy the given range to the given output for.
 * @param output The output to copy the given range from the given input for.
 * @param start Start of the byte range.
 * @param length Length of the byte range.
 * @throws IOException If something fails at I/O level.
 *///from  w  w w .j  a v  a 2  s . c  o  m
private static void copy(RandomAccessFile input, OutputStream output, long start, long length)
        throws IOException {
    byte[] buffer = new byte[DEFAULT_BUFFER_SIZE];
    int read;

    if (input.length() == length) {
        // Write full range.
        while ((read = input.read(buffer)) > 0) {
            output.write(buffer, 0, read);
        }
    } else {
        // Write partial range.
        input.seek(start);
        long toRead = length;

        while ((read = input.read(buffer)) > 0) {
            if ((toRead -= read) > 0) {
                output.write(buffer, 0, read);
            } else {
                output.write(buffer, 0, (int) toRead + read);
                break;
            }
        }
    }
}

From source file:azkaban.common.utils.Utils.java

/**
 * Read in content of a file and get the last *lineCount* lines. It is
 * equivalent to *tail* command/* www  .  ja va  2  s. c  o m*/
 * 
 * @param filename
 * @param lineCount
 * @param chunkSize
 * @return
 */
public static Vector<String> tail(String filename, int lineCount, int chunkSize) {
    try {
        // read in content of the file
        RandomAccessFile file = new RandomAccessFile(filename, "r");
        // destination vector
        Vector<String> lastNLines = new Vector<String>();
        // current position
        long currPos = file.length() - 1;
        long startPos;
        byte[] byteArray = new byte[chunkSize];

        // read in content of the file in reverse order
        while (true) {
            // read in from *fromPos*
            startPos = currPos - chunkSize;

            if (startPos <= 0) { // toward the beginning of the file
                file.seek(0);
                file.read(byteArray, 0, (int) currPos); // only read in
                                                        // curPos bytes
                parseLinesFromLast(byteArray, 0, (int) currPos, lineCount, lastNLines);
                break;
            } else {
                file.seek(startPos);
                if (byteArray == null)
                    byteArray = new byte[chunkSize];
                file.readFully(byteArray);
                if (parseLinesFromLast(byteArray, lineCount, lastNLines)) {
                    break; // we got the last *lineCount* lines
                }

                // move the current position
                currPos = startPos; // + lastLine.getBytes().length;
            }
        }

        // there might be lineCount + 1 lines and the first line (now it is the last line)
        // might not be complete
        for (int index = lineCount; index < lastNLines.size(); index++)
            lastNLines.removeElementAt(index);

        // reverse the order of elements in lastNLines
        Collections.reverse(lastNLines);
        return lastNLines;
    } catch (Exception e) {
        return null;
    }

}

From source file:org.jcodec.movtool.Undo.java

private void undo(String fineName) throws IOException {
    List<Atom> versions = list(fineName);
    if (versions.size() < 2) {
        System.err.println("Nowhere to rollback.");
        return;/*  w w  w.  j a v a2s.  c o m*/
    }
    RandomAccessFile raf = null;
    try {
        raf = new RandomAccessFile(new File(fineName), "rw");
        raf.seek(versions.get(versions.size() - 2).getOffset() + 4);
        raf.write(new byte[] { 'm', 'o', 'o', 'v' });
        raf.seek(versions.get(versions.size() - 1).getOffset() + 4);
        raf.write(new byte[] { 'f', 'r', 'e', 'e' });
    } finally {
        raf.close();
    }
}

From source file:ch.cyberduck.core.io.FileBuffer.java

@Override
public synchronized int write(final byte[] chunk, final Long offset) throws IOException {
    final RandomAccessFile file = random();
    file.seek(offset);
    file.write(chunk, 0, chunk.length);/* ww w.  jav  a  2 s. co  m*/
    length = Math.max(length, file.length());
    return chunk.length;
}

From source file:ch.cyberduck.core.io.FileBuffer.java

@Override
public synchronized int read(final byte[] chunk, final Long offset) throws IOException {
    final RandomAccessFile file = random();
    if (offset < file.length()) {
        file.seek(offset);
        if (chunk.length + offset > file.length()) {
            return file.read(chunk, 0, (int) (file.length() - offset));
        } else {//  ww w.  j  av a2 s.  c o m
            return file.read(chunk, 0, chunk.length);
        }
    } else {
        final NullInputStream nullStream = new NullInputStream(length);
        if (nullStream.available() > 0) {
            nullStream.skip(offset);
            return nullStream.read(chunk, 0, chunk.length);
        } else {
            return IOUtils.EOF;
        }
    }
}

From source file:com.tcl.lzhang1.mymusic.MusicUtil.java

/**
 * get the music info//from w  w w . j  a v  a2s  . c  o m
 * 
 * @param musicFile
 * @return
 */
public static SongModel getMusicInfo(File musicFile) {
    SongModel model = new SongModel();
    // retrun null if music file is null or is or directory
    if (musicFile == null || !musicFile.isFile()) {
        return null;
    }

    byte[] buf = new byte[128];
    try {
        Log.d(LOG_TAG, "process music file{" + musicFile.getAbsolutePath() + "}");
        // tag_v1
        RandomAccessFile music = new RandomAccessFile(musicFile, "r");

        music.seek(music.length() - 128);
        music.read(buf);// read tag to buffer
        // tag_v2
        byte[] header = new byte[10];
        music.seek(0);
        music.read(header, 0, 10);
        // if ("ID3".equalsIgnoreCase(new String(header, 0, 3))) {
        // int ID3V2_frame_size = (int) (header[6] & 0x7F) * 0x200000
        // | (int) (header[7] & 0x7F) * 0x400
        // | (int) (header[8] & 0x7F) * 0x80
        // | (int) (header[9] & 0x7F);
        // byte[] FrameHeader = new byte[4];
        // music.seek(ID3V2_frame_size + 10);
        // music.read(FrameHeader, 0, 4);
        // model = getTimeInfo(FrameHeader, ID3V2_frame_size, musicFile);
        // } else {
        // byte[] FrameHeader = new byte[4];
        // music.read(FrameHeader, 0, 4);
        // model = getTimeInfo(FrameHeader, 0, musicFile);
        // }

        music.close();// close file
        // check length
        // if (buf.length != 128) {
        // throw new
        // ErrorMusicLength(String.format("error music info length, length is:%i",
        // buf.length));
        // }
        //
        // if (!"TAG".equalsIgnoreCase(new String(buf, 0, 3))) {
        // throw new UnknownTagException("unknown tag exception");
        // }
        String songName = null;
        // try {
        // songName = new String(buf, 3, 30, "gbk").trim();
        // } catch (UnsupportedEncodingException e) {
        // // TODO: handle exception
        // e.printStackTrace();
        // songName = new String(buf, 3, 30).trim();
        // }
        String singerName = "";
        // try {
        // singerName = new String(buf, 33, 30, "gbk").trim();
        // } catch (UnsupportedEncodingException e) {
        // // TODO: handle exception
        // singerName = new String(buf, 33, 30).trim();
        // }
        String ablum = "";
        // try {
        // ablum = new String(buf, 63, 30, "gbk").trim();
        // } catch (UnsupportedEncodingException e) {
        // // TODO: handle exception
        // ablum = new String(buf, 63, 30).trim();
        // }
        String year = "";
        // try {
        // year = new String(buf, 93, 4, "gbk").trim();
        // } catch (UnsupportedEncodingException e) {
        // year = new String(buf, 93, 4).trim();
        // // TODO: handle exception
        // }

        String reamrk = "";
        ContentResolver contentResolver = sContext.getContentResolver();
        Cursor cursor = contentResolver.query(MediaStore.Audio.Media.EXTERNAL_CONTENT_URI, null, "_data=?",
                new String[] { musicFile.getAbsolutePath() }, null);
        cursor.moveToFirst();
        if (cursor != null && cursor.getCount() != 0) {
            try {
                if (TextUtils.isEmpty(songName)) {
                    songName = cursor.getString(cursor.getColumnIndex(MediaStore.Audio.AudioColumns.TITLE));
                    singerName = cursor.getString(cursor.getColumnIndex(MediaStore.Audio.AudioColumns.ARTIST));
                    ablum = cursor.getString(cursor.getColumnIndex(MediaStore.Audio.AudioColumns.ALBUM));
                    year = cursor.getString(cursor.getColumnIndex(MediaStore.Audio.AudioColumns.YEAR));
                }

                long secs = cursor.getLong(cursor.getColumnIndex(MediaStore.Audio.AudioColumns.DURATION));
                model.setTime(secs);
                secs /= 1000;
                model.setHours((int) secs / 3600);
                model.setMinutes(((int) secs % 3600) / 60);
                model.setSeconds(((int) secs % 3600) % 60);
                cursor.close();
            } catch (CursorIndexOutOfBoundsException e) {
                // TODO: handle exception
                if (null != cursor) {
                    cursor.close();
                    cursor = null;
                }
                Log.d(LOG_TAG, "CursorIndexOutOfBoundsException:" + e.getMessage());
                try {
                    songName = new String(buf, 3, 30, "gbk").trim();
                } catch (UnsupportedEncodingException e0) {
                    // TODO: handle exception
                    e.printStackTrace();
                    songName = new String(buf, 3, 30).trim();
                }
                try {
                    singerName = new String(buf, 33, 30, "gbk").trim();
                } catch (UnsupportedEncodingException e1) {
                    // TODO: handle exception
                    singerName = new String(buf, 33, 30).trim();
                }
                try {
                    ablum = new String(buf, 63, 30, "gbk").trim();
                } catch (UnsupportedEncodingException e2) {
                    // TODO: handle exception
                    ablum = new String(buf, 63, 30).trim();
                }
                try {
                    year = new String(buf, 93, 4, "gbk").trim();
                } catch (UnsupportedEncodingException e3) {
                    year = new String(buf, 93, 4).trim();
                    // TODO: handle exception
                }

                try {
                    reamrk = new String(buf, 97, 28, "gbk").trim();
                } catch (UnsupportedEncodingException e4) {
                    // TODO: handle exception
                    reamrk = new String(buf, 97, 28).trim();
                }

            }
        }

        //

        // get the time len

        model.setSongName(songName);
        model.setSingerName(singerName);
        model.setAblumName(ablum);
        model.setFile(musicFile.getAbsolutePath());
        model.setRemark("");
        Log.d(LOG_TAG, String.format("scaned music file[%s],album name[%s],song name[%s],singer name[%s]",
                model.getFile(), model.getAblumName(), model.getSingerName(), model.getSingerName()));

        mSongs.add(model);

        return model;
    } catch (IOException e) {
        // TODO: handle exception
        e.printStackTrace();
    }
    return model;
}