Example usage for java.io RandomAccessFile getFilePointer

Introduction

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

Prototype

public native long getFilePointer() throws IOException;

Source Link

Document

Returns the current offset in this file.

Usage

From source file:org.scriptbox.util.common.io.Tailer.java

/**
 * Read new lines.//  www.j  ava2s .  c o m
 *
 * @param reader The file to read
 * @return The new position after the lines have been read
 * @throws java.io.IOException if an I/O error occurs.
 */
private long readLines(RandomAccessFile reader) throws IOException {
    StringBuilder sb = new StringBuilder();

    long pos = reader.getFilePointer();
    long rePos = pos; // position to re-read

    int num;
    boolean seenCR = false;
    while (run && ((num = reader.read(inbuf)) != -1)) {
        for (int i = 0; i < num; i++) {
            byte ch = inbuf[i];
            switch (ch) {
            case '\n':
                seenCR = false; // swallow CR before LF
                listener.handle(sb.toString());
                sb.setLength(0);
                rePos = pos + i + 1;
                break;
            case '\r':
                if (seenCR) {
                    sb.append('\r');
                }
                seenCR = true;
                break;
            default:
                if (seenCR) {
                    seenCR = false; // swallow final CR
                    listener.handle(sb.toString());
                    sb.setLength(0);
                    rePos = pos + i + 1;
                }
                sb.append((char) ch); // add character, not its ascii value
            }
        }

        pos = reader.getFilePointer();
    }

    reader.seek(rePos); // Ensure we can re-read if necessary
    return rePos;
}

---

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

protected String readUtf8Line(RandomAccessFile logFile) throws IOException {
    int c = -1;//from  w ww  .  j av a  2 s .  com
    boolean eol = false;
    ByteArrayOutputStream input = new ByteArrayOutputStream();

    while (!eol) {
        switch (c = logFile.read()) {
        case -1:
        case '\n':
            eol = true;
            break;
        case '\r':
            eol = true;
            long cur = logFile.getFilePointer();
            if ((logFile.read()) != '\n') {
                logFile.seek(cur);
            }
            break;
        default:
            input.write((byte) c);
            break;
        }
    }
    if ((c == -1) && (input.size() == 0)) {
        return null;
    }

    return new String(input.toByteArray(), StandardCharsets.UTF_8);
}

---

From source file:dk.netarkivet.common.utils.FileUtils.java

/**
 * Read the last line in a file. Note this method is not UTF-8 safe.
 *
 * @param file input file to read last line from.
 * @return The last line in the file (ending newline is irrelevant),
 * returns an empty string if file is empty.
 * @throws ArgumentNotValid on null argument, or file is not a readable
 * file.//from   ww  w  . ja  va 2  s.  co  m
 * @throws IOFailure on IO trouble reading file.
 */
public static String readLastLine(File file) {
    ArgumentNotValid.checkNotNull(file, "File file");
    if (!file.isFile() || !file.canRead()) {
        final String errMsg = "File '" + file.getAbsolutePath() + "' is not a readable file.";
        log.warn(errMsg);
        throw new ArgumentNotValid(errMsg);
    }
    if (file.length() == 0) {
        return "";
    }
    RandomAccessFile rafile = null;
    try {
        rafile = new RandomAccessFile(file, "r");
        //seek to byte one before end of file (remember we know the file is
        // not empty) - this ensures that an ending newline is not read
        rafile.seek(rafile.length() - 2);
        //now search to the last linebreak, or beginning of file
        while (rafile.getFilePointer() != 0 && rafile.read() != '\n') {
            //search back two, because we just searched forward one to find
            //newline
            rafile.seek(rafile.getFilePointer() - 2);
        }
        return rafile.readLine();
    } catch (IOException e) {
        final String errMsg = "Unable to access file '" + file.getAbsolutePath() + "'";
        log.warn(errMsg, e);
        throw new IOFailure(errMsg, e);
    } finally {
        try {
            if (rafile != null) {
                rafile.close();
            }
        } catch (IOException e) {
            log.debug("Unable to close file '" + file.getAbsolutePath() + "' after reading", e);
        }
    }
}

---

From source file:com.microsoft.azure.management.datalake.store.uploader.SingleSegmentUploader.java

/**
 * Uploads the segment contents./*w ww  . j a  v  a  2 s  . co  m*/
 *
 * @param inputStream The input stream.
 * @param endPosition The end position.
 * @throws Exception if there is any failure attempting to upload the contents of a single segment.
 */
private void uploadSegmentContents(RandomAccessFile inputStream, long endPosition) throws Exception {
    long bytesCopiedSoFar = 0; // we start off with a fresh stream

    byte[] buffer = new byte[BUFFER_LENGTH];
    int residualBufferLength = 0; //the number of bytes that remained in the buffer from the last upload (bytes which were not uploaded)

    while (inputStream.getFilePointer() < endPosition) {
        //read a block of data, and keep track of how many bytes are actually read
        int bytesRead = readIntoBuffer(inputStream, buffer, residualBufferLength, endPosition);
        int bufferDataLength = residualBufferLength + bytesRead;

        //determine the cutoff offset for upload - everything before will be uploaded, everything after is residual; (the position of the last record in this buffer)
        int uploadCutoff = bufferDataLength;
        if (!metadata.isBinary()) {
            uploadCutoff = determineUploadCutoffForTextFile(buffer, bufferDataLength, inputStream);
        }

        bytesCopiedSoFar = uploadBuffer(buffer, uploadCutoff, bytesCopiedSoFar);

        residualBufferLength = bufferDataLength - uploadCutoff;
        if (residualBufferLength > 0) {
            //move the remainder of the buffer to the front
            System.arraycopy(buffer, uploadCutoff, buffer, 0, residualBufferLength);
        }
    }

    //make sure we don't leave anything behind
    if (residualBufferLength > 0) {
        uploadBuffer(buffer, residualBufferLength, bytesCopiedSoFar);
    }

    buffer = null;
}

---

From source file:edu.msu.cme.rdp.readseq.readers.core.SFFCore.java

@Override
public LinkedHashMap<String, Long> scanInternal() throws IOException {
    if (commonHeader.indexOffset > commonHeader.headerLength) {
        return readIndex();
    }// w  w w .  java 2 s .  c  o m

    RandomAccessFile seqFile = super.getRawFile();

    seqFile.seek(commonHeader.headerLength);
    LinkedHashMap<String, Long> seqIndex = new LinkedHashMap(commonHeader.numReads);

    for (int index = 0; index < commonHeader.numReads; index++) {
        long pos = seqFile.getFilePointer();
        ReadBlock block = readReadBlock();
        seqIndex.put(block.name, pos);
    }

    return seqIndex;
}

---

From source file:com.aol.advertising.qiao.injector.file.AbstractFileTailer.java

protected long checksum(RandomAccessFile raFile) throws IOException, InsufficientFileLengthException {
    long pos = raFile.getFilePointer();
    try {//from ww w  . j av  a  2  s . c om
        byte[] buffer = new byte[checksumByteLength];
        raFile.seek(0);
        int n = raFile.read(buffer);
        if (n < checksumByteLength) {
            String s;
            logger.warn(s = ("not enough data for checksum: current file size=" + n));
            throw new InsufficientFileLengthException(s);
        }

        synchronized (_crc) {
            _crc.reset();
            _crc.update(buffer);

            return _crc.getValue();
        }
    } finally {
        raFile.seek(pos);
    }

}

---

From source file:com.qumasoft.qvcslib.CompareFilesWithApacheDiff.java

private CompareLineInfo[] buildLinesFromFile(File inFile) throws IOException {
    List<CompareLineInfo> lineInfoList = new ArrayList<>();
    RandomAccessFile randomAccessFile = new RandomAccessFile(inFile, "r");
    long fileLength = randomAccessFile.length();
    int startOfLineSeekPosition = 0;
    int currentSeekPosition = 0;
    byte character;
    while (currentSeekPosition < fileLength) {
        character = randomAccessFile.readByte();
        currentSeekPosition = (int) randomAccessFile.getFilePointer();
        if (character == '\n') {
            int endOfLine = (int) randomAccessFile.getFilePointer();
            byte[] buffer = new byte[endOfLine - startOfLineSeekPosition];
            randomAccessFile.seek(startOfLineSeekPosition);
            randomAccessFile.readFully(buffer);
            String line = new String(buffer, UTF8);
            CompareLineInfo lineInfo = new CompareLineInfo(startOfLineSeekPosition, createCompareLine(line));
            lineInfoList.add(lineInfo);//from   w  w w  .j  av a 2 s  . c  o  m
            startOfLineSeekPosition = endOfLine;
        }
    }
    // Add the final line which can happen if it doesn't end in a newline.
    if ((fileLength - startOfLineSeekPosition) > 0L) {
        byte[] buffer = new byte[(int) fileLength - startOfLineSeekPosition];
        randomAccessFile.seek(startOfLineSeekPosition);
        randomAccessFile.readFully(buffer);
        String line = new String(buffer, UTF8);
        CompareLineInfo lineInfo = new CompareLineInfo(startOfLineSeekPosition, createCompareLine(line));
        lineInfoList.add(lineInfo);
    }
    CompareLineInfo[] lineInfoArray = new CompareLineInfo[lineInfoList.size()];
    int i = 0;
    for (CompareLineInfo lineInfo : lineInfoList) {
        lineInfoArray[i++] = lineInfo;
    }
    return lineInfoArray;
}

---

From source file:org.multibit.file.FileHandler.java

/**
 * Delete a file with an overwrite of all of the data.
 * /*from   w  w w .  j  av  a 2s  . c o m*/
 * Set bit patterns are used rather than random numbers to avoid a
 * futex_wait_queue_me error on Linux systems (related to /dev/random usage)
 * 
 * @param file
 * @throws IOException
 */
public static void secureDelete(File file) throws IOException {
    log.debug("Start of secureDelete");

    RandomAccessFile raf = null;
    if (file != null && file.exists()) {
        try {
            // Prep for file delete as this can be fiddly on windows.
            // Make sure it is writable and any references to it are garbage
            // collected and finalized.
            file.setWritable(true);
            System.gc();

            long length = file.length();
            raf = new RandomAccessFile(file, "rws");
            raf.seek(0);
            raf.getFilePointer();
            int pos = 0;
            while (pos < length) {
                raf.write(SECURE_DELETE_FILL_BYTES);
                pos += SECURE_DELETE_FILL_BYTES.length;
            }
        } finally {
            if (raf != null) {
                raf.close();
                raf = null;
            }
        }
        boolean deleteSuccess = file.delete();
        log.debug("Result of delete of file '" + file.getAbsolutePath() + "' was " + deleteSuccess);
    }
    log.debug("End of secureDelete");
}

---

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 {//ww  w .  j  a va  2 s  .  c  om
        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:org.commoncrawl.service.crawler.CrawlLog.java

/**
 * seek out next instance of sync bytes in the file input stream
 * //from  w  w  w  .j  av a 2s.  c o m
 * @param file
 * @throws IOException
 */
private static boolean seekToNextSyncBytesPos(byte[] syncBytesBuffer, RandomAccessFile file, long maxFileSize)
        throws IOException {

    while (file.getFilePointer() < maxFileSize) {
        try {
            // read in a sync.length buffer amount
            file.read(syncBytesBuffer);

            int syncLen = SYNC_BYTES_SIZE;

            // start scan for next sync position ...
            for (int i = 0; file.getFilePointer() < maxFileSize; i++) {
                int j = 0;
                for (; j < syncLen; j++) {
                    if (_sync[j] != syncBytesBuffer[(i + j) % syncLen])
                        break;
                }
                if (j == syncLen) {
                    // found matching sync bytes - reset file pos to before sync bytes
                    file.seek(file.getFilePointer() - SYNC_BYTES_SIZE); // position
                    // before
                    // sync
                    return true;
                }
                syncBytesBuffer[i % syncLen] = file.readByte();
            }
        } catch (IOException e) {
            LOG.warn("IOException at:" + file.getFilePointer() + " Exception:"
                    + CCStringUtils.stringifyException(e));
            LOG.warn("Skipping to:" + file.getFilePointer() + 4096);
            file.seek(file.getFilePointer() + 4096);
        }
    }
    return false;
}

---

• «
• 1
• 2
• 3
• 4
• 5
• 6
• 7
• 8
• 9
• »