Example usage for java.io RandomAccessFile readFully

Introduction

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

Prototype

public final void readFully(byte b[]) throws IOException 

Source Link

Document

Reads b.length bytes from this file into the byte array, starting at the current file pointer.

Usage

From source file:com.sky.drovik.player.media.DiskCache.java

public byte[] get(long key, long timestamp) {
    // Look up the record for the given key.
    Record record = null;/* w w w  .  j  av  a 2  s  . c  om*/
    synchronized (mIndexMap) {
        record = mIndexMap.get(key);
    }
    if (record != null) {
        // Read the chunk from the file.
        if (record.timestamp < timestamp) {
            Log.i(TAG, "File has been updated to " + timestamp + " since the last time " + record.timestamp
                    + " stored in cache.");
            return null;
        }
        try {
            RandomAccessFile chunkFile = getChunkFile(record.chunk);
            if (chunkFile != null) {
                byte[] data = new byte[record.size];
                chunkFile.seek(record.offset);
                chunkFile.readFully(data);
                return data;
            }
        } catch (Exception e) {
            Log.e(TAG, "Unable to read from chunk file");
        }
    }
    return null;
}

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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/*from   ww w .ja v a 2  s . c  om*/
 * 
 * @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;
    }

}

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From source file:hudson.util.TextFile.java

/**
 * Efficiently reads the last N characters (or shorter, if the whole file is shorter than that.)
 *
 * <p>/*from w w w  .j  a  v a  2 s  .  c om*/
 * This method first tries to just read the tail section of the file to get the necessary chars.
 * To handle multi-byte variable length encoding (such as UTF-8), we read a larger than
 * necessary chunk.
 *
 * <p>
 * Some multi-byte encoding, such as Shift-JIS (http://en.wikipedia.org/wiki/Shift_JIS) doesn't
 * allow the first byte and the second byte of a single char to be unambiguously identified,
 * so it is possible that we end up decoding incorrectly if we start reading in the middle of a multi-byte
 * character. All the CJK multi-byte encodings that I know of are self-correcting; as they are ASCII-compatible,
 * any ASCII characters or control characters will bring the decoding back in sync, so the worst
 * case we just have some garbage in the beginning that needs to be discarded. To accommodate this,
 * we read additional 1024 bytes.
 *
 * <p>
 * Other encodings, such as UTF-8, are better in that the character boundary is unambiguous,
 * so there can be at most one garbage char. For dealing with UTF-16 and UTF-32, we read at
 * 4 bytes boundary (all the constants and multipliers are multiples of 4.)
 *
 * <p>
 * Note that it is possible to construct a contrived input that fools this algorithm, and in this method
 * we are willing to live with a small possibility of that to avoid reading the whole text. In practice,
 * such an input is very unlikely.
 *
 * <p>
 * So all in all, this algorithm should work decently, and it works quite efficiently on a large text.
 */
public @Nonnull String fastTail(int numChars, Charset cs) throws IOException {
    RandomAccessFile raf = new RandomAccessFile(file, "r");

    try {
        long len = raf.length();
        // err on the safe side and assume each char occupies 4 bytes
        // additional 1024 byte margin is to bring us back in sync in case we started reading from non-char boundary.
        long pos = Math.max(0, len - (numChars * 4 + 1024));
        raf.seek(pos);

        byte[] tail = new byte[(int) (len - pos)];
        raf.readFully(tail);

        String tails = cs.decode(java.nio.ByteBuffer.wrap(tail)).toString();

        return new String(tails.substring(Math.max(0, tails.length() - numChars))); // trim the baggage of substring by allocating a new String
    } finally {
        raf.close();
    }
}

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From source file:name.martingeisse.stackd.server.section.storage.FolderBasedSectionStorage.java

/**
 * /*  w ww .  ja  va 2s.  co  m*/
 */
private boolean loadSectionFromFile(final OutputStream out, final RandomAccessFile access, final int tocIndex)
        throws IOException {

    // read the ToC entry
    access.seek(tocIndex * 12);
    final int dataStartAddress = access.readInt();
    final int dataSize = access.readInt();
    /* int dataFlags = */access.readInt();

    // handle missing sections
    if (dataStartAddress < 1) {
        return false;
    }

    // read the data
    final byte[] compressedCubeData = new byte[dataSize];
    access.seek(dataStartAddress);
    access.readFully(compressedCubeData);

    // write data to the stream
    out.write(compressedCubeData);

    return true;

}

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From source file:com.sun.faban.harness.webclient.ResultAction.java

private String editResultInfo(String runID) throws FileNotFoundException, IOException {
    RunId runId = new RunId(runID);
    String ts = null;/*from   w w w .j a v a2 s . co  m*/
    String[] status = new String[2];
    File file = new File(Config.OUT_DIR + runID + '/' + Config.RESULT_INFO);
    RandomAccessFile rf = new RandomAccessFile(file, "rwd");
    long size = rf.length();
    byte[] buffer = new byte[(int) size];
    rf.readFully(buffer);
    String content = new String(buffer, 0, (int) size);
    int idx = content.indexOf('\t');
    if (idx != -1) {
        status[0] = content.substring(0, idx).trim();
        status[1] = content.substring(++idx).trim();
    } else {
        status[0] = content.trim();
        int lastIdxln = status[0].lastIndexOf("\n");
        if (lastIdxln != -1)
            status[0] = status[0].substring(0, lastIdxln - 1);
    }
    if (status[1] != null) {
        ts = status[1];
    } else {
        String paramFileName = runId.getResultDir().getAbsolutePath() + File.separator + "run.xml";
        File paramFile = new File(paramFileName);
        long dt = paramFile.lastModified();
        ts = dateFormat.format(new Date(dt));
        rf.seek(rf.length());
        rf.writeBytes('\t' + ts.trim());
    }
    rf.close();
    return ts;
}

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From source file:org.commoncrawl.service.listcrawler.HDFSFileIndex.java

private HDFSFileIndex.IndexDataBlock demandLoadIndexDataBlock(long fingerprint, int itemDataOffset,
        int itemDataSize) throws IOException {
    // ok time to load this block ...
    RandomAccessFile file = new RandomAccessFile(_localIndexFilePath, "r");

    try {/*from  w w w .j  a va  2 s .c o  m*/

        ByteBuffer bufferOut = ByteBuffer.allocate(itemDataSize);

        if (bufferOut != null) {
            file.seek(_indexDataOffset + itemDataOffset);
            file.readFully(bufferOut.array());
            HDFSFileIndex.IndexDataBlock dataBlock = new IndexDataBlock(fingerprint, 0, bufferOut);
            return dataBlock;
        } else {
            throw new IOException("Unable to allocate byte buffer!!!");
        }
    } finally {
        if (file != null) {
            file.close();
        }
    }
}

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From source file:org.kchine.r.server.RListener.java

public static void pager(String fileName, String header, String title, String deleteFile) {
    HashMap<String, Object> attributes = new HashMap<String, Object>();

    byte[] buffer = null;
    try {//  w w w. j  a  va 2 s  .c  o m
        RandomAccessFile raf = new RandomAccessFile(fileName, "r");
        buffer = new byte[(int) raf.length()];
        raf.readFully(buffer);
        raf.close();
    } catch (Exception e) {
        e.printStackTrace();
    }

    attributes.put("fileName", new File(fileName).getName());
    attributes.put("content", buffer);
    attributes.put("header", header);
    attributes.put("title", title);
    attributes.put("deleteFile", new Boolean(deleteFile));

    DirectJNI.getInstance().notifyRActionListeners(new RConsoleAction("PAGER", attributes));

}

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From source file:edu.tsinghua.lumaqq.qq.Util.java

/**
 * MD5???10002432//from w ww . j  a v  a  2s.c  o  m
 * @param file RandomAccessFile
 * @return MD5
 */
public static byte[] getFileMD5(RandomAccessFile file) {
    try {
        file.seek(0);
        byte[] buf = (file.length() > QQ.QQ_MAX_FILE_MD5_LENGTH) ? new byte[QQ.QQ_MAX_FILE_MD5_LENGTH]
                : new byte[(int) file.length()];
        file.readFully(buf);
        return DigestUtils.md5(buf);
    } catch (IOException e) {
        return null;
    }
}

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From source file:edu.sfsu.csc780.chathub.ui.ChannelActivity.java

private Uri saveAudio(String mFileName) {
    File returnAudioFile = null;//from  www.j  a v  a  2 s  .  c  o m

    try {
        returnAudioFile = createAudioFile();
    } catch (IOException e) {
        e.printStackTrace();
    }
    if (returnAudioFile == null) {
        Log.d(TAG, "Error creating media file");
        return null;
    }

    try {
        RandomAccessFile f = new RandomAccessFile(mFileName, "r");
        byte[] b = new byte[(int) f.length()];
        f.readFully(b);
        FileOutputStream fos = new FileOutputStream(returnAudioFile);
        fos.write(b);
        fos.close();
    } catch (FileNotFoundException e) {
        Log.d(TAG, "File not found: " + e.getMessage());
    } catch (IOException e) {
        Log.d(TAG, "Error accessing file: " + e.getMessage());
    }
    return Uri.fromFile(returnAudioFile);
}

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From source file:org.exist.util.VirtualTempFile.java

/**
  * The method <code>getChunk</code>
  *// w  ww. ja  v a2  s  .c  o  m
  * @param offset a <code>long</code> value
  * @return a <code>byte[]</code> value
  * @exception IOException if an error occurs
  */
public byte[] getChunk(long offset) throws IOException {
    byte[] data = null;

    if (os != null) {
        close();
    }

    if (tempFile != null) {
        final RandomAccessFile raf = new RandomAccessFile(tempFile, "r");
        raf.seek(offset);
        long remaining = raf.length() - offset;
        if (remaining > maxChunkSize) {
            remaining = maxChunkSize;
        } else if (remaining < 0) {
            remaining = 0;
        }
        data = new byte[(int) remaining];
        raf.readFully(data);
        raf.close();
    } else if (tempBuffer != null) {
        long remaining = tempBuffer.length - offset;
        if (remaining > maxChunkSize) {
            remaining = maxChunkSize;
        } else if (remaining < 0) {
            remaining = 0;
        }
        data = new byte[(int) remaining];
        if (remaining > 0) {
            System.arraycopy(tempBuffer, (int) offset, data, 0, (int) remaining);
        }
    }

    return data;
}

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