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.multibit.file.FileHandler.java

/**
 * Delete a file with an overwrite of all of the data.
 * /*  w  w  w  .j  a va 2 s. 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.tencent.wcdb.sample.repairdb.MainActivity.java

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    // Extract test database from assets.
    new AsyncTask<Void, Void, Void>() {
        @Override//from  w  ww . ja v  a 2  s  .co  m
        protected Void doInBackground(Void... params) {
            File dbFile = getDatabasePath(DBHelper.DATABASE_NAME);

            if (!dbFile.exists()) {
                dbFile.getParentFile().mkdirs();

                InputStream in = null;
                OutputStream out = null;
                try {
                    byte[] buffer = new byte[1024];
                    in = getAssets().open(DBHelper.DATABASE_NAME);
                    out = new FileOutputStream(dbFile);
                    int len;
                    while ((len = in.read(buffer)) != -1) {
                        out.write(buffer, 0, len);
                    }
                } catch (IOException e) {
                    throw new RuntimeException(e);
                } finally {
                    if (in != null)
                        try {
                            in.close();
                        } catch (IOException e) {
                        }
                    if (out != null)
                        try {
                            out.close();
                        } catch (IOException e) {
                        }
                }
            }
            return null;
        }
    }.execute();

    setContentView(R.layout.activity_main);

    mListView = (ListView) findViewById(R.id.list);
    mAdapter = new SimpleCursorAdapter(this, R.layout.main_listitem, null, new String[] { "a", "b" },
            new int[] { R.id.list_tv_a, R.id.list_tv_b }, 0);

    mListView.setAdapter(mAdapter);

    findViewById(R.id.btn_init_db).setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            new AsyncTask<Void, Void, SQLiteException>() {
                @Override
                protected void onPreExecute() {
                    mAdapter.changeCursor(null);
                }

                @Override
                protected SQLiteException doInBackground(Void... params) {
                    if (mDB != null && mDB.isOpen()) {
                        mDBHelper.close();
                        mDB = null;
                    }

                    try {
                        mDBHelper.setWriteAheadLoggingEnabled(true);
                        mDB = mDBHelper.getWritableDatabase();

                        // After successfully opened the database, backup its master info.
                        RepairKit.MasterInfo.save(mDB, mDB.getPath() + "-mbak", DBHelper.PASSPHRASE);
                    } catch (SQLiteException e) {
                        // Failed to open database, probably due to corruption.
                        mDB = null;
                        return e;
                    }

                    return null;
                }

                @Override
                protected void onPostExecute(SQLiteException e) {
                    if (e == null) {
                        // Database is successfully opened, query and refresh ListView.
                        Cursor cursor = mDB.rawQuery("SELECT rowid as _id, a, b FROM t1;", null);
                        mAdapter.changeCursor(cursor);

                        Toast.makeText(MainActivity.this, "Database is successfully opened.",
                                Toast.LENGTH_SHORT).show();
                    } else {
                        // Database could not be opened, show toast.
                        Toast.makeText(MainActivity.this,
                                "Database cannot be opened, exception: " + e.getMessage(), Toast.LENGTH_LONG)
                                .show();
                    }
                }
            }.execute();
        }
    });

    findViewById(R.id.btn_corrupt_db).setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            new AsyncTask<Void, Void, Exception>() {
                @Override
                protected void onPreExecute() {
                    mAdapter.changeCursor(null);
                }

                @Override
                protected Exception doInBackground(Void... params) {
                    if (mDB != null && mDB.isOpen()) {
                        mDBHelper.close();
                        mDB = null;
                    }

                    // Write random noise to the first page to corrupt the database.
                    RandomAccessFile raf = null;
                    try {
                        File dbFile = getDatabasePath(DBHelper.DATABASE_NAME);
                        raf = new RandomAccessFile(dbFile, "rw");
                        byte[] buffer = new byte[1024];
                        new Random().nextBytes(buffer);
                        raf.seek(0);
                        raf.write(buffer);
                    } catch (IOException e) {
                        return e;
                    } finally {
                        if (raf != null)
                            try {
                                raf.close();
                            } catch (IOException e) {
                            }
                    }

                    return null;
                }

                @Override
                protected void onPostExecute(Exception e) {
                    if (e == null) {
                        Toast.makeText(MainActivity.this, "Database is now CORRUPTED!", Toast.LENGTH_SHORT)
                                .show();
                    } else {
                        Toast.makeText(MainActivity.this, "Unable to overwrite database: " + e.getMessage(),
                                Toast.LENGTH_LONG).show();
                    }
                }
            }.execute();
        }
    });

    findViewById(R.id.btn_repair_db).setOnClickListener(new View.OnClickListener() {

        @Override
        public void onClick(View v) {
            new AsyncTask<Void, Void, SQLiteException>() {
                @Override
                protected void onPreExecute() {
                    mAdapter.changeCursor(null);
                }

                @Override
                protected SQLiteException doInBackground(Void... params) {
                    if (mDB != null && mDB.isOpen()) {
                        mDBHelper.close();
                        mDB = null;
                    }

                    RepairKit.MasterInfo master = null;
                    File dbFile = getDatabasePath(DBHelper.DATABASE_NAME);
                    File masterFile = new File(dbFile.getPath() + "-mbak");
                    File newDbFile = getDatabasePath(DBHelper.DATABASE_NAME + "-recover");

                    if (masterFile.exists()) {
                        try {
                            master = RepairKit.MasterInfo.load(masterFile.getPath(), DBHelper.PASSPHRASE, null);
                        } catch (SQLiteException e) {
                            // Could not load master info. Maybe backup file itself corrupted?
                        }
                    }

                    RepairKit repair = null;
                    try {
                        repair = new RepairKit(dbFile.getPath(), // corrupted database file
                                DBHelper.PASSPHRASE, // passphrase to the database
                                DBHelper.CIPHER_SPEC, // cipher spec to the database
                                master // backup master info just loaded
                        );

                        if (newDbFile.exists())
                            newDbFile.delete();

                        SQLiteDatabase newDb = SQLiteDatabase.openOrCreateDatabase(newDbFile,
                                DBHelper.PASSPHRASE, DBHelper.CIPHER_SPEC, null, DBHelper.ERROR_HANDLER);
                        boolean result = repair.output(newDb, 0);
                        if (!result) {
                            throw new SQLiteException("Repair returns false on output.");
                        }

                        newDb.setVersion(DBHelper.DATABASE_VERSION);
                        newDb.close();
                        repair.release();
                        repair = null;

                        if (!dbFile.delete() || !newDbFile.renameTo(dbFile))
                            throw new SQLiteException("Cannot rename database.");
                    } catch (SQLiteException e) {
                        return e;
                    } finally {
                        if (repair != null)
                            repair.release();
                    }

                    return null;
                }

                @Override
                protected void onPostExecute(SQLiteException e) {
                    if (e == null) {
                        Toast.makeText(MainActivity.this, "Repair succeeded.", Toast.LENGTH_SHORT).show();
                    } else {
                        Toast.makeText(MainActivity.this, "Repair failed: " + e.getMessage(), Toast.LENGTH_LONG)
                                .show();
                    }
                }
            }.execute();
        }
    });
}

From source file:com.asakusafw.runtime.util.lock.LocalFileLockProvider.java

@Override
public LocalFileLockObject<T> tryLock(T target) throws IOException {
    if (baseDirectory.mkdirs() == false && baseDirectory.isDirectory() == false) {
        throw new IOException(MessageFormat.format("Failed to create lock directory: {0}", baseDirectory));
    }/*from ww w  .ja  v a  2s  .  co  m*/
    String fileName = String.format("%08x.lck", target == null ? -1 : target.hashCode()); //$NON-NLS-1$
    File lockFile = new File(baseDirectory, fileName);
    RandomAccessFile fd = new RandomAccessFile(lockFile, "rw"); //$NON-NLS-1$
    boolean success = false;
    try {
        if (LOG.isDebugEnabled()) {
            LOG.debug(MessageFormat.format("Start to acquire lock for \"{0}\" ({1})", //$NON-NLS-1$
                    target, lockFile));
        }
        FileLock lockEntity = getLock(target, lockFile, fd);
        if (lockEntity == null) {
            return null;
        } else {
            if (LOG.isDebugEnabled()) {
                LOG.debug(MessageFormat.format("Finished to acquire lock for \"{0}\" ({1})", //$NON-NLS-1$
                        target, lockFile));
            }
            try {
                fd.seek(0L);
                fd.setLength(0L);
                fd.write(String.valueOf(target).getBytes(ENCODING));
                success = true;
                return new LocalFileLockObject<>(target, lockFile, fd, lockEntity);
            } finally {
                if (success == false) {
                    lockEntity.release();
                }
            }
        }
    } finally {
        if (success == false) {
            fd.close();
        }
    }
}

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

protected long checksum(RandomAccessFile raFile) throws IOException, InsufficientFileLengthException {
    long pos = raFile.getFilePointer();
    try {//  w  ww  .ja v a 2  s .  com
        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:org.apache.flume.channel.file.TestFileChannelRestart.java

@Test
public void testCorruptCheckpointVersionMostSignificant4Bytes() throws Exception {
    Map<String, String> overrides = Maps.newHashMap();
    channel = createFileChannel(overrides);
    channel.start();//from w  w w  .ja v a 2  s.co  m
    Assert.assertTrue(channel.isOpen());
    Set<String> in = putEvents(channel, "restart", 10, 100);
    Assert.assertEquals(100, in.size());
    forceCheckpoint(channel);
    channel.stop();
    File checkpoint = new File(checkpointDir, "checkpoint");
    RandomAccessFile writer = new RandomAccessFile(checkpoint, "rw");
    writer.seek(EventQueueBackingStoreFile.INDEX_VERSION * Serialization.SIZE_OF_LONG);
    writer.write(new byte[] { (byte) 1, (byte) 5 });
    writer.getFD().sync();
    writer.close();
    channel = createFileChannel(overrides);
    channel.start();
    Assert.assertTrue(channel.isOpen());
    Set<String> out = consumeChannel(channel);
    Assert.assertTrue(channel.didFullReplayDueToBadCheckpointException());
    compareInputAndOut(in, out);
}

From source file:org.apache.flume.channel.file.TestFileChannelRestart.java

@Test
public void testCorruptCheckpointCompleteMarkerMostSignificant4Bytes() throws Exception {
    Map<String, String> overrides = Maps.newHashMap();
    channel = createFileChannel(overrides);
    channel.start();/*  w  ww  . ja  va2s . c om*/
    Assert.assertTrue(channel.isOpen());
    Set<String> in = putEvents(channel, "restart", 10, 100);
    Assert.assertEquals(100, in.size());
    forceCheckpoint(channel);
    channel.stop();
    File checkpoint = new File(checkpointDir, "checkpoint");
    RandomAccessFile writer = new RandomAccessFile(checkpoint, "rw");
    writer.seek(EventQueueBackingStoreFile.INDEX_CHECKPOINT_MARKER * Serialization.SIZE_OF_LONG);
    writer.write(new byte[] { (byte) 1, (byte) 5 });
    writer.getFD().sync();
    writer.close();
    channel = createFileChannel(overrides);
    channel.start();
    Assert.assertTrue(channel.isOpen());
    Set<String> out = consumeChannel(channel);
    Assert.assertTrue(channel.didFullReplayDueToBadCheckpointException());
    compareInputAndOut(in, out);
}

From source file:com.android.strictmodetest.StrictModeActivity.java

private void fileReadLoop() {
    RandomAccessFile raf = null;
    File filename = getFileStreamPath("test.dat");
    try {//from www  .j a va2 s . c  o m
        long sumNanos = 0;
        byte[] buf = new byte[512];

        //raf = new RandomAccessFile(filename, "rw");
        //raf.write(buf);
        //raf.close();
        //raf = null;

        // The data's almost certainly cached -- it's not clear what we're testing here
        raf = new RandomAccessFile(filename, "r");
        raf.seek(0);
        raf.read(buf);
    } catch (IOException e) {
        Log.e(TAG, "File read failed", e);
    } finally {
        try {
            if (raf != null)
                raf.close();
        } catch (IOException e) {
        }
    }
}

From source file:org.apache.flume.channel.file.TestFileChannelRestart.java

private void doTestBadCheckpointVersion(boolean backup) throws Exception {
    Map<String, String> overrides = Maps.newHashMap();
    overrides.put(FileChannelConfiguration.USE_DUAL_CHECKPOINTS, String.valueOf(backup));
    channel = createFileChannel(overrides);
    channel.start();/*from  w ww.j  av a  2  s. c  o  m*/
    Assert.assertTrue(channel.isOpen());
    Set<String> in = putEvents(channel, "restart", 10, 100);
    Assert.assertEquals(100, in.size());
    forceCheckpoint(channel);
    if (backup) {
        Thread.sleep(2000);
    }
    channel.stop();
    File checkpoint = new File(checkpointDir, "checkpoint");
    RandomAccessFile writer = new RandomAccessFile(checkpoint, "rw");
    writer.seek(EventQueueBackingStoreFile.INDEX_VERSION * Serialization.SIZE_OF_LONG);
    writer.writeLong(2L);
    writer.getFD().sync();
    writer.close();
    channel = createFileChannel(overrides);
    channel.start();
    Assert.assertTrue(channel.isOpen());
    Assert.assertTrue(!backup || channel.checkpointBackupRestored());
    Set<String> out = consumeChannel(channel);
    compareInputAndOut(in, out);
}

From source file:org.apache.flume.channel.file.TestFileChannelRestart.java

private void doTestIncompleteCheckpoint(boolean backup) throws Exception {
    Map<String, String> overrides = Maps.newHashMap();
    overrides.put(FileChannelConfiguration.USE_DUAL_CHECKPOINTS, String.valueOf(backup));
    channel = createFileChannel(overrides);
    channel.start();/*from   w ww . jav a2  s. c o m*/
    Assert.assertTrue(channel.isOpen());
    Set<String> in = putEvents(channel, "restart", 10, 100);
    Assert.assertEquals(100, in.size());
    forceCheckpoint(channel);
    if (backup) {
        Thread.sleep(2000);
    }
    channel.stop();
    File checkpoint = new File(checkpointDir, "checkpoint");
    RandomAccessFile writer = new RandomAccessFile(checkpoint, "rw");
    writer.seek(EventQueueBackingStoreFile.INDEX_CHECKPOINT_MARKER * Serialization.SIZE_OF_LONG);
    writer.writeLong(EventQueueBackingStoreFile.CHECKPOINT_INCOMPLETE);
    writer.getFD().sync();
    writer.close();
    channel = createFileChannel(overrides);
    channel.start();
    Assert.assertTrue(channel.isOpen());
    Assert.assertTrue(!backup || channel.checkpointBackupRestored());
    Set<String> out = consumeChannel(channel);
    compareInputAndOut(in, out);
}

From source file:it.drwolf.ridire.session.async.JobDBDataUpdater.java

private String getJobStatus(String encodedJobName) throws HttpException, IOException, DocumentException {
    // back compatibility Heritrix 2
    if (encodedJobName.startsWith("completed-")) {
        return CrawlStatus.FINISHED.toString();
    }/*ww w.  j  a  v  a  2s  . c o  m*/
    File jobDir = new File(this.jobsDir + CrawlerManager.FILE_SEPARATOR + encodedJobName);
    String[] files = jobDir.list();
    if (files == null || files.length < 2) {
        return CrawlStatus.CREATED.toString();
    }
    String ret = CrawlStatus.CREATED.toString();
    RandomAccessFile progressStatistics = null;
    Calendar now = new GregorianCalendar();
    Date comparingDate = DateUtils.addDays(now.getTime(), -3);
    try {
        progressStatistics = new RandomAccessFile(
                this.jobsDir + CrawlerManager.FILE_SEPARATOR + encodedJobName + CrawlerManager.FILE_SEPARATOR
                        + "logs" + CrawlerManager.FILE_SEPARATOR + "progress-statistics.log",
                "r");
        if (progressStatistics != null) {
            progressStatistics.seek(Math.max(0, progressStatistics.length() - 3000));
            String line = progressStatistics.readLine();
            StringBuffer buffer = new StringBuffer();
            while (line != null) {
                buffer.append(line + "\n");
                line = progressStatistics.readLine();
            }
            String progressStatisticsContent = buffer.toString();
            Matcher m = this.progressStatisticsDatePattern.matcher(progressStatisticsContent);
            int start = 0;
            String lastDateString = "";
            while (m.find(start)) {
                start = m.end();
                lastDateString = m.group();
            }
            Date lastDate = this.progressStatisticsDateFormat.parse(lastDateString);
            if (!progressStatisticsContent.contains("CRAWL ENDED - Finished")
                    && lastDate.after(comparingDate)) {
                ret = CrawlStatus.RUNNING.toString();
            } else {
                ret = CrawlStatus.FINISHED.toString();
            }

        }
    } catch (FileNotFoundException e) {
        // TODO: handle exception
    } catch (ParseException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    } finally {
        if (progressStatistics != null) {
            progressStatistics.close();
        }
    }
    // File crawlReport = new File(this.jobsDir + FILE_SEPARATOR
    // + encodedJobName + FILE_SEPARATOR + "reports" + FILE_SEPARATOR
    // + "crawl-report.txt");
    // if (crawlReport != null && crawlReport.canRead()) {
    // String crawlReportContent = FileUtils.readFileToString(crawlReport);
    // if (crawlReportContent.contains("crawl status: Finished")) {
    // ret = CrawlStatus.FINISHED.toString();
    // }
    // }
    return ret;
}