Example usage for java.util Random nextBytes

Introduction

In this page you can find the example usage for java.util Random nextBytes.

Prototype

public void nextBytes(byte[] bytes) 

Source Link

Document

Generates random bytes and places them into a user-supplied byte array.

Usage

From source file:org.apache.hadoop.fs.TestCopyFiles.java

private static void updateFiles(FileSystem fs, String topdir, MyFile[] files, int nupdate) throws IOException {
    assert nupdate <= NFILES;

    Path root = new Path(topdir);

    for (int idx = 0; idx < nupdate; ++idx) {
        Path fPath = new Path(root, files[idx].getName());
        // overwrite file
        assertTrue(fPath.toString() + " does not exist", fs.exists(fPath));
        FSDataOutputStream out = fs.create(fPath);
        files[idx].reset();/* w  w w . ja v  a  2 s .co  m*/
        byte[] toWrite = new byte[files[idx].getSize()];
        Random rb = new Random(files[idx].getSeed());
        rb.nextBytes(toWrite);
        out.write(toWrite);
        out.close();
    }
}

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From source file:org.apache.hadoop.fs.TestCopyFiles.java

private static boolean checkFiles(FileSystem fs, String topdir, MyFile[] files, boolean existingOnly)
        throws IOException {
    Path root = new Path(topdir);

    for (int idx = 0; idx < files.length; idx++) {
        Path fPath = new Path(root, files[idx].getName());
        try {/*w ww  .  j  a v  a2s . c  o m*/
            fs.getFileStatus(fPath);
            FSDataInputStream in = fs.open(fPath);
            byte[] toRead = new byte[files[idx].getSize()];
            byte[] toCompare = new byte[files[idx].getSize()];
            Random rb = new Random(files[idx].getSeed());
            rb.nextBytes(toCompare);
            assertEquals("Cannnot read file.", toRead.length, in.read(toRead));
            in.close();
            for (int i = 0; i < toRead.length; i++) {
                if (toRead[i] != toCompare[i]) {
                    return false;
                }
            }
            toRead = null;
            toCompare = null;
        } catch (FileNotFoundException fnfe) {
            if (!existingOnly) {
                throw fnfe;
            }
        }
    }

    return true;
}

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From source file:org.syncany.tests.unit.util.TestFileUtil.java

public static void changeRandomPartOfBinaryFile(File file) throws IOException {
    if (file != null && !file.exists()) {
        throw new IOException("File does not exist: " + file);
    }/*from ww w . ja  v a  2  s . c  o m*/

    if (file.isDirectory()) {
        throw new IOException("Cannot change directory: " + file);
    }

    // Prepare: random bytes at random position
    Random randomEngine = new Random();

    int fileSize = (int) file.length();
    int maxChangeBytesLen = 20;
    int maxChangeBytesStartPos = (fileSize - maxChangeBytesLen - 1 >= 0) ? fileSize - maxChangeBytesLen - 1 : 0;

    int changeBytesStartPos = (maxChangeBytesStartPos > 0) ? randomEngine.nextInt(maxChangeBytesStartPos) : 0;
    int changeBytesLen = (fileSize - changeBytesStartPos < maxChangeBytesLen)
            ? fileSize - changeBytesStartPos - 1
            : maxChangeBytesLen;

    byte[] changeBytes = new byte[changeBytesLen];
    randomEngine.nextBytes(changeBytes);

    // Write to file
    RandomAccessFile randomAccessFile = new RandomAccessFile(file, "rw");

    randomAccessFile.seek(changeBytesStartPos);
    randomAccessFile.write(changeBytes);

    randomAccessFile.close();
}

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From source file:microsoft.exchange.webservices.data.core.ExchangeServiceBase.java

/**
 * Gets the session key.//w ww .j a va2s  .co m
 * @return session key
 */
public static byte[] getSessionKey() {
    // this has to be computed only once.
    synchronized (ExchangeServiceBase.class) {
        if (ExchangeServiceBase.binarySecret == null) {
            Random randomNumberGenerator = new Random();
            ExchangeServiceBase.binarySecret = new byte[256 / 8];
            randomNumberGenerator.nextBytes(binarySecret);
        }

        return ExchangeServiceBase.binarySecret;
    }
}

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From source file:org.zenoss.zep.dao.impl.IndexMetadataDaoImplIT.java

@Test
public void testIndexMetadataDao() throws ZepException {
    byte[] sha1 = new byte[20];
    Random r = new Random();
    r.nextBytes(sha1);

    IndexMetadata md = new IndexMetadata();
    md.setIndexName("myindex");
    md.setIndexVersion(5);/*  w w w.j  a  v  a  2s .com*/
    md.setIndexVersionHash(sha1);
    md.setZepInstance(zepInstance.getId());

    assertNull(indexMetadataDao.findIndexMetadata(md.getIndexName()));

    indexMetadataDao.updateIndexVersion(md.getIndexName(), md.getIndexVersion(), md.getIndexVersionHash());

    IndexMetadata mdFromDb = indexMetadataDao.findIndexMetadata(md.getIndexName());
    assertArrayEquals(md.getIndexVersionHash(), mdFromDb.getIndexVersionHash());
    assertEquals(md.getIndexName(), mdFromDb.getIndexName());
    assertEquals(md.getIndexVersion(), mdFromDb.getIndexVersion());
    assertEquals(md.getZepInstance(), mdFromDb.getZepInstance());
}

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From source file:com.microsoft.azure.keyvault.test.CertificateOperationsTest.java

/**
 * Verify a RSA key pair with a simple encrypt/decrypt test.
 * /*  w  w w . j a v  a  2 s .co  m*/
 * @throws NoSuchPaddingException
 * @throws NoSuchAlgorithmException
 * @throws InvalidKeyException
 * @throws BadPaddingException
 * @throws IllegalBlockSizeException
 */
private static void verifyRSAKeyPair(KeyPair keyPair) throws NoSuchAlgorithmException, NoSuchPaddingException,
        InvalidKeyException, IllegalBlockSizeException, BadPaddingException {
    // Validate algorithm is RSA
    Assert.assertTrue(keyPair.getPublic().getAlgorithm().equals(ALGO_RSA));
    Assert.assertTrue(keyPair.getPrivate().getAlgorithm().equals(ALGO_RSA));

    // Generate an array of 10 random bytes
    byte[] plainData = new byte[10];
    Random random = new Random();
    random.nextBytes(plainData);

    // Encrypt using the public key
    Cipher encryptCipher = Cipher.getInstance(ALGO_RSA);
    encryptCipher.init(Cipher.ENCRYPT_MODE, keyPair.getPublic());
    byte[] encryptedData = encryptCipher.doFinal(plainData);

    // Decrypt using the private key
    Cipher decryptCipher = Cipher.getInstance(ALGO_RSA);
    decryptCipher.init(Cipher.DECRYPT_MODE, keyPair.getPrivate());
    byte[] decryptedData = decryptCipher.doFinal(encryptedData);

    // Validate plainData is equal to decryptedData
    Assert.assertArrayEquals(plainData, decryptedData);
}

---

From source file:microsoft.exchange.webservices.data.ExchangeServiceBase.java

/**
 * Gets the session key.//  w w  w . jav a  2s .c o m
 */
protected static byte[] getSessionKey() {
    // this has to be computed only once.
    synchronized (ExchangeServiceBase.class) {
        if (ExchangeServiceBase.binarySecret == null) {
            Random randomNumberGenerator = new Random();
            ExchangeServiceBase.binarySecret = new byte[256 / 8];
            randomNumberGenerator.nextBytes(binarySecret);
        }

        return ExchangeServiceBase.binarySecret;
    }
}

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From source file:filters.SaltingPasswordFilter.java

@Override
public String executePreProcessing(String request) {
    final Random r = new SecureRandom();
    byte[] salt = new byte[32];
    r.nextBytes(salt);
    byte[] encodedSalt = Base64.encodeBase64(salt);
    String saltString = new String(encodedSalt);
    request = request.concat(saltString);
    return request;
}

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From source file:org.apache.apex.malhar.lib.utils.IOUtilsTest.java

private void createDataFile(File file, int dataSize) throws IOException {
    byte[] val = new byte[dataSize];
    Random random = new Random();
    random.nextBytes(val);

    FileUtils.write(file, new String(val));
}

---

From source file:org.apache.hadoop.tools.TestIntegrationByChunk.java

private static void touchFile(String path, long totalFileSize, boolean preserveBlockSize,
        Options.ChecksumOpt checksumOpt, long seed) throws IOException {
    FileSystem fs;//from   w  w w .j av a 2  s.  c o  m
    DataOutputStream outputStream = null;
    try {
        fs = cluster.getFileSystem();
        final Path qualifiedPath = new Path(path).makeQualified(fs.getUri(), fs.getWorkingDirectory());
        final long blockSize = preserveBlockSize ? NON_DEFAULT_BLOCK_SIZE
                : fs.getDefaultBlockSize(qualifiedPath) * 2;
        FsPermission permission = FsPermission.getFileDefault().applyUMask(FsPermission.getUMask(fs.getConf()));
        outputStream = fs.create(qualifiedPath, permission, EnumSet.of(CreateFlag.CREATE, CreateFlag.OVERWRITE),
                0, (short) (fs.getDefaultReplication(qualifiedPath) * 2), blockSize, null, checksumOpt);
        try {

            if (totalFileSize > 0) {
                int bufferLen = DEFAULT_BUFFER_SIZE;
                byte[] toWrite = new byte[bufferLen];
                Random rb = new Random(seed);
                long bytesToWrite = totalFileSize;
                while (bytesToWrite > 0) {
                    rb.nextBytes(toWrite);
                    int bytesToWriteNext = (bufferLen < bytesToWrite) ? bufferLen : (int) bytesToWrite;

                    outputStream.write(toWrite, 0, bytesToWriteNext);
                    bytesToWrite -= bytesToWriteNext;
                }
            }
        } finally {
            if (outputStream != null) {
                outputStream.close();
            }
        }

        FileStatus fileStatus = fs.getFileStatus(qualifiedPath);
        System.out.println(fileStatus.getBlockSize());
        System.out.println(fileStatus.getReplication());
    } finally {
        IOUtils.cleanup(null, outputStream);
    }
}

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