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.accumulo.server.test.TestIngest.java

public static byte[] genRandomValue(Random random, byte dest[], int seed, int row, int col) {
    random.setSeed((row ^ seed) ^ col);/*w w w  .  j av a2  s.c o  m*/
    random.nextBytes(dest);
    toPrintableChars(dest);

    return dest;
}

From source file:jBittorrentAPI.utils.Utils.java

/**
 * Generate the client id, which is a fixed string of length 8 concatenated with 12 random bytes
 * @return byte[]//from   ww w.j  a  v  a2  s . com
 */
public static byte[] generateID() {
    byte[] id = new byte[12];

    Random r = new Random(System.currentTimeMillis());
    r.nextBytes(id);
    return Utils.concat("-UT3200-".getBytes(), id);
}

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

public static void createFile(FileSystem fs, Path fileName, long fileLen, short replFactor, long seed)
        throws IOException {
    if (!fs.mkdirs(fileName.getParent())) {
        throw new IOException("Mkdirs failed to create " + fileName.getParent().toString());
    }//  w w  w .  j a  v  a2  s. co m
    FSDataOutputStream out = null;
    try {
        out = fs.create(fileName, replFactor);
        byte[] toWrite = new byte[1024];
        Random rb = new Random(seed);
        long bytesToWrite = fileLen;
        while (bytesToWrite > 0) {
            rb.nextBytes(toWrite);
            int bytesToWriteNext = (1024 < bytesToWrite) ? 1024 : (int) bytesToWrite;

            out.write(toWrite, 0, bytesToWriteNext);
            bytesToWrite -= bytesToWriteNext;
        }
        out.close();
        out = null;
    } finally {
        IOUtils.closeStream(out);
    }
}

From source file:io.undertow.server.security.DigestAuthenticationAuthTestCase.java

private static String createNonce() {
    // This if just for testing so we are not concerned with how securely the client side nonce is.
    Random rand = new Random();
    byte[] nonceBytes = new byte[32];
    rand.nextBytes(nonceBytes);

    return HexConverter.convertToHexString(nonceBytes);
}

From source file:org.apache.hadoop.yarn.server.resourcemanager.security.TestHopsworksRMAppSecurityActions.java

@BeforeClass
public static void beforeClass() throws Exception {
    Security.addProvider(new BouncyCastleProvider());
    classPath = KeyStoreTestUtil.getClasspathDir(TestHopsworksRMAppSecurityActions.class);
    byte[] jwtIssuerSecret = new byte[32];
    Random rand = new Random();
    rand.nextBytes(jwtIssuerSecret);
    jwtIssuer = new MockJWTIssuer(jwtIssuerSecret);
}

From source file:org.gradle.caching.internal.tasks.AbstractTaskOutputPackagingBenchmark.java

private static ImmutableList<DataSource> createInputFiles(int fileCount, int minFileSize, int maxFileSize,
        DataAccessor accessor) throws IOException {
    Random random = new Random(1234L);
    ImmutableList.Builder<DataSource> inputs = ImmutableList.builder();
    for (int idx = 0; idx < fileCount; idx++) {
        String name = "input-" + idx + ".bin";
        int fileSize = minFileSize + random.nextInt(maxFileSize - minFileSize);
        byte[] buffer = new byte[fileSize];
        random.nextBytes(buffer);
        DataSource input = accessor.createSource(name, buffer, Level.Trial);
        inputs.add(input);//from   w  ww  .  ja  v  a2s  . c om
    }
    return inputs.build();
}

From source file:MyServlet.UserController.java

public static String hashAndSalt(String password) throws NoSuchAlgorithmException {
    Random r = new SecureRandom();
    byte[] saltBytes = new byte[32];
    r.nextBytes(saltBytes);
    salt = Base64.encodeBase64String(saltBytes);
    return hashPassword(password + salt);
}

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

private static long createTestFile(FileSystem fileSys, Path name, int repl, int numBlocks, long blocksize)
        throws IOException {
    CRC32 crc = new CRC32();
    Random rand = new Random();
    FSDataOutputStream stm = fileSys.create(name, true, fileSys.getConf().getInt("io.file.buffer.size", 4096),
            (short) repl, blocksize);
    // fill random data into file
    final byte[] b = new byte[(int) blocksize];
    for (int i = 0; i < numBlocks; i++) {
        rand.nextBytes(b);
        stm.write(b);//from w w  w.  ja va  2 s. com
        crc.update(b);
    }
    stm.close();
    return crc.getValue();
}

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

private static void writeToFile(Random random, FSDataOutputStream out, int len, DataChecksum checksum)
        throws IOException {
    if (len == 0) {
        return;/*from  ww  w .ja v  a  2  s.c o  m*/
    }

    LOG.info("Write " + len + " bytes to file.");
    int bufferSize = 1024 * 1024;
    byte[] buffer = new byte[bufferSize];
    int toLen = len;
    while (toLen > 0) {
        random.nextBytes(buffer);
        int numWrite = Math.min(toLen, buffer.length);
        out.write(buffer, 0, numWrite);
        checksum.update(buffer, 0, numWrite);
        toLen -= numWrite;

        // randomly do sync or not.
        if (random.nextBoolean()) {
            out.sync();
        }
    }
}

From source file:org.apache.flink.runtime.blob.BlobCacheCorruptionTest.java

/**
 * Checks the GET operation fails when the downloaded file (from {@link BlobServer} or HA store)
 * is corrupt, i.e. its content's hash does not match the {@link BlobKey}'s hash.
 *
 * @param jobId//from w  ww  . ja  v a  2 s .com
 *       job ID or <tt>null</tt> if job-unrelated
 * @param blobType
 *       whether the BLOB should become permanent or transient
 * @param corruptOnHAStore
 *       whether the file should be corrupt in the HA store (<tt>true</tt>, required
 *       <tt>highAvailability</tt> to be set) or on the {@link BlobServer}'s local store
 *       (<tt>false</tt>)
 * @param config
 *       blob server configuration (including HA settings like {@link HighAvailabilityOptions#HA_STORAGE_PATH}
 *       and {@link HighAvailabilityOptions#HA_CLUSTER_ID}) used to set up <tt>blobStore</tt>
 * @param blobStore
 *       shared HA blob store to use
 * @param expectedException
 *       expected exception rule to use
 */
private static void testGetFailsFromCorruptFile(@Nullable JobID jobId, BlobKey.BlobType blobType,
        boolean corruptOnHAStore, Configuration config, BlobStore blobStore,
        ExpectedException expectedException) throws IOException {

    assertTrue("corrupt HA file requires a HA setup", !corruptOnHAStore || blobType == PERMANENT_BLOB);

    Random rnd = new Random();

    try (BlobServer server = new BlobServer(config, blobStore);
            BlobCacheService cache = new BlobCacheService(config,
                    corruptOnHAStore ? blobStore : new VoidBlobStore(),
                    new InetSocketAddress("localhost", server.getPort()))) {

        server.start();

        byte[] data = new byte[2000000];
        rnd.nextBytes(data);

        // put content addressable (like libraries)
        BlobKey key = put(server, jobId, data, blobType);
        assertNotNull(key);

        // change server/HA store file contents to make sure that GET requests fail
        byte[] data2 = Arrays.copyOf(data, data.length);
        data2[0] ^= 1;
        if (corruptOnHAStore) {
            File tmpFile = Files.createTempFile("blob", ".jar").toFile();
            try {
                FileUtils.writeByteArrayToFile(tmpFile, data2);
                blobStore.put(tmpFile, jobId, key);
            } finally {
                //noinspection ResultOfMethodCallIgnored
                tmpFile.delete();
            }

            // delete local (correct) file on server to make sure that the GET request does not
            // fall back to downloading the file from the BlobServer's local store
            File blobFile = server.getStorageLocation(jobId, key);
            assertTrue(blobFile.delete());
        } else {
            File blobFile = server.getStorageLocation(jobId, key);
            assertTrue(blobFile.exists());
            FileUtils.writeByteArrayToFile(blobFile, data2);
        }

        // issue a GET request that fails
        expectedException.expect(IOException.class);
        expectedException.expectCause(CoreMatchers.allOf(instanceOf(IOException.class),
                hasProperty("message", containsString("data corruption"))));

        get(cache, jobId, key);
    }
}