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.hdfs.server.datanode.TestFiDataTransferProtocol2.java

/**
 * 1. create files with dfs/*from w w  w  .j ava2s  .c om*/
 * 2. write MIN_N_PACKET to MAX_N_PACKET packets
 * 3. close file
 * 4. open the same file
 * 5. read the bytes and compare results
 */
private static void writeSeveralPackets(String methodName) throws IOException {
    final Random r = FiTestUtil.RANDOM.get();
    final int nPackets = FiTestUtil.nextRandomInt(MIN_N_PACKET, MAX_N_PACKET + 1);
    final int lastPacketSize = FiTestUtil.nextRandomInt(1, PACKET_SIZE + 1);
    final int size = (nPackets - 1) * PACKET_SIZE + lastPacketSize;

    FiTestUtil.LOG.info("size=" + size + ", nPackets=" + nPackets + ", lastPacketSize=" + lastPacketSize);

    final MiniDFSCluster cluster = new MiniDFSCluster.Builder(conf).numDataNodes(REPLICATION + 2).build();
    final FileSystem dfs = cluster.getFileSystem();
    try {
        final Path p = new Path("/" + methodName + "/foo");
        final FSDataOutputStream out = createFile(dfs, p);

        final long seed = r.nextLong();
        final Random ran = new Random(seed);
        ran.nextBytes(bytes);
        out.write(bytes, 0, size);
        out.close();

        final FSDataInputStream in = dfs.open(p);
        int totalRead = 0;
        int nRead = 0;
        while ((nRead = in.read(toRead, totalRead, size - totalRead)) > 0) {
            totalRead += nRead;
        }
        Assert.assertEquals("Cannot read file.", size, totalRead);
        for (int i = 0; i < size; i++) {
            Assert.assertTrue("File content differ.", bytes[i] == toRead[i]);
        }
    } finally {
        dfs.close();
        cluster.shutdown();
    }
}

From source file:org.apache.kylin.job.tools.GridTableHBaseBenchmark.java

private static byte[] randomBytes() {
    byte[] bytes = new byte[CELL_SIZE];
    Random rand = new Random();
    rand.nextBytes(bytes);
    return bytes;
}

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

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());
    }/*from   w  ww . j a  v  a2s .  c  om*/
    FSDataOutputStream 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();
}

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

/**
 * Checks the GET operation fails when the downloaded file (from HA store)
 * is corrupt, i.e. its content's hash does not match the {@link BlobKey}'s hash.
 *
 * @param config/*  w  w w . j  av  a 2  s.  c om*/
 *       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
 */
public static void testGetFailsFromCorruptFile(Configuration config, BlobStore blobStore,
        ExpectedException expectedException) throws IOException {

    Random rnd = new Random();
    JobID jobId = new JobID();

    try (BlobServer server = new BlobServer(config, blobStore)) {

        server.start();

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

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

        // delete local file to make sure that the GET requests downloads from HA
        File blobFile = server.getStorageLocation(jobId, key);
        assertTrue(blobFile.delete());

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

        // issue a GET request that fails
        expectedException.expect(IOException.class);
        expectedException.expectMessage("data corruption");

        get(server, jobId, key);
    }
}

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

protected 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();//from w ww.  j a v a 2  s .  c o  m
        byte[] toWrite = new byte[files[idx].getSize()];
        Random rb = new Random(files[idx].getSeed());
        rb.nextBytes(toWrite);
        out.write(toWrite);
        out.close();
    }
}

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

protected 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 {//from  w  w w  . j  a va2 s.  co m
            byte[] toCompare = new byte[files[idx].getSize()];
            Random rb = new Random(files[idx].getSeed());
            rb.nextBytes(toCompare);
            if (!checkContentOfFile(fs, fPath, toCompare)) {
                return false;
            }
        } catch (FileNotFoundException fnfe) {
            if (!existingOnly) {
                throw fnfe;
            }
        } catch (EOFException eofe) {
            throw (EOFException) new EOFException("Cannot read file" + fPath);
        }
    }

    return true;
}

From source file:org.apache.hadoop.tools.mapred.filechunk.TestCopyChunkMapper.java

/**
 * Append specified length of bytes to a given file
 *//*from   www.ja  v a2  s.c o  m*/
private static void appendFile(Path p, int length) throws IOException {
    byte[] toAppend = new byte[length];
    Random random = new Random();
    random.nextBytes(toAppend);
    FSDataOutputStream out = cluster.getFileSystem().append(p);
    try {
        out.write(toAppend);
    } finally {
        IOUtils.closeStream(out);
    }
}

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

public static byte[] createArray(int size, Random randomGen) {
    byte[] ret = new byte[size];
    randomGen.nextBytes(ret);
    return ret;/*  w w w. j a  v  a2  s .  c  o  m*/
}

From source file:org.zkoss.poi.ss.util.SheetUtil.java

public static String base64Random16Bytes() {
    Random rand = new Random(new Date().getTime());
    byte[] bytes = new byte[16];
    rand.nextBytes(bytes);
    final Base64 base64 = new Base64();
    return base64.encodeAsString(bytes);
}

From source file:org.sonar.server.user.UserUpdater.java

private static void setEncryptedPassWord(String password, UserDto userDto) {
    Random random = new SecureRandom();
    byte[] salt = new byte[32];
    random.nextBytes(salt);
    String saltHex = DigestUtils.sha1Hex(salt);
    userDto.setSalt(saltHex);/*from   www  .  ja  v  a2  s . c  o  m*/
    userDto.setCryptedPassword(encryptPassword(password, saltHex));
}