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.hbase.regionserver.throttle.TestFlushWithThroughputController.java

/**
 * Test the tuning task of {@link PressureAwareFlushThroughputController}
 *///  ww w  .ja va  2  s  .  co m
@Test
public void testFlushThroughputTuning() throws Exception {
    Configuration conf = TEST_UTIL.getConfiguration();
    conf.set(StoreEngine.STORE_ENGINE_CLASS_KEY, DefaultStoreEngine.class.getName());
    conf.setLong(PressureAwareFlushThroughputController.HBASE_HSTORE_FLUSH_MAX_THROUGHPUT_UPPER_BOUND,
            20L * 1024 * 1024);
    conf.setLong(PressureAwareFlushThroughputController.HBASE_HSTORE_FLUSH_MAX_THROUGHPUT_LOWER_BOUND,
            10L * 1024 * 1024);
    conf.set(FlushThroughputControllerFactory.HBASE_FLUSH_THROUGHPUT_CONTROLLER_KEY,
            PressureAwareFlushThroughputController.class.getName());
    conf.setInt(PressureAwareFlushThroughputController.HBASE_HSTORE_FLUSH_THROUGHPUT_TUNE_PERIOD, 3000);
    TEST_UTIL.startMiniCluster(1);
    Connection conn = ConnectionFactory.createConnection(conf);
    try {
        HTableDescriptor htd = new HTableDescriptor(tableName);
        htd.addFamily(new HColumnDescriptor(family));
        htd.setCompactionEnabled(false);
        TEST_UTIL.getHBaseAdmin().createTable(htd);
        TEST_UTIL.waitTableAvailable(tableName);
        HRegionServer regionServer = TEST_UTIL.getRSForFirstRegionInTable(tableName);
        PressureAwareFlushThroughputController throughputController = (PressureAwareFlushThroughputController) regionServer
                .getFlushThroughputController();
        for (Region region : regionServer.getOnlineRegions()) {
            region.flush(true);
        }
        assertEquals(0.0, regionServer.getFlushPressure(), EPSILON);
        Thread.sleep(5000);
        assertEquals(10L * 1024 * 1024, throughputController.getMaxThroughput(), EPSILON);
        Table table = conn.getTable(tableName);
        Random rand = new Random();
        for (int i = 0; i < 10; i++) {
            for (int j = 0; j < 10; j++) {
                byte[] value = new byte[256 * 1024];
                rand.nextBytes(value);
                table.put(new Put(Bytes.toBytes(i * 10 + j)).addColumn(family, qualifier, value));
            }
        }
        Thread.sleep(5000);
        double expectedThroughPut = 10L * 1024 * 1024 * (1 + regionServer.getFlushPressure());
        assertEquals(expectedThroughPut, throughputController.getMaxThroughput(), EPSILON);

        conf.set(FlushThroughputControllerFactory.HBASE_FLUSH_THROUGHPUT_CONTROLLER_KEY,
                NoLimitThroughputController.class.getName());
        regionServer.onConfigurationChange(conf);
        assertTrue(throughputController.isStopped());
        assertTrue(regionServer.getFlushThroughputController() instanceof NoLimitThroughputController);
    } finally {
        conn.close();
        TEST_UTIL.shutdownMiniCluster();
    }
}

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From source file:org.apache.hadoop.hdfs.server.namenode.TestDecommissioningStatus.java

private FSDataOutputStream writeIncompleteFile(FileSystem fileSys, Path name, short repl) throws IOException {
    // create and write a file that contains three blocks of data
    FSDataOutputStream stm = fileSys.create(name, true,
            fileSys.getConf().getInt(CommonConfigurationKeys.IO_FILE_BUFFER_SIZE_KEY, 4096), repl, blockSize);
    byte[] buffer = new byte[fileSize];
    Random rand = new Random(seed);
    rand.nextBytes(buffer);
    stm.write(buffer);//www .  j av a2s  . c o m
    // need to make sure that we actually write out both file blocks
    // (see FSOutputSummer#flush)
    stm.flush();
    // Do not close stream, return it
    // so that it is not garbage collected
    return stm;
}

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From source file:org.bibsonomy.webapp.controller.actions.PasswordReminderController.java

/**
 * Creates the random string//  w ww  .j  av  a  2s .  c om
 * 
 * @return String
 */
private String getRandomString() {
    final Random rand = new Random();
    final byte[] bytes = new byte[8];
    rand.nextBytes(bytes);
    return HashUtils.toHexString(bytes);
}

---

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

@Test
public void testCopyFile() throws Exception {
    // Create binary file of a couple of MB
    java.nio.file.Path binary = Paths.get(classpathDir, "binary_file.bin");
    filesToPurge.add(binary);//from   w  w w  .  ja v a2  s  . co  m
    Random rand = new Random();
    byte[] buffer = new byte[1024];
    int count = 0;
    try (BufferedOutputStream bos = new BufferedOutputStream(new FileOutputStream(binary.toFile()))) {
        while (count < 5000) {
            rand.nextBytes(buffer);
            bos.write(buffer);
            count++;
        }
        bos.flush();
    }
    // Copy it to DFS
    dfs1 = cluster.getFileSystem();
    Path target = new Path("binary_file");
    dfs1.copyFromLocalFile(new Path(binary.toString()), target);
    assertTrue(dfs1.exists(target));
    // Copy back the file
    java.nio.file.Path localCopy = Paths.get(classpathDir, "copied_remote_file");
    dfs1.copyToLocalFile(target, new Path(localCopy.toString()));
    filesToPurge.add(localCopy);
    assertTrue(localCopy.toFile().exists());
}

---

From source file:org.apache.metron.stellar.dsl.functions.HashFunctionsTest.java

@Test
public void tlsh_multithread() throws Exception {
    //we want to ensure that everything is threadsafe, so we'll spin up some random data
    //generate some hashes and then do it all in parallel and make sure it all matches.
    Map<Map.Entry<byte[], Map<String, Object>>, String> hashes = new HashMap<>();
    Random r = new Random(0);
    for (int i = 0; i < 20; ++i) {
        byte[] d = new byte[256];
        r.nextBytes(d);
        Map<String, Object> config = new HashMap<String, Object>() {
            {/*from  www .ja v  a  2  s.c om*/
                put(TLSHHasher.Config.BUCKET_SIZE.key, r.nextBoolean() ? 128 : 256);
                put(TLSHHasher.Config.CHECKSUM.key, r.nextBoolean() ? 1 : 3);
            }
        };
        String hash = (String) run("HASH(data, 'tlsh', config)", ImmutableMap.of("config", config, "data", d));
        Assert.assertNotNull(hash);
        hashes.put(new AbstractMap.SimpleEntry<>(d, config), hash);
    }
    ForkJoinPool forkJoinPool = new ForkJoinPool(5);

    forkJoinPool.submit(() -> hashes.entrySet().parallelStream().forEach(kv -> {
        Map<String, Object> config = kv.getKey().getValue();
        byte[] data = kv.getKey().getKey();
        String hash = (String) run("HASH(data, 'tlsh', config)",
                ImmutableMap.of("config", config, "data", data));
        Assert.assertEquals(hash, kv.getValue());
    }));
}

---

From source file:org.commonjava.vertx.vabr.util.VertXInputStreamTest.java

@Test
//    @Ignore/*w w  w  . j av  a2s.  c om*/
public void readViaHttpHandler() throws InterruptedException {
    final ByteArrayOutputStream result = new ByteArrayOutputStream();

    final Vertx v = new DefaultVertx();
    final HttpServer server = v.createHttpServer().requestHandler(new Handler<HttpServerRequest>() {
        @Override
        public void handle(final HttpServerRequest request) {
            request.pause();

            new Thread(new Runnable() {
                @Override
                public void run() {
                    logger.info("GOT IT");
                    final VertXInputStream stream = new VertXInputStream(request);
                    try {
                        IOUtils.copy(stream, result);

                        logger.info("READ DONE");
                        synchronized (result) {
                            result.notifyAll();
                        }
                    } catch (final IOException e) {
                        throw new RuntimeException("Failed to read stream: " + e.getMessage(), e);
                    }
                }
            }, "server-request").start();
        }
    }).listen(port, "localhost");

    final HttpClient client = v.createHttpClient().setHost("localhost").setPort(port);
    final HttpClientRequest put = client.put("/put", new Handler<HttpClientResponse>() {
        @Override
        public void handle(final HttpClientResponse response) {
            logger.info("Response: {} {}", response.statusCode(), response.statusMessage());
        }
    });

    final ByteArrayOutputStream check = new ByteArrayOutputStream();
    final Random rand = new Random();

    // 4Mb file...
    final byte[] txfr = new byte[4];
    for (int i = 0; i < 1048576; i++) {
        rand.nextBytes(txfr);
        check.write(txfr, 0, txfr.length);
    }

    put.setChunked(true).write(new Buffer(check.toByteArray())).end();

    logger.info("SENT: {}", check.toByteArray().length);

    synchronized (result) {
        result.wait();
    }

    final byte[] checkedArry = check.toByteArray();
    final byte[] resultArry = result.toByteArray();
    assertThat(checkedArry.length, equalTo(resultArry.length));

    boolean match = true;
    for (int i = 0; i < checkedArry.length; i++) {
        if (resultArry[i] != checkedArry[i]) {
            logger.error("Index {} mismatch! Was: {}, expected: {}", i, resultArry[i], checkedArry[i]);
            match = false;
        }
    }

    assertThat("Byte arrays do not match.", match, equalTo(true));

    server.close();
    client.close();
}

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From source file:org.ejbca.ui.cmpclient.CmpClientMessageHelper.java

/** Creates a 16 bytes random sender nonce
 * //from   www .  jav a2  s  . com
 * @return byte array of length 16
 */
public byte[] createSenderNonce() {
    // Sendernonce is a random number
    byte[] senderNonce = new byte[16];
    Random randomSource;
    randomSource = new Random();
    randomSource.nextBytes(senderNonce);
    return senderNonce;
}

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From source file:org.apache.hadoop.hbase.regionserver.compactions.TestCompactionWithThroughputController.java

private Store prepareData() throws IOException {
    HBaseAdmin admin = TEST_UTIL.getHBaseAdmin();
    if (admin.tableExists(tableName)) {
        admin.disableTable(tableName);/*from w  w  w  .  ja va 2 s. co m*/
        admin.deleteTable(tableName);
    }
    Table table = TEST_UTIL.createTable(tableName, family);
    Random rand = new Random();
    for (int i = 0; i < 10; i++) {
        for (int j = 0; j < 10; j++) {
            byte[] value = new byte[128 * 1024];
            rand.nextBytes(value);
            table.put(new Put(Bytes.toBytes(i * 10 + j)).add(family, qualifier, value));
        }
        admin.flush(tableName);
    }
    return getStoreWithName(tableName);
}

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From source file:com.intel.chimera.stream.AbstractCryptoStreamTest.java

@Before
public void before() throws IOException {
    Random random = new SecureRandom();
    random.nextBytes(data);
    random.nextBytes(key);//  ww w.ja  va 2s.com
    random.nextBytes(iv);
    setUp();
    prepareData();
}

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From source file:com.alliander.osgp.webdevicesimulator.service.RegisterDevice.java

private byte[] createRandomDeviceUid() {
    // Generate random bytes for UID
    final byte[] deviceUid = new byte[OslpEnvelope.DEVICE_ID_LENGTH];
    final Random byteGenerator = new Random();
    byteGenerator.nextBytes(deviceUid);
    // Combine manufacturer id of 2 bytes (1 is AME) and device UID of 10
    // bytes.//from  ww  w.  ja v a  2  s .c  o m
    return ArrayUtils.addAll(new byte[] { 0, 1 }, deviceUid);
}

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