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:net.sf.ehcache.DiskStoreTest.java

/**
 * This test is designed to be used with a profiler to explore the ways in which DiskStore
 * uses memory. It does not do much on its own.
 *//* w w w.  j  a  v a  2  s  .co m*/
public void testOutOfMemoryErrorOnOverflowToDisk() throws Exception {

    //Set size so the second element overflows to disk.
    Cache cache = new Cache("test", 1000, MemoryStoreEvictionPolicy.LRU, true, null, true, 500, 500, false, 1,
            null);
    manager.addCache(cache);
    int i = 0;

    Random random = new Random();
    for (; i < 5500; i++) {
        byte[] bytes = new byte[10000];
        random.nextBytes(bytes);
        cache.put(new Element("" + i, bytes));
    }
    LOG.info("Elements written: " + i);
    //Thread.sleep(100000);
}

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From source file:org.opencastproject.util.ZipUtilTest.java

/**
 * Test compression of >4GB file//w  w  w.ja va 2 s  .c  o m
 */
@Test
@Ignore
public void testOver4GB() throws Exception {

    if (bigFile.exists() || bigFile.createNewFile()) {
        if (bigFile.getUsableSpace() >= bigFileSize) {

            FileOutputStream fos = new FileOutputStream(bigFile);
            byte[] buffer = new byte[1024];
            Random rdn = new Random();
            File destZip = new File(destDir, "bigZip.zip");

            for (long i = 0; i < bigFileSize; i += buffer.length) {
                rdn.nextBytes(buffer);
                fos.write(buffer);
            }

            fos.close();

            ZipUtil.zip(new File[] { bigFile }, destZip, ZipUtil.NO_COMPRESSION);

            Assert.assertTrue(destZip.exists());
            Assert.assertTrue(destZip.length() >= bigFileSize);
        } else {
            logger.warn("This test needs more than 4GB of disk free space: {}", bigFile.getUsableSpace());
            logger.warn("Skipping...");
        }
    } else
        logger.warn("Couldn't create the File descriptor");
}

---

From source file:syndeticlogic.catena.array.ArrayTest.java

@Test
public void updateVariableLengthArrayTest() {
    CompositeKey newKey = new CompositeKey();
    newKey.append(this.key);
    newKey.append(1);/*from  w  w  w.  ja  v  a2s. c  o  m*/
    this.key = newKey;

    arrayRegistry.createArray(key, Type.BINARY);
    array = arrayRegistry.createArrayInstance(key);

    VariableLengthArrayGenerator vlag = new VariableLengthArrayGenerator(37, 13);
    List<byte[]> arrayValues = vlag.generateMemoryArray(300);
    Random r = new Random(337);
    int skip = r.nextInt() % 13;
    List<byte[]> skipList = new LinkedList<byte[]>();

    assertEquals(0, array.position());

    for (byte[] value : arrayValues) {
        array.append(value, 0, value.length);
    }

    assertEquals(300, array.position());
    assertFalse(array.hasMore());

    for (int i = 0; i < arrayValues.size(); i++) {
        if (i % skip == 0) {
            byte[] updateBytes = new byte[r.nextInt(8192) + 1];
            r.nextBytes(updateBytes);
            skipList.add(updateBytes);
            array.position(i, LockType.WriteLock);
            array.update(updateBytes, 0, updateBytes.length);
            array.complete(LockType.WriteLock);
        }
    }

    array.position(0, BinaryArray.LockType.ReadLock);
    for (int i = 0, j = 0; i < arrayValues.size(); i++) {
        byte[] value = arrayValues.get(i);
        if (i % skip == 0) {
            value = skipList.get(j);
            j++;
        }
        byte[] buffer = new byte[value.length];
        array.scan(array.createIODescriptor(buffer, 0));
        assertArrayEquals(value, buffer);
    }
    array.complete(BinaryArray.LockType.ReadLock);

}

---

From source file:syndeticlogic.catena.array.ArrayTest.java

@Test
public void commitUpdateVariableLengthArrayTest() {
    CompositeKey newKey = new CompositeKey();
    newKey.append(this.key);
    newKey.append("1" + System.getProperty("file.separator"));
    key = newKey;/*  w  w w  . ja  v  a 2  s . c om*/
    arrayRegistry.createArray(key, Type.BINARY);
    array = arrayRegistry.createArrayInstance(key);
    VariableLengthArrayGenerator vlag = new VariableLengthArrayGenerator(37, 13);
    List<byte[]> arrayValues = vlag.generateMemoryArray(300);
    Random r = new Random(337);
    int skip = r.nextInt() % 13;
    List<byte[]> updateList = new LinkedList<byte[]>();

    assertEquals(0, array.position());

    for (byte[] value : arrayValues) {
        array.append(value, 0, value.length);
    }
    assertEquals(300, array.position());
    assertFalse(array.hasMore());
    //int cumdelta = 0;
    for (int i = 0; i < arrayValues.size(); i++) {
        if (i % skip == 0) {
            byte[] updateBytes = new byte[r.nextInt(8192) + 1];
            r.nextBytes(updateBytes);
            updateList.add(updateBytes);
            array.position(i, LockType.WriteLock);

            //int delta = updateBytes.length - arrayValues.get(i).length;
            //cumdelta += delta;
            array.update(updateBytes, 0, updateBytes.length);
            array.complete(LockType.WriteLock);
        }
    }
    array.commit();
    reconfigure();
    array.position(0, BinaryArray.LockType.ReadLock);
    for (int i = 0, j = 0; i < arrayValues.size(); i++) {
        byte[] value = arrayValues.get(i);
        if (i % skip == 0) {
            value = updateList.get(j);
            j++;
        }

        byte[] buffer = new byte[value.length];
        array.scan(array.createIODescriptor(buffer, 0));
        System.out.println("i = " + i + " value.size = " + value.length);
        assertArrayEquals(value, buffer);

    }
    array.complete(BinaryArray.LockType.ReadLock);
    assertFalse(array.hasMore());
}

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From source file:dk.statsbiblioteket.util.LineReaderTest.java

public void dumpSpeed() throws Exception {
    Random random = new Random();
    int[] sizes = new int[] { 100, 10000, 1000000, 10000000 };
    Profiler profiler = new Profiler();
    for (int size : sizes) {
        System.out.print("Creating test-file of size " + size + "...");
        File temp = createTempFile();
        LineReader lr = new LineReader(temp, "rw");
        byte[] bytes = new byte[size];
        random.nextBytes(bytes);
        System.gc();//from www . j  a v a 2 s  .  co  m
        profiler.reset();
        lr.write(bytes);
        lr.close();
        System.out.println(" in " + profiler.getSpendTime());
        dumpSpeed2Helper(temp);
        temp.delete();
    }
}

---

From source file:org.commonjava.indy.promote.data.PromotionManagerTest.java

@Test
@Ignore("volatile, owing to galley fs locks")
public void promoteAllByPath_RaceToPromote_FirstLocksTargetStore() throws Exception {
    Random rand = new Random();
    final HostedRepository[] sources = { new HostedRepository(MAVEN_PKG_KEY, "source1"),
            new HostedRepository(MAVEN_PKG_KEY, "source2") };
    final String[] paths = { "/path/path1", "/path/path2", "/path3", "/path/path/4" };
    Stream.of(sources).forEach((source) -> {
        try {//from www  . jav  a 2 s.  c  o  m
            storeManager.storeArtifactStore(source, new ChangeSummary(ChangeSummary.SYSTEM_USER, "test setup"),
                    false, true, new EventMetadata());

            Stream.of(paths).forEach((path) -> {
                byte[] buf = new byte[1024 * 1024 * 2];
                rand.nextBytes(buf);
                try {
                    contentManager.store(source, path, new ByteArrayInputStream(buf), TransferOperation.UPLOAD,
                            new EventMetadata());
                } catch (IndyWorkflowException e) {
                    e.printStackTrace();
                    Assert.fail("failed to store generated file to: " + source + path);
                }
            });
        } catch (IndyDataException e) {
            e.printStackTrace();
            Assert.fail("failed to store hosted repository: " + source);
        }
    });

    final HostedRepository target = new HostedRepository(MAVEN_PKG_KEY, "target");
    storeManager.storeArtifactStore(target, new ChangeSummary(ChangeSummary.SYSTEM_USER, "test setup"), false,
            true, new EventMetadata());

    PathsPromoteResult[] results = new PathsPromoteResult[2];
    CountDownLatch cdl = new CountDownLatch(2);

    AtomicInteger counter = new AtomicInteger(0);
    Stream.of(sources).forEach((source) -> {
        int idx = counter.getAndIncrement();
        executor.execute(() -> {
            try {
                results[idx] = manager.promotePaths(
                        new PathsPromoteRequest(source.getKey(), target.getKey(), paths), FAKE_BASE_URL);
            } catch (Exception e) {
                e.printStackTrace();
                Assert.fail("Promotion from source: " + source + " failed.");
            } finally {
                cdl.countDown();
            }
        });

        try {
            Thread.sleep(25);
        } catch (InterruptedException e) {
            Assert.fail("Test interrupted");
        }
    });

    assertThat("Promotions failed to finish.", cdl.await(30, TimeUnit.SECONDS), equalTo(true));

    // first one should succeed.
    PathsPromoteResult result = results[0];
    assertThat(result.getRequest().getSource(), equalTo(sources[0].getKey()));
    assertThat(result.getRequest().getTarget(), equalTo(target.getKey()));

    Set<String> pending = result.getPendingPaths();
    assertThat(pending == null || pending.isEmpty(), equalTo(true));

    Set<String> skipped = result.getSkippedPaths();
    assertThat(skipped == null || skipped.isEmpty(), equalTo(true));

    Set<String> completed = result.getCompletedPaths();
    assertThat(completed, notNullValue());
    assertThat(completed.size(), equalTo(paths.length));

    assertThat(result.getError(), nullValue());

    Stream.of(paths).forEach((path) -> {
        HostedRepository src = sources[0];
        Transfer sourceRef = downloadManager.getStorageReference(src, path);
        Transfer targetRef = downloadManager.getStorageReference(target, path);
        assertThat(targetRef.exists(), equalTo(true));
        try (InputStream sourceIn = sourceRef.openInputStream();
                InputStream targetIn = targetRef.openInputStream()) {
            int s = -1, t = -1;
            while ((s = sourceIn.read()) == (t = targetIn.read())) {
                if (s == -1) {
                    break;
                }
            }

            if (s != -1 && s != t) {
                Assert.fail(path + " doesn't match between source: " + src + " and target: " + target);
            }
        } catch (IOException e) {
            e.printStackTrace();
            Assert.fail("Failed to compare contents of: " + path + " between source: " + src + " and target: "
                    + target);
        }
    });

    // second one should be completely skipped.
    result = results[1];
    assertThat(result.getRequest().getSource(), equalTo(sources[1].getKey()));
    assertThat(result.getRequest().getTarget(), equalTo(target.getKey()));

    pending = result.getPendingPaths();
    assertThat(pending == null || pending.isEmpty(), equalTo(true));

    skipped = result.getSkippedPaths();
    assertThat(skipped, notNullValue());
    assertThat(skipped.size(), equalTo(paths.length));

    completed = result.getCompletedPaths();
    assertThat(completed == null || completed.isEmpty(), equalTo(true));

    assertThat(result.getError(), nullValue());
}

---

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

static void writeFile(FileSystem fileSys, Path name, int repl) throws IOException {
    FSDataOutputStream stm = fileSys.create(name, true,
            fileSys.getConf().getInt(CommonConfigurationKeys.IO_FILE_BUFFER_SIZE_KEY, 4096), (short) repl,
            blockSize);/*  w ww  .  j a v  a2 s  .  c  o  m*/
    byte[] buffer = new byte[TestCheckpoint.fileSize];
    Random rand = new Random(TestCheckpoint.seed);
    rand.nextBytes(buffer);
    stm.write(buffer);
    stm.close();
}

---

From source file:syndeticlogic.catena.array.ArrayTest.java

@Test
public void updateDeleteVariableLengthArrayTest() {
    CompositeKey key = new CompositeKey();
    key.append(this.key);
    key.append(1);/*from   ww  w  .j  a  va 2  s . c o  m*/

    arrayRegistry.createArray(key, Type.BINARY);
    array = arrayRegistry.createArrayInstance(key);
    VariableLengthArrayGenerator vlag = new VariableLengthArrayGenerator(37, 13);
    List<byte[]> arrayValues = vlag.generateMemoryArray(300);
    Random r = new Random(337);
    int skip = r.nextInt() % 13;
    List<byte[]> skipList = new LinkedList<byte[]>();

    assertEquals(0, array.position());

    for (byte[] value : arrayValues) {
        array.append(value, 0, value.length);
    }

    assertEquals(300, array.position());
    assertFalse(array.hasMore());

    for (int i = 0; i < arrayValues.size(); i++) {
        if (i % skip == 0) {
            if (i % 2 == 0) {
                array.position(i, LockType.WriteLock);
                array.delete();
                array.complete(LockType.WriteLock);
                arrayValues.remove(i);
            } else {
                byte[] updateBytes = new byte[r.nextInt(8192) + 1];
                r.nextBytes(updateBytes);
                skipList.add(updateBytes);
                array.position(i, LockType.WriteLock);
                array.update(updateBytes, 0, updateBytes.length);
                array.complete(LockType.WriteLock);
            }
        }
    }

    array.position(0, BinaryArray.LockType.ReadLock);
    for (int i = 0, j = 0; i < arrayValues.size(); i++) {
        byte[] value = arrayValues.get(i);
        if (i % skip == 0 && i % 2 != 0) {
            value = skipList.get(j);
            j++;
        }

        byte[] buffer = new byte[value.length];
        array.scan(array.createIODescriptor(buffer, 0));
        assertArrayEquals(value, buffer);
    }
    array.complete(BinaryArray.LockType.ReadLock);
    assertFalse(array.hasMore());
}

---

From source file:syndeticlogic.catena.array.ArrayTest.java

@Test
public void commitUpdateDeleteVariableLengthArrayTest() {
    CompositeKey newKey = new CompositeKey();
    newKey.append(this.key);
    newKey.append("1" + System.getProperty("file.separator"));
    key = newKey;// ww  w. j  a  v a  2  s. c o m
    System.out.println("---------------------------------------key = " + key.toString());
    arrayRegistry.createArray(key, Type.BINARY);
    array = arrayRegistry.createArrayInstance(key);
    VariableLengthArrayGenerator vlag = new VariableLengthArrayGenerator(37, 13);
    List<byte[]> arrayValues = vlag.generateMemoryArray(300);
    Random r = new Random(337);
    int skip = r.nextInt() % 13;
    List<byte[]> updateList = new LinkedList<byte[]>();

    assertEquals(0, array.position());

    for (byte[] value : arrayValues) {
        array.append(value, 0, value.length);
    }

    assertEquals(300, array.position());
    assertFalse(array.hasMore());

    for (int i = 0, alternator = 0; i < arrayValues.size(); i++) {
        if (i % skip == 0) {

            if (alternator % 2 == 0) {
                array.position(i, LockType.WriteLock);
                array.delete();
                array.complete(LockType.WriteLock);
                arrayValues.remove(i);

            } else {
                byte[] updateBytes = new byte[r.nextInt(8192) + 1];
                r.nextBytes(updateBytes);
                updateList.add(updateBytes);
                array.position(i, LockType.WriteLock);
                array.update(updateBytes, 0, updateBytes.length);
                array.complete(LockType.WriteLock);
            }
            alternator++;
        }
    }

    array.commit();
    reconfigure();

    array.position(0, BinaryArray.LockType.ReadLock);
    for (int i = 0, j = 0, alternator = 0; i < arrayValues.size(); i++) {
        byte[] value = arrayValues.get(i);
        if (i % skip == 0) {
            if (alternator % 2 != 0) {
                value = updateList.get(j);
                j++;
            }
            alternator++;
        }

        byte[] buffer = new byte[value.length];
        array.scan(array.createIODescriptor(buffer, 0));
        System.out.println("i = " + i + " value.size = " + value.length);
        assertArrayEquals(value, buffer);

    }
    array.complete(BinaryArray.LockType.ReadLock);
    assertFalse(array.hasMore());
}

---

From source file:org.apache.beam.sdk.io.synthetic.SyntheticOptions.java

public KV<byte[], byte[]> genKvPair(long seed) {
    Random random = new Random(seed);

    byte[] key = new byte[(int) keySizeBytes];
    // Set the user-key to contain characters other than ordered-code escape characters
    // (specifically '\0' or '\xff'). The user-key is encoded into the shuffle-key using
    // ordered-code, and the shuffle-key is then checked for size limit violations. A user-key
    // consisting of '\0' keySizeBytes would produce a shuffle-key encoding double in size,
    // which would go over the shuffle-key limit (see b/28770924).
    for (int i = 0; i < keySizeBytes; ++i) {
        key[i] = 42;//from   w  ww  .  j a  v  a 2 s  . co m
    }
    // Determines whether to generate hot key or not.
    if (random.nextDouble() < hotKeyFraction) {
        // Generate hot key.
        // An integer is randomly selected from the range [0, numHotKeys-1] with equal probability.
        int randInt = random.nextInt((int) numHotKeys);
        ByteBuffer.wrap(key).putInt(hashFunction().hashInt(randInt).asInt());
    } else {
        // Note that the random generated key might be a hot key.
        // But the probability of being a hot key is very small.
        random.nextBytes(key);
    }

    byte[] val = new byte[(int) valueSizeBytes];
    random.nextBytes(val);
    return KV.of(key, val);
}

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