Example usage for java.lang Math random

Introduction

In this page you can find the example usage for java.lang Math random.

Prototype

public static double random()

Source Link

Document

Returns a double value with a positive sign, greater than or equal to 0.0 and less than 1.0 .

Usage

From source file:edu.kit.dama.transfer.client.util.TestDataBuilder.java

/**
 * Build a random data array with the provided size
 *
 * @param size The byte array size/*from   w  w w.  j a v a  2  s  .c om*/
 *
 * @return The byte array containing random data
 */
private static byte[] buildRandomData(int size) {
    byte[] oneMegaByte = new byte[size];
    for (int i = 0; i < size; i++) {
        oneMegaByte[i] = (byte) (Math.random() * MAX_BYTES);
    }
    return oneMegaByte;
}

From source file:com.streamreduce.util.SecurityUtil.java

public static String generateRandomString(int n) {

    Random rd = new Random();

    char lowerChars[] = "abcdefghijklmnopqrstuvwxyz".toCharArray();
    char upperChars[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZ".toCharArray();
    char numbers[] = "0123456789".toCharArray();
    //char specialChars[] = "~!@#$%^&*()-_=+[{]}|;:<>/?".toCharArray();
    char specialChars[] = "!$-_+".toCharArray(); // limited subset

    List<Character> pwdLst = new ArrayList<>();
    for (int g = 0; g <= n; g++) {
        for (int z = 0; z < 1; z++) {
            if (g == 0) {
                pwdLst.add(numbers[rd.nextInt(10)]); // must match char array length(s) above
            } else if (g == 1) {
                pwdLst.add(lowerChars[rd.nextInt(26)]);
            } else if (g == 2) {
                pwdLst.add(upperChars[rd.nextInt(26)]);
            } else if (g == 3) {
                pwdLst.add(specialChars[rd.nextInt(5)]);
            }/*  w w  w . ja  va 2 s. c o  m*/
        }
        if (pwdLst.size() == n) {
            break;
        }
        if (g + 1 == 4) {
            g = (int) (Math.random() * 5);

        }
    }
    StringBuilder password = new StringBuilder();
    Collections.shuffle(pwdLst);
    for (Character aPwdLst : pwdLst) {
        password.append(aPwdLst);
    }
    return password.toString();
}

From source file:com.github.jmnarloch.spring.cloud.feign.app.resource.InvoiceResource.java

private List<Invoice> createInvoiceList(int count) {
    final List<Invoice> invoices = new ArrayList<>();
    for (int ind = 0; ind < count; ind++) {
        final Invoice invoice = new Invoice();
        invoice.setTitle("Invoice " + (ind + 1));
        invoice.setAmount(new BigDecimal(String.format(Locale.US, "%.2f", Math.random() * 1000)));
        invoices.add(invoice);//from   w w w.  ja va2s  .c  o m
    }
    return invoices;
}

From source file:io.apiman.test.integration.runner.handlers.AbstractAnnotationHandler.java

/**
 * Create semi-unique name by appending current system time millis if requested
 *
 * @param name base name//from   w w w. j  a v  a 2s  .c  om
 * @return unique name
 */
protected String uniqueName(String name, boolean unique) {
    if (!unique) {
        return name;
    }
    return name + System.currentTimeMillis() + (int) (Math.random() * 10000 + 1);
}

From source file:ch.entwine.weblounge.test.site.GreeterTag.java

/**
 * {@inheritDoc}//  w ww . j  a  v  a 2s .c  o  m
 * 
 * @see javax.servlet.jsp.tagext.TagSupport#doStartTag()
 */
public int doStartTag() throws JspException {
    try {
        Map<String, String> greetings = TestSiteUtils.loadGreetings();
        String greeting = null;
        if (language != null) {
            greeting = greetings.get(language);
            if (greeting == null)
                greeting = "Excuse me?";
        } else {
            String[] languages = greetings.keySet().toArray(new String[greetings.size()]);
            language = languages[(int) Math.random() * languages.length];
            greeting = greetings.get(language);
        }
        String encodedGreeting = StringEscapeUtils.escapeHtml(greeting);
        pageContext.getOut().print("<div id=\"greeting\">");
        pageContext.getOut().print(encodedGreeting);
        pageContext.getOut().println("</div>");
        pageContext.getOut().flush();
    } catch (IOException ioe) {
        throw new JspException("IOException while writing to client" + ioe.getMessage());
    }
    return SKIP_BODY;
}

From source file:com.ciphertool.genetics.algorithms.mutation.GroupMutationAlgorithm.java

@Override
public void mutateChromosome(Chromosome chromosome) {
    if (maxMutationsPerChromosome == null) {
        throw new IllegalStateException("The maxMutationsPerChromosome cannot be null.");
    }/*from   w w  w  .  j  a va 2s.c om*/

    /*
     * Choose a random number of mutations constrained by the configurable
     * max and the total number of genes
     */
    int numMutations = (int) (Math.random() * Math.min(maxMutationsPerChromosome, chromosome.getGenes().size()))
            + 1;

    Map<Integer, Integer> geneIndices = new HashMap<Integer, Integer>();
    for (int i = 0; i < numMutations; i++) {
        // Keep track of the mutated indices by passing the map by reference
        mutateRandomGeneGroup(chromosome, geneIndices);
    }
}

From source file:ThreeThreadsTest.java

public void run() {
    for (int i = 0; i < 10; i++) {
        System.out.println(i + " " + getName());
        try {/*w w w . j  a  v  a 2  s  .com*/
            sleep((long) (Math.random() * 1000));
        } catch (InterruptedException e) {
        }
    }
    System.out.println("DONE! " + getName());
}

From source file:com.siblinks.ws.common.BaseException.java

/**
 * @param aThrowable//www . j a  v  a 2  s  . co m
 * @param aUserMessage
 * @param level
 */
public BaseException(final Throwable aThrowable, final String aUserMessageKey,
        final Serializable[] aValueReplacementArray, final ErrorLevel level) {
    this.throwable = aThrowable;
    this.userMessageKey = aUserMessageKey;
    this.valueReplacementArray = aValueReplacementArray;
    this.errorLevel = level;
    this.uniqueID = new Double(Math.random()).toString();
}

From source file:dk.itst.oiosaml.sp.ConfigurationTest.java

@Before
public void setUp() throws Exception {
    tmpdir = new File(System.getProperty("java.io.tmpdir") + "/oiosaml-" + Math.random());
    if (tmpdir.exists()) {
        FileUtils.cleanDirectory(tmpdir);
    }//from  w w  w  . ja va 2 s  .  c o m
    tmpdir.mkdir();

    SAMLConfiguration.setSystemConfiguration(null);
    IdpMetadata.setMetadata(null);
    SPMetadata.setMetadata(null);
    System.setProperty(SAMLUtil.OIOSAML_HOME, tmpdir.getAbsolutePath());

    server = new Server(8808);
    WebAppContext wac = new WebAppContext();
    wac.setClassLoader(Thread.currentThread().getContextClassLoader());
    wac.setContextPath("/saml");
    wac.setWar("webapp/");

    server.setHandler(wac);
    server.start();

    client = new WebClient();
    page = (HtmlPage) client.getPage(BASE + "/saml/configure");
}

From source file:jetbrains.exodus.entitystore.BackupTests.java

public void testSingular() throws Exception {
    final PersistentEntityStoreImpl store = getEntityStore();
    store.getConfig().setMaxInPlaceBlobSize(0); // no in-place blobs
    final String randomDescription[] = { null };
    store.executeInTransaction(new StoreTransactionalExecutable() {
        @Override/*  ww w  .  j av  a2 s .c  o m*/
        public void execute(@NotNull StoreTransaction txn) {
            final Entity issue = txn.newEntity("Issue");
            randomDescription[0] = Double.toString(Math.random());
            issue.setBlobString("description", randomDescription[0]);
        }
    });
    final File backupDir = TestUtil.createTempDir();
    try {
        final File backup = CompressBackupUtil.backup(store, backupDir, null, true);
        final File restoreDir = TestUtil.createTempDir();
        try {
            extractEntireZip(backup, restoreDir);
            final PersistentEntityStoreImpl newStore = PersistentEntityStores.newInstance(restoreDir);
            try {
                newStore.executeInReadonlyTransaction(new StoreTransactionalExecutable() {
                    @Override
                    public void execute(@NotNull final StoreTransaction txn) {
                        assertEquals(1, txn.getAll("Issue").size());
                        final Entity issue = txn.getAll("Issue").getFirst();
                        assertNotNull(issue);
                        assertEquals(randomDescription[0], issue.getBlobString("description"));
                    }
                });
            } finally {
                newStore.close();
            }
        } finally {
            IOUtil.deleteRecursively(restoreDir);
        }
    } finally {
        IOUtil.deleteRecursively(backupDir);
    }
}