Example usage for java.lang NullPointerException NullPointerException

Introduction

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

Prototype

public NullPointerException(String s)

Source Link

Document

Constructs a NullPointerException with the specified detail message.

Usage

From source file:Main.java

/**
 * Checks whether or not the specified collection contains a <code>null</code>.
 *
 * @param col//  w  ww.  ja  v a2  s .c  om
 *            the collection to check
 * @throws NullPointerException
 *             if the specified collection contains a null
 */
public static void checkCollectionForNulls(Collection<?> col) {
    for (Object entry : col) {
        if (entry == null) {
            throw new NullPointerException("collection contains a null entry");
        }
    }
}

From source file:Main.java

private static void checkNotNull(Object reference, String name) {
    if (reference == null)
        throw new NullPointerException(name + " is null");
}

From source file:Main.java

public static void checkNotNull(Object object, String msg) {
    if (object == null) {
        throw new NullPointerException(msg);
    }/*  w w w  . ja v  a  2  s.c  o m*/
}

From source file:Main.java

static NullPointerException arrayOfValuesToLookForIsNull() {
    return new NullPointerException("The array of values to look for should not be null");
}

From source file:Main.java

/***
 * Computes RFC 2104-compliant HMAC signature. This can be used to sign the Amazon S3
 * request urls//  w  w w .j a va 2 s. co m
 * 
 * @param data The data to be signed.
 * @param key The signing key.
 * @return The Base64-encoded RFC 2104-compliant HMAC signature.
 * @throws SignatureException when signature generation fails
 */
public static String getHMac(String data, String key) throws SignatureException {

    if (data == null) {
        throw new NullPointerException("Data to be signed cannot be null");
    }

    String result = null;
    try {

        final String HMAC_SHA1_ALGORITHM = "HmacSHA1";

        // get an hmac_sha1 key from the raw key bytes
        SecretKeySpec signingKey = new SecretKeySpec(key.getBytes(), HMAC_SHA1_ALGORITHM);

        // get an hmac_sha1 Mac instance &
        // initialize with the signing key
        Mac mac = Mac.getInstance(HMAC_SHA1_ALGORITHM);
        mac.init(signingKey);

        // compute the hmac on input data bytes
        byte[] digest = mac.doFinal(data.getBytes());

        if (digest != null) {
            // Base 64 Encode the results
            result = Base64.encodeToString(digest, Base64.NO_WRAP);
        }

    } catch (Exception e) {
        throw new SignatureException("Failed to generate HMAC : " + e.getMessage());
    }

    return result;
}

From source file:Main.java

public static void checkNotNull(Object reference, String name) {
    if (reference == null) {
        throw new NullPointerException(
                String.format("Please set the %1$s constant and recompile the app.", name));
    }/*w  ww  . j av a  2  s  .  co  m*/
}

From source file:Main.java

/**
 * Returns the child element with the specified tagName for the specified
 * parent element.//from w w w  . java 2s.  co m
 * @param parent The parent whose child we're looking for.
 * @param tagName the name of the child to find
 * @return The child with the specified name or null if no such child was
 *         found.
 * @throws NullPointerException if parent or tagName are null
 */
public static Element findChild(Element parent, String tagName) {
    if (parent == null || tagName == null)
        throw new NullPointerException(
                "Parent or tagname were null! " + "parent = " + parent + "; tagName = " + tagName);

    NodeList nodes = parent.getChildNodes();
    Node node;
    int len = nodes.getLength();
    for (int i = 0; i < len; i++) {
        node = nodes.item(i);
        if (node.getNodeType() == Node.ELEMENT_NODE && ((Element) node).getNodeName().equals(tagName))
            return (Element) node;
    }

    return null;
}

From source file:Main.java

/**
 * Returns a token string from a collection. Uses {@code Object#toString()}
 * to get the collection elements strings.
 *
 * @param collection           collection
 * @param delimiter            delimiter
 * @param delimiterReplacement replacement for all delimiters contained in
 *                             a collection's element
 * @return                     token string
 *//*from   w w w  .  j av  a  2s.  com*/
public static String toTokenString(Collection<? extends Object> collection, String delimiter,
        String delimiterReplacement) {
    if (collection == null) {
        throw new NullPointerException("collection == null");
    }

    if (delimiter == null) {
        throw new NullPointerException("delimiter == null");
    }

    if (delimiterReplacement == null) {
        throw new NullPointerException("delimiterReplacement == null");
    }

    StringBuilder tokenString = new StringBuilder();
    int index = 0;

    for (Object o : collection) {
        tokenString.append(((index == 0) ? EMPTY_STRING : delimiter));
        tokenString.append(o.toString().replace(delimiter, delimiterReplacement));
        index++;
    }

    return tokenString.toString();
}

From source file:Main.java

/**
 * Returns the children elements with the specified tagName for the
 * specified parent element.//from w  w  w.  java 2s.co m
 *
 * @param parent The parent whose children we're looking for.
 * @param tagName the name of the child to find
 * @return List of the children with the specified name
 * @throws NullPointerException if parent or tagName are null
 */
public static List<Element> findChildren(Element parent, String tagName) {
    if (parent == null || tagName == null)
        throw new NullPointerException(
                "Parent or tagname were null! " + "parent = " + parent + "; tagName = " + tagName);

    List<Element> result = new ArrayList<Element>();
    NodeList nodes = parent.getChildNodes();
    Node node;
    int len = nodes.getLength();
    for (int i = 0; i < len; i++) {
        node = nodes.item(i);
        if (node.getNodeType() == Node.ELEMENT_NODE) {
            Element element = (Element) node;
            if (element.getNodeName().equals(tagName))
                result.add(element);
        }
    }

    return result;
}

From source file:Main.java

/**
 * Remove identical adjacent tags from {@code decorations}.
 * /*from   w  w  w . j  a  v  a2  s.c  o m*/
 * @param decorations see {@link prettify.parser.Job#decorations}
 * @param source the source code
 * 
 * @return the {@code decorations} after treatment
 * 
 * @throws IllegalArgumentException the size of {@code decoration} is not
 * a multiple of 2
 */
public static List<Object> removeDuplicates(List<Object> decorations, String source) {
    if (decorations == null) {
        throw new NullPointerException("argument 'decorations' cannot be null");
    }
    if (source == null) {
        throw new NullPointerException("argument 'source' cannot be null");
    }
    if ((decorations.size() & 0x1) != 0) {
        throw new IllegalArgumentException("the size of argument 'decorations' should be a multiple of 2");
    }

    List<Object> returnList = new ArrayList<Object>();

    // use TreeMap to remove entrys with same pos
    Map<Integer, Object> orderedMap = new TreeMap<Integer, Object>();
    for (int i = 0, iEnd = decorations.size(); i < iEnd; i += 2) {
        orderedMap.put((Integer) decorations.get(i), decorations.get(i + 1));
    }

    // remove adjacent style
    String previousStyle = null;
    for (Integer pos : orderedMap.keySet()) {
        String style = (String) orderedMap.get(pos);
        if (previousStyle != null && previousStyle.equals(style)) {
            continue;
        }
        returnList.add(pos);
        returnList.add(style);
        previousStyle = style;
    }

    // remove last zero length tag
    int returnListSize = returnList.size();
    if (returnListSize >= 4 && returnList.get(returnListSize - 2).equals(source.length())) {
        returnList.remove(returnListSize - 2);
        returnList.remove(returnListSize - 2);
    }

    return returnList;
}