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

/**
 * @param file/*from w w w .  j  av  a 2s.c  om*/
 * @return
 */
public static int getNumFilesInFolder(File file) {
    if (file == null) {
        throw new NullPointerException("file cannot be null");
    }
    if (!file.exists()) {
        throw new NullPointerException("file does not exist");
    }
    if (file.isFile()) {
        throw new ClassCastException("file is not a directory");
    }
    return getSubfilesNumberInFolder(file, false, true);
}

From source file:Main.java

/**
 * Makes a window visible - if invisible - and brings it to front.
 *
 * @param window window/*  w  w w.ja va 2  s .  c  om*/
 */
public static void show(Window window) {
    if (window == null) {
        throw new NullPointerException("window == null");
    }

    if (!window.isVisible()) {
        window.setVisible(true);
    }

    window.toFront();
}

From source file:Main.java

public static void runAndWait(Runnable action) {
    if (action == null)
        throw new NullPointerException("action");

    // run synchronously on JavaFX thread
    if (Platform.isFxApplicationThread()) {
        action.run();/*from  w  w  w.j a  va  2  s . com*/
        return;
    }

    // queue on JavaFX thread and wait for completion
    final CountDownLatch doneLatch = new CountDownLatch(1);
    Platform.runLater(() -> {
        try {
            action.run();
        } finally {
            doneLatch.countDown();
        }
    });

    try {
        doneLatch.await();
    } catch (InterruptedException e) {
        // ignore exception
    }
}

From source file:Main.java

public static NodeList findNodes(Document document, String nodeName) {
    if (document == null)
        throw new NullPointerException("Document cannot be null!");
    if (nodeName == null)
        throw new NullPointerException("Nodename cannot be null!");
    return document.getElementsByTagName(nodeName);
}

From source file:Main.java

private static void setHeader(HttpUriRequest request, Map<String, String> headers) {
    if (headers == null || headers.size() == 0) {
        throw new NullPointerException("headers not be null");
    }/*from  w  w  w.  j a va  2  s  .  c  om*/
    for (Entry<String, String> entry : headers.entrySet()) {
        request.addHeader(entry.getKey(), entry.getValue());
    }
}

From source file:Main.java

@Deprecated
public static NdefRecord createExternal(String domain, String type, byte[] data) {
    if (domain == null)
        throw new NullPointerException("domain is null");
    if (type == null)
        throw new NullPointerException("type is null");

    domain = domain.trim().toLowerCase(Locale.US);
    type = type.trim().toLowerCase(Locale.US);

    if (domain.length() == 0)
        throw new IllegalArgumentException("domain is empty");
    if (type.length() == 0)
        throw new IllegalArgumentException("type is empty");

    byte[] byteDomain = domain.getBytes(Charset.forName("UTF_8"));
    byte[] byteType = type.getBytes(Charset.forName("UTF_8"));
    byte[] b = new byte[byteDomain.length + 1 + byteType.length];
    System.arraycopy(byteDomain, 0, b, 0, byteDomain.length);
    b[byteDomain.length] = ':';
    System.arraycopy(byteType, 0, b, byteDomain.length + 1, byteType.length);

    return new NdefRecord(NdefRecord.TNF_EXTERNAL_TYPE, b, new byte[0], data);
}

From source file:Main.java

public static Element findNode(Element parentNode, String nodeName) {
    if (parentNode == null)
        throw new NullPointerException("Parent Node cannot be null!");
    if (nodeName == null)
        throw new NullPointerException("Nodename cannot be null!");
    NodeList nodes = parentNode.getElementsByTagName(nodeName);
    if (nodes == null || nodes.getLength() == 0)
        return null;
    if (nodes.getLength() > 1)
        throw new RuntimeException(nodes.getLength() + " nodes found where only 1 was expected");
    return (Element) nodes.item(0);
}

From source file:Main.java

public static void playAudio(Context context, int resId) {

    if (context == null)
        throw new NullPointerException("context cannot be null");

    mediaPlayer = MediaPlayer.create(context, resId);
    mediaPlayer.start();//from  w w  w.j a  v  a2 s .c o m
    mediaPlayer.setOnCompletionListener(new MediaPlayer.OnCompletionListener() {
        @Override
        public void onCompletion(MediaPlayer mp) {
            mp.release();
        }
    });
}

From source file:Main.java

public static boolean launchActivity(Context from, Intent intent) {
    if (from == null)
        throw new NullPointerException("from == null");
    try {/*from  ww  w.  j  a  v  a  2 s  . c  om*/
        from.startActivity(intent);
        return true;
    } catch (ActivityNotFoundException e) {
        e.printStackTrace();
        return false;
    }
}

From source file:Main.java

protected static void writeXMLwalkTree(Node node, int indent, PrintWriter out) {
    if (node == null)
        throw new NullPointerException("Null node passed to writeXMLwalkTree()");
    if (node.hasChildNodes()) {
        if (node instanceof Element) {
            Element elem = (Element) node;
            //elem.normalize();
            out.print("\n");
            for (int j = 0; j < indent; j++) {
                out.print(" ");
            }//from  w  ww. j a va  2s .  c  om
            out.print("<" + elem.getTagName());
            NamedNodeMap attrs = elem.getAttributes();
            for (int i = 0; i < attrs.getLength(); i++) {
                Attr a = (Attr) attrs.item(i);
                out.print(" " + a.getName() + "=\"" + a.getValue() + "\"");
            }
            out.print(">");
            NodeList nl = node.getChildNodes();
            for (int i = 0; i < nl.getLength(); i++) {
                writeXMLwalkTree(nl.item(i), indent + 2, out);
            }
            //              for(int j=0;j<indent;j++) {
            //                  out.print(" ");
            //              }
            out.println("</" + elem.getTagName() + ">");
        }
    } else {
        if (node instanceof Element) {
            Element elem = (Element) node;
            out.print("\n");
            for (int j = 0; j < indent; j++) {
                out.print(" ");
            }
            out.print("<" + elem.getTagName());
            NamedNodeMap attrs = elem.getAttributes();
            for (int i = 0; i < attrs.getLength(); i++) {
                Attr a = (Attr) attrs.item(i);
                out.print(" " + a.getName() + "=\"" + a.getValue() + "\"");
            }
            out.println("/>");
        } else if (node instanceof CDATASection) {
            CDATASection cdata = (CDATASection) node;
            //              for(int j=0;j<indent;j++) {
            //                  out.print(" ");
            //              }
            out.print("<![CDATA[" + cdata.getData() + "]]>");
        } else if (node instanceof Text) {
            Text text = (Text) node;
            StringBuilder buf = new StringBuilder(text.getData().length());
            for (int i = 0; i < text.getData().length(); i++) {
                if (text.getData().charAt(i) == '\n' || text.getData().charAt(i) == '\r'
                        || text.getData().charAt(i) == ' ' || text.getData().charAt(i) == '\t') {
                    if (buf.length() > 0 && buf.charAt(buf.length() - 1) != ' ') {
                        buf.append(' ');
                    }
                } else {
                    buf.append(text.getData().charAt(i));
                }
            }
            if (buf.length() > 0 && !buf.toString().equals(" ")) {
                StringBuilder buf2 = new StringBuilder(buf.length() + indent);
                //                  for(int j=0;j<indent;j++) {
                //                      buf2.append(' ');
                //                  }
                buf2.append(buf.toString());
                out.print(buf2);
            }
        }
    }
}