Example usage for java.util List isEmpty

Introduction

In this page you can find the example usage for java.util List isEmpty.

Prototype

boolean isEmpty();

Source Link

Document

Returns true if this list contains no elements.

Usage

From source file:Main.java

public static boolean isEmpty(List<?> list) {
    return list == null || list.isEmpty();
}

From source file:Main.java

public static <T> T mostCommon(List<T> list, double percent) {
    if (list.isEmpty())
        return null;

    Map<T, Integer> map = new HashMap<>();

    for (T t : list) {
        Integer count = map.get(t);
        map.put(t, count == null ? 1 : count + 1);
    }/*from  ww  w  .  j  a  v  a 2 s .  c  o m*/

    double freq = map.size() / (double) list.size();
    if (1.0 == freq || (1.0 - freq) < percent)
        return null;

    Entry<T, Integer> max = null;
    for (Entry<T, Integer> e : map.entrySet()) {
        if (max == null || e.getValue() > max.getValue()) {
            max = e;
        }
    }

    return max.getKey();
}

From source file:Main.java

public static boolean isEmpty(List<? extends Object> list) {
    return list == null || list.isEmpty();
}

From source file:Main.java

public static <T> List<T> subList(List<T> list, int first, int end) {
    if (null == list || list.isEmpty())
        return null;
    int size = list.size();
    int fromIndex = first;
    int toIndex = end;
    if (fromIndex < 0) {
        toIndex = 0;/*w w  w .j  a  v  a  2s  .c om*/
    }
    if (toIndex > size) {
        toIndex = size;
    }
    if (fromIndex > toIndex)
        return null;
    return list.subList(fromIndex, toIndex);
}

From source file:Main.java

public static Element getChildNode(Element parent, String name) {
    List<Element> childNodes = getChildNodes(parent, name);
    if (childNodes.isEmpty()) {
        return null;
    }/*from  w  ww. ja v a 2  s  .c o m*/
    return childNodes.get(0);
}

From source file:Main.java

/**
 * Returns the first found frame of {@code #findFramesWithIcons()}. <p> Especially for usage in a
 * <code>JOptionPane#show...Dialog()</code> instead of null. Then in the dialog frame an icon will be displayed that
 * is different to the Java "coffee cup" icon.
 *
 * @return frame or null/* w w w .j a  v  a  2s  .  c o m*/
 */
public static Frame findFrameWithIcon() {
    List<Frame> frames = findFramesWithIcons();

    return (frames.isEmpty()) ? null : frames.get(0);
}

From source file:com.xpfriend.fixture.cast.temp.TempDynaSet.java

private static TempDynaClass getTempDynaClass(List<DynaBean> table) {
    if (table.isEmpty()) {
        throw new IllegalArgumentException();
    }/*from  w  w w.java 2 s  .  c  o  m*/
    return (TempDynaClass) table.get(0).getDynaClass();
}

From source file:Main.java

public static Element getChildElement(Element parent, String tagName) {
    List children = getChildElements(parent, tagName);
    return children.isEmpty() ? null : (Element) children.get(0);
}

From source file:Main.java

public static <T> T getSingle(List<T> collection) {
    boolean hasAnyElements = collection != null && !collection.isEmpty();
    if (!hasAnyElements) {
        throw new RuntimeException("Collection is null or empty");
    }//from  ww  w  .  j  a v a  2 s .  c  o  m

    boolean hasMultipleResults = collection.size() > 1;
    if (hasMultipleResults) {
        throw new RuntimeException("Collection contains multiple elements");
    }

    return collection.get(0);
}

From source file:Main.java

public static List<String> stringToList(String weeksStr) {
    List<String> weekList = new ArrayList<>();
    if (weeksStr == null || weekList.isEmpty()) {
        return weekList;
    }/* w  ww  .  j  a va 2 s.  c  o  m*/
    String[] weeksArray = weeksStr.split(",");
    if (weeksArray.length != 0) {
        weekList = Arrays.asList(weeksArray);
    } else {
        weekList.add(weeksStr);
    }
    return weekList;
}