Example usage for java.util Collections unmodifiableList

Introduction

In this page you can find the example usage for java.util Collections unmodifiableList.

Prototype

public static <T> List<T> unmodifiableList(List<? extends T> list)

Source Link

Document

Returns an unmodifiable view of the specified list.

Usage

From source file:Main.java

/**
 * @return an <b>UNMODIFIABLE</b> List&lt;T&gt;
 *///from  ww w. ja  v a  2 s . co m
public static <T> List<T> list(final T... elements) {
    return Collections.unmodifiableList(Arrays.asList(elements));
}

From source file:Main.java

/**
 * Copies the contents of a List to a new, unmodifiable List.  If the List is null, an empty List will be returned.
 * <p>// w  ww  .ja v a  2 s.co  m
 * This is especially useful for methods which take List parameters.  Directly assigning such a List to a member
 * variable can allow external classes to modify internal state.  Classes may have different state depending on the
 * size of a List; for example, a button might be disabled if the the List size is zero.  If an external object
 * can change the List, the containing class would have no way have knowing a modification occurred.
 * 
 * @param <T> The type of element in the List.
 * @param list The List to copy.
 * @return A new, unmodifiable List which contains all of the elements of the List parameter.  Will never be null.
 */
public static <T> List<T> copyToUnmodifiableList(List<T> list) {
    if (list != null) {
        List<T> listCopy = new ArrayList(list);
        return Collections.unmodifiableList(listCopy);
    } else {
        return Collections.emptyList();
    }
}

From source file:Main.java

@Nullable
static <T> List<T> nonEmptyOrNull(Collection<T> collection) {
    List<T> list = Collections.unmodifiableList(new ArrayList<>(collection));
    return list.isEmpty() ? null : list;
}

From source file:Main.java

/**
 * Wraps a possibly null list in an immutable wrapper.
 *
 * @param <T>    the type parameter
 * @param source Nullable list to wrap./*from www  .  j a  va  2  s .  c o m*/
 * @return {@link Collections#unmodifiableList(List)} if given list is not null, otherwise {@link java.util.Collections#EMPTY_LIST}.
 */
public static <T> List<T> wrap(final List<T> source) {
    if (source != null) {
        return Collections.unmodifiableList(source);
    }
    return Collections.emptyList();
}

From source file:Main.java

public static <T> List<T> nonNullFrom(List<T> list) {
    if (list == null || list.isEmpty()) {
        return Collections.emptyList();
    }//  w ww .j a v a 2 s  .c  om
    return Collections.unmodifiableList(list);
}

From source file:Main.java

static <E> List<E> getList(List<E> orig, Class<E> elemType) {
    if (orig == null || orig.isEmpty()) {
        return Collections.emptyList();
    } else if (orig.size() == 1) {
        return Collections.singletonList(orig.get(0));
    } else {/*  w ww  .  ja va 2 s .c o m*/
        return Collections.unmodifiableList(Arrays.asList(orig.toArray(createArray(elemType, orig.size()))));
    }
}

From source file:Main.java

private static List<Color> buildPalette(int[] raw) {
    Preconditions.checkArgument(raw.length == 256 * 3);
    Color[] pal = new Color[256];
    for (int i = 0; i < pal.length; i++) {
        pal[i] = new Color(raw[i * 3], raw[i * 3 + 1], raw[i * 3 + 2]);
    }/*from ww w  .java2s. com*/
    return Collections.unmodifiableList(Arrays.asList(pal));
}

From source file:com.mmj.app.web.tools.EnumViewTools.java

public static List<RightMenuEnum> getAllRightMenu() {
    if (rightMenuEnumList == null) {
        rightMenuEnumList = new ArrayList<RightMenuEnum>();
        for (RightMenuEnum _enum : RightMenuEnum.values()) {
            rightMenuEnumList.add(_enum);
        }//  w w w .j  a v a 2  s . c  o  m
        rightMenuEnumList = Collections.unmodifiableList(rightMenuEnumList);
    }
    return rightMenuEnumList;
}

From source file:com.github.blindpirate.gogradle.util.CollectionUtils.java

public static <T> List<T> immutableList(T... elements) {
    return Collections.unmodifiableList(asList(elements));
}

From source file:Main.java

/**
 * @param <T>      the element type
 * @param elements the elements//from w  w  w .  j  a  va  2 s  . c  o m
 *
 * @return an <b>UNMODIFIABLE</b> List&lt;T&gt;
 */
@SafeVarargs
@SuppressWarnings("varargs")
public static <T> List<T> list(T... elements) {
    return Collections.unmodifiableList(Arrays.asList(elements));
}