org.omnifaces.util

Class Utils

java.lang.Object

org.omnifaces.util.Utils

public final class Utils
extends Object

Collection of general utility methods that do not fit in one of the more specific classes.

Author:

Arjan Tijms, Bauke Scholtz

Method Summary

Methods

Modifier and Type	Method and Description
static IOException	close(Closeable resource) Check if the given resource is not null and then close it, whereby any caught IOException is been returned instead of thrown, so that the caller can if necessary handle (log) or just ignore it without the need to put another try-catch.
static <T> T	coalesce(T... objects) Returns the first non-null object of the argument list, or null if there is no such element.
static boolean	isEmpty(Collection<?> collection) Returns true if the given collection is null or is empty.
static boolean	isEmpty(Object value) Returns true if the given value is null or is empty.
static boolean	isEmpty(Object[] array) Returns true if the given array is null or is empty.
static boolean	isEmpty(String string) Returns true if the given string is null or is empty.
static <T> boolean	isOneOf(T object, T... objects) Returns true if the given object equals one of the given objects.
static long	stream(InputStream input, OutputStream output) Stream the given input to the given output by NIO ByteBuffer.
static <T> Set<T>	unmodifiableSet(Object... values) Creates an unmodifiable set based on the given values.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

isEmpty

public static boolean isEmpty(String string)

Returns true if the given string is null or is empty.

Parameters:

string - The string to be checked on emptiness.

Returns:

True if the given string is null or is empty.

isEmpty

public static boolean isEmpty(Object[] array)

Returns true if the given array is null or is empty.

Parameters:

array - The array to be checked on emptiness.

Returns:

True if the given array is null or is empty.

isEmpty

public static boolean isEmpty(Collection<?> collection)

Returns true if the given collection is null or is empty.

Parameters:

collection - The collection to be checked on emptiness.

Returns:

True if the given collection is null or is empty.

isEmpty

public static boolean isEmpty(Object value)

Returns true if the given value is null or is empty. Types of String, Object[], Collection and Map are recognized. If none is recognized, then examine the emptiness of the toString() representation instead.

Parameters:

value - The value to be checked on emptiness.

Returns:

True if the given value is null or is empty.

coalesce

public static <T> T coalesce(T... objects)

Returns the first non-null object of the argument list, or null if there is no such element.

Type Parameters:

T - The generic object type.

Parameters:

objects - The argument list of objects to be tested for non-null.

Returns:

The first non-null object of the argument list, or null if there is no such element.

isOneOf

public static <T> boolean isOneOf(T object,
                  T... objects)

Returns true if the given object equals one of the given objects.

Type Parameters:

T - The generic object type.

Parameters:

object - The object to be checked if it equals one of the given objects.

objects - The argument list of objects to be tested for equality.

Returns:

true if the given object equals one of the given objects.

stream

public static long stream(InputStream input,
          OutputStream output)
                   throws IOException

Stream the given input to the given output by NIO ByteBuffer. Both the input and output streams will implicitly be closed after streaming, regardless of whether an exception is been thrown or not.

Parameters:

input - The input stream.

output - The output stream.

Returns:

The length of the written bytes.

Throws:

IOException - When an I/O error occurs.

close

public static IOException close(Closeable resource)

Check if the given resource is not null and then close it, whereby any caught IOException is been returned instead of thrown, so that the caller can if necessary handle (log) or just ignore it without the need to put another try-catch.

Parameters:

resource - The closeable resource to be closed.

Returns:

The caught IOException, or null if none is been thrown.

unmodifiableSet

public static <T> Set<T> unmodifiableSet(Object... values)

Creates an unmodifiable set based on the given values. If one of the values is an instance of an array or a collection, then each of its values will also be merged into the set. Nested arrays or collections will result in a ClassCastException.

Parameters:

values - The values to create an unmodifiable set for.

Returns:

An unmodifiable set based on the given values.

Throws:

ClassCastException - When one of the values or one of the arrays or collections is of wrong type.

Since:

1.1