com.rometools.utils

Class Lists

java.lang.Object

com.rometools.utils.Lists

public final class Lists
extends Object

Method Summary

Methods

Modifier and Type	Method and Description
static <T> List<T>	create(T item) Creates a new List with the given item as the first entry.
static <T> List<T>	createWhenNull(List<T> list) Returns the list when it is not null.
static <T> List<T>	emptyToNull(List<T> list) Returns null, when the given list is empty or null
static <T> T	firstEntry(List<T> list) Extracts the first entry of the list when it is not null and contains values.
static boolean	isEmpty(List<?> list) Checks whether the list is null or empty.
static boolean	isNotEmpty(List<?> list) Checks whether the list is not null and not empty.
static boolean	sizeIs(List<?> list, int size) Checks whether the list has the given size.

Methods inherited from class java.lang.Object

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

Method Detail

createWhenNull

public static <T> List<T> createWhenNull(List<T> list)

Returns the list when it is not null. Returns a new list otherwise.

Parameters:

list - The list to process, can be null

Returns:

The input list when it is not null, a new list otherwise

create

public static <T> List<T> create(T item)

Creates a new List with the given item as the first entry.

Parameters:

item - The item to add to the new list

Returns:

List containing the given item

firstEntry

public static <T> T firstEntry(List<T> list)

Extracts the first entry of the list when it is not null and contains values.

Parameters:

list - The list to extract the first entry from, can be null

Returns:

The first entry of the list when it is not null or empty, null otherwise

isEmpty

public static boolean isEmpty(List<?> list)

Checks whether the list is null or empty.

Parameters:

list - The list to check

Returns:

true when the list is null or empty, false otherwise

isNotEmpty

public static boolean isNotEmpty(List<?> list)

Checks whether the list is not null and not empty.

Parameters:

list - The list to check

Returns:

true when the list is not null and not empty

sizeIs

public static boolean sizeIs(List<?> list,
             int size)

Checks whether the list has the given size. A null list is treated like a list without entries.

Parameters:

list - The list to check

size - The size to check

Returns:

true when the list has the given size or when size = 0 and the list is null, false otherwise

emptyToNull

public static <T> List<T> emptyToNull(List<T> list)

Returns null, when the given list is empty or null

Parameters:

list - The list to process

Returns:

null when the list is empty or null, the given list otherwise