| java.lang.Object
 org.mortbay.util.LazyList
| LazyList | | public class LazyList implements Cloneable,Serializable(Code) | | Lazy List creation.
A List helper class that attempts to avoid unneccessary List
creation. If a method needs to create a List to return, but it is
expected that this will either be empty or frequently contain a
single item, then using LazyList will avoid additional object
creations by using Collections.EMPTY_LIST or
Collections.singletonList where possible.
Usage
Object lazylist =null;
while(loopCondition)
{
Object item = getItem();
if (item.isToBeAdded())
lazylist = LazyList.add(lazylist,item);
}
return LazyList.getList(lazylist);
An ArrayList of default size is used as the initial LazyList.
See Also: java.util.List
author:
Greg Wilkins (gregw) |
| Method Summary | |
| public static Object | add(Object list, Object item)
Add an item to a LazyList
Parameters:
list - The list to add to or null if none yet created.
Parameters:
item - The item to add. | | public static Object | add(Object list, int index, Object item)
Add an item to a LazyList
Parameters:
list - The list to add to or null if none yet created.
Parameters:
index - The index to add the item at.
Parameters:
item - The item to add. | | public static Object | addArray(Object list, Object[] array)
Add the contents of an array to a LazyList
Parameters:
list - The list to add to or null if none yet created.
Parameters:
collection - The Collection whose contents should be added. | | public static Object | addCollection(Object list, Collection collection)
Add the contents of a Collection to a LazyList
Parameters:
list - The list to add to or null if none yet created.
Parameters:
collection - The Collection whose contents should be added. | | public static Object[] | addToArray(Object[] array, Object item, Class type)
| | public static List | array2List(Object[] array)
| | public static Object | clone(Object list)
| | public static boolean | contains(Object list, Object item)
| | public static Object | ensureSize(Object list, int initialSize)
Ensure the capcity of the underlying list. | | public static Object | get(Object list, int i)
| | public static List | getList(Object list)
Get the real List from a LazyList. | | public static List | getList(Object list, boolean nullForEmpty)
Get the real List from a LazyList.
Parameters:
list - A LazyList returned from LazyList.add(Object) or null
Parameters:
nullForEmpty - If true, null is returned instead of anempty list. | | public static Iterator | iterator(Object list)
| | public static ListIterator | listIterator(Object list)
| | public static Object | remove(Object list, Object o)
| | public static Object | remove(Object list, int i)
| | public static Object[] | removeFromArray(Object[] array, Object item)
| | public static int | size(Object list)
| | public static Object | toArray(Object list, Class aClass)
| | public static String | toString(Object list)
| | public static String[] | toStringArray(Object list)
|
| add | | public static Object add(Object list, Object item)(Code) | | Add an item to a LazyList
Parameters:
list - The list to add to or null if none yet created.
Parameters:
item - The item to add. The lazylist created or added to. |
| add | | public static Object add(Object list, int index, Object item)(Code) | | Add an item to a LazyList
Parameters:
list - The list to add to or null if none yet created.
Parameters:
index - The index to add the item at.
Parameters:
item - The item to add. The lazylist created or added to. |
| addArray | | public static Object addArray(Object list, Object[] array)(Code) | | Add the contents of an array to a LazyList
Parameters:
list - The list to add to or null if none yet created.
Parameters:
collection - The Collection whose contents should be added. The lazylist created or added to. |
| addCollection | | public static Object addCollection(Object list, Collection collection)(Code) | | Add the contents of a Collection to a LazyList
Parameters:
list - The list to add to or null if none yet created.
Parameters:
collection - The Collection whose contents should be added. The lazylist created or added to. |
| addToArray | | public static Object[] addToArray(Object[] array, Object item, Class type)(Code) | | Add element to an array
Parameters:
array - The array to add to (or null)
Parameters:
item - The item to add
Parameters:
type - The type of the array (in case of null array) new array with contents of array plus item |
| array2List | | public static List array2List(Object[] array)(Code) | |
Parameters:
array - Any array of object A new modifiable list initialised with the elements from array. |
| ensureSize | | public static Object ensureSize(Object list, int initialSize)(Code) | | Ensure the capcity of the underlying list.
|
| get | | public static Object get(Object list, int i)(Code) | | Get item from the list
Parameters:
list - A LazyList returned from LazyList.add(Object) or null
Parameters:
i - int index the item from the list. |
| getList | | public static List getList(Object list)(Code) | | Get the real List from a LazyList.
Parameters:
list - A LazyList returned from LazyList.add(Object) The List of added items, which may be an EMPTY_LISTor a SingletonList. |
| getList | | public static List getList(Object list, boolean nullForEmpty)(Code) | | Get the real List from a LazyList.
Parameters:
list - A LazyList returned from LazyList.add(Object) or null
Parameters:
nullForEmpty - If true, null is returned instead of anempty list. The List of added items, which may be null, an EMPTY_LISTor a SingletonList. |
| size | | public static int size(Object list)(Code) | | The size of a lazy List
Parameters:
list - A LazyList returned from LazyList.add(Object) or null the size of the list. |
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