org.apache.tapestry5.internal.util
Class NamedSet<T>

java.lang.Object
  org.apache.tapestry5.internal.util.NamedSet<T>

Type Parameters:

T - the type of value stored

public class NamedSet<T>
extends Object

Simple, thread-safe associative array that relates a name to a value. Names are case-insensitive. This is optimized to use less memory (than a CaseInsensitiveMap (it uses a singly-liked list), though the cost of a lookup is more expensive. However, this is a good match against many of the structures inside a page instance, where most lookups occur only during page constructions, and the number of values is often small.

We use simple synchronization, as uncontested synchronized locks are very, very cheap.

Constructor Summary

NamedSet()

Method Summary

static <T> NamedSet<T>	create() Convienience method for creating a new, empty set.
void	eachValue(Worker<T> worker) Iterates over the values, passing each in turn to the supplied worker.
static <T> T	get(NamedSet<T> set, String name) Convienience method for getting a value from a set that may be null.
T	get(String name) Gets the value for the provided name.
Set<String>	getNames() Returns a set of the names of all stored values.
static Set<String>	getNames(NamedSet<?> set) Gets the names in the set, returning an empty set if the NamedSet is null.
Set<T>	getValues() Returns a set of all the values in the set.
static <T> Set<T>	getValues(NamedSet<T> set) Returns the values in the set, returning an empty set if the NamedSet is null.
void	put(String name, T newValue) Stores a new value into the set, replacing any previous value with the same name.
boolean	putIfNew(String name, T newValue) Puts a new value, but only if it does not already exist.

Methods inherited from class java.lang.Object

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

Constructor Detail

NamedSet

public NamedSet()

Method Detail

getNames

public Set<String> getNames()

Returns a set of the names of all stored values.

getValues

public Set<T> getValues()

Returns a set of all the values in the set.

get

public T get(String name)

Gets the value for the provided name.

Parameters:

name - used to locate the value

Returns:

the value, or null if not found

put

public void put(String name,
                T newValue)

Stores a new value into the set, replacing any previous value with the same name. Name comparisons are case insensitive.

Parameters:

name - to store the value. May not be blank.

newValue - non-null value to store

eachValue

public void eachValue(Worker<T> worker)

Iterates over the values, passing each in turn to the supplied worker.

Parameters:

worker - performs an operation on, or using, the value

putIfNew

public boolean putIfNew(String name,
                        T newValue)

Puts a new value, but only if it does not already exist.

Parameters:

name - name to store (comparisons are case insensitive) may not be blank

newValue - non-null value to store

Returns:

true if value stored, false if name already exists

create

public static <T> NamedSet<T> create()

Convienience method for creating a new, empty set.

get

public static <T> T get(NamedSet<T> set,
                        String name)

Convienience method for getting a value from a set that may be null.

Type Parameters:

T -

Parameters:

set - set to search, may be null

name - name to lookup

Returns:

value from set, or null if not found, or if set is null

getNames

public static Set<String> getNames(NamedSet<?> set)

Gets the names in the set, returning an empty set if the NamedSet is null.

getValues

public static <T> Set<T> getValues(NamedSet<T> set)

Returns the values in the set, returning an empty set if the NamedSet is null.