org.kuali.rice.kns.util.properties
Class PropertyTree

java.lang.Object
  org.kuali.rice.kns.util.properties.PropertyTree

All Implemented Interfaces:

Map

public class PropertyTree
extends Object
implements Map

This class is a Recursive container for single- and multi-level key,value pairs. It relies on the assumption that the consumer (presumably a JSP) will (implicitly) call toString at the end of the chain, which will return the String value of the chain's endpoint. It implements Map because that's how we fool jstl into converting "a.b.c" into get("a").get("b").get("c") instead of getA().getB().getC() Uses LinkedHashMap and LinkedHashSet because iteration order is now important.

Nested Class Summary

Nested classes/interfaces inherited from interface java.util.Map

Map.Entry<K,V>

Field Summary

(package private) Map	children
(package private) String	directValue
(package private) boolean	flat
private static org.apache.log4j.Logger	LOG
(package private) PropertyTree	parent

Constructor Summary

	PropertyTree() Creates an empty instance with no parent
	PropertyTree(boolean flat) Creates an empty instance with no parent.
	PropertyTree(Properties properties) Creates an instance pre-loaded with the given Properties
private	PropertyTree(PropertyTree parent) Creates an empty instance with the given parent.

Method Summary

void	clear() Unsupported, since you can't change the contents of a PropertyTree once it has been initialized.
private Map	collectEntries(String prefix, boolean flattenEntries) Builds a HashMap containing all of the key,value pairs stored in this PropertyTree
boolean	containsKey(Object key)
boolean	containsValue(Object value)
Set	entrySet() Returns an unmodifiable Set containing all key,value pairs in this PropertyTree and its children.
Object	get(Object key) Traverses the tree structure until it finds the PropertyTree pointed to by the given key, and returns that PropertyTree instance.
private PropertyTree	getChild(String key) Returns the PropertyTree associated with the given key.
Map	getDirectChildren()
private String	getDirectValue()
String	getProperty(String key)
private PropertyTree	getSubtree(String key) Returns the PropertyTree object with the given key, or null if there is none.
private boolean	hasChildren()
private boolean	hasDirectValue()
boolean	isEmpty()
Set	keySet() Returns an unmodifiable Set containing the keys of all of the entries of this PropertyTree.
Object	put(Object key, Object value) Unsupported, since you can't change the contents of a PropertyTree once it has been initialized.
void	putAll(Map t) Unsupported, since you can't change the contents of a PropertyTree once it has been initialized.
Object	remove(Object key) Unsupported, since you can't change the contents of a PropertyTree once it has been initialized.
private void	setDirectValue(String value) Sets the directValue of this PropertyTree to the given value.
void	setProperties(Properties properties) Inserts all properties from the given Properties instance into this PropertyTree.
void	setProperty(String key, String value) Associates the given key with the given value.
int	size()
String	toString() Returns the directValue of this PropertyTree, or null if there is none.
private void	validateKey(Object key)
private void	validateValue(Object value)
Collection	values() Returns an unmodifiable Collection containing the values of all of the entries of this PropertyTree.

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.Map

equals, hashCode

Field Detail

LOG

private static org.apache.log4j.Logger LOG

flat

final boolean flat

parent

final PropertyTree parent

directValue

String directValue

children

Map children

Constructor Detail

PropertyTree

public PropertyTree()

Creates an empty instance with no parent

PropertyTree

public PropertyTree(boolean flat)

Creates an empty instance with no parent. If flat is true, entrySet and size and the iterators will ignore entries in subtrees.

PropertyTree

private PropertyTree(PropertyTree parent)

Creates an empty instance with the given parent. If flat is true, entrySet and size and the iterators will ignore entries in subtrees.

PropertyTree

public PropertyTree(Properties properties)

Creates an instance pre-loaded with the given Properties

Parameters:

properties -

Method Detail

setProperty

public void setProperty(String key,
                        String value)

Associates the given key with the given value. If the given key has multiple levels (consists of multiple strings separated by '.'), the property value is stored such that it can be retrieved either directly, by calling get() and passing the entire key; or indirectly, by decomposing the key into its separate levels and calling get() successively on the result of the previous level's get.
For example, given
PropertyTree tree = new PropertyTree(); tree.set( "a.b.c", "something" ); the following statements are equivalent ways to retrieve the value:
Object one = tree.get( "a.b.c" ); Object two = tree.get( "a" ).get( "b" ).get( "c" );
Note: since I can't have the get method return both a PropertyTree and a String, getting an actual String requires calling toString on the PropertyTree returned by get.

Parameters:

key -

value -

Throws:

IllegalArgumentException - if the key is null

IllegalArgumentException - if the value is null

setProperties

public void setProperties(Properties properties)

Inserts all properties from the given Properties instance into this PropertyTree.

Parameters:

properties -

Throws:

IllegalArgumentException - if the Properties object is null

IllegalArgumentException - if a property's key is null

IllegalArgumentException - if a property's value is null

getSubtree

private PropertyTree getSubtree(String key)

Returns the PropertyTree object with the given key, or null if there is none.

Parameters:

key -

Returns:

Throws:

IllegalArgumentException - if the key is null

getProperty

public String getProperty(String key)

Parameters:

key -

Returns:

the directValue of the PropertyTree associated with the given key, or null if there is none

getDirectChildren

public Map getDirectChildren()

Returns:

an unmodifiable copy of the direct children of this PropertyTree

toString

public String toString()

Returns the directValue of this PropertyTree, or null if there is none.

This is the hack that makes it possible for jstl to get what it needs when trying to retrive the value of a simple key or of a complex (multi-part) key.

Overrides:

toString in class Object

setDirectValue

private void setDirectValue(String value)

Sets the directValue of this PropertyTree to the given value.

Parameters:

value -

getDirectValue

private String getDirectValue()

Returns:

directValue of this PropertyTree, or null if there is none

hasDirectValue

private boolean hasDirectValue()

Returns:

true if the directValue of this PropertyTree is not null

hasChildren

private boolean hasChildren()

Returns:

true if the this PropertyTree has children

getChild

private PropertyTree getChild(String key)

Returns the PropertyTree associated with the given key. If none exists, creates a new PropertyTree associates it with the given key, and returns it.

Parameters:

key -

Returns:

PropertyTree associated with the given key

Throws:

IllegalArgumentException - if the given key is null

validateKey

private void validateKey(Object key)

Parameters:

key -

Throws:

IllegalArgumentException - if the given key is not a String, or is null

validateValue

private void validateValue(Object value)

Parameters:

value -

Throws:

IllegalArgumentException - if the given value is not a String, or is null

entrySet

public Set entrySet()

Returns an unmodifiable Set containing all key,value pairs in this PropertyTree and its children.

Specified by:

entrySet in interface Map

See Also:

Map.entrySet()

collectEntries

private Map collectEntries(String prefix,
                           boolean flattenEntries)

Builds a HashMap containing all of the key,value pairs stored in this PropertyTree

Returns:

size

public int size()

Specified by:

size in interface Map

Returns:

the number of keys contained, directly or indirectly, in this PropertyTree

isEmpty

public boolean isEmpty()

Specified by:

isEmpty in interface Map

See Also:

Map.isEmpty()

values

public Collection values()

Returns an unmodifiable Collection containing the values of all of the entries of this PropertyTree.

Specified by:

values in interface Map

See Also:

Map.values()

keySet

public Set keySet()

Returns an unmodifiable Set containing the keys of all of the entries of this PropertyTree.

Specified by:

keySet in interface Map

See Also:

Map.keySet()

containsKey

public boolean containsKey(Object key)

Specified by:

containsKey in interface Map

See Also:

Map.containsKey(java.lang.Object)

containsValue

public boolean containsValue(Object value)

Specified by:

containsValue in interface Map

See Also:

Map.containsValue(java.lang.Object)

get

public Object get(Object key)

Traverses the tree structure until it finds the PropertyTree pointed to by the given key, and returns that PropertyTree instance.

Only returns PropertyTree instances; if you want the String value pointed to by a given key, you must call toString() on the returned PropertyTree (after verifying that it isn't null, of course).

Specified by:

get in interface Map

See Also:

Map.get(java.lang.Object)

clear

public void clear()

Unsupported, since you can't change the contents of a PropertyTree once it has been initialized.

Specified by:

clear in interface Map

putAll

public void putAll(Map t)

Unsupported, since you can't change the contents of a PropertyTree once it has been initialized.

Specified by:

putAll in interface Map

remove

public Object remove(Object key)

Unsupported, since you can't change the contents of a PropertyTree once it has been initialized.

Specified by:

remove in interface Map

put

public Object put(Object key,
                  Object value)

Unsupported, since you can't change the contents of a PropertyTree once it has been initialized.

Specified by:

put in interface Map