org.springframework.core.env
Class EnumerablePropertySource<T>

java.lang.Object
  org.springframework.core.env.PropertySource<T>
      org.springframework.core.env.EnumerablePropertySource<T>

Direct Known Subclasses:

MapPropertySource, PortletConfigPropertySource, PortletContextPropertySource, ServletConfigPropertySource, ServletContextPropertySource

public abstract class EnumerablePropertySource<T>
extends PropertySource<T>

A PropertySource implementation capable of interrogating its underlying source object to enumerate all possible property name/value pairs. Exposes the getPropertyNames() method to allow callers to introspect available properties without having to access the underlying source object. This also facilitates a more efficient implementation of containsProperty(String), in that it can call getPropertyNames() and iterate through the returned array rather than attempting a call to PropertySource.getProperty(String) which may be more expensive. Implementations may consider caching the result of getPropertyNames() to fully exploit this performance opportunity. Most framework-provided PropertySource implementations are enumerable; a counter-example would be JndiPropertySource where, due to the nature of JNDI it is not possible to determine all possible property names at any given time; rather it is only possible to try to access a property (via PropertySource.getProperty(String)) in order to evaluate whether it is present or not.

Since:

3.1

Author:

Chris Beams

Nested Class Summary

Nested classes/interfaces inherited from class org.springframework.core.env.PropertySource

PropertySource.StubPropertySource

Field Summary

protected static String[]	EMPTY_NAMES_ARRAY
protected Log	logger

Fields inherited from class org.springframework.core.env.PropertySource

name, source

Constructor Summary

EnumerablePropertySource(String name, T source)

Method Summary

boolean	containsProperty(String name) Return whether this PropertySource contains a property with the given name.
abstract String[]	getPropertyNames() Return the names of all properties contained by the source object (never null).

Methods inherited from class org.springframework.core.env.PropertySource

equals, getName, getProperty, getSource, hashCode, named, toString

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

EMPTY_NAMES_ARRAY

protected static final String[] EMPTY_NAMES_ARRAY

logger

protected final Log logger

Constructor Detail

EnumerablePropertySource

public EnumerablePropertySource(String name,
                                T source)

Method Detail

getPropertyNames

public abstract String[] getPropertyNames()

Return the names of all properties contained by the source object (never null).

containsProperty

public boolean containsProperty(String name)

Return whether this PropertySource contains a property with the given name.

This implementation checks for the presence of the given name within the getPropertyNames() array.

Overrides:

containsProperty in class PropertySource<T>

Parameters:

name - the property to find