Package org.apache.sling.api.resource

Interface ValueMap

All Superinterfaces:

Map<String,Object>

All Known Subinterfaces:

ModifiableValueMap, PersistableValueMap

All Known Implementing Classes:

CachingValueMap, CompositeValueMap, DeepReadModifiableValueMapDecorator, DeepReadValueMapDecorator, MergingValueMap, ModifiableValueMapDecorator, ValueMapDecorator

@ConsumerType
public interface ValueMap
extends Map<String,Object>

The ValueMap is an easy way to access properties of a resource. With resources you can use Resource.getValueMap() to obtain the value map of a resource. The various getter methods can be used to get the properties of the resource.

In addition a value map returned by a resource supports getting of deep values, like get("content/title") which is equivalent to call getChild("content") on the resource, get the value map of that resource and call get("title") - but without requiring to do all the checks. Only the following methods support deep reads: Map.get(Object), get(String, Class), get(String, Object) and Map.containsKey(Object). A ValueMap should be immutable.

Nested Class Summary

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

Map.Entry<K extends Object,V extends Object>

Field Summary

Fields

Modifier and Type	Field	Description
static ValueMap	EMPTY	Empty immutable value map.

Method Summary

Modifier and Type	Method	Description
default <T> T	get(@NotNull String name, @NotNull Class<T> type)	Get a named property and convert it into the given type.
default <T> T	get(@NotNull String name, T defaultValue)	Get a named property and convert it into the given type.

Methods inherited from interface java.util.Map

clear, compute, computeIfAbsent, computeIfPresent, containsKey, containsValue, entrySet, equals, forEach, get, getOrDefault, hashCode, isEmpty, keySet, merge, put, putAll, putIfAbsent, remove, remove, replace, replace, replaceAll, size, values

Field Detail

EMPTY

static final ValueMap EMPTY

Empty immutable value map.

Method Detail

get

@Nullable
default <T> T get(@NotNull
                  @NotNull String name,
                  @NotNull
                  @NotNull Class<T> type)

Get a named property and convert it into the given type. This method does not support conversion into a primitive type or an array of a primitive type. It should return null in this case.

Type Parameters:

T - The class of the type

Parameters:

name - The name of the property

type - The class of the type

Returns:

Return named value converted to type T or null if non existing or can't be converted.

get

@NotNull
default <T> T get(@NotNull
                  @NotNull String name,
                  @NotNull
                  T defaultValue)

Get a named property and convert it into the given type. This method does not support conversion into a primitive type or an array of a primitive type. It should return the default value in this case.

Implementation hint: In the past it was allowed to call this with a 2nd parameter being null. Therefore all implementations should internally call Map.get(Object) when the 2nd parameter has value null.

Type Parameters:

T - The expected type

Parameters:

name - The name of the property

defaultValue - The default value to use if the named property does not exist or cannot be converted to the requested type. The default value is also used to define the type to convert the value to. Must not be null. If you want to return null by default rather rely on get(String, Class).

Returns:

Return named value converted to type T or the default value if non existing or can't be converted.