de.team33.patterns.collection.ceres

Class Mapping

java.lang.Object

de.team33.patterns.collection.ceres.Mapping

public final class Mapping
extends Object

Some convenience methods to deal with Maps.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	Mapping.Builder<K,V,M extends Map<K,V>> Builder implementation to build target instances of Map.
static class	Mapping.Charger<K,V,M extends Map<K,V>> Charger implementation to charge target instances of Map.
static interface	Mapping.Setup<K,V,M extends Map<K,V>,S extends Mapping.Setup<K,V,M,S>> Utility interface to set up a target instance of Map.

Method Summary

Modifier and Type	Method and Description
static <K,V,M extends Map<K,V>> Mapping.Builder<K,V,M>	builder(Supplier<M> newTarget) Returns a new Mapping.Builder for target instances as supplied by the given Supplier.
static <K,V,M extends Map<K,V>> Mapping.Charger<K,V,M>	charger(M target) Returns a new Mapping.Charger for a given target instance.
static <M extends Map<?,?>> M	clear(M subject) Just like subject.clear() for a given subject but returns the subject.
static boolean	containsKey(Map<?,?> subject, Object key) Just like Map.containsKey(Object) for a given subject.
static boolean	containsValue(Map<?,?> subject, Object value) Just like Map.containsValue(Object) for a given subject.
static <V> V	get(Map<?,V> subject, Object key) Just like Map.get(Object) for a given subject.
static <K,V> Map<K,V>	proxy(Map<K,V> subject) Supplies a proxy for a given subject that may be used to implement some Map-specific methods, e.g.: Object.toString() Map.equals(Object) Map.hashCode() ...
static <K,V,M extends Map<K,V>> M	put(M subject, K key, V value) Just like subject.put(key, value) for a given subject, but returns the subject.
static <K,V,M extends Map<? super K,? super V>> M	putAll(M subject, Map<? extends K,? extends V> origin) Just like subject.putAll(origin) for a given subject, but returns the subject.
static <M extends Map<?,?>> M	remove(M subject, Object key) Just like subject.remove(key) for a given subject but returns the subject.

Methods inherited from class java.lang.Object

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

Method Detail

put

public static <K,V,M extends Map<K,V>> M put(M subject,
                                             K key,
                                             V value)

Just like subject.put(key, value) for a given subject, but returns the subject.

Throws:

UnsupportedOperationException - if Map.put(Object, Object) is not supported by the subject.

NullPointerException - if subject is null or ...

NullPointerException - if the specified key or value is null and the subject does not permit null keys or values

ClassCastException - if the class of the specified key or value prevents it from being put into the subject (may occur only if used raw or forced in a mismatched class context).

IllegalArgumentException - if some property of the specified key or value prevents it from being stored in the subject.

See Also:

Map.put(Object, Object)

putAll

public static <K,V,M extends Map<? super K,? super V>> M putAll(M subject,
                                                                Map<? extends K,? extends V> origin)

Just like subject.putAll(origin) for a given subject, but returns the subject.

Throws:

UnsupportedOperationException - if Map.putAll(Map) is not supported by the subject.

NullPointerException - if subject or origin is null or ...

NullPointerException - if any of the specified keys or values are null and the subject does not permit null keys or values.

ClassCastException - if the class of any specified key or value prevents it from being put into the subject (may occur only if used raw or forced in a mismatched class context).

IllegalArgumentException - if some property of any key or value in the specified origin prevents it from being stored in the subject.

See Also:

Map.putAll(Map)

clear

public static <M extends Map<?,?>> M clear(M subject)

Just like subject.clear() for a given subject but returns the subject.

Throws:

UnsupportedOperationException - if Collection.clear() is not supported by the subject.

NullPointerException - if subject is null.

See Also:

Map.clear()

remove

public static <M extends Map<?,?>> M remove(M subject,
                                            Object key)

Just like subject.remove(key) for a given subject but returns the subject.

Avoids an unnecessary ClassCastException or NullPointerException which might be caused by Map.remove(Object) when the subject does not support the requested key.

Throws:

UnsupportedOperationException - if Map.remove(Object) is not supported by the subject.

NullPointerException - if subject is null.

containsKey

public static boolean containsKey(Map<?,?> subject,
                                  Object key)

Just like Map.containsKey(Object) for a given subject.

Avoids an unnecessary ClassCastException or NullPointerException which might be caused by Map.containsKey(Object) when the subject does not support the requested key.

Throws:

NullPointerException - if subject is null.

containsValue

public static boolean containsValue(Map<?,?> subject,
                                    Object value)

Just like Map.containsValue(Object) for a given subject.

Avoids an unnecessary ClassCastException or NullPointerException which might be caused by Map.containsValue(Object) when the subject does not support the requested value.

Throws:

NullPointerException - if subject is null.

get

public static <V> V get(Map<?,V> subject,
                        Object key)

Just like Map.get(Object) for a given subject.

Avoids an unnecessary ClassCastException or NullPointerException which might be caused by Map.get(Object) when the subject does not support the requested key.

Returns:

The value or null if the subject doesn't contain (an entry for) the key.

Throws:

NullPointerException - if subject is null.

proxy

public static <K,V> Map<K,V> proxy(Map<K,V> subject)

Supplies a proxy for a given subject that may be used to implement some Map-specific methods, e.g.:

• Object.toString()
• Map.equals(Object)
• Map.hashCode()
• ...

Parameters:

subject - A Map, that at least provides independently ...

• Map.entrySet()

builder

public static <K,V,M extends Map<K,V>> Mapping.Builder<K,V,M> builder(Supplier<M> newTarget)

Returns a new Mapping.Builder for target instances as supplied by the given Supplier.

Type Parameters:

K - The key type of the target instance.

V - The value type of the target instance.

M - The final type of the target instance, at least Map.

charger

public static <K,V,M extends Map<K,V>> Mapping.Charger<K,V,M> charger(M target)

Returns a new Mapping.Charger for a given target instance.

Type Parameters:

K - The key type of the target instance.

V - The value type of the target instance.

M - The final type of the target instance, at least Map.