PutIfAbsentMap (JABB 1.0.49 API)

java.lang.Object
- net.sf.jabb.util.col.PutIfAbsentMap<K,V>

Type Parameters:

K - Type of the key of the Map entries
Map的key的类型

V - Type of the value of the Map entries
Map的value的类型

All Implemented Interfaces:

Map<K,V>
```
public class PutIfAbsentMap<K,V>
extends Object
implements Map<K,V>
```
Encapsulates Map so that a new entry is put in to the Map whenever there is a get for a non-existing entry.
把Map进一步封装，使得每次get的时候，如果没有，就自动put。
Please note that only these methods are synchronized: get/put/putAll/remove/clear.
注意只有这几个方法是同步的：get/put/putAll/remove/clear。

Author:

Zhengmao HU (James)

Nested Class Summary
- Nested classes/interfaces inherited from interface java.util.Map
  Map.Entry<K,V>

Field Summary

Fields
Modifier and Type Field and Description

protected Map<K,V> map

protected Object structureLock

protected MapValueFactory<K,V> valueFactory

Fields
Modifier and Type	Field and Description
`protected Map<K,V>`	`map`
`protected Object`	`structureLock`
`protected MapValueFactory<K,V>`	`valueFactory`

Constructor Summary

Constructors
Constructor and Description
`PutIfAbsentMap(Class<? extends Map> mapClazz, Class<? extends V> valueClazz)` Constructor.
`PutIfAbsentMap(Class<? extends Map> mapClazz, Class<? extends V> valueClazz, Object valueParam)` Constructor.
`PutIfAbsentMap(Class<? extends Map> mapClazz, MapValueFactory<K,V> valueFactory)` Constructor.
`PutIfAbsentMap(Class<? extends V> valueClazz)` Constructor.
`PutIfAbsentMap(Class<? extends V> valueClazz, Object valueParam)` Constructor.
`PutIfAbsentMap(Map<K,V> originalMap, Class<? extends V> valueClazz)` Constructs an instance with specified Map instance and value Class. 给定Map实例以及value的类，把一个普通的Map实例封装成“每次get的时候，如果没有，就自动put”。
`PutIfAbsentMap(Map<K,V> originalMap, Class<? extends V> valueClazz, Object valueParam)` Constructs an instance with specified Map instance and value Class. 给定Map实例以及value的类，把一个普通的Map实例封装成“每次get的时候，如果没有，就自动put”。
`PutIfAbsentMap(Map<K,V> originalMap, MapValueFactory<K,V> valueFactory)` Constructor.
`PutIfAbsentMap(MapValueFactory<K,V> valueFactory)` Constructor.

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`void`	`clear()`
`boolean`	`containsKey(Object obj)`
`boolean`	`containsValue(Object obj)`
`Set<Map.Entry<K,V>>`	`entrySet()`
`V`	`get(Object key)` Get the value object corresponding to the key object specified, if such entry does not exist in the Map, then create one and put into the Map and return the value object in the newly created entry. 取得key所对应的value，如果目前在Map里没有，则在Map里新建一个并返回新建的这个value对象。
`Map<K,V>`	`getMap()` Get the encapsulated Map instance. 获得最初被封装的那个Map。
`protected static Map`	`instantiateMap(Class<? extends Map> mapClazz)`
`boolean`	`isEmpty()`
`Set<K>`	`keySet()`
`V`	`put(K key, V value)`
`void`	`putAll(Map<? extends K,? extends V> anotherMap)`
`V`	`remove(Object obj)`
`int`	`size()`
`String`	`toString()`
`Collection<V>`	`values()`

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.util.Map
compute, computeIfAbsent, computeIfPresent, equals, forEach, getOrDefault, hashCode, merge, putIfAbsent, remove, replace, replace, replaceAll

- Field Detail
  - map
```
protected Map<K,V> map
```
  - valueFactory
```
protected MapValueFactory<K,V> valueFactory
```
  - structureLock
```
protected Object structureLock
```
- Constructor Detail
  - PutIfAbsentMap
```
public PutIfAbsentMap(Map<K,V> originalMap,
                      MapValueFactory<K,V> valueFactory)
```
    Constructor.
    
    Parameters:
    
    originalMap - The map to be encapsulated.
    
    valueFactory - The factory for creating values to be put into this map.
  - PutIfAbsentMap
```
public PutIfAbsentMap(Map<K,V> originalMap,
                      Class<? extends V> valueClazz)
```
    Constructs an instance with specified Map instance and value Class.
    给定Map实例以及value的类，把一个普通的Map实例封装成“每次get的时候，如果没有，就自动put”。
    
    Parameters:
    
    originalMap - The Map instance that will be encapsulated.
    被封装进来的Map实例。
    
    valueClazz - Class of the value of the Map entry.
    Map的value的类。
    
    Throws:
    
    RuntimeException - If no non-argument constructor can be found in valueClazz.
  - PutIfAbsentMap
```
public PutIfAbsentMap(Map<K,V> originalMap,
                      Class<? extends V> valueClazz,
                      Object valueParam)
```
    Constructs an instance with specified Map instance and value Class.
    给定Map实例以及value的类，把一个普通的Map实例封装成“每次get的时候，如果没有，就自动put”。
    
    Parameters:
    
    originalMap - The Map instance that will be encapsulated.
    被封装进来的Map实例。
    
    valueClazz - Class of the value of the Map entry.
    Map的value的类。
    
    valueParam - Parameter to be passed in to the constructor of valueClazz.
    
    Throws:
    
    RuntimeException - if no correct constructor in valueClazz can be found.
  - PutIfAbsentMap
```
public PutIfAbsentMap(Class<? extends Map> mapClazz,
                      MapValueFactory<K,V> valueFactory)
```
    Constructor.
    
    Parameters:
    
    mapClazz - The class type of the encapsulated class.
    
    valueFactory - The factory of values to be put into this map.
    
    Throws:
    
    RuntimeException - if cannot instantiate a new map instance.
  - PutIfAbsentMap
```
public PutIfAbsentMap(Class<? extends Map> mapClazz,
                      Class<? extends V> valueClazz)
```
    Constructor.
    
    Parameters:
    
    mapClazz - The class type of the encapsulated class.
    
    valueClazz - The class type of the value class.
    
    Throws:
    
    RuntimeException - if cannot instantiate a new map instance.
    
    RuntimeException - if no non-argument constructor can be found in valueClazz
  - PutIfAbsentMap
```
public PutIfAbsentMap(Class<? extends Map> mapClazz,
                      Class<? extends V> valueClazz,
                      Object valueParam)
```
    Constructor.
    
    Parameters:
    
    mapClazz - The class type of the encapsulated class.
    
    valueClazz - The class type of the value class.
    
    valueParam - Parameter that will be passed in to the constructor of valueClazz
    
    Throws:
    
    RuntimeException - if cannot instantiate a new map instance.
    
    RuntimeException - if no non-argument constructor can be found in valueClazz
  - PutIfAbsentMap
```
public PutIfAbsentMap(MapValueFactory<K,V> valueFactory)
```
    Constructor. A HashMap will be created and encapsulated.
    
    Parameters:
    
    valueFactory - The factory of map values.
  - PutIfAbsentMap
```
public PutIfAbsentMap(Class<? extends V> valueClazz)
               throws NoSuchMethodException
```
    Constructor. A HashMap will be created and encapsulated.
    
    Parameters:
    
    valueClazz - Type of the value classes
    
    Throws:
    
    NoSuchMethodException - if valueClazz does not have a non-argument constructor.
  - PutIfAbsentMap
```
public PutIfAbsentMap(Class<? extends V> valueClazz,
                      Object valueParam)
```
    Constructor. A HashMap will be created and encapsulated.
    
    Parameters:
    
    valueClazz - Type of the value classes
    
    valueParam - Parameter that will be passed in to the constructor of valueClazz
    
    Throws:
    
    NoSuchMethodException - if valueClazz does not have a non-argument constructor.
- Method Detail
  - instantiateMap
```
protected static Map instantiateMap(Class<? extends Map> mapClazz)
```
  - getMap
```
public Map<K,V> getMap()
```
    Get the encapsulated Map instance.
    获得最初被封装的那个Map。
    
    Returns:
    
    The map instance that is encapsulated inside.
  - get
```
public V get(Object key)
```
    Get the value object corresponding to the key object specified, if such entry does not exist in the Map, then create one and put into the Map and return the value object in the newly created entry.
    取得key所对应的value，如果目前在Map里没有，则在Map里新建一个并返回新建的这个value对象。
    
    Specified by:
    
    get in interface Map<K,V>
    
    Parameters:
    
    key - The key object that will be used to look for the value object.
  - put
```
public V put(K key,
             V value)
```
    Specified by:
    
    put in interface Map<K,V>
  - putAll
```
public void putAll(Map<? extends K,? extends V> anotherMap)
```
    Specified by:
    
    putAll in interface Map<K,V>
  - remove
```
public V remove(Object obj)
```
    Specified by:
    
    remove in interface Map<K,V>
  - clear
```
public void clear()
```
    Specified by:
    
    clear in interface Map<K,V>
  - containsKey
```
public boolean containsKey(Object obj)
```
    Specified by:
    
    containsKey in interface Map<K,V>
  - containsValue
```
public boolean containsValue(Object obj)
```
    Specified by:
    
    containsValue in interface Map<K,V>
  - entrySet
```
public Set<Map.Entry<K,V>> entrySet()
```
    Specified by:
    
    entrySet in interface Map<K,V>
  - isEmpty
```
public boolean isEmpty()
```
    Specified by:
    
    isEmpty in interface Map<K,V>
  - keySet
```
public Set<K> keySet()
```
    Specified by:
    
    keySet in interface Map<K,V>
  - size
```
public int size()
```
    Specified by:
    
    size in interface Map<K,V>
  - values
```
public Collection<V> values()
```
    Specified by:
    
    values in interface Map<K,V>
  - toString
```
public String toString()
```
    Overrides:
    
    toString in class Object

Class PutIfAbsentMap<K,V>

Nested Class Summary

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

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Methods inherited from interface java.util.Map

Field Detail

map

valueFactory

structureLock

Constructor Detail

PutIfAbsentMap

PutIfAbsentMap

PutIfAbsentMap

PutIfAbsentMap

PutIfAbsentMap

PutIfAbsentMap

PutIfAbsentMap

PutIfAbsentMap

PutIfAbsentMap

Method Detail

instantiateMap

getMap

get

put

putAll

remove

clear

containsKey

containsValue

entrySet

isEmpty

keySet

size

values

toString