MapUtil (Hazelcast Root 3.12.12 API)

java.lang.Object
- com.hazelcast.util.MapUtil

public final class MapUtil
extends Object

Utility class for Maps

Method Summary

All Methods Static Methods Concrete Methods
Modifier and Type	Method and Description
`static int`	`calculateInitialCapacity(int expectedMapSize)` Returns the initial hash map capacity needed for the expected map size.
`static <K,V> ConcurrentMap<K,V>`	`createConcurrentHashMap(int expectedMapSize)` Utility method that creates an `LinkedHashMap` with its initialCapacity calculated to minimize rehash operations
`static <K,V> Map<K,V>`	`createHashMap(int expectedMapSize)` Utility method that creates an `HashMap` with its initialCapacity calculated to minimize rehash operations
`static <K,V> Map<K,V>`	`createHashMapAdapter(int expectedMapSize)` Utility method that creates an `HashMapAdapter` with its initialCapacity calculated to minimize rehash operations
`static <V> Int2ObjectHashMap<V>`	`createInt2ObjectHashMap(int expectedMapSize)` Utility method that creates an `Int2ObjectHashMap` with its initialCapacity calculated to minimize rehash operations
`static <K,V> Map<K,V>`	`createLinkedHashMap(int expectedMapSize)` Utility method that creates an `LinkedHashMap` with its initialCapacity calculated to minimize rehash operations
`static boolean`	`isNullOrEmpty(Map map)` Test the given map and return `true` if the map is null or empty.
`static int`	`toIntSize(long size)` Converts `long` map size to `int`.

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

- Method Detail
  - createHashMap
```
public static <K,V> Map<K,V> createHashMap(int expectedMapSize)
```
    Utility method that creates an HashMap with its initialCapacity calculated to minimize rehash operations
  - createHashMapAdapter
```
public static <K,V> Map<K,V> createHashMapAdapter(int expectedMapSize)
```
    Utility method that creates an HashMapAdapter with its initialCapacity calculated to minimize rehash operations
  - createLinkedHashMap
```
public static <K,V> Map<K,V> createLinkedHashMap(int expectedMapSize)
```
    Utility method that creates an LinkedHashMap with its initialCapacity calculated to minimize rehash operations
  - createConcurrentHashMap
```
public static <K,V> ConcurrentMap<K,V> createConcurrentHashMap(int expectedMapSize)
```
    Utility method that creates an LinkedHashMap with its initialCapacity calculated to minimize rehash operations
  - createInt2ObjectHashMap
```
public static <V> Int2ObjectHashMap<V> createInt2ObjectHashMap(int expectedMapSize)
```
    Utility method that creates an Int2ObjectHashMap with its initialCapacity calculated to minimize rehash operations
  - calculateInitialCapacity
```
public static int calculateInitialCapacity(int expectedMapSize)
```
    Returns the initial hash map capacity needed for the expected map size. To avoid resizing the map, the initial capacity should be different than the expected size, depending on the load factor.
    
    Parameters:
    
    expectedMapSize - the expected map size
    
    Returns:
    
    the necessary initial capacity
    
    See Also:
    
    HashMap
  - isNullOrEmpty
```
public static boolean isNullOrEmpty(Map map)
```
    Test the given map and return true if the map is null or empty.
    
    Parameters:
    
    map - the map to test
    
    Returns:
    
    true if map is null or empty, otherwise false.
  - toIntSize
```
public static int toIntSize(long size)
```
    Converts long map size to int. If size is greater than Integer.MAX_VALUE then Integer.MAX_VALUE is returned.
    
    Parameters:
    
    size - map size
    
    Returns:
    
    map size in int type

Class MapUtil

Method Summary

Methods inherited from class java.lang.Object

Method Detail

createHashMap

createHashMapAdapter

createLinkedHashMap

createConcurrentHashMap

createInt2ObjectHashMap

calculateInitialCapacity

isNullOrEmpty

toIntSize