com.jalios.util

Class MapUtils

java.lang.Object

com.jalios.util.MapUtils

public final class MapUtils
extends java.lang.Object

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	MapUtils.ConcurrentMapBuilder<K,V>
static class	MapUtils.MapBuilder<K,V>

Method Summary

Modifier and Type	Method and Description
static <K,V> MapUtils.MapBuilder<K,V>	builder() Create a new MapBuilder.
static <K,V> MapUtils.MapBuilder<K,V>	builder(java.util.Map<K,V> map) Create a new MapBuilder initialized with the given Map. Usage :
static <K,V> MapUtils.ConcurrentMapBuilder<K,V>	concurrentBuilder() Create a new ConcurrentMapBuilder.
static <K,V> MapUtils.ConcurrentMapBuilder<K,V>	concurrentBuilder(java.util.concurrent.ConcurrentMap<K,V> map) Create a new ConcurrentMapBuilder initialized with the given ConcurrentMap.
static <K,V> java.util.Map<K,V>	filterMap(java.util.Map<K,V> map, java.util.function.Predicate<java.util.Map.Entry<K,V>> predicate) Filter the given map according to the condition defined by the given Predicate. Usage:

Methods inherited from class java.lang.Object

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

Method Detail

filterMap

public static <K,V> java.util.Map<K,V> filterMap(java.util.Map<K,V> map,
                                                 java.util.function.Predicate<java.util.Map.Entry<K,V>> predicate)

Filter the given map according to the condition defined by the given Predicate.
Usage:

 
 Map<Integer, String> map = MapUtils.<Integer, String>builder()
                                    .put(new Integer(1), "January")
                                    .put(new Integer(2), "February")
                                    .put(new Integer(3), "March")
                                    .put(new Integer(4), "April")
                                    .put(new Integer(5), "May")    
                                    .put(new Integer(6), "June")
                                    .put(new Integer(7), "July")
                                    .put(new Integer(8), "August")
                                    .put(new Integer(9), "September")
                                    .put(new Integer(10), "October")
                                    .put(new Integer(11), "November")
                                    .put(new Integer(12), "December")
                                    .build();
 
 Map filterMap1 = MapUtils.filterMap(mapBuilder.build(), (entry) -> {
   String v = entry.getValue();
   return v.length() == 4;
 });
 
 Map filterMap2 = MapUtils.filterMap(mapBuilder.build(), (entry) -> {
   Integer k = entry.getKey();
   return k > 4 && k < 8;
 });
 
 

Output :

• filterMap1: {6=June, 7=July}
• filterMap2: {5=May, 6=June, 7=July}

Parameters:

map - map to filter

predicate - Predicate

Returns:

Filtered Map

builder

public static <K,V> MapUtils.MapBuilder<K,V> builder()

Create a new MapBuilder. The type of Map implementation used is HashMap.
Usage :

 
 Map<Integer, String> map = MapUtils.<Integer, String>builder()
                                    .put(new Integer(1), "January")
                                    .put(new Integer(2), "February")
                                    .put(new Integer(3), "March")
                                    .put(new Integer(4), "April")
                                    .put(new Integer(5), "May")    
                                    .put(new Integer(6), "June")
                                    .put(new Integer(7), "July")
                                    .put(new Integer(8), "August")
                                    .put(new Integer(9), "September")
                                    .put(new Integer(10), "October")
                                    .put(new Integer(11), "November")
                                    .put(new Integer(12), "December")
                                    .build();
 
 

Returns:

MapBuilder

builder

public static <K,V> MapUtils.MapBuilder<K,V> builder(java.util.Map<K,V> map)

Create a new MapBuilder initialized with the given Map.
Usage :

 
 Map<Integer, String> map = MapUtils.<Integer, String>builder(new LinkedHashMap<>())
                                    .put(new Integer(1), "January")
                                    .put(new Integer(2), "February")
                                    .put(new Integer(3), "March")
                                    .put(new Integer(4), "April")
                                    .put(new Integer(5), "May")    
                                    .put(new Integer(6), "June")
                                    .put(new Integer(7), "July")
                                    .put(new Integer(8), "August")
                                    .put(new Integer(9), "September")
                                    .put(new Integer(10), "October")
                                    .put(new Integer(11), "November")
                                    .put(new Integer(12), "December")
                                    .build();
 
 

Parameters:

map - Map to initialize the MapBuilder with a specific Map

Returns:

MapBuilder

concurrentBuilder

public static <K,V> MapUtils.ConcurrentMapBuilder<K,V> concurrentBuilder()

Create a new ConcurrentMapBuilder. The type of Map implementation used is ConcurrentHashMap.

Returns:

ConcurrentMapBuilder

concurrentBuilder

public static <K,V> MapUtils.ConcurrentMapBuilder<K,V> concurrentBuilder(java.util.concurrent.ConcurrentMap<K,V> map)

Create a new ConcurrentMapBuilder initialized with the given ConcurrentMap.

Parameters:

map - Map to initialize the MapBuilder with a specific ConcurrentMap

Returns:

ConcurrentMapBuilder