joinquery.util

类 CollectionUtil

java.lang.Object

joinquery.util.CollectionUtil

public class CollectionUtil
extends java.lang.Object

构造器概要

构造器

构造器和说明
CollectionUtil()

方法概要

限定符和类型	方法和说明
static <K,V> V	computeIfAbsent(java.util.Map<K,V> concurrentHashMap, K key, java.util.function.Function<? super K,? extends V> mappingFunction) 主要是用于修复 concurrentHashMap 在 jdk1.8 下的死循环问题
static boolean	isEmpty(java.util.Collection<?> coll)
static boolean	isEmpty(java.util.Map<?,?> map)
static boolean	isNotEmpty(java.util.Collection<?> coll)
static boolean	isNotEmpty(java.util.Map<?,?> map)
static <T> java.util.List<T>	merge(java.util.List<T> list, java.util.List<T> other) 合并 list
static <T> java.util.List<T>	newArrayList(T... elements)
static <K,V> java.util.HashMap<K,V>	newHashMap()
static <T> java.util.Set<T>	newHashSet(T... elements)

从类继承的方法 java.lang.Object

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

构造器详细资料

CollectionUtil

public CollectionUtil()

方法详细资料

isEmpty

public static boolean isEmpty(java.util.Collection<?> coll)

isNotEmpty

public static boolean isNotEmpty(java.util.Collection<?> coll)

isEmpty

public static boolean isEmpty(java.util.Map<?,?> map)

isNotEmpty

public static boolean isNotEmpty(java.util.Map<?,?> map)

merge

public static <T> java.util.List<T> merge(java.util.List<T> list,
                                          java.util.List<T> other)

合并 list

newHashMap

public static <K,V> java.util.HashMap<K,V> newHashMap()

computeIfAbsent

public static <K,V> V computeIfAbsent(java.util.Map<K,V> concurrentHashMap,
                                      K key,
                                      java.util.function.Function<? super K,? extends V> mappingFunction)

主要是用于修复 concurrentHashMap 在 jdk1.8 下的死循环问题

另请参阅:

https://bugs.openjdk.org/browse/JDK-8161372

newHashSet

public static <T> java.util.Set<T> newHashSet(T... elements)

newArrayList

public static <T> java.util.List<T> newArrayList(T... elements)