Question

import java.util.*;包含哪些类

Answer 1

接口
Collection
Comparator
Enumeration
EventListener
Formattable
Iterator
List
ListIterator
Map
Map.Entry
Observer
Queue
RandomAccess
Set
SortedMap
SortedSet
类
AbstractCollection
AbstractList
AbstractMap
AbstractQueue
AbstractSequentialList
AbstractSet
ArrayList
Arrays
BitSet
Calendar
Collections
Currency
Date
Dictionary
EnumMap
EnumSet
EventListenerProxy
EventObject
FormattableFlags
Formatter
GregorianCalendar
HashMap
HashSet
Hashtable
IdentityHashMap
LinkedHashMap
LinkedHashSet
LinkedList
ListResourceBundle
Locale
Observable
PriorityQueue
Properties
PropertyPermission
PropertyResourceBundle
Random
ResourceBundle
Scanner
SimpleTimeZone
Stack
StringTokenizer
Timer
TimerTask
TimeZone
TreeMap
TreeSet
UUID
Vector
WeakHashMap
枚举
Formatter.BigDecimalLayoutForm
异常
ConcurrentModificationException
DuplicateFormatFlagsException
EmptyStackException
FormatFlagsConversionMismatchException
FormatterClosedException
IllegalFormatCodePointException
IllegalFormatConversionException
IllegalFormatException
IllegalFormatFlagsException
IllegalFormatPrecisionException
IllegalFormatWidthException
InputMismatchException
InvalidPropertiesFormatException
MissingFormatArgumentException
MissingFormatWidthException
MissingResourceException
NoSuchElementException
TooManyListenersException
UnknownFormatConversionException
UnknownFormatFlagsException

Answer 2

自己看API 这都不会别学JAVA了