java-util-120826225201-phpapp01

7/29/2019 java-util-120826225201-phpapp01

1/81

Prof. Ashish BhatiaAvailable at : http://www.asbspace.in/ppt

java.util and

CollectionFramework

7/29/2019 java-util-120826225201-phpapp01

2/81


This presentation is for teaching purpose only.

This presentation may contain some material

from books / api documentation / internet.

No intention of breaking any rights or what so

ever.

7/29/2019 java-util-120826225201-phpapp01

3/81


Date and Time Related Classes

Date

TimeZone

Calendar GregorianCalendar

Epoch : 1st Jan 1970 0:0:0.0 GMT 1st January 1970 5:30:0.0 IST

7/29/2019 java-util-120826225201-phpapp01

4/81


Simple Program

????????? toString()

7/29/2019 java-util-120826225201-phpapp01

5/81


Constructor

7/29/2019 java-util-120826225201-phpapp01

6/81


Comparing Date

7/29/2019 java-util-120826225201-phpapp01

7/81Prof. Ashish BhatiaAvailable at : http://www.asbspace.in/ppt

Calendar

Abstract Class

No public constructor

day, month, year, hour, minutes , seconds, era Many int constants

Many methods

7/29/2019 java-util-120826225201-phpapp01

8/81Prof. Ashish BhatiaAvailable at : http://www.asbspace.in/ppt

7/29/2019 java-util-120826225201-phpapp01

9/81


Some Methods

7/29/2019 java-util-120826225201-phpapp01

10/81


TimeZone

Class

Maintains offset value

ID for instances

public static TimeZone getDefault()

public static void setDefault(TimeZone zone)

7/29/2019 java-util-120826225201-phpapp01

11/81


7/29/2019 java-util-120826225201-phpapp01

12/81


public String getId()

public String getDisplayName()

public int getOffset(long date) public int getRawOffset

public void setRawOffset(int offmilliseconds)

public static TimeZone getTimeZone(String ID)

7/29/2019 java-util-120826225201-phpapp01

13/81


7/29/2019 java-util-120826225201-phpapp01

14/81


7/29/2019 java-util-120826225201-phpapp01

15/81


7/29/2019 java-util-120826225201-phpapp01

16/81


7/29/2019 java-util-120826225201-phpapp01

17/81


GregorianCalendar

Concrete class of Calendar

Two fields AD and BC for era

7 constructors GreogrianCalendar gc = new

GregorianCalendar();

Current date and time in default locale and timezone

7/29/2019 java-util-120826225201-phpapp01

18/81


GregorianCalendar

Ff

Year = Number of year elapsed from 1900Month = 0 indicating Jan

7/29/2019 java-util-120826225201-phpapp01

19/81


GregorianCalendar

fd

boolean isLeapYear(int year)

Test for leap year

7/29/2019 java-util-120826225201-phpapp01

20/81


DateFormat

7/29/2019 java-util-120826225201-phpapp01

21/81


7/29/2019 java-util-120826225201-phpapp01

22/81


7/29/2019 java-util-120826225201-phpapp01

23/81


Array Class

Contains various methods for manipulatingarrays - mostly static methods

Contains a static factory that allows arrays to

be viewed as lists.

fill, equals, sort, binarysearch, toString

7/29/2019 java-util-120826225201-phpapp01

24/81


fill method

public static void fill(datatype[] array, datatype

value)

public static void fill(datatype[] array, int

fromindex , int toindex, datatype value)

datatype = Primitive Datatype + Object

7/29/2019 java-util-120826225201-phpapp01

25/81


Program

7/29/2019 java-util-120826225201-phpapp01

26/81


Output

7/29/2019 java-util-120826225201-phpapp01

27/81


fill()

7/29/2019 java-util-120826225201-phpapp01

28/81


fill()

7/29/2019 java-util-120826225201-phpapp01

29/81


equals()

Return Boolean

Take two arguments

public static boolean equals( datatype [] a,datatype[] b)

Compare each element and size of array

7/29/2019 java-util-120826225201-phpapp01

30/81


equals()

7/29/2019 java-util-120826225201-phpapp01

31/81


sort()

Sort the array

Ascending Order

7/29/2019 java-util-120826225201-phpapp01

32/81


sort()

7/29/2019 java-util-120826225201-phpapp01

33/81


binarySearch()

Uses binary search method to find the index

of element

Prerequisites : Sorted Array

7/29/2019 java-util-120826225201-phpapp01

34/81


binarySearch()

7/29/2019 java-util-120826225201-phpapp01

35/81


Collection Framework

Standardizing and having interoperability

between various data structures

Introduced in Java 1.2

Relies on Standard interfaces

7/29/2019 java-util-120826225201-phpapp01

36/81



Eight generics interfaces type

Determined the common methods for all

collection class

Operations

Basic Operations

Array Operations

Bulk Operations

7/29/2019 java-util-120826225201-phpapp01

37/81


7/29/2019 java-util-120826225201-phpapp01

38/81


Basic Operations

7/29/2019 java-util-120826225201-phpapp01

39/81


Basic Operations

7/29/2019 java-util-120826225201-phpapp01

40/81


Array Operations

7/29/2019 java-util-120826225201-phpapp01

41/81


Bulk Operation

7/29/2019 java-util-120826225201-phpapp01

42/81


Iterator

Lets you cycle through collection

7/29/2019 java-util-120826225201-phpapp01

43/81


Example

7/29/2019 java-util-120826225201-phpapp01

44/81


Set Interface

Defines a set

Collection of unique element [ no duplication]

Extends the Collection

All the methods

HashSet and TreeSet are concrete classes

AbstractSet : base abstract class

7/29/2019 java-util-120826225201-phpapp01

45/81


List Interface

Extends Collection

Insertion, updating, all are index based

Index starts from 0

It can store duplicates value

It adds its own methods

7/29/2019 java-util-120826225201-phpapp01

46/81


Methods

7/29/2019 java-util-120826225201-phpapp01

47/81


Methods

7/29/2019 java-util-120826225201-phpapp01

48/81


Methods

7/29/2019 java-util-120826225201-phpapp01

49/81


List Iterator

public interface ListIterator extends

Iterator

A ListIterator has no current element;

its cursor position always lies between the

element that would be returned by a call

toprevious() and the element that would be

returned by a call to next(). An iterator for a list of length n has

n+1 possible cursor positions,
http://e/JavaSoft/jdk-7-ea-apidocs/docs/api/java/util/Iterator.htmlhttp://e/JavaSoft/jdk-7-ea-apidocs/docs/api/java/util/Iterator.html

7/29/2019 java-util-120826225201-phpapp01

50/81


List Iterator

7/29/2019 java-util-120826225201-phpapp01

51/81


7/29/2019 java-util-120826225201-phpapp01

52/81


7/29/2019 java-util-120826225201-phpapp01

53/81

7/29/2019 java-util-120826225201-phpapp01

54/81


Vector Class

7/29/2019 java-util-120826225201-phpapp01

55/81


Vector Class

Dynamic Array

The size of a Vector can grow or shrink as needed

to accommodate adding and removing items after

the Vector has been created

Synchronized

Each vector tries to optimize storagemanagement by maintaining a capacity and

a capacityIncrement

7/29/2019 java-util-120826225201-phpapp01

56/81


Vector Class

Modified from Java 1.2 [ IS IT SAME AS JAVA

2]

To implement List and become part of


7/29/2019 java-util-120826225201-phpapp01

57/81


Vector Class Constructors

The increment specifies the number ofelements to allocate each time that a vector is

resized upward.

Initial Size 10

7/29/2019 java-util-120826225201-phpapp01

58/81


Vector Class

Starts with initial capacity

Allocates more space for new objects once the

capacity is reached

It allocates more space that required so

allocation is done minimal time

Double size if nothing is specified

What if incr size = 0 [ Default Value]

7/29/2019 java-util-120826225201-phpapp01

59/81


Vector Class

7/29/2019 java-util-120826225201-phpapp01

60/81


Vector Class

7/29/2019 java-util-120826225201-phpapp01

61/81


Vector Class

7/29/2019 java-util-120826225201-phpapp01

62/81


Vector Class

7/29/2019 java-util-120826225201-phpapp01

63/81


Vector Class

7/29/2019 java-util-120826225201-phpapp01

64/81


Vector Class

7/29/2019 java-util-120826225201-phpapp01

65/81


Vector Class

7/29/2019 java-util-120826225201-phpapp01

66/81


7/29/2019 java-util-120826225201-phpapp01

67/81


Now Lets add elements

addElement(Object o)

Size = ? Capacity = ?

7/29/2019 java-util-120826225201-phpapp01

68/81


Size = 4 Capacity = 5

WHY

Size = ? Capacity = ?

5,5 5,8

Any Other Option

7/29/2019 java-util-120826225201-phpapp01

69/81


7/29/2019 java-util-120826225201-phpapp01

70/81


7/29/2019 java-util-120826225201-phpapp01

71/81


7/29/2019 java-util-120826225201-phpapp01

72/81


Solution : Generics

Specifies the data type

Vector v = new Vector ();

Vector v = new

Vector ();

7/29/2019 java-util-120826225201-phpapp01

73/81


Printing Vector

7/29/2019 java-util-120826225201-phpapp01

74/81


One Example

7/29/2019 java-util-120826225201-phpapp01

75/81


Lets Create Vector

Size = ?? Capacity = ?? DEFAULT = 10

7/29/2019 java-util-120826225201-phpapp01

76/81


Will This Work !!!

7/29/2019 java-util-120826225201-phpapp01

77/81


How to Print area ?

7/29/2019 java-util-120826225201-phpapp01

78/81


Stack

7/29/2019 java-util-120826225201-phpapp01

79/81


ArrayList

7/29/2019 java-util-120826225201-phpapp01

80/81


ArrayList

Resizable-array implementation of

the List interface.

Implements all optional list operations, and

permits all elements, including null.

This class is roughly equivalent to Vector,

except that it is unsynchronized.

f

7/29/2019 java-util-120826225201-phpapp01

81/81

Map Interface

Continued to Next Presentation

Date post:	03-Apr-2018
Category:	Documents
Upload:	sasirekha-perumalvijayan
View:	214 times
Download:	0 times

java-util-120826225201-phpapp01

Documents