Seminar01 Generic Collections

Lp trnh ng dng Java 14HCB

Seminar 01: Generic Collection

Ni dung

Thng tin mn hc Java Collections Java Generics Bi tp

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THNG TIN MN HCH Tun Thanh

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Thng tin

GVLT: p Thy Nguyn Vn Khit

nvkhiet@fit.hcmus.edu.vn

GV HDTH:p Thy Trng Phc Lc

tploc@fit.hcmus.edu.vnp Thy H Tun Thanh

htthanh@fit.hcmus.edu.vn

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Lu

Khng xin SDT ca GV Gp GV:p Gi email xin gpp ngh ra vi option GV quyt nhp Nhn confirm t GVp I82, g ca bc vo

Gi email:p Tiu : r rngp Ni dung: MSSV, H tn, Lp, nu r l do gip CC cho cc GV trong mn hc

Trao i hc tp:p Moodle

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JAVA COLLECTIONSH Tun Thanh

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Mng V d

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Mng Nhn xt

Phi cho bit trc s lng phn t trong mng

Ko th thay i kch thc v sau (m rng)p Khai bo mng mi cars3p Copy d liu qua mng mi cars3p Cp vng nh mi cho cars2p Copy d liu t cars3 qua cars2

Thm phn t x vo v tr k Xa phn t x

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Java Collections

Collection:p Mt i tng c kh nng cha cc i tng khcp Mt danh sch, mt mng

Cc thao tc thng dng:p Khi to collectionp Thm mt i tng vo collectionp Xa mt phn t ra khi collectionp Kim trong mt i tng c trong collection kop Ly mt phn t trong collectionp Duyt qua cc phn t trong collection

Thay i kch thc d dng

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S lp

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Collection Framework

Interfaces: cc giao tip th hin tnh cht ca cc loi collection khc nhau

Implementations (Classes): cc lp ci t cc collection interfacep C th to class mi, ci t li interface

Algorithms: cc phng thc tnh, x l trn collectionp Sp xpp Tm kim

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Interface Collection

Mc cao nht trong Collection Framework Cc method thng dng:p boolean add(Object obj);p boolean contains(Object obj);p boolean isEmpty( );p Iterator iterator( );p boolean remove(Object obj);p int size( );p Object[ ] toArray( );

1 class khi khng mun ci t method no UnsupportedOperationException

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Interface List

K tha interface Collection Cha danh sch cc phn t, truy cp thng qua

ch s C th cha cc phn t trng nhau Mt s method ring:p Object get(int index);p Object set(int index, Object o);p void add(int index, Object o);p Object remove(int index);p int indexOf(Object o);p int lastIndexOf(Object o);

p kiu ko ng CastClassException

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Interface Set

K tha interface Collection Cha tp hp cc phn t (ko trng

nhau) Mt s method ring:p set1.addAll(set2); // php hip set1.retainAll(set2); // php giaop set1.removeAll(set2); // php tr

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Interface SortedSet

K tha interface Set Qun l tp hp c xp tng dn Lp i tng phi ci t interface

Comparable hoc phi truyn vo lp ci t SortedSet mt Comparator

Mt s phng thc ring:p Object first( );p Object last( );p SortedSet headSet(Object end); // =startp SortedSet subSet(Object start, Object end);

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Interface Queue

K tha interface Collection Hot ng theo c ch FIFO Mt s method ring:p boolean offer(Object obj); // Thm vo queuep Object poll(); // Xa khi queue, tr v phn

t up Object peek(); // Ly phn t u, ko xa

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Interface Map

Mc cao nht trong Collection Framework Ko k tha interface Collection Qun l cc phn t theo c ch key-

valuep Cc Key khng trng nhau

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Interface Map

Mt s method thng dng:p Object put(Object key, Object value);p Object get(Object key);p Object remove(Object key);p boolean containsKey(Object key);p boolean containsValue(Object value);p Set keySet(); // Tr v cc keyp Collection values(); // Tr v cc valuep Set entrySet(); // Tr v cc cp key-value

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Interface SortedMap

K tha interface Map Cha cc phn t c sp xp Mt s method ring:p Object firstKey( );p Object lastKey( );p SortedMap headMap(Object end);p SortedMap tailMap(Object start);p SortedMap subMap(Object start, Object end);

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Interface Iterator

Duyt qua Collection Mt s phng thc thng dng:p boolean hasNext( );p Object next( );

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Class ArrayList

Ci t interface List Khi to:p ArrayList( );p ArrayList(int capacity);

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Class ArrayList

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Class LinkedList

Ci t 2 interface List v Queue Ci t dng danh sch lin kt

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Class LinkedList

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Queue V d

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Class Vector

Ci t interface List Tng t ArrayList Khi to:p Vector( );p Vector(int size);p Vector(int size, int incr);

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Class Vector

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Class Stack

K tha class Vector Hot ng theo c ch LIFO Mt s method thng dng:p boolean empty() ;p Object peek( );p Object pop( );p Object push(Object element);

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Class Stack

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Class HashSet

Ci t interface Set

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Class TreeSet

Ci t SortedSet

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Class TreeSet

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class Student implements Comparable{

private String code;private double score;

public Student(String code, double score){

this.code = code;this.score = score;

}

public double getScore(){

return score;}

public String toString(){

return "(" + code + "," + score + ")";}

Class TreeSet

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public boolean equals(Object other){

Student otherStu = (Student) other;return code.equals(otherStu.code);

}

public int compareTo(Object other){

Student otherStu = (Student) other;return code.compareTo(otherStu.code);

}}

Class TreeSet

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// This programs sorts a set of students by name and then by scoreimport java.util.*;

public class TreeSetTest2{

public static void main(String[] args){

SortedSet stu = new TreeSet();stu.add(new Student("A05726", 8.5));stu.add(new Student("A06338", 7.0));stu.add(new Student("A05379", 7.5));stu.add(new Student("A06178", 9.5));

System.out.println(stu);

SortedSet sortByScore = new TreeSet(new Comparator()// create an inner class

Class TreeSet

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{ public int compare(Object a, Object b){

Student itemA = (Student) a;Student itemB = (Student) b;double scoreA = itemA.getScore();double scoreB = itemB.getScore();

if ( scoreA < scoreB )return -1;

elsereturn 1;

}}); // end of inner class

sortByScore.addAll(stu);System.out.println(sortByScore);

}}

Class HashMap

Ci t interface Map

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Class TreeMap

Ci t SortedMap

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Algorithm

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Algorithm

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JAVA GENERICSH Tun Thanh

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t vn

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Khc phc

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Li khuyn

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Generic Class

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Generic Function

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Output

Wildcards

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?

? extends type

? super type

Ti liu tham kho

Slide Java Collections Professor Evan Korth

Slide Java Generics & Collections thy Nguyn L Hong Dng

http://www.tutorialspoint.com/java/java_collections.htm

http://www.tutorialspoint.com/java/java_generics.htm

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BI TPH Tun Thanh

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Bi tp

Bi tp c nhn Vit chng trnh ng dng WinForm

1. Hin th danh sch sinh vin2. Tm sinh vin theo t nht 2 tiu ch (ngi

dng c th nhp vo 1 hoc 2 tiu ch)3. Thm mi sinh vin4. Cp nht thng tin sinh vin5. Xa thng tin sinh vin

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Bi tp

Yu cu k thutp Javap Lu tr plain text filep Swingp Generic, collections

Bi np: MSSV.rar/zipp Checklist.txt: t chm im cho 5 chc nng trn,

mi chc nng thang 10p Th mc Source code: cha ton b m ngunp Th mc Data: cha file d liu, sinhvien.txtp Th mc Demo: hnh nh demo cc chc nng, mi

chc nng c th chp >=1 hnh, t STT (1-5) ngp Th mc EXE: cha file jar chy c

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