The life of TB

The Observer Pattern defines a one-to-many dependency between objects so that when one object changes state, all of its dependents are notified and updated automatically. Being Loosely Coupled - Subjects and observers are "loosely coupled"They interact,but have little knowledge of each other. - Subject only knowsThe observer implements a specific interface.Does not need to know concrete class or..

Java 2017. 4. 28. 17:29

Inheritance - Inheritance is a core principle of OO programming.- But we tend to overuse it.- Often results in design and code that is inflexible. Problems with Our Design - We have code duplicated across classes.- Hard to gain knowledge of all the ducks.- Changes can affect other ducks.- Runtime behavior changes are difficult. What About Using Interfaces? - Allow different classes to share simi..

Java 2017. 4. 28. 16:04

# GenericSingletonFactory.java public class GenericSingletonFactory { private static applySame IDENTITY = new applySame() { @Overridepublic Object apply(Object arg) { return arg;} }; @SuppressWarnings("unchecked") public static applySame identityFunction() {return (applySame) IDENTITY; } public static void main(String[] args) { String[] strings = { "x", "y", "z" };applySame sameString = identity..

Java 2016. 7. 25. 20:37

# Main.java import java.util.Arrays;import java.util.HashSet;import java.util.Set; public class Main { public static Set union(Set s1, Set s2) {Set result = new HashSet(s1);result.addAll(s2);return result; } public static void main(String[] args) {Set guys = new HashSet(Arrays.asList("Tom", "Dick", "Harry"));Set numbers = new HashSet(Arrays.asList("1", "2", "3"));Set mix = union(guys, numbers);S..

Java 2016. 7. 25. 20:09

# StringLengthComparator.java import java.util.Comparator; public class StringLengthComparator implements Comparator { @Override public int compare(String o1, String o2) {if (o1.length() == o2.length()) { return 0;} else { return o1.length() > o2.length() ? 1 : -1;} }} # Main.java public class Main { public static void main(String[] args) {String[] strArray = {"aaa", "bb", "c"};Arrays.sort(strAr..

Java 2016. 7. 25. 16:44

# Item.java public class Item { private String name; private int id; public Item(String name) {this.name = name; } public String getName() { return name; } public int getId() { return id; } public void setName(String name) { this.name = name; } public void setId(int id) { this.id = id; }} # ItemProcess.java public interface ItemProcess { void process(T t);} # ItemManager.java import java.util.Ar..

Java 2016. 7. 25. 15:46

# Main.java import java.util.ArrayList;import java.util.Collections;import java.util.Comparator;import java.util.List; public class Main { public static void main(String[] args) { List al = new ArrayList();al.add("ab");al.add("c"); Collections.sort(al, new Comparator() { // sorted by string length @Override public int compare(String o1, String o2) {if (o1.length() == o2.length()) { return 0;} re..

Java 2016. 7. 25. 14:37

# 골격 구현 추상 클래스를 이용한 List 인터페이스 구현 메소드 package Item18; import java.util.AbstractList; import java.util.Iterator; import java.util.List; public class Main { public static void main(String[] args) { int[] i = { 1, 2, 3 }; List l = intArrayAsList(i); // 배열을 넣었지만 get 메소드를 사용할 수 있다. System.out.println(l.get(1)); System.out.println("\n"); // 배열에 이터레이터를 사용할 수 있다. Iterator itr = l.iterator(); while (itr...

Java 2016. 7. 23. 23:30