Java:应用Observer接口实践Observer模式
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void addObserver(Observer o)
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setChanged();
notifyObservers();
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void update(Observable o,
Object arg)
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package com.zj.observer;
import java.util.Observable;
public class NumObservable extends Observable {
private int data = 0;
public int getData() {
return data;
}
public void setData(int i) {
data = i;
setChanged();
notifyObservers();
}
}
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package com.zj.observer;
import java.util.Observable;
import java.util.Observer;
public class NumObserver implements Observer{
public void update(Observable o, Object
arg) {
NumObservable myObserable=(NumObservable)
o;
System.out.println("Data has changed to " +myObserable.getData());
}
}
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package com.zj.observer;
public class SingleTest {
public static void main(String[] args) {
NumObservable number = new NumObservable();
number.addObserver(new NumObserver());
number.setData(1);
number.setData(2);
number.setData(3);
}
}
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package com.zj.observers;
import java.util.Observable;
public class NumsObservable extends Observable {
public final static Integer ODD = 1;
public final static Integer EVEN = 2;
private int data = 0;
public int getData() {
return data;
}
public void setData(int i) {
data = i;
Integer flag = EVEN;
if ((data & 0x0001) == 1)
flag = ODD;
setChanged();
notifyObservers(flag);
}
}
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package com.zj.observers;
import java.util.Observable;
import java.util.Observer;
public class OddObserver implements Observer {
public void update(Observable o, Object
arg) {
if (arg == NumsObservable.ODD) {
NumsObservable myObserable =
(NumsObservable) o;
System.out.println("OddObserver:Data has changed to " + myObserable.getData());
}
}
}
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package com.zj.observers;
import java.util.Observable;
import java.util.Observer;
public class EvenObserver implements Observer {
public void update(Observable o, Object
arg) {
if (arg == NumsObservable.EVEN) {
NumsObservable myObserable =
(NumsObservable) o;
System.out.println("EvenObserver:Data has changed to " + myObserable.getData());
}
}
}
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package com.zj.observers;
public class MultiTest {
public static void main(String[] args) {
NumsObservable number = new
NumsObservable();
number.addObserver(new OddObserver());
number.addObserver(new EvenObserver());
number.setData(1);
number.setData(2);
number.setData(3);
}
}
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本文出自 “子 孑” 博客，请务必保留此出处http://zhangjunhd.blog.51cto.com/113473/68949
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 深蓝2012、mushiqianmeng |
2人 |
了这篇文章 |
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