کلاس های تو در تو در جاوا

public class MyOuterClass{ ... public class MyInnerClass{ ... } }

public static void main(String[] args){ MyOuterClass outer = new MyOuterClass(); //A new instance of inner class by an object of outer class. MyInnerClass inner = outer.new MyInnerClass(); }

public class MyOuterClass{ private String outerField = "This is an outer data field"; public class MyInnerClass{ public void displayOuterDataField(){ System.out.println(outerField); } } }

public static void main(String[] args){ MyOuterClass outer = new MyOuterClass(); MyInnerClass inner = outer.new MyInnerClass(); inner.displayOuterDataField(); }

public class StringArray { private String[] elements; public StringArray(String[] elements){ this.elements = elements; } public int size(){ return elements.length; } public Iterator getIterator(){ return new Iterator(); } public class Iterator{ private int currentIndex; public boolean hasNext(){ return currentIndex < elements.length; } public String next(){ return elements[currentIndex++]; } public void reset(){ currentIndex = 0; } } }

public static void main(String[] args){ String[] names = {"Billie", "Jessy", "Jill", "Lura"}; StringArray arr = new StringArray(names); System.out.println("There are " + arr.size() + " elements that array holds"); System.out.println("Here are contents of the array: "); StringArray.Iterator iterator = arr.getIterator(); while (iterator.hasNext()) System.out.print(iterator.next() + " "); }

public class MyOuterClass{ ... public static class MyInnerClass{ ... } }

public class MyOuterClass{ private static void printMessage(){ System.out.println("A message from static method of outer class"); } public static class MyInnerClass{ public MyInnerClass(){ System.out.println("An object created from Inner class."); printMessage(); } } }

MyOuterClass.MyInnerClass myInnerObject = new MyOuterClass.MyInnerClass();

public class TV { public static final int MAXIMUM_VOLUME_LEVEL = 10; public static final int MINIMUM_VOLUME_LEVEL = 0; public static final int MAXIMUM_CHANNEL_NUMBER = 120; public static final int MINIMUM_CHANNEL_NUMBER = 1; private String panel; private int channel = 1; private int volume = 1; private boolean on; private TV(Factory factory){ this.panel = factory.panel; } public void turnOn(){ on = true; } public void turnOff(){ on = false; } public void setChannel(int channel) { if (channel >= MINIMUM_CHANNEL_NUMBER && channel <= MAXIMUM_CHANNEL_NUMBER) this.channel = channel; } public void setVolume(int volume) { if (on && volume >= MINIMUM_VOLUME_LEVEL && volume <= MAXIMUM_VOLUME_LEVEL) this.volume = volume; } public String getPanel() { return panel; } public int getChannel() { return channel; } public int getVolume() { return volume; } public void channelUp(){ if (on && channel < MAXIMUM_CHANNEL_NUMBER) channel++; } public void channelDown(){ if (on && channel > MINIMUM_CHANNEL_NUMBER ) channel --; } public void volumeUp(){ if (on && volume < MAXIMUM_VOLUME_LEVEL) volume++; } public void volumeDown(){ if (on && volume > MINIMUM_VOLUME_LEVEL) volume --; } public boolean isOn() { return on; } public boolean isMuted(){ return volume == MINIMUM_VOLUME_LEVEL; } public static class Factory{ private String panel = "FLATIRON"; public Factory panel(String panel){ this.panel = panel; return this; } public TV build(){ return new TV(this); } } }

public static void main(String[] args) { TV tv1 = TV.Factory().panel("TFT").build(); tv1.turnOn(); tv1.setChannel(42); tv1.setVolume(6); TV tv2 = TV.Factory().panel("IPS").build(); tv2.turnOn(); tv2.channelUp(); tv2.channelUp(); tv2.volumeUp(); System.out.println("tv1 has been built by " + tv1.getPanel() + " panel"); System.out.println("tv1's channel is " + tv1.channel + " and volume level is " + tv1.volumeLevel); System.out.println("tv2 has been built by " + tv2.getPanel() + " panel"); System.out.println("tv2's channel is " + tv2.channel + " and volume level is " + tv2.volumeLevel); }