Bridge

1// Implementation Interface
2public interface Device {
3    boolean isEnabled();
4    void enable();
5    void disable();
6    int getVolume();
7    void setVolume(int percent);
8}
9
10// Concrete Implementations
11public class Tv implements Device {
12    private boolean on = false;
13    private int volume = 30;
14    
15    @Override public boolean isEnabled() { return on; }
16    @Override public void enable() { on = true; }
17    @Override public void disable() { on = false; }
18    @Override public int getVolume() { return volume; }
19    @Override public void setVolume(int percent) { this.volume = percent; }
20}
21
22public class Radio implements Device {
23    private boolean on = false;
24    private int volume = 10;
25    
26    @Override public boolean isEnabled() { return on; }
27    @Override public void enable() { on = true; }
28    @Override public void disable() { on = false; }
29    @Override public int getVolume() { return volume; }
30    @Override public void setVolume(int percent) { this.volume = percent; }
31}
32
33// Abstraction
34public class RemoteControl {
35    protected Device device;
36    
37    public RemoteControl(Device device) {
38        this.device = device;
39    }
40    
41    public void togglePower() {
42        if (device.isEnabled()) device.disable();
43        else device.enable();
44    }
45    
46    public void volumeDown() {
47        device.setVolume(device.getVolume() - 10);
48    }
49    
50    public void volumeUp() {
51        device.setVolume(device.getVolume() + 10);
52    }
53}
54
55// Refined Abstraction
56public class AdvancedRemoteControl extends RemoteControl {
57    public AdvancedRemoteControl(Device device) {
58        super(device);
59    }
60    
61    public void mute() {
62        device.setVolume(0);
63    }
64}
65
66// Client
67public class Main {
68    public static void main(String[] args) {
69        Device tv = new Tv();
70        RemoteControl remote = new RemoteControl(tv);
71        remote.togglePower();
72        
73        Device radio = new Radio();
74        AdvancedRemoteControl advancedRemote = new AdvancedRemoteControl(radio);
75        advancedRemote.togglePower();
76        advancedRemote.mute();
77    }
78}