android源码设计模式怎么样,android源码中的设计模式举例

单例模式

package android.app;

@SystemService(Context.ACTIVITY_SERVICE)

public class ActivityManager {

public static IActivityManager getService() {

return IActivityManagerSingleton.get();

}

private static final Singleton IActivityManagerSingleton =

new Singleton() {

@Override

protected IActivityManager create() {

final IBinder b = ServiceManager.getService(Context.ACTIVITY_SERVICE);

final IActivityManager am = IActivityManager.Stub.asInterface(b);

return am;

}

};

}

package android.util;

public abstract class Singleton {

private T mInstance;

protected abstract T create();

public final T get() {

synchronized (this) {

if (mInstance == null) {

mInstance = create();

}

return mInstance;

}

}

}