Android IPC机制Messenger实例详解

public final class Messenger implements Parcelable {  private final IMessenger mTarget;  public Messenger(Handler target) {    mTarget = target.getIMessenger();  }  public void send(Message message) throws RemoteException {    mTarget.send(message);  }  public IBinder getBinder() {    return mTarget.asBinder();  }  public boolean equals(Object otherObj) {    if (otherObj == null) {      return false;    }    try {      return mTarget.asBinder().equals(((Messenger)otherObj)          .mTarget.asBinder());    } catch (ClassCastException e) {    }    return false;  }  public int hashCode() {    return mTarget.asBinder().hashCode();  }  public int describeContents() {    return 0;  }  public void writeToParcel(Parcel out, int flags) {    out.writeStrongBinder(mTarget.asBinder());  }  public static final Parcelable.Creator<Messenger> CREATOR      = new Parcelable.Creator<Messenger>() {    public Messenger createFromParcel(Parcel in) {      IBinder target = in.readStrongBinder();      return target != null ? new Messenger(target) : null;    }    public Messenger[] newArray(int size) {      return new Messenger[size];    }  };  public static void writeMessengerOrNullToParcel(Messenger messenger,      Parcel out) {    out.writeStrongBinder(messenger != null ? messenger.mTarget.asBinder()        : null);  }  public static Messenger readMessengerOrNullFromParcel(Parcel in) {    IBinder b = in.readStrongBinder();    return b != null ? new Messenger(b) : null;  }  public Messenger(IBinder target) {    mTarget = IMessenger.Stub.asInterface(target);  }}