问Android：如何对我的对象实现Parcelable？

public class ConstantData{

       public static String project_title = "project title";
       public static String organization_title = "organization title";
       public static String keyword = "keyword";
       public static String short_code = "short code";
       public static String project_description = "description";
       public static String smallImageUrl = "smallImageUrl";
       public static String bigImageUrl = "bigImageUrl";
       public static String price= "price";
       public static String country= "country";



        public static ArrayList<Project> projectsList = new ArrayList<Project>();


        public int describeContents() {
            return 0;
        }

        public void writeToParcel(Parcel out, int flags) {
            out.writeString(project_title);
            out.writeString(organization_title);
            out.writeString(keyword);
            out.writeString(short_code);
            out.writeString(project_description);
            out.writeString(smallImageUrl);
            out.writeString(bigImageUrl);
            out.writeString(price);
            out.writeString(country);
        }

        public static final Parcelable.Creator<ConstantData> CREATOR
                = new Parcelable.Creator<ConstantData>() {
            public ConstantData createFromParcel(Parcel in) {
                return new ConstantData(in);
            }

            public ConstantData[] newArray(int size) {
                return new ConstantData[size];
            }
        };

        private ConstantData(Parcel in) {
            project_title = in.readString();
            organization_title = in.readString();
            keyword = in.readString();
            short_code = in.readString();
            project_description = in.readString();
            smallImageUrl = in.readString();
            bigImageUrl = in.readString();
            price = in.readString();
            country = in.readString();
        }
    }