Android中的Parcelable接口

之前在写一个android一个小项目时，遇到一个问题，当一个实体类中持有一个Bitmap类的对象时，并且该实体类需要进行网络传输时，仅仅实现Serializable会抛出一个异常： 

android.os.BadParcelableException: Parcelable protocol requires a Parcelable.Creator object called  CREATOR on class com.txrj.sms.model.TxrjContact      

这个异常了之后才知道，Bitmap是android 中的类，默认该类是实现了Parcelable的，并且这个接口不同于java中提供的Serializable。

Serializable，即串行化，或序列化，这是一个标记接口，其作用是将数据对象写入字节流中，必要时可从字节流取出对象，这就是对象的序列化，可用于将数据存储到外存中或者用于网络传输。而android中则提供了Parcelable这个接口，该接口并不像Serializable那样是个标记接口，Parcelable需要实现方法以实现数据能够高效地传输。实现该接口的类的对象可以存储到Parcel中或写入到Parcel中，由于android的系统资源有限，提供Parcelable接口就是为了提高性能，Parcelable接口比Serializable接口性能更高。

下面是实现Parcelable的接口的方法：

package cn.edu.aust.enjoychat.entity;
import java.io.Serializable;
import java.util.Date;
import android.graphics.Bitmap;
import android.os.Parcel;
import android.os.Parcelable;
public class ContactItem implements Parcelable,Serializable{
	private static final long serialVersionUID = 1L; 
	// 用户名
	private String contactName = "";
	// 用户头像图片类型
	private String iconType = "jpg";
	
	// 用户头像的图片存储问题
	private Bitmap image;
	
	// 出生日期
	private String birthday;
	
	// 昵称
	private String nickname = "";
	// 性别
	private String gender = "";
	// 地址
	private String address = "";
	// 所在地区
	private String areaLocation = "";
	// 个性签名
	private String signature = "";
	// 邮箱
	private String emial = "";
	//联系人拥有者名称
	private String ownerName;
	
	//联系人经纬度信息
	private Position position;
	
	public String getOwnerName() {
		return ownerName;
	}
	public Position getPosition() {
		return position;
	}
	public void setPosition(Position position) {
		this.position = position;
	}
	public void setOwnerName(String ownerName) {
		this.ownerName = ownerName;
	}
	public String getContactName() {
		return contactName;
	}
	public void setContactName(String contactName) {
		this.contactName = contactName;
	}
	public String getIconType() {
		return iconType;
	}
	public void setIconType(String iconType) {
		this.iconType = iconType;
	}
	public Bitmap getImage() {
		return image;
	}
	public void setImage(Bitmap image) {
		this.image = image;
	}
	public String getBirthday() {
		return birthday;
	}
	public void setBirthday(String birthday) {
		this.birthday = birthday;
	}
	public String getNickname() {
		return nickname;
	}
	public void setNickname(String nickname) {
		this.nickname = nickname;
	}
	public String getGender() {
		return gender;
	}
	public void setGender(String gender) {
		this.gender = gender;
	}
	public String getAddress() {
		return address;
	}
	public void setAddress(String address) {
		this.address = address;
	}
	public String getAreaLocation() {
		return areaLocation;
	}
	public void setAreaLocation(String areaLocation) {
		this.areaLocation = areaLocation;
	}
	public String getSignature() {
		return signature;
	}
	public void setSignature(String signature) {
		this.signature = signature;
	}
	public String getEmial() {
		return emial;
	}
	public void setEmial(String emial) {
		this.emial = emial;
	}
	
	 public static final Parcelable.Creator<ContactItem> CREATOR = new Creator<ContactItem>() { 
         public ContactItem createFromParcel(Parcel source) { 
        	 ContactItem item = new ContactItem(); 
        	 item.contactName = source.readString();
        	 item.iconType = source.readString();
        	 item.image = Bitmap.CREATOR.createFromParcel(source);
        	 item.birthday = source.readString();
        	 item.nickname = source.readString();
        	 item.gender = source.readString();
        	 item.address = source.readString();
        	 item.areaLocation = source.readString();
        	 item.signature = source.readString();
        	 item.emial = source.readString();
             return item; 
         } 
         public ContactItem[] newArray(int size) { 
             return new ContactItem[size]; 
         } 
     }; 
     @Override
	public int describeContents() {
		return 0;
	}
	@Override
	public void writeToParcel(Parcel dest, int flags) {
		dest.writeString(contactName);
		dest.writeString(iconType);
		image.writeToParcel(dest, 0);
		dest.writeString(birthday);
		dest.writeString(nickname);
		dest.writeString(gender);
		dest.writeString(address);
		dest.writeString(areaLocation);
		dest.writeString(signature);
		dest.writeString(emial);
	}
	
}