android 开发Parcelable 怎么传值ArrayList

public class TradeEntity implements Parcelable{
public String id;

//有关进度条的参数
ArrayList<TradeStateNodeInfo> nodes;
public TradeEntity() {
nodes = new ArrayList<TradeStateNodeInfo>();
}
/////////////////////////实现parcel接口///////////////////////////////
@Override
public int describeContents() {
return 0;
}
@Override
public void writeToParcel(Parcel out, int arg1) {
out.writeString(id);
out.writeList(nodes);
}
private TradeEntity(Parcel in)
{
id = in.readString();
nodes = in.readArrayList(TradeStateNodeInfo.class.getClassLoader());
}
public static final Parcelable.Creator<TradeEntity> CREATOR = new Parcelable.Creator<TradeEntity>()
{
public TradeEntity createFromParcel(Parcel in)
{
return new TradeEntity(in);
}

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

import android.os.Parcel;
import android.os.Parcelable;

/**
* 交易状态
* @author huqiang
*
*/
public class TradeStateNodeInfo implements Parcelable{

public int active;   //颜色激活（-1、错误；0、未激活；1、激活；2、当前步骤成功）
public String time ;
public String name ; //节点名称

public TradeStateNodeInfo()
{}
private TradeStateNodeInfo(Parcel in)
{
active = in.readInt();
time = in.readString();
name = in.readString();
}
@Override
public int describeContents() {
return 0;
}
@Override
public void writeToParcel(Parcel out, int flag) {
out.writeInt(active);
out.writeString(time);
out.writeString(name);
}
public static final Parcelable.Creator<TradeStateNodeInfo> CREATOR = new Parcelable.Creator<TradeStateNodeInfo>()
{
public TradeStateNodeInfo createFromParcel(Parcel in)
{
return new TradeStateNodeInfo(in);
}

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