该代码适用于Java运行时，但不适用于android

Question

此代码在Java运行时上正常工作。

public static void main(String[] args) {
    // TODO Auto-generated method stub
    extendedList array=new extendedList();//extendedList:class extendedList extends ArrayList<XXX> implements Serializable


    //....unimportant code...


    FileOutputStream out;
    ObjectOutputStream oout;
    try {

        out=new FileOutputStream("Data.dat");
        oout=new ObjectOutputStream(out);
        oout.writeObject(array);


    } catch (FileNotFoundException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    } catch (IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
    FileInputStream fin;
    ObjectInputStream ofin;

    try {
        fin=new FileInputStream("Data.dat");
        ofin=new ObjectInputStream(fin);
        extendedList ret=(extendedList) ofin.readObject();
        for(int i=0;i<ret.size();i++)
        System.out.print(ret.get(i).getnum()+":"+ret.get(i).getename()+":"+ret.get(i).getfname()+"\n");


    } catch (IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    } catch (ClassNotFoundException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }



}

但是当我想在android.it中读取Data.dat时会抛出ClassNotFoundException。这有什么问题？

ObjectInputStream对象;

    InputStream input;

    try {
        Log.d("adapter","befor Open");

        input=assets.open("Data.dat");

        Log.d("adapter","after Open");
        object= new ObjectInputStream(input);
        Array=(extendedList) object.readObject();

        //........hidden code

    } catch (IOException e) {
        // TODO Auto-generated catch block
        Log.d("adapter","IOException has detected");
        e.printStackTrace();
    } catch (ClassNotFoundException e) {
        // TODO Auto-generated catch block
        Log.d("adapter","ClassNotFoundException has detected");
        e.printStackTrace();
    }

当我用FileInputStream替换InputStream并强制转换asset.open（＆＃34; Data.dat＆＃34;）。当调试器到达该行时。未找到源。