Question

我正在尝试在文件上写一个对象，然后从同一个文件中读取它我从一个简单的文本文件中填充了一个对象的arraylist。当我正在尝试写文件

时，我有一个EOFException

public class CaricaTestoScriviOggetti_Copia {

    public static void main(String[] args) {
        File fileIn = new File("src/Lista.txt");
        Scanner input = null;
        try {
            input = new Scanner(fileIn);
        } catch (FileNotFoundException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

        ArrayList<Persona> persone = new ArrayList<Persona>();
        ArrayList<Persona> maggiorenni = new ArrayList<Persona>();
        String nome = null;
        String cognome = null;
        int eta = 0;
        while (input.hasNext()) {
            nome = input.next();
            cognome = input.next();
            eta = input.nextInt();
            if (input.hasNext("\n"))
                input.nextLine();
            persone.add(new Persona(nome, cognome, eta));
        }

        for (Persona p : persone) {
            System.out.println(p);
            if (p.getEta() > 17)
                maggiorenni.add(p);
        }

        input.close();

        FileOutputStream fos = null;
        ObjectOutputStream oos = null;
        try {
            fos = new FileOutputStream("src/ListaObj.dat");
        } catch (FileNotFoundException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        try {
            oos = new ObjectOutputStream(fos);
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

        for (Persona p : maggiorenni) {
            try {
                oos.writeObject(p);
                oos.flush();
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
        // END FOR

        try {
            fos.close();
            oos.close();
        } catch (IOException e1) {
            // TODO Auto-generated catch block
            e1.printStackTrace();
        }

        FileOutputStream fos2 = null;
        ObjectOutputStream oos2 = null;
        try {
            fos2 = new FileOutputStream("src/Oggetto.dat");
        } catch (FileNotFoundException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        try {
            oos2 = new ObjectOutputStream(fos);
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

        try {
            oos2.writeObject(maggiorenni.get(1));
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

        try {
            fos2.close();
            oos2.close();
        } catch (IOException e1) {
            // TODO Auto-generated catch block
            e1.printStackTrace();
        }

        FileInputStream fis = null;
        ObjectInputStream ois = null;
        try {
            fis = new FileInputStream("src/Oggetto.dat");
        } catch (FileNotFoundException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        try {
            ois = new ObjectInputStream(fis);
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

        Persona catched = null;

        try {
            catched = (Persona) ois.readObject();
        } catch (ClassNotFoundException | IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

        // END FOR

        try {
            fis.close();
            ois.close();
        } catch (IOException e1) {
            // TODO Auto-generated catch block
            e1.printStackTrace();
        }

        System.out.println("<------------Oggetto Letto------------>");
        System.out.println(catched);

        // END MAIN
    }
    // END CLASS
}

Answer 1

p = (Persona) ois.readObject();
k++;
while (p != null) {
    persone.add(p);
    p = (Persona) ois.readObject();
}

您的读取循环无效。 readObject()在流结束时不返回null，因此将其作为循环终止条件进行测试是没有意义的。

for (;;) {
    try {
        p = (Persona) ois.readObject();
        k++;
        persone.add(p);
    } catch (EOFException exc) {
        break;
    }
}

从文件中读取和写入Java中的Obj。 EOFException类

1 个答案: