java - 如何通过字节缓冲区写入对象？

Question

我正在尝试:

• 将一个对象(或一系列不同类型/类别的对象)写入文件
• 复读
• 检查实例并再次将它们转换为相同类型/类的对象

我可以找到这两个类，这就是我使用它们的方式。但是 data[] 数组对我来说意义不大。为什么一定要在 deserialize 方法中放入一个空的数据数组？

public static byte[] serialize(Object obj) throws IOException {
    ByteArrayOutputStream out = new ByteArrayOutputStream();
    ObjectOutputStream os = new ObjectOutputStream(out);
    os.writeObject(obj);
    return out.toByteArray();
}
public static Object deserialize(byte[] data)
        throws IOException, ClassNotFoundException {
    ByteArrayInputStream in = new ByteArrayInputStream(data);
    ObjectInputStream is = new ObjectInputStream(in);
    return is.readObject();
}

public static void main(String[] args) {

    try {
        Thing p = new Thing(2,4);

        byte[]data = new byte[10240];
        serialize(p);
        Object des = deserialize(data);

    } catch (IOException | ClassNotFoundException ex) {
        Logger.getLogger(Pruebiña.class.getName())
            .log(Level.SEVERE, null, ex);
    }

}

我该如何解决这个问题？现在我遇到以下错误，当程序到达 deserialize 行时:

java.io.StreamCorruptedException: invalid stream header: 00000000
     at java.io.ObjectInputStream.readStreamHeader(ObjectInputStream.java:806)

我能做些什么来解决这个问题，并能够写回和读回对象？是的，Thing 类是Serializable。

Answer 1

如果你想写一个文件你根本不需要字节数组使用FileInputStream 和 FileOutputStream 例如。

public static void serialize(Object obj, File f) throws IOException {
    try (ObjectOutputStream out = new ObjectOutputStream(new FileOutputStream(f))) {
       out.writeObject(obj);
    }
}

public static Object deserialize(File f)
        throws IOException, ClassNotFoundException {
    try (ObjectInputStream is = new ObjectInputStream(new FileInputStream(f))) {
        return is.readObject();
    }
}

static class Thing implements Serializable {
    int a,b,c;
}
public static void main(String[] args) throws IOException, ClassNotFoundException {

    File f = new File("object.dat");
    Thing orig = new Thing();
    serialize(orig, f);
    Thing back = (Thing) deserialize(f);
}