关于JavaEOFException的不理解

鄙人大一Java课结课需求是简单的学生成绩管理系统
现在想要存储系统用户的数据，打算在注册的界面先读取用户数据，然后以链表的形式添加新用户
但是控制台显示EOFException，调试发现读取失败
想知道怎么解决
希望尽可能说的浅显一点，听说这个好像是因为数据不完整，但就是第一次打开才只有空文件
代码如下

//流与表的实例
        try {
            fos=new FileOutputStream("user.txt");
        } catch (FileNotFoundException e2) {
            // TODO 自动生成的 catch 块
            e2.printStackTrace();
        }
        try {
            fis=new FileInputStream("user.txt");
        } catch (FileNotFoundException e2) {
            // TODO 自动生成的 catch 块
            e2.printStackTrace();
        }
        try {
            oos=new ObjectOutputStream(fos);
        } catch (IOException e2) {
            // TODO 自动生成的 catch 块
            e2.printStackTrace();
        }
        try {
            ois=new ObjectInputStream(fis);
        } catch (IOException e2) {
            // TODO 自动生成的 catch 块
            e2.printStackTrace();
        }
        Users=new LinkedList<User>();
        
        
        //读文件
        try {
            Users=(LinkedList) ois.readObject();
            System.out.println("读取成功");
        } catch (ClassNotFoundException e2) {
            // TODO 自动生成的 catch 块
            System.out.println("没读上ClassNotFound");
            e2.printStackTrace();
        } catch (IOException e2) {
            // TODO 自动生成的 catch 块
            System.out.println("没读上IO");
            e2.printStackTrace();
        }


//构造文件流与链表
    FileOutputStream fos;
    FileInputStream fis;
    ObjectOutputStream oos;
    ObjectInputStream ois;
    LinkedList<User> Users;

运行结果如下

没读上IO
java.io.EOFException
    at java.base/java.io.ObjectInputStream$BlockDataInputStream.peekByte(ObjectInputStream.java:3214)
    at java.base/java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1684)
    at java.base/java.io.ObjectInputStream.readObject(ObjectInputStream.java:509)
    at java.base/java.io.ObjectInputStream.readObject(ObjectInputStream.java:467)
    at SPMS_CourseDesign/ha.design.register_frame.RegisterSettings(register_frame.java:81)
    at SPMS_CourseDesign/ha.design.register_frame.<init>(register_frame.java:46)
    at SPMS_CourseDesign/ha.design.MyFrame$1.actionPerformed(MyFrame.java:50)
    at java.desktop/javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:1972)
    at java.desktop/javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2313)
    at java.desktop/javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:405)
    at java.desktop/javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:262)
    at java.desktop/javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:279)
    at java.desktop/java.awt.Component.processMouseEvent(Component.java:6626)
    at java.desktop/javax.swing.JComponent.processMouseEvent(JComponent.java:3389)
    at java.desktop/java.awt.Component.processEvent(Component.java:6391)
    at java.desktop/java.awt.Container.processEvent(Container.java:2266)
    at java.desktop/java.awt.Component.dispatchEventImpl(Component.java:5001)
    at java.desktop/java.awt.Container.dispatchEventImpl(Container.java:2324)
    at java.desktop/java.awt.Component.dispatchEvent(Component.java:4833)
    at java.desktop/java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4948)
    at java.desktop/java.awt.LightweightDispatcher.processMouseEvent(Container.java:4575)
    at java.desktop/java.awt.LightweightDispatcher.dispatchEvent(Container.java:4516)
    at java.desktop/java.awt.Container.dispatchEventImpl(Container.java:2310)
    at java.desktop/java.awt.Window.dispatchEventImpl(Window.java:2780)
    at java.desktop/java.awt.Component.dispatchEvent(Component.java:4833)
    at java.desktop/java.awt.EventQueue.dispatchEventImpl(EventQueue.java:773)
    at java.desktop/java.awt.EventQueue$4.run(EventQueue.java:722)
    at java.desktop/java.awt.EventQueue$4.run(EventQueue.java:716)
    at java.base/java.security.AccessController.doPrivileged(AccessController.java:399)
    at java.base/java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:86)
    at java.base/java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:97)
    at java.desktop/java.awt.EventQueue$5.run(EventQueue.java:746)
    at java.desktop/java.awt.EventQueue$5.run(EventQueue.java:744)
    at java.base/java.security.AccessController.doPrivileged(AccessController.java:399)
    at java.base/java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:86)
    at java.desktop/java.awt.EventQueue.dispatchEvent(EventQueue.java:743)
    at java.desktop/java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:203)
    at java.desktop/java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:124)
    at java.desktop/java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:113)
    at java.desktop/java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:109)
    at java.desktop/java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101)
    at java.desktop/java.awt.EventDispatchThread.run(EventDispatchThread.java:90)