Java android的I/O问题（主要是ObjectInputStream）

第一次在这里发布，所以对我放松点

尝试创建读取omw.data的方法时，检查文件中是否已存在SavedSession对象。如果确实如此，则忽略它，否则将其附加到文件末尾

我可以添加一个对象，当添加相同的SavedSession时，它可以正常工作，表示它已经添加。当添加另一种类型的SavedSession时，它表示已添加，但当尝试读取omw.data时，它会抛出

java.io.StreamCorruptedException:格式错误：ac

SavedSession不保存地理点对象，而是使用它来获取纬度和经度

任何帮助都将不胜感激。我确实尝试过搜索，尝试过很多不同的方法，或者说我不太明白到底是什么问题

谢谢，如果我遗漏了什么，请告诉我，我会把它挂起来的

public void saveDestination(GeoPoint to, String message,
        List<String> contactNumbers) throws IOException {
    SavedSession newSession = new SavedSession(to, message, contactNumbers);

    FileOutputStream fos = c.openFileOutput("omw.data", Context.MODE_APPEND);
    fos.close();

    FileInputStream fis = c.openFileInput("omw.data");      

    try {
        ObjectInputStream ois = new ObjectInputStream(fis);
        List<SavedSession> previousSessions = new LinkedList<SavedSession>();           

        try {
            Object prevSession = null;
            while ((prevSession = ois.readObject()) != null) {
                previousSessions.add((SavedSession) prevSession);
            }
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        } catch(EOFException ex){
            System.out.println("End of file reached found: " + previousSessions.size());
        }
        finally {
            System.out.println("ois closed");
            ois.close();
        }

        if (previousSessions.contains(newSession)) {
            Toast.makeText(c, "Already contained!", Toast.LENGTH_LONG)
                    .show();
            return;
        }

    } catch (EOFException ex) {
        ex.printStackTrace();
    }

    fos = c.openFileOutput("omw.data", Context.MODE_APPEND);        

    ObjectOutputStream oos = new ObjectOutputStream(fos);

    oos.writeObject(newSession);
    oos.flush();
    oos.close();        


    Toast.makeText(c, "Added Item", Toast.LENGTH_LONG).show();

}

编辑：

---

发现由于某些原因无法追加，不太确定原因。每次都更改代码以重写数据，但效率似乎很低。

好文章！您的编辑不是很明显，而且很重要，因此我将突出显示它：请参见

03-03 01:56:27.452: W/System.err(3631): java.io.StreamCorruptedException: Wrong format: ac
03-03 01:56:27.452: W/System.err(3631):     at java.io.ObjectInputStream.corruptStream(ObjectInputStream.java:830)
03-03 01:56:27.452: W/System.err(3631):     at java.io.ObjectInputStream.readNonPrimitiveContent(ObjectInputStream.java:943)
03-03 01:56:27.462: W/System.err(3631):     at java.io.ObjectInputStream.readObject(ObjectInputStream.java:2262)
03-03 01:56:27.462: W/System.err(3631):     at java.io.ObjectInputStream.readObject(ObjectInputStream.java:2217)
03-03 01:56:27.462: W/System.err(3631):     at com.mat.omw.fileoperations.FileSaver.saveDestination(FileSaver.java:41)
03-03 01:56:27.462: W/System.err(3631):     at com.mat.omw.maps.MapDestination.onOptionsItemSelected(MapDestination.java:284)
03-03 01:56:27.462: W/System.err(3631):     at android.app.Activity.onMenuItemSelected(Activity.java:2337)
03-03 01:56:27.462: W/System.err(3631):     at com.android.internal.policy.impl.PhoneWindow.onMenuItemSelected(PhoneWindow.java:795)
03-03 01:56:27.462: W/System.err(3631):     at com.android.internal.view.menu.MenuItemImpl.invoke(MenuItemImpl.java:160)
03-03 01:56:27.462: W/System.err(3631):     at com.android.internal.view.menu.MenuBuilder.performItemAction(MenuBuilder.java:885)
03-03 01:56:27.462: W/System.err(3631):     at com.android.internal.view.menu.IconMenuView.invokeItem(IconMenuView.java:545)
03-03 01:56:27.462: W/System.err(3631):     at com.android.internal.view.menu.IconMenuItemView.performClick(IconMenuItemView.java:122)
03-03 01:56:27.462: W/System.err(3631):     at android.view.View$PerformClick.run(View.java:9293)
03-03 01:56:27.462: W/System.err(3631):     at android.os.Handler.handleCallback(Handler.java:587)
03-03 01:56:27.462: W/System.err(3631):     at android.os.Handler.dispatchMessage(Handler.java:92)
03-03 01:56:27.462: W/System.err(3631):     at android.os.Looper.loop(Looper.java:150)
03-03 01:56:27.462: W/System.err(3631):     at android.app.ActivityThread.main(ActivityThread.java:4277)
03-03 01:56:27.462: W/System.err(3631):     at java.lang.reflect.Method.invokeNative(Native Method)
03-03 01:56:27.462: W/System.err(3631):     at java.lang.reflect.Method.invoke(Method.java:507)
03-03 01:56:27.462: W/System.err(3631):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
03-03 01:56:27.462: W/System.err(3631):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
03-03 01:56:27.462: W/System.err(3631):     at dalvik.system.NativeStart.main(Native Method)