java - 无法在另一个 Activity 中读取同一个文件

Question

我有这段代码返回一个文件的内容:

private ArrayList<String> readFromFile1(Context context) {
        ArrayList<String> list = new ArrayList<String>();
        try {
            ObjectInputStream ois = new ObjectInputStream( context.openFileInput("jokesNames2.bjk"));
            try {
                list = (ArrayList)ois.readObject();
            } catch (ClassNotFoundException e) {
                e.printStackTrace();
            }
            ois.close();
            } catch (IOException e) {
            Log.e("log activity", "Can not read file: " + e.toString());
        }

我是这样调用它的: System.out.println("文件内容:"+ readFromFile1(this));

一切都完美运行。

现在在另一个 Activity 中我使用了几乎相同的代码，但它不会运行。

这里是:

@SuppressLint("NewApi")
public class FavoriteJokes extends Activity {

    public static ArrayAdapter<String> adapter;
    public static ListView listView;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_favorite_jokes);

        final GlobalsHolder globals = (GlobalsHolder)getApplication();

        TextView text = (TextView) findViewById(R.id.txtJoke);
        text.setText(globals.getList().get(globals.clickedPosition));

        ArrayList<String> jokeNamesList = new ArrayList<String>();


        jokeNamesList.addAll(readFromFile1(this));       

        System.out.println("FILE CONTENT: " + readFromFile1(this));
        globals.setFavJokeNamesList(readFromFile1(this));

    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.favorite_jokes, menu);
        return true;
    }

    /* Read file's content */
    private ArrayList<String> readFromFile1(Context context) {
        ArrayList<String> list = new ArrayList<String>();
        try {
            ObjectInputStream ois = new ObjectInputStream( context.openFileInput("jokesNames2.bjk"));
            try {
                list = (ArrayList)ois.readObject();
            } catch (ClassNotFoundException e) {
                e.printStackTrace();
            }
            ois.close();
            } catch (IOException e) {
            Log.e("log activity", "Can not read file: " + e.toString());
        }

        return list;
    }

}

这是错误输出:

03-03 10:50:21.055: E/AndroidRuntime(1038): FATAL EXCEPTION: main
03-03 10:50:21.055: E/AndroidRuntime(1038): Process: com.gs.britishjokes, PID: 1038
03-03 10:50:21.055: E/AndroidRuntime(1038): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.gs.britishjokes/com.gs.britishjokes.FavoriteJokes}: java.lang.IndexOutOfBoundsException: Invalid index 0, size is 0
03-03 10:50:21.055: E/AndroidRuntime(1038):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2176)
03-03 10:50:21.055: E/AndroidRuntime(1038):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2226)
03-03 10:50:21.055: E/AndroidRuntime(1038):     at android.app.ActivityThread.access$700(ActivityThread.java:135)
03-03 10:50:21.055: E/AndroidRuntime(1038):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1397)
03-03 10:50:21.055: E/AndroidRuntime(1038):     at android.os.Handler.dispatchMessage(Handler.java:102)
03-03 10:50:21.055: E/AndroidRuntime(1038):     at android.os.Looper.loop(Looper.java:137)
03-03 10:50:21.055: E/AndroidRuntime(1038):     at android.app.ActivityThread.main(ActivityThread.java:4998)
03-03 10:50:21.055: E/AndroidRuntime(1038):     at java.lang.reflect.Method.invokeNative(Native Method)
03-03 10:50:21.055: E/AndroidRuntime(1038):     at java.lang.reflect.Method.invoke(Method.java:515)
03-03 10:50:21.055: E/AndroidRuntime(1038):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:777)
03-03 10:50:21.055: E/AndroidRuntime(1038):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:593)
03-03 10:50:21.055: E/AndroidRuntime(1038):     at dalvik.system.NativeStart.main(Native Method)
03-03 10:50:21.055: E/AndroidRuntime(1038): Caused by: java.lang.IndexOutOfBoundsException: Invalid index 0, size is 0
03-03 10:50:21.055: E/AndroidRuntime(1038):     at java.util.ArrayList.throwIndexOutOfBoundsException(ArrayList.java:255)
03-03 10:50:21.055: E/AndroidRuntime(1038):     at java.util.ArrayList.get(ArrayList.java:308)
03-03 10:50:21.055: E/AndroidRuntime(1038):     at com.gs.britishjokes.FavoriteJokes.onCreate(FavoriteJokes.java:31)
03-03 10:50:21.055: E/AndroidRuntime(1038):     at android.app.Activity.performCreate(Activity.java:5243)
03-03 10:50:21.055: E/AndroidRuntime(1038):     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087)
03-03 10:50:21.055: E/AndroidRuntime(1038):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2140)
03-03 10:50:21.055: E/AndroidRuntime(1038):     ... 11 more

我真的不明白我的代码有什么问题。我很确定我遗漏了一小部分，但我找不到它。你能推我一下吗？

Answer 1

错误日志 (logcat) 指示 IndexOutOfBoundsException 异常:访问空数组的元素 0。

似乎是这一行导致了问题:text.setText(globals.getList().get(globals.clickedPosition));

也许你可以检查 globals.getList() 的大小？