Question

我正在尝试按照本教程www.josecgomez.com/2010/05/03/android-putting-custom-objects-in-listview/ 我从本地json文件中获取数据而不是webservice。我已经实现了几乎所有的东西，但我总是得到同样的错误。 logcat显示：

java.lang.NoClassDefFoundError: src.blablabla.List_Messages$1
at src.blablabla.soundboard.List_Messages.onCreate(List_Messages.java:72)

第72行是：

Type collectionType = new TypeToken<ArrayList<messages>>(){}.getType();

我不熟悉Types和TypeTokens，我做错了什么？

为了给你更多的上下文，下面是我的其余代码，包括第72行

public class List_Messages extends Activity {
JSONArray myJsonArray = null;
String s = "";

//ListView that will hold our items references back to main.xml
ListView listView;
//Array Adapter that will hold our ArrayList and display the items on the ListView
MessagesAdapter arrayAdapter;     
//List that will host our items and allow us to modify that array adapter
ArrayList<messages> messagesArray=null;



@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_list_messages);
    //Initialize ListView
    listView = (ListView)findViewById(R.id.listView);

  //Initialize our ArrayList
    messagesArray = new ArrayList<messages>();
    //Initialize our array adapter notice how it references the ress_list_row.xml layout
    arrayAdapter = new MessagesAdapter(List_Messages.this, R.layout.ress_list_row, messagesArray);

  //Set the above adapter as the adapter of choice for our list
    listView.setAdapter(arrayAdapter);

  //Pass the parameters if needed , if not then pass dummy one as follows
    Map<String, String> params = new HashMap<String, String>();
    params.put("var", "");

    myJsonArray = fromJsonFileToJsonArray("mssg_source.txt", this);  
    String response = myJsonArray.toString();

    try
    {
        //Parse Response into our object
        Type collectionType = new TypeToken<ArrayList<messages>>(){}.getType();

        //JSON expects an list so can't use our ArrayList from the lstart
        List<messages> lst= new Gson().fromJson(response, collectionType);

        //Now that we have that list lets add it to the ArrayList which will hold our items.
        for(messages m : lst)
        {
            messagesArray.add(m);
        }

        //Since we've modified the arrayList we now need to notify the adapter that
        //its data has changed so that it updates the UI
        arrayAdapter.notifyDataSetChanged();
    }
    catch(Exception e)
    {
        Log.d("Error: ", e.getMessage());
    }

感谢您宝贵的时间

Answer 1

看起来jar没有正确包含在我的项目中，它现在不再触发错误。虽然，我仍然有问题，因为视图是空的，它不会显示消息，因为它应该

ArrayList的TypeToken错误

1 个答案: