Question

我有数据到json arraylist当我试图使用green dao将数据存储到数据库时出错了。我不能认识到出了什么问题

我的活动课程如下

package com.example.vollyexample;

import java.util.ArrayList;

import org.json.JSONArray;
import org.json.JSONObject;

import com.android.volley.Request;
import com.android.volley.Request.Method;
import com.android.volley.Response;
import com.android.volley.Response.ErrorListener;
import com.android.volley.Response.Listener;
import com.android.volley.VolleyError;
import com.android.volley.toolbox.JsonArrayRequest;
import com.android.volley.toolbox.JsonObjectRequest;
import com.android.volley.toolbox.Volley;
import com.example.dao.Details;
import com.example.dao.DetailsDao;

import android.app.Activity;
import android.os.Bundle;
import android.os.IBinder.DeathRecipient;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.ListView;
import android.widget.Toast;

public class MainActivity extends Activity {

    DetailsDao detailsDao;
    Details details = new Details();
    Button bt_display;
    ListView lv;

    Vollyapp vapp;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        vapp=(Vollyapp) Vollyapp.getContext();
        detailsDao = Vollyapp.dsession.getDetailsDao();

        bt_display = (Button) findViewById(R.id.display_button);
        lv = (ListView) findViewById(R.id.listView);
        lv.setOnItemClickListener(new OnItemClickListener() {

            @Override
            public void onItemClick(AdapterView<?> parent, View view,
                    int position, long id) {
                // TODO Auto-generated method stub

            String item=String.valueOf(lv.getItemIdAtPosition(position));

        Toast.makeText(getApplicationContext(),""+item,Toast.LENGTH_LONG).show();
            }
        });
        bt_display.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                getdata();
            }
        });

        String url = "http://api.androidhive.info/volley/person_array.json";

        // Request a string response

        JsonArrayRequest requast = new JsonArrayRequest(url,
                new Listener<JSONArray>() {

                    @Override
                    public void onResponse(JSONArray detailJsonArray) {
                        // TODO Auto-generated method stub

                        try {
                            for (int i = 0; i < detailJsonArray.length(); i++) {
                                JSONObject obj1 = detailJsonArray
                                        .getJSONObject(i);

                                String name = obj1.getString("name");
                                String email = obj1.getString("email");
                                JSONObject phone = obj1.getJSONObject("phone");
                                String home=phone.getString("home");
                                String mobile=phone.getString("mobile");




                                details.setEmail(email);
                                details.setName(name);
                                details.setHome(home);
                                details.setMobile(mobile);
                                addData(details);

                            }
                        } catch (Exception e) {

                            Log.d("Error",
                                    "error ocures from exception............");
                        }

                        // Toast.makeText(MainActivity.this, arg0.toString(),
                        // Toast.LENGTH_SHORT).show();

                    }
                }, new ErrorListener() {

                    @Override
                    public void onErrorResponse(VolleyError arg0) {
                        // TODO Auto-generated method stub

                    }
                });

        Volley.newRequestQueue(MainActivity.this).add(requast);
    }

    public void addData(Details details) {
        // TODO Auto-generated method stub

        detailsDao.insert(details);

    }

    public void getdata() {
        // TODO Auto-generated method stub
        ArrayList<Details> details = (ArrayList<Details>) detailsDao.loadAll();

        display(details);
    }

    @SuppressWarnings("rawtypes")
    private void display(ArrayList<Details> details) {

    //show here
    }

}

当我运行代码时，我得到了以下错误

07-06 11:12:33.536: E/AndroidRuntime(17841): FATAL EXCEPTION: main
07-06 11:12:33.536: E/AndroidRuntime(17841): java.lang.NoClassDefFoundError: com.example.dao.DaoMaster
07-06 11:12:33.536: E/AndroidRuntime(17841):    at com.example.dao.DaoMaster$OpenHelper.onCreate(DaoMaster.java:39)
07-06 11:12:33.536: E/AndroidRuntime(17841):    at android.database.sqlite.SQLiteOpenHelper.getDatabaseLocked(SQLiteOpenHelper.java:252)
07-06 11:12:33.536: E/AndroidRuntime(17841):    at android.database.sqlite.SQLiteOpenHelper.getWritableDatabase(SQLiteOpenHelper.java:164)
07-06 11:12:33.536: E/AndroidRuntime(17841):    at com.example.vollyexample.Vollyapp.setDao(Vollyapp.java:35)
07-06 11:12:33.536: E/AndroidRuntime(17841):    at com.example.vollyexample.Vollyapp.onCreate(Vollyapp.java:28)
07-06 11:12:33.536: E/AndroidRuntime(17841):    at android.app.Instrumentation.callApplicationOnCreate(Instrumentation.java:1065)
07-06 11:12:33.536: E/AndroidRuntime(17841):    at android.app.ActivityThread.handleBindApplication(ActivityThread.java:4640)
07-06 11:12:33.536: E/AndroidRuntime(17841):    at android.app.ActivityThread.access$1300(ActivityThread.java:165)
07-06 11:12:33.536: E/AndroidRuntime(17841):    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1433)
07-06 11:12:33.536: E/AndroidRuntime(17841):    at android.os.Handler.dispatchMessage(Handler.java:107)
07-06 11:12:33.536: E/AndroidRuntime(17841):    at android.os.Looper.loop(Looper.java:194)
07-06 11:12:33.536: E/AndroidRuntime(17841):    at android.app.ActivityThread.main(ActivityThread.java:5370)
07-06 11:12:33.536: E/AndroidRuntime(17841):    at java.lang.reflect.Method.invokeNative(Native Method)
07-06 11:12:33.536: E/AndroidRuntime(17841):    at java.lang.reflect.Method.invoke(Method.java:525)
07-06 11:12:33.536: E/AndroidRuntime(17841):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:833)
07-06 11:12:33.536: E/AndroidRuntime(17841):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:600)
07-06 11:12:33.536: E/AndroidRuntime(17841):    at dalvik.system.NativeStart.main(Native Method)

Answer 1

NoClassDefFoundError 表示负责动态加载类的类加载器无法找到.class。

使用vapp=(Vollyapp) Vollyapp.getApplicationContext();

getContext() - 仅返回当前运行活动的上下文视图。 getApplicationContext() - 返回在应用程序中运行的所有活动的上下文。我不确定它是否有用。我想你会受此影响。

使用绿色Dao时出错

1 个答案: