Android實例化錯誤即無法實例化活動

Question

我試圖將分析的數據保存到數據庫中，但存在實例化異常。我使用Parcelable將解析的arraylist從一個活動傳遞到另一個活動。我需要將這些arraylist從一個活動傳遞到另一個活動並將其存儲在sqlite中。

public class AndroidXMLParsingActivity extends ListActivity implements Parcelable{ 
//private ScheduleClient scheduleClient; 
public Calendar cal; 
//TextView desciption1; 
TextView name1; 
    private GetData mGetData; 
// All static variables 
static final String URL = "http address"; 
// XML node keys 
static final String KEY_ITEM = "group_header"; // parent node 
static String KEY_NAME = "name"; 
static String KEY_ID = "group_day"; 
static String KEY_COST = "day_sun_mrg"; 
static String KEY_DESC = "day_sun_evn"; 
static final String KEY_COST1 = "day_mon_mrg"; 
static final String KEY_DESC1 = "day_mon_evn"; 
static final String KEY_COST2 = "day_tue_mrg"; 
static final String KEY_DESC2 = "day_tue_evn"; 
static final String KEY_COST3 = "day_wed_mrg"; 
static final String KEY_DESC3 = "day_wed_evn"; 
static final String KEY_COST4 = "day_thu_mrg"; 
static final String KEY_DESC4 = "day_thu_evn"; 
static final String KEY_COST5 = "day_fri_mrg"; 
static final String KEY_DESC5 = "day_fri_evn"; 
static final String KEY_COST6 = "day_sat_mrg"; 
static final String KEY_DESC6 = "day_sat_evn"; 

ArrayList<HashMap<String, String>> menuItems = new ArrayList<HashMap<String, String>>(); 

// creating new HashMap 
HashMap<String, String> map = new HashMap<String, String>(); 


@Override 
public void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity_main); 



    XMLParser parser = new XMLParser(); 
    String xml = parser.getXmlFromUrl(URL); // getting XML 
    Document doc = parser.getDomElement(xml); // getting DOM element 

    NodeList nl = doc.getElementsByTagName(KEY_ITEM); 
    // looping through all item nodes <item> 
    for (int i = 0; i < nl.getLength(); i++) { 

     Element e = (Element) nl.item(i); 
     // adding each child node to HashMap key => value 
     map.put(KEY_ID, parser.getValue(e, KEY_ID)); 
     map.put(KEY_NAME, parser.getValue(e, KEY_NAME)); 
     map.put(KEY_COST,parser.getValue(e, KEY_COST)); 
     map.put(KEY_DESC, parser.getValue(e, KEY_DESC)); 
     map.put(KEY_COST1,parser.getValue(e, KEY_COST1)); 
     map.put(KEY_DESC1, parser.getValue(e,KEY_DESC1)); 
     map.put(KEY_COST2,parser.getValue(e, KEY_COST2)); 
     map.put(KEY_DESC2, parser.getValue(e,KEY_DESC2)); 
     map.put(KEY_COST3,parser.getValue(e, KEY_COST3)); 
     map.put(KEY_DESC3, parser.getValue(e,KEY_DESC3)); 
     map.put(KEY_COST4,parser.getValue(e, KEY_COST4)); 
     map.put(KEY_DESC4, parser.getValue(e,KEY_DESC4)); 
     map.put(KEY_COST5,parser.getValue(e, KEY_COST5)); 
     map.put(KEY_DESC5, parser.getValue(e,KEY_DESC5)); 
     map.put(KEY_COST6,parser.getValue(e, KEY_COST6)); 
     map.put(KEY_DESC6, parser.getValue(e,KEY_DESC6)); 

     // adding HashList to ArrayList 
     menuItems.add(map); 

     //Passing Data to Store Page 
     mGetData.addLoad(menuItems); 
     //putStringArrayListExtra(menuItems, ArrayList<String> menuItems); 



} 
    // Adding menuItems to ListView 
    ListAdapter adapter = new SimpleAdapter(this, menuItems, 
      R.layout.list_item, 
      new String[] { KEY_NAME, KEY_DESC, KEY_COST }, new int[] { 
      R.id.name, R.id.desciption, R.id.cost}); 

    setListAdapter(adapter); 

    // selecting single ListView item 
    ListView lv = getListView(); 

    lv.setOnItemClickListener(new OnItemClickListener() { 

     public void onItemClick(AdapterView<?> parent, View view, 
       int position, long id) { 
      // getting values from selected ListItem 
      String name = ((TextView) view.findViewById(R.id.name)).getText().toString(); 
      String cost = ((TextView) view.findViewById(R.id.cost)).getText().toString(); 
      String description = ((TextView) view.findViewById(R.id.desciption)).getText().toString(); 

      // Starting new intent 
      Intent in = new Intent(getApplicationContext(), SingleMenuItemActivity.class); 
      in.putExtra(KEY_NAME, name); 
      in.putExtra(KEY_COST, cost); 
      in.putExtra(KEY_DESC, description); 

      startActivity(in); 


     } 

    }); 
} 

public int describeContents() { 
    // TODO Auto-generated method stub 
    return 0; 
} 

public void writeToParcel(Parcel dest, int flags) { 
    // TODO Auto-generated method stub 
    dest.writeString(KEY_NAME); 
    dest.writeString(KEY_COST); 
    dest.writeString(KEY_DESC); 
} 

public AndroidXMLParsingActivity(Parcel source){ 
    KEY_NAME=source.readString(); 
    KEY_COST=source.readString(); 
    KEY_DESC=source.readString(); 
    source.readArrayList(getClassLoader()); 
} 

而且我的SQLite代碼如下[WORKS]

public class DBAdapter { 

// Contacts Table Columns names 
public static final String KEY_ROWID = "_id"; 
private static final String KEY_NAME = "group_id"; 
private static final String KEY_SUNM = "sunm"; 
private static final String KEY_SUNE = "sune"; 
private static final String KEY_MONM = "monm"; 
private static final String KEY_MONE = "mone"; 
private static final String KEY_TUEM = "tuem"; 
private static final String KEY_TUEE = "tuee"; 
private static final String KEY_WEDM = "wedm"; 
private static final String KEY_WEDE = "wede"; 
private static final String KEY_THUM = "thum"; 
private static final String KEY_THUE = "thue"; 
private static final String KEY_FRIM = "frim"; 
private static final String KEY_FRIE = "frie"; 
private static final String KEY_SATM = "satm"; 
private static final String KEY_SATE = "sate"; 

AsyncTask sch; 

// Database Name 
private static final String DATABASE_NAME = "DB_NAME"; 

// Contacts table name 
private static final String DATABASE_TABLE= "TABLE_NAME"; 

// Database Version 
private static final int DATABASE_VERSION = 1; 

// Creating Tables 
private static final String DATABASE_CREATE ="create table if not exists TABLE_NAME (_id integer primary key autoincrement,group_id text,sunm text ,sune text ,monm text,mone text ,tuem text,tuee text,wedm text ,wede text ,thum text,thue text ,frim text ,frie text ,satm text,sate text)"; 

private final Context context; 

private DatabaseHelper DBHelper; 

private static SQLiteDatabase db; 

public DBAdapter(Context ctx) 
{ 
     this.context = ctx; 
     DBHelper = new DatabaseHelper(context); 
} 

private static class DatabaseHelper extends SQLiteOpenHelper 
{ 
    private static final String TAG = null; 

    DatabaseHelper(Context context) 
    { 
     super(context, DATABASE_NAME, null, DATABASE_VERSION); 
    } 

    @Override 
    public void onCreate(SQLiteDatabase db) 
    { 
     db.execSQL(DATABASE_CREATE); 
    } 

    @Override 
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) 
    { 
     Log.e(TAG, "Upgrading database from version " + oldVersion + " to " 
       + newVersion + ", which will destroy all old data"); 

     db.execSQL("DROP TABLE IF EXISTS schedules"); 
     onCreate(db); 
    } 
}  

//---opens the database--- 
public DBAdapter open() throws SQLException 
{ 
    db = DBHelper.getWritableDatabase(); 
    return this; 
} 

//---closes the database---  
public void close() 
{ 
    DBHelper.close(); 
} 

//Inserting data into the table 
public void insertData(String group_id, String sunm, String sune, String monm, String mone, String tuem, String tuee, 
     String wedm, String wede, String thum, String thue, String frim, String frie, String satm, String sate) { 
    try{ 
     Cursor cur = db.rawQuery("SELECT COUNT(*) FROM schedules", null); 
    if (cur!=null && cur.getCount() > 0){ 
     cur.moveToFirst(); 
     if (cur.getInt(0) <= 6) {//put in these statements contained in array 
      Log.i("DB getCount", " getcount less than 0, should read array");//log message 

      String insertQuery ="INSERT INTO schedules(group_id,sunm,sune,monm,mone,tuem,tuee,wedm,wede,thum,thue,frim,frie," + 
        "satm,sate)"+ "VALUES" + "("+"'"+group_id+"'"+","+"'"+sunm+"'"+","+"'"+sune+"'"+","+"'"+monm+"'"+"," + 
        ""+"'"+mone+"'"+","+"'"+tuem+"'"+","+"'"+tuee+"'"+","+"'"+wedm+"'"+","+"'"+wede+"'"+","+"'"+thum+"'"+"," + 
          ""+"'"+thue+"'"+","+"'"+frim+"'"+","+"'"+frie+"'"+","+"'"+satm+"'"+","+"'"+sate+"'"+")"; 
      db.execSQL(insertQuery); 

      Log.e("a", ""+cur.getCount()); 
     } 
    } 
    else{ 
      //do nothing everything's as it should be 
     Log.i("DB getCount", " getcount greater than 0"); //log message 
    } 
    cur.close(); 
    db.close(); 

    } 
    catch(SQLiteException e){System.err.println("Exception @ rawQuery: " + e.getMessage());} 
} 

    //---retrieves all the title--- 
public Cursor getAllTitles() 
{ 
    return db.query(DATABASE_TABLE, new String[] {KEY_ROWID,KEY_NAME,KEY_SUNM,KEY_SUNE,KEY_MONM,KEY_MONE,KEY_MONM,KEY_TUEM, 
    KEY_TUEE,KEY_WEDM,KEY_WEDE,KEY_THUM,KEY_THUE,KEY_FRIM,KEY_FRIE,KEY_SATM,KEY_SATE}, null, null, null, null, null, null);   
} 

//---retrieves a particular title--- 
public ScheduleItem getSelectedItem(String group){ 

ScheduleItem schedule = new ScheduleItem(); 

    // Select All Query 
    String searchQuery = "select * from schedules where group_id = '"+group+"'"; 
    Log.e("DBAdapter", group); 
     try{ 
      //Database not open error 
      Cursor cur = db.rawQuery(searchQuery, null); 

     if (cur!=null && cur.getCount() > 0){ 
      cur.moveToFirst(); 
     //Setting DB value to model scheduleitem.java 
      schedule.setName(cur.getString(cur.getColumnIndex("group_id"))); 
      schedule.setSunm(cur.getString(cur.getColumnIndex("sunm"))); 
      schedule.setSune(cur.getString(cur.getColumnIndex("sune"))); 
      schedule.setMonm(cur.getString(cur.getColumnIndex("monm"))); 
      schedule.setMone(cur.getString(cur.getColumnIndex("mone"))); 
      schedule.setTuem(cur.getString(cur.getColumnIndex("tuem"))); 
      schedule.setTuee(cur.getString(cur.getColumnIndex("tuee"))); 
      schedule.setWedm(cur.getString(cur.getColumnIndex("wedm"))); 
      schedule.setWede(cur.getString(cur.getColumnIndex("wede"))); 
      schedule.setThum(cur.getString(cur.getColumnIndex("thum"))); 
      schedule.setThue(cur.getString(cur.getColumnIndex("thue"))); 
      schedule.setFrim(cur.getString(cur.getColumnIndex("frim"))); 
      schedule.setFrie(cur.getString(cur.getColumnIndex("frie"))); 
      schedule.setSatm(cur.getString(cur.getColumnIndex("satm"))); 
      schedule.setSate(cur.getString(cur.getColumnIndex("sate"))); 
      } 

     cur.close(); 
     db.close(); 
     return schedule; 

     }catch(SQLiteException e){System.err.println("Exception @ rawQuery: " + e.getMessage());} 
     return schedule; 
    } 

    public void scheduleupdate(){ 

     Log.e(DATABASE_NAME, "Data Removed"); 
     //String delQuery="DELETE FROM TABLE schedules"; 
     context.deleteDatabase(DATABASE_NAME); 
     //db.execSQL(delQuery); 
     db.close(); 

    } 
} 

幫助我 logcat的錯誤

09-18 13:11:03.362: E/AndroidRuntime(471): FATAL EXCEPTION: main 
09-18 13:11:03.362: E/AndroidRuntime(471): java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{com.mokshya.multinodeparse/com.mokshya.multinodeparse.parse.AndroidXMLParsingActivity}: java.lang.InstantiationException: 
09-18 13:11:03.362: E/AndroidRuntime(471): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2585) 
09-18 13:11:03.362: E/AndroidRuntime(471): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2679) 
09-18 13:11:03.362: E/AndroidRuntime(471): at android.app.ActivityThread.access$2300(ActivityThread.java:125) 
09-18 13:11:03.362: E/AndroidRuntime(471): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2033) 
09-18 13:11:03.362: E/AndroidRuntime(471): at android.os.Handler.dispatchMessage(Handler.java:99) 
09-18 13:11:03.362: E/AndroidRuntime(471): at android.os.Looper.loop(Looper.java:123) 
09-18 13:11:03.362: E/AndroidRuntime(471): at android.app.ActivityThread.main(ActivityThread.java:4627) 
09-18 13:11:03.362: E/AndroidRuntime(471): at java.lang.reflect.Method.invokeNative(Native Method) 
09-18 13:11:03.362: E/AndroidRuntime(471): at java.lang.reflect.Method.invoke(Method.java:521) 
09-18 13:11:03.362: E/AndroidRuntime(471): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868) 
09-18 13:11:03.362: E/AndroidRuntime(471): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626) 
09-18 13:11:03.362: E/AndroidRuntime(471): at dalvik.system.NativeStart.main(Native Method) 
09-18 13:11:03.362: E/AndroidRuntime(471): Caused by: java.lang.InstantiationException: com.mokshya.multinodeparse.parse.AndroidXMLParsingActivity 
09-18 13:11:03.362: E/AndroidRuntime(471): at java.lang.Class.newInstanceImpl(Native Method) 
09-18 13:11:03.362: E/AndroidRuntime(471):  at java.lang.Class.newInstance(Class.java:1429) 
09-18 13:11:03.362: E/AndroidRuntime(471): at android.app.Instrumentation.newActivity(Instrumentation.java:1021) 
09-18 13:11:03.362: E/AndroidRuntime(471): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2577) 
09-18 13:11:03.362: E/AndroidRuntime(471): ... 11 more 
com.mokshya.multinodeparse.parse.AndroidXMLParsingActivity 

Answer 1

我認爲這可能會幫助一些新手解決，所以我張貼我的答案。在這裏我已經解析了這個值並且直接使用AsyncTask從同一個函數傳遞給了sqlite。代碼如下：

public class LoadScheduleAsyncTask extends AsyncTask<String, String, String> { 

DBAdapter dba; 

Boolean isInternetPresent = false; 

// Connection Detector Class 
ConnectionDetector cd; 

private ProgressDialog pDialog; 

// Alert Dialog Manager 
AlertDialogManager alert = new AlertDialogManager(); 

// XML Parsing URL 
static final String URL = "url address"; 

// XML node keys 
static final String KEY_ITEM = "group_header"; // Parent Node 
static final String KEY_ROWID = "_id"; 
static final String KEY_NAME = "name"; 
static final String KEY_SUNM = "day_sun_mrg"; 
static final String KEY_SUNE = "day_sun_evn"; 
static final String KEY_MONM = "day_mon_mrg"; 
static final String KEY_MONE = "day_mon_evn"; 
static final String KEY_TUEM = "day_tue_mrg"; 
static final String KEY_TUEE = "day_tue_evn"; 
static final String KEY_WEDM = "day_wed_mrg"; 
static final String KEY_WEDE = "day_wed_evn"; 
static final String KEY_THUM = "day_thu_mrg"; 
static final String KEY_THUE = "day_thu_evn"; 
static final String KEY_FRIM = "day_fri_mrg"; 
static final String KEY_FRIE = "day_fri_evn"; 
static final String KEY_SATM = "day_sat_mrg"; 
static final String KEY_SATE = "day_sat_evn"; 

public static ArrayList<HashMap<String, String>> menuItems = new ArrayList<HashMap<String, String>>(); 

// Creating new HashMap 
HashMap<String, String> map = new HashMap<String, String>(); 
Context context; 

public LoadScheduleAsyncTask(Context ctxt){ 
    dba=new DBAdapter(ctxt); 
    context=ctxt; 
} 

/** 
* Before starting background thread Show Progress Dialog 
**/ 
@SuppressLint("NewApi") 
@Override 
protected void onPreExecute() { 
    super.onPreExecute(); 
    pDialog = new ProgressDialog(context); 
    pDialog.setMessage("Updating Data ..."); 
    pDialog.setIndeterminate(false); 
    pDialog.setCancelable(false); 
    pDialog.show(); 
} 

/** 
* getting Schedule XML 
**/ 
protected String doInBackground(String... args) { 
    XMLParser parser = new XMLParser(); 
    String xml = parser.getXmlFromUrl(URL); // getting XML 
    Document doc = parser.getDomElement(xml); // getting DOM element 
    NodeList nl = doc.getElementsByTagName(KEY_ITEM); 
    // looping through all item nodes <item> 
    for (int i = 0; i < nl.getLength(); i++) { 
     Element e = (Element) nl.item(i); 
     // adding each child node to HashMap key => value 
     map.put(KEY_NAME, parser.getValue(e, KEY_NAME)); 
     map.put(KEY_SUNM, parser.getValue(e, KEY_SUNM)); 
     map.put(KEY_SUNE, parser.getValue(e, KEY_SUNE)); 
     map.put(KEY_MONM, parser.getValue(e, KEY_MONM)); 
     map.put(KEY_MONE, parser.getValue(e, KEY_MONE)); 
     map.put(KEY_TUEM, parser.getValue(e, KEY_TUEM)); 
     map.put(KEY_TUEE, parser.getValue(e, KEY_TUEE)); 
     map.put(KEY_WEDM, parser.getValue(e, KEY_WEDM)); 
     map.put(KEY_WEDE, parser.getValue(e, KEY_WEDE)); 
     map.put(KEY_THUM, parser.getValue(e, KEY_THUM)); 
     map.put(KEY_THUE, parser.getValue(e, KEY_THUE)); 
     map.put(KEY_FRIM, parser.getValue(e, KEY_FRIM)); 
     map.put(KEY_FRIE, parser.getValue(e, KEY_FRIE)); 
     map.put(KEY_SATM, parser.getValue(e, KEY_SATM)); 
     map.put(KEY_SATE, parser.getValue(e, KEY_SATE)); 
     // adding HashList to ArrayList 
     menuItems.add(map); 

     /** 
     * Updating parsed JSON data into ListView 
     **/ 
     String group_id = map.get(KEY_NAME); 
     String sunm = map.get(KEY_SUNM); 
     String sune = map.get(KEY_SUNE); 
     String monm = map.get(KEY_MONM); 
     String mone = map.get(KEY_MONE); 
     String tuem = map.get(KEY_TUEM); 
     String tuee = map.get(KEY_TUEE); 
     String wedm = map.get(KEY_WEDM); 
     String wede = map.get(KEY_WEDE); 
     String thum = map.get(KEY_THUM); 
     String thue = map.get(KEY_THUE); 
     String frim = map.get(KEY_FRIM); 
     String frie = map.get(KEY_FRIE); 
     String satm = map.get(KEY_SATM); 
     String sate = map.get(KEY_SATE); 

     try { 
      dba.open(); 
     } catch (SQLException e1) { 
      // TODO Auto-generated catch block 
      e1.printStackTrace(); 
     } 
     dba.insertData(group_id, sunm, sune, monm, mone, tuem, tuee, wedm, 
       wede, thum, thue, frim, frie, satm, sate); 
     dba.close(); 
    } 
    return null; 
} 

/** 
* After completing background task Dismiss the progress dialog 
**/ 
protected void onPostExecute(String file_url) { 
    // dismiss the dialog after getting all schedules 
    pDialog.dismiss(); 

} 
} 

這個答案是基於不同的方法比我的問題。

Answer 2

我想在你的AndroidManifest.xml

您尚未註冊您的活動

請在您的AndroidManifest.xml中註冊您的活動。

每當您創建新的活動時，您都必須在AndroidManifest.xml中註冊該活動。

Answer 3

您正在爲AndroidXMLParsingActivity創建自己的構造函數。

我不認爲你應該重寫構造函數。也不要讓你的活動Serializable。創建一個自定義的Serializable類，其中包含要傳遞的數據的字段。然後通過這個類，而不是你的活動