Question

基本上，我想更新我的应用程序数据库从网页获取数据...我已经写了这个类来处理我的目标：

private class updateDatabase extends AsyncTask<Void, Void, String> {
    String html, minerals, url;
    List<String> allMinerals;
    boolean alreadyHas = false;
    int isFavorite;

    @Override
    protected String doInBackground(Void... params) {
        url = "http://minerais.cf/app.php";
        allMinerals = dbHandler.getAllMineraisNames("external");
        int i, j;
        try {
            org.jsoup.nodes.Document doc = Jsoup.connect(url).get();
            html = doc.toString();
            minerals = Jsoup.parse(html).text();
        } catch (IOException e) {
            e.printStackTrace();
        }
        String[] elemento = minerals.split("959");
        for(i=0; i<elemento.length-1; i++){
            alreadyHas = false;
            String[] dados = elemento[i].split("858");
            for(j=0; j<allMinerals.size()-1; j++){
                if(dados[0].equals(allMinerals.get(j))){
                    alreadyHas = true;
                    if(dbHandler.isFavorite(allMinerals.get(j))){
                        isFavorite = 1;
                    }
                    else{
                        isFavorite = 0;
                    }
                }
            }
            if(alreadyHas){
                Mineral updating = new Mineral(
                        i,
                        dados[0],
                        dados[1],
                        dados[2],
                        dados[3],
                        dados[4],
                        dados[5],
                        dados[6],
                        dados[7],
                        dados[8],
                        dados[9],
                        dados[10],
                        dados[11],
                        dados[12],
                        dados[13],
                        dados[14],
                        dados[15],
                        dados[16],
                        dados[17],
                        isFavorite
                        );
                dbHandler.updateMineral("external", updating);
            }
            else{
                Mineral adding = new Mineral(
                        allMinerals.size(),
                        dados[0],
                        dados[1],
                        dados[2],
                        dados[3],
                        dados[4],
                        dados[5],
                        dados[6],
                        dados[7],
                        dados[8],
                        dados[9],
                        dados[10],
                        dados[11],
                        dados[12],
                        dados[13],
                        dados[14],
                        dados[15],
                        dados[16],
                        dados[17],
                        isFavorite
                );
                dbHandler.addMineral("external", adding);
            }
        }
        return null;
    }
    @Override
    protected void onPostExecute(String result) {
        loadList("");
    }
    @Override
    protected void onPreExecute() {

    }
}

DbHandler.java：

// Getting All Minerais
public List<String> getAllMineraisNames(String table) {
    List<String> mineralList = new ArrayList<>();
    // Select All Query
    String selectQuery = "SELECT " + KEY_NOME + " FROM " + table + " ORDER BY " + KEY_FAVORITE + " DESC, " + KEY_NOME;
    //String selectQuery = "SELECT * FROM " + table + " WHERE " + KEY_FAVORITE + "=1";

    SQLiteDatabase db = this.getWritableDatabase();
    Cursor cursor = db.rawQuery(selectQuery, null);

    // looping through all rows and adding to list
    if (cursor.moveToFirst()) {
        do {
            mineralList.add(cursor.getString(0));
        } while (cursor.moveToNext());
    }

    // return mineral list
    return mineralList;
}

// Updating single mineral
public int updateMineral(String table, Mineral mineral) {
    SQLiteDatabase db = this.getWritableDatabase();

    ContentValues values = new ContentValues();
    values.put(KEY_NOME, mineral.getNome());
    values.put(KEY_FORMULAQUIMICA, mineral.getFormulaQuimica());
    values.put(KEY_COMPOSICAO, mineral.getComposicao());
    values.put(KEY_CRISTALOGRAFIA, mineral.getCristalografia());
    values.put(KEY_PROPRIEDADESOPTICAS, mineral.getPropriedadesOpticas());
    values.put(KEY_HABITO, mineral.getHabito());
    values.put(KEY_CLIVAGEM, mineral.getClivagem());
    values.put(KEY_DUREZA, mineral.getDureza());
    values.put(KEY_DENSIDADERELATIVA, mineral.getDensidadeRelativa());
    values.put(KEY_FRATURA, mineral.getFratura());
    values.put(KEY_BRILHO, mineral.getBrilho());
    values.put(KEY_COR, mineral.getCor());
    values.put(KEY_ASSOCIACAO, mineral.getAssociacao());
    values.put(KEY_PROPRIEDADESDIAGNOSTICAS, mineral.getPropriedadesDiagnosticas());
    values.put(KEY_OCORRENCIA, mineral.getOcorrencia());
    values.put(KEY_USOS, mineral.getUsos());
    values.put(KEY_VARIEDADES, mineral.getVariedades());
    values.put(KEY_OBSERVACOES, mineral.getObservacoes());
    values.put(KEY_FAVORITE, mineral.getFavorite());

    // updating row
    return db.update(table, values, KEY_ID + " = ?",
            new String[] { String.valueOf(mineral.getID()) });
}

boolean isFavorite (String name) {
    SQLiteDatabase db = this.getReadableDatabase();
    Cursor cursor = db.query(TABLE_MINERAIS_EXTERNAL, new String[] { KEY_FAVORITE
            }, KEY_NOME + "=?",
            new String[] { name }, null, null, null, null);
    if (cursor != null)
        cursor.moveToFirst();

    assert cursor != null;
    int isFavorite = cursor.getInt(0);

    return isFavorite==1;
}

 void addMineral(String table, Mineral mineral) {
    SQLiteDatabase db = this.getWritableDatabase();

    ContentValues values = new ContentValues();
    values.put(KEY_NOME, mineral.getNome());
    values.put(KEY_FORMULAQUIMICA, mineral.getFormulaQuimica());
    values.put(KEY_COMPOSICAO, mineral.getComposicao());
    values.put(KEY_CRISTALOGRAFIA, mineral.getCristalografia());
    values.put(KEY_PROPRIEDADESOPTICAS, mineral.getPropriedadesOpticas());
    values.put(KEY_HABITO, mineral.getHabito());
    values.put(KEY_CLIVAGEM, mineral.getClivagem());
    values.put(KEY_DUREZA, mineral.getDureza());
    values.put(KEY_DENSIDADERELATIVA, mineral.getDensidadeRelativa());
    values.put(KEY_FRATURA, mineral.getFratura());
    values.put(KEY_BRILHO, mineral.getBrilho());
    values.put(KEY_COR, mineral.getCor());
    values.put(KEY_ASSOCIACAO, mineral.getAssociacao());
    values.put(KEY_PROPRIEDADESDIAGNOSTICAS, mineral.getPropriedadesDiagnosticas());
    values.put(KEY_OCORRENCIA, mineral.getOcorrencia());
    values.put(KEY_USOS, mineral.getUsos());
    values.put(KEY_VARIEDADES, mineral.getVariedades());
    values.put(KEY_OBSERVACOES, mineral.getObservacoes());
    values.put(KEY_FAVORITE, mineral.getFavorite());

    // Inserting Row
    db.insert(table, null, values);
    db.close(); // Closing database connection
}

当我执行该函数时，它会抛出：

E/AndroidRuntime: FATAL EXCEPTION: AsyncTask #1
                                                         Process: cf.minerais, PID: 12076
                                                         java.lang.RuntimeException: An error occurred while executing doInBackground()
                                                             at android.os.AsyncTask$3.done(AsyncTask.java:309)
                                                             at java.util.concurrent.FutureTask.finishCompletion(FutureTask.java:354)
                                                             at java.util.concurrent.FutureTask.setException(FutureTask.java:223)
                                                             at java.util.concurrent.FutureTask.run(FutureTask.java:242)
                                                             at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:234)
                                                             at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1113)
                                                             at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:588)
                                                             at java.lang.Thread.run(Thread.java:818)
                                                          Caused by: android.database.CursorIndexOutOfBoundsException: Index 0 requested, with a size of 0
                                                             at android.database.AbstractCursor.checkPosition(AbstractCursor.java:460)
                                                             at android.database.AbstractWindowedCursor.checkPosition(AbstractWindowedCursor.java:136)
                                                             at android.database.AbstractWindowedCursor.getInt(AbstractWindowedCursor.java:68)
                                                             at cf.minerais.DatabaseHandler.isFavorite(DatabaseHandler.java:164)
                                                             at cf.minerais.Main$updateDatabase.doInBackground(Main.java:134)
                                                             at cf.minerais.Main$updateDatabase.doInBackground(Main.java:109)
                                                             at android.os.AsyncTask$2.call(AsyncTask.java:295)
                                                             at java.util.concurrent.FutureTask.run(FutureTask.java:237)
                                                             at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:234) 
                                                             at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1113) 
                                                             at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:588) 
                                                             at java.lang.Thread.run(Thread.java:818)

我做错了什么？提前致谢

Answer 1

提示在你的堆栈跟踪中：

gsutil cp

错误位于Caused by: android.database.CursorIndexOutOfBoundsException: Index 0 requested, with a size of 0 at android.database.AbstractCursor.checkPosition(AbstractCursor.java:460) at android.database.AbstractWindowedCursor.checkPosition(AbstractWindowedCursor.java:136) at android.database.AbstractWindowedCursor.getInt(AbstractWindowedCursor.java:68) at cf.minerais.DatabaseHandler.isFavorite(DatabaseHandler.java:164)，您不是checking the result光标移动：

isFavorite()

（您的IDE中可能会发出一条警告：您忽略了if (cursor != null) cursor.moveToFirst();的回复;这些都值得关注。）

moveToFirst()查询没有返回任何行（没有与名称匹配），因此没有第一行要移动，因此当您调用select时，将抛出超出范围的索引。做类似的事情：

cursor.getInt(0)

我建议你输入一堆调试日志（或者只是在调试器中单步执行），这样你就可以看到你传递了什么输入以及它在哪里失败。

通过Jsoup更新效果不佳

1 个答案: