Android 使用gson将sqlite数据转换为json

我想将sqlite数据发送到jsonarray，但遇到了一些问题 我编写了这段代码，用hasmap将sqlite解析为arraylist，并使用gson将其转换为json

public ArrayList<HashMap<String, String>> tampil_semua_pesanan() {
    SQLiteDatabase database = this.getWritableDatabase();

    // deklarasikan sebuah arraylist yang bisa menampung hashmap
    ArrayList<HashMap<String, String>> arrayListBiodata = new ArrayList<HashMap<String, String>>();

    Cursor cursor = database.rawQuery("SELECT * FROM "+ TABLE_PESAN , null);

    // kursor langsung diarkan ke posisi paling awal data pada tabel_biodata
    if (cursor.moveToFirst()) {
        do {
            // deklarasikan sebuah hashmap, yang bisa menamp
            HashMap<String, String> hashMapBiodata = new HashMap<String, String>();

            hashMapBiodata.put("id", cursor.getString(0));
            hashMapBiodata.put("nama", cursor.getString(1));
            hashMapBiodata.put("jumlah", cursor.getString(2));

            // masukkan hashMapBiodata ke dalam arrayListBiodata
            arrayListBiodata.add(hashMapBiodata);

        } while (cursor.moveToNext());
    }
    cursor.close();
    return arrayListBiodata;
}

我想成为这样

[{"id":"11","jjumlah":"12","nama":"Ayam Goreng"},{"id":"11","jjumlah":"12","nama":"Ayam Goreng"},{"id":"11","jjumlah":"12","nama":"Ayam Goreng"}]

["makanan":{"id":"11","jumlah":"12","nama":"Ayam Goreng"},{"id":"11","jumlah":"12","nama":"Ayam Goreng"},{"id":"11","jumlah":"12","nama":"Ayam Goreng"}]

---

有人能帮我吗？

试试这段代码，希望能奏效

    public ArrayList<HashMap<String, HashMap<String, String>>> tampil_meja() {
    SQLiteDatabase database = this.getWritableDatabase();
    ArrayList<HashMap<String, HashMap<String, String>>> arrayListMeja = new ArrayList<HashMap<String, HashMap<String, String>>>();

    Cursor cursor = database.rawQuery("SELECT * FROM "+ TABLE_MEJA , null);

    HashMap<String, HashMap<String, String>> hashMap = new HashMap<String, HashMap<String, String>>();
    if (cursor.moveToFirst()) {
        do {
            HashMap<String, String> hashMapBiodata = new HashMap<String, String>();
            hashMapBiodata.put("id", cursor.getString(0));
            hashMap.put("makanan", hashMapBiodata);
        } while (cursor.moveToNext());
    }
    cursor.close();

    arrayListMeja.add(hashMap);
    return arrayListMeja;
}

此链接可以帮助您：

    public ArrayList<HashMap<String, HashMap<String, String>>> tampil_meja() {
    SQLiteDatabase database = this.getWritableDatabase();
    ArrayList<HashMap<String, HashMap<String, String>>> arrayListMeja = new ArrayList<HashMap<String, HashMap<String, String>>>();

    Cursor cursor = database.rawQuery("SELECT * FROM "+ TABLE_MEJA , null);

    HashMap<String, HashMap<String, String>> hashMap = new HashMap<String, HashMap<String, String>>();
    if (cursor.moveToFirst()) {
        do {
            HashMap<String, String> hashMapBiodata = new HashMap<String, String>();
            hashMapBiodata.put("id", cursor.getString(0));
            hashMap.put("makanan", hashMapBiodata);
        } while (cursor.moveToNext());
    }
    cursor.close();

    arrayListMeja.add(hashMap);
    return arrayListMeja;
}