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ANDROID-将数据插入数据库,报告无法启动活动组件信息:java.lang.NullPointerException_Android_Mysql_Sql_Database - Fatal编程技术网

ANDROID-将数据插入数据库,报告无法启动活动组件信息:java.lang.NullPointerException

ANDROID-将数据插入数据库,报告无法启动活动组件信息:java.lang.NullPointerException,android,mysql,sql,database,Android,Mysql,Sql,Database,我被困于将资产文件夹中的数据(包含insert SQL)放入数据库。我尝试了很多改变,但我的薪酬报告: "Unable to start activity ComponentInfo{com.restaurant.sesame/com.restaurant.sesame.Food}: java.lang.NullPointerException" 这是我的food.txt文件内容: INSERT INTO Food (name,detail,price)VALUES ('Cow Rib

我被困于将资产文件夹中的数据(包含insert SQL)放入数据库。我尝试了很多改变,但我的薪酬报告:

"Unable to start activity ComponentInfo{com.restaurant.sesame/com.restaurant.sesame.Food}:   java.lang.NullPointerException"
这是我的food.txt文件内容:

 INSERT INTO Food (name,detail,price)VALUES ('Cow Rib Steak', '1h 37m Shipping: $11.00', '11.00')
 INSERT INTO Food (name,detail,price)VALUES ('Cow Rib Steak', '1h 37m Shipping: $11.00', '11.00')
 INSERT INTO Food (name,detail,price)VALUES ('Cow Rib Steak', '1h 37m Shipping: $11.00', '11.00')
 INSERT INTO Food (name,detail,price)VALUES ('Cow Rib Steak', '1h 37m Shipping: $11.00', '11.00')
我挣扎了很长时间。我访问了很多网站来研究这个问题。 有人能提出一个更可靠的方法来帮助我解决这个错误吗

  public class Restaurant extends Activity {
public static final String KEY_ROWID = "_id";
public static final String KEY_NAME = "name";
public static final String KEY_DETAIL = "detail";
public static final String KEY_PRICE = "price";


private static final String DATABASE_NAME ="Restaurantdb";
private static final String DATABASE_TABLE ="Food";
private static final int DATABASE_VERSION = 1;


private SQLiteDatabase ourDatabase;
private final Context ourContext;
private DBHelper ourHelper;

InputStream input;
AssetManager assetManager = getAssets();
static String value;

@Override
protected void onCreate(Bundle savedInstanceState) {
    // TODO Auto-generated method stub
    super.onCreate(savedInstanceState);
    try {
           input = assetManager.open("food.txt");

                  int size = input.available();
                  byte[] buffer = new byte[size];
                  input.read(buffer);
                  input.close();

                  // byte buffer into a string
                   value = new String(buffer);


      } catch (IOException e) {
           // TODO Auto-generated catch block
           e.printStackTrace();
          }
}

private static class DBHelper extends SQLiteOpenHelper{

    public DBHelper(Context context) {
        super(context, DATABASE_NAME, null, DATABASE_VERSION);

    }

    public void onCreate(SQLiteDatabase db)
    {
        db.execSQL("CREATE TABLE Food (" + KEY_ROWID +" INTEGER PRIMARY KEY AUTOINCREMENT, "
                    +KEY_NAME+" TEXT NOT NULL, "+KEY_DETAIL+ " TEXT NOT NULL, " + KEY_PRICE+ " DECIMAL (18,2) NOT NULL );"
                );
        db.execSQL("CREATE TABLE Bill ( _id INTEGER PRIMARY KEY AUTOINCREMENT, name TEXT NOT NULL,"+
                " price  DECIMAL (18,2) NOT NULL, quantity INTEGER NOT NULL, total DECIMAL (18,2) NOT NULL );"
            );



        db.rawQuery(value, null);

        Log.w("my app", "insert data into NEW DB");
    }

我认为你找错了方向:)

无法启动活动组件信息

所以我建议问题可能出在这个活动onCreate()中


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请提供更多stacktrace以查找问题所在?对不起,我不明白。我是指你所谓的“公司报告”,即“无法启动…”。请发布剩余的行,以便跟踪问题所在!!04-01 20:45:24.463:E/AndroidRuntime(363):在android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2496)04-01 20:45:24.463:E/AndroidRuntime(363):在android.app.ActivityThread.access$2200(ActivityThread.java:119)04-01 20:45:24.463:E/AndroidRuntime(363):在android.app.ActivityThread.H$H.handleMessage(ActivityThread.java:1863)04-01 20:45:24.463:E/AndroidRuntime(363):在android.os.Handler.dispatchMessage(Handler.java:99)04-01 20:45:24.463:E/AndroidRuntime(363):在android.os.Looper.loop(Looper.java:123)