2016-06-29 47 views
-2

我试图从MSSQL数据库中将数据数据提取到微调器中,但我无法这样做。我得到这个例外: Exception due to Array adapter or 'Method invocation spnVnames.setAdapter(NoCoreAdapter) may produce java.lang.NullPointerException'请帮我找到我在下面的代码中的错误。阵列适配器<String >错误

@Override 
protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity_main); 
    Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar); 
    setSupportActionBar(toolbar); 
    currentDate = (TextView) findViewById(R.id.currentDate); 
    long date = System.currentTimeMillis(); 
    SimpleDateFormat sdf = new SimpleDateFormat(" dd/MM/ yyyy"); 
    String dateString = sdf.format(date); 
    currentDate.setText(dateString); 
    Spinner spnVnames = (Spinner) findViewById(R.id.spinner); 

    String query = " SELECT TaxName FROM tblTax "; //select query 

    try { 
     Connection con = connectionClass.CONN(); 
     Statement stmt = con.prepareStatement(query); 
     ResultSet rs = stmt.executeQuery(query); 
     List <String> data = new ArrayList < >(); 

     while (rs.next()) { 
      String id = rs.getString("TaxName"); 
      data.add(id); 
     } 

     String[] array = data.toArray(new String[data.size()]); 
     ArrayAdapter <String> NoCoreAdapter = new ArrayAdapter < > (MainActivity.this, android.R.layout.simple_list_item_1, array); 
     spnVnames.setAdapter(NoCoreAdapter); 

    } catch (SQLException e) { 
     e.printStackTrace(); 
    } 
} 
+3

的 “...可能会产生显示java.lang.NullPointerException” 的事情只是一个警告。如果您在运行时实际得到'Exception',则需要发布堆栈跟踪。 –

+0

致命例外:主进程:com.example.aits.cherrysales,PID:23161 java.lang.RuntimeException:无法启动活动ComponentInfo {com.example.aits.cherrysales/com.example.aits.cherrysales.MainActi vity} :java.lang.NullPointerException ---这是例外情况... hw继续? –

+0

格式。添加标签。改进拼写 – Patrick2607

回答

0

试试这个:

ArrayAdapter NoCoreAdapter = new ArrayAdapter<String>(MainActivity.this, android.R.layout.simple_spinner_item,array); 
+0

试过上面的代码仍然不工作prashanth..New to android so kindly help! –

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