Eclipse 数据未插入 SQLite 数据库并崩溃

Question

当我点击按钮时，它应该将输入的数据连同从单独活动中收集的经度和纬度一起存储到数据库中。我不确定我做错了什么，我的其他数据库工作正常。任何帮助，将不胜感激。我将在下面发布代码：

这是活动java。

public class NoteActivity extends Activity implements OnClickListener {

Button buttonLeaveNote; 

private EditText mTitle;
private EditText mDesc;

protected NoteDBHelper noteDB = new NoteDBHelper(NoteActivity.this);

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_note);

    buttonLeaveNote = (Button) findViewById(R.id.buttonLeaveNote);
    buttonLeaveNote.setOnClickListener(this);

    mTitle = (EditText)findViewById(R.id.etitle);
    mDesc = (EditText)findViewById(R.id.edesc);
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.note, menu);
    return true;
}

@Override
public void onClick(View v) {
    switch(v.getId()){

    case R.id.buttonLeaveNote:

           String title = mTitle.getText().toString();
           String desc = mDesc.getText().toString();
           Intent intent = getIntent();
           String lati = intent.getExtras().getString("lati");
           String lng = intent.getExtras().getString("lng");

           boolean invalid = false;

           if(title.equals(""))
           {
            invalid = true;
            Toast.makeText(getApplicationContext(), "Please enter a title",          Toast.LENGTH_SHORT).show();
           }
           else
               if(desc.equals(""))
               {
                  invalid = true;
                  Toast.makeText(getApplicationContext(), "Please enter description", Toast.LENGTH_SHORT).show();

               } 

               else

                   if(invalid == false)
                   {
                       addEntry(title, desc, lati, lng);
                       Intent i_note = new Intent(NoteActivity.this, JustWanderingActivity.class);
                       startActivity(i_note);
                       //finish();
                      }

                      break;
                      }
                    }

public void onDestroy()
{
    super.onDestroy();
    noteDB.close();
}

private void addEntry(String title, String desc, String lati, String lng) 
 {
    SQLiteDatabase notedb = noteDB.getWritableDatabase();
    ContentValues values = new ContentValues();
      values.put("title", title);
      values.put("desc", desc);
      values.put("lati", lati);
      values.put("lng", lng);
      try
      {
       long newRowId;
       newRowId = notedb.insert(NoteDBHelper.DATABASE_TABLE_NAME, null, values);

       Toast.makeText(getApplicationContext(), "Note successfully added", Toast.LENGTH_SHORT).show();
      }

      catch(Exception e)
      {
       e.printStackTrace();
      } 
}
}

这是 SQLite DB Java

public class NoteDBHelper extends SQLiteOpenHelper 

{
private SQLiteDatabase notedb;

public static final String NOTE_ID = "_nid";
public static final String NOTE_TITLE = "title";
public static final String NOTE_DESC = "desc";
public static final String NOTE_LAT = "lati";
public static final String NOTE_LONG = "lng";


NoteDBHelper noteDB = null;
private static final String DATABASE_NAME = "stepsaway.db";
private static final int DATABASE_VERSION = 2;
public static final String DATABASE_TABLE_NAME = "notes";


private static final String DATABASE_TABLE_CREATE =
        "CREATE TABLE" + DATABASE_TABLE_NAME + "(" +
        "_nid INTEGER PRIMARY KEY AUTOINCREMENT," +
        "title TEXT NOT NULL, desc LONGTEXT NOT NULL, lati TEXT NOT NULL, lng, TEXT NOT NULL);";

 public NoteDBHelper(Context context) {

 super(context, DATABASE_NAME, null, DATABASE_VERSION);
 System.out.println("In constructor");
}


@Override
public void onCreate(SQLiteDatabase notedb) {

try{

notedb.execSQL(DATABASE_TABLE_CREATE);


}catch(Exception e){
e.printStackTrace();
}
}



@Override
public void onUpgrade(SQLiteDatabase notedb, int oldVersion, int newVersion) {
// TODO Auto-generated method stub

}




public Cursor rawQuery(String string, String[] strings) {
// TODO Auto-generated method stub
return null;
}




public void open() {

getWritableDatabase(); 
}


public Cursor getDetails(String text) throws SQLException 
{

Cursor mCursor =
        notedb.query(true, DATABASE_TABLE_NAME, 
          new String[]{NOTE_ID, NOTE_TITLE, NOTE_DESC, NOTE_LAT, NOTE_LONG}, 
          NOTE_TITLE + "=" + text, 
          null, null, null, null, null);
if (mCursor != null) 
{
    mCursor.moveToFirst();
}
return mCursor;


}
}

这是日志猫

FATAL EXCEPTION: main
java.lang.NullPointerException
atcom.example.stepsaway.NoteActivity.onClick(NoteActivity.java:53)
at android.view.View.performClick(View.java:4240)
at android.view.View$PerformClick.run(View.java:17721)
at android.os.Handler.handleCallback(Handler.java:730)
at android.os.Handler.dispatchMessage(Handler.java:92)
at android.os.Looper.loop(Looper.java:137)
at android.app.ActivityThread.main(ActivityThread.java:5103)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:525)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:737)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
at dalvik.system.NativeStart.main(Native Method)

这里是 putExtra() 调用。

    tvLatitude.setText("Latitude:" +  location.getLatitude());
    tvLongitude.setText("Longitude:" + location.getLongitude());
    String lati = tvLatitude.getText().toString();
    String lng = tvLongitude.getText().toString();
    Intent i = new Intent(this, NoteActivity.class);
    i.putExtra("lati", lati);
    i.putExtra("lng", lng);

Answer 1

没有 logcat 很难帮助你...所以也发布logcat

一个错误是在您的NoteDBHelper class 内创建表查询...

您忘记在keyword table 和表名(DATABASE_TABLE_NAME) 之间放置空格

所以要么改成：

private static final String DATABASE_TABLE_CREATE =
        "CREATE TABLE " + DATABASE_TABLE_NAME + "(" +
        "_nid INTEGER PRIMARY KEY AUTOINCREMENT," +
        "title TEXT NOT NULL, desc LONGTEXT NOT NULL, lati TEXT NOT NULL, lng, TEXT NOT NULL);";

或者到：

public static final String DATABASE_TABLE_NAME = " notes";

附言。

NullPointerException

在使用intent.getExtras() 之前检查null，并确保您在intent.putExtra() 中传递String 而不是double

intent.putExtra("lati","CheckHere it must be String not double");
intent.putExtra("lng","CheckHere it must be String not double");

以下代码也可以避免崩溃并帮助您正确调试

Intent intent = getIntent();
if(intent != null)
{
    String lati = intent.getExtras().getString("lati");
    String lng = intent.getExtras().getString("lng");
   if(lati == null)
    {
      Log.e("Checking lati","Its Null");
      lati="0";
    }
   if(lng == null)
    {
      Log.e("Checking lng","Its Null");
      lng="0";
    }
}
else
{
  Log.e("Checking intent","Its Null");
}

Answer 2

addentry 方法应该调用如下：

noteDB.addEntry(title, desc, lati, lng);