我为“银行模拟”开发了一个应用程序，它使用 sqlite 创建数据库...当我在手机上运行该应用程序时，它意外停止...。我是否需要安装任何服务器才能在手机上运行基于 sqlite 的应用程序？提前致谢！
DbHelper.java
private static final String DATABASE_NAME = "saket.db";
private static final int DATABASE_VERSION = 1;
public static final String SUBH_TABLE_NAME = "login";
public static final String SUBH_TABLE_DATA = "TBL_Transaction";
public static final String KEY_ROWID = "_id";
private static final String SUBH_TABLE_CREATE =
"CREATE TABLE " + SUBH_TABLE_NAME + "(" +
"_id INTEGER PRIMARY KEY AUTOINCREMENT,"+
"username TEXT NOT NULL, password TEXT NOT NULL, email TEXT NOT NULL, balance INTEGER);";
private static final String SUBH_TABLE_DATA_CREATE =
"CREATE TABLE " + SUBH_TABLE_DATA + "(" +
"trans_id INTEGER PRIMARY KEY AUTOINCREMENT, "+
"user_id INTEGER, " +
"trans TEXT NOT NULL);";
private static final String SAKET_DB_ADMIN = "INSERT INTO "+ SUBH_TABLE_NAME +" values(1, admin, password, admin@gmail.com);";
//private static final String SAKET_DB_ADMIN_Trans = "INSERT INTO "+ SUBH_TABLE_DATA +" values(1, asdf);";
public DbHelper(Context context) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
System.out.println("In constructor");
}
/* (non-Javadoc)
* @see android.database.sqlite.SQLiteOpenHelper#onCreate(android.database.sqlite.SQLiteDatabase)
*/
@Override
public void onCreate(SQLiteDatabase db) {
try{
//Create Database
db.execSQL(SUBH_TABLE_CREATE);
//create transaction account
db.execSQL(SUBH_TABLE_DATA_CREATE);
//create admin account
db.execSQL(SAKET_DB_ADMIN);
//db.execSQL(SAKET_DB_ADMIN_Trans);
System.out.println("In onCreate");
}catch(Exception e){
e.printStackTrace();
}
}
数据库活动.java
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
mNewUser = (Button) findViewById(R.id.buttonNewUser);
mNewUser.setOnClickListener(this);
mLogin = (Button) findViewById(R.id.buttonLogin);
mLogin.setOnClickListener(this);
mShowAll = (Button) findViewById(R.id.buttonShowAll);
mShowAll.setOnClickListener(this);
}
public void onClick(View v) {
switch (v.getId()) {
case R.id.buttonLogin:
mUsername = (EditText) findViewById(R.id.editUsername);
mPassword = (EditText) findViewById(R.id.editPassword);
String uname = mUsername.getText().toString();
String pass = mPassword.getText().toString();
if (uname.equals("") || uname == null) {
Toast.makeText(getApplicationContext(), "Username Empty",
Toast.LENGTH_SHORT).show();
} else if (pass.equals("") || pass == null) {
Toast.makeText(getApplicationContext(), "Password Empty",
Toast.LENGTH_SHORT).show();
} else {
boolean validLogin = false;
try {
validLogin = validateLogin(uname, pass,
DatabaseActivity.this);
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
if (validLogin) {
System.out.println("In Valid");
Intent i_login = new Intent(DatabaseActivity.this,
UserLoggedInPage.class);
try {
id = getID(uname, pass, DatabaseActivity.this);
Ubal = getBAL(uname, pass, DatabaseActivity.this);
} catch (NumberFormatException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
Log.d(TAG, "putting the extra " + id);
i_login.putExtra("key", id);
i_login.putExtra("bkey", Ubal);
startActivity(i_login);
finish();
}
}
break;
case R.id.buttonNewUser:
Intent i = new Intent(DatabaseActivity.this, NewUserActivity.class);
startActivity(i);
finish();
break;
case R.id.buttonShowAll:
Intent i_admin = new Intent(DatabaseActivity.this, AdminPage.class);
startActivity(i_admin);
finish();
break;
}
}
public boolean validateLogin(String uname, String pass, Context context)
throws Exception {
myDb = new DbHelper(context);
SQLiteDatabase db = myDb.getReadableDatabase();
// SELECT
String[] columns = { "_id" };
// WHERE clause
String selection = "username=? AND password=?";
// WHERE clause arguments
String[] selectionArgs = { uname, pass };
Cursor cursor = null;
try {
// SELECT _id FROM login WHERE username = uname AND password=pass
cursor = db.query(DbHelper.SUBH_TABLE_NAME, columns, selection,
selectionArgs, null, null, null);
startManagingCursor(cursor);
} catch (Exception e) {
e.printStackTrace();
}
int numberOfRows = cursor.getCount();
if (numberOfRows <= 0) {
Toast.makeText(getApplicationContext(),
"Login Failed..\nTry Again", Toast.LENGTH_SHORT).show();
return false;
}
return true;
}
// get rowid
// public int getID(String uname, String pass, Context context)
// throws Exception {
//
// myDb = new DbHelper(context);
// SQLiteDatabase db = myDb.getReadableDatabase();
// cursor = db.rawQuery("select * from " + DbHelper.SUBH_TABLE_NAME +
// " where username = " + uname + "&" + "password = " + pass + ";)", null);
// if (cursor != null) {
// if(cursor.moveToFirst()){
// int id = cursor.getInt(cursor.getColumnIndex(DbHelper.KEY_ROWID));
// }
//
// }
//
// return id;
//
// }
public String getID(String uname, String pass, Context context) {
try {
String idddd = null;
SQLiteDatabase db = myDb.getReadableDatabase();
String[] columns = { "_id" };
// WHERE clause
String selection = "username=? AND password=?";
// WHERE clause arguments
String[] selectionArgs = { uname, pass };
Cursor cursor = db.query(DbHelper.SUBH_TABLE_NAME, columns,
selection, selectionArgs, null, null, null);
if (cursor != null) {
startManagingCursor(cursor);
while (cursor.moveToNext()) {
idddd = cursor.getString(0);
}
return idddd;
}
System.out.println("Cursor NuLL");
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
private String getBAL(String uname, String pass,
DatabaseActivity databaseActivity) {
try {
String ballll = null;
SQLiteDatabase db = myDb.getReadableDatabase();
String[] columns = { "balance" };
// WHERE clause
String selection = "username=? AND password=?";
// WHERE clause arguments
String[] selectionArgs = { uname, pass };
Cursor cursor = db.query(DbHelper.SUBH_TABLE_NAME, columns,
selection, selectionArgs, null, null, null);
if (cursor != null) {
startManagingCursor(cursor);
while (cursor.moveToNext()) {
ballll = cursor.getString(0);
}
return ballll;
}
System.out.println("Cursor NuLL");
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
protected void onDestroy() {
super.onDestroy();
if (myDb != null && cursor != null ) {
cursor.close();
myDb.close();
}
}
}