我在stackoverflow上看了很多关于这个错误的帖子,看起来修复是在重写onDestroy()方法并关闭数据库.但这似乎不适用于我的情况.当Eclipse最初在我的手机上运行应用程序时,我实际上没有收到任何错误,但当我关闭应用程序并在我的手机上重新启动它时 – 就是在LogCat中从未在数据库显示上显式调用close()时.我正在调用我的资产文件夹中的外部数据库,不确定它是否与它有关.
将对DBAdapter:
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlException;
import android.database.sqlite.sqliteDatabase;
import android.database.sqlite.sqliteException;
import android.database.sqlite.sqliteOpenHelper;
public class DBAdapter extends sqliteOpenHelper {
public static final String KEY_ROWID = "_id";
public static final String KEY_HDATE = "date";
public static final String KEY_MONTHDAY = "monthday";
public static final String KEY_YEAR = "year";
public static final String KEY_HD = "happened";
// The Android's default system path of your application database.
private static String DB_PATH = "/data/data/com.vdm.whtt/databases/";
private static String DB_NAME = "wht.db";
private static final String DB_TABLE = "historydaytable";
private sqliteDatabase db;
private final Context ourContext;
public DBAdapter(Context context) {
super(context,DB_NAME,null,1);
this.ourContext = context;
}
public void createDataBase() throws IOException {
boolean dbExist = checkDataBase();
if (dbExist) {
// do nothing - database already exist
} else {
// By calling this method and empty database will be created into
// the default system path
// of your application so we are gonna be able to overwrite that
// database with our database.
this.getReadableDatabase();
try {
copyDataBase();
} catch (IOException e) {
throw new Error("Error copying database");
}
}
}
private boolean checkDataBase() {
sqliteDatabase checkDB = null;
try {
String myPath = DB_PATH + DB_NAME;
checkDB = sqliteDatabase.openDatabase(myPath,sqliteDatabase.OPEN_READONLY);
} catch (sqliteException e) {
// database does't exist yet.
}
if (checkDB != null) {
checkDB.close();
}
return checkDB != null ? true : false;
}
private void copyDataBase() throws IOException {
InputStream myInput = ourContext.getAssets().open(DB_NAME);
String outFileName = DB_PATH + DB_NAME;
OutputStream myOutput = new FileOutputStream(outFileName);
byte[] buffer = new byte[1024];
int length;
while ((length = myInput.read(buffer)) > 0) {
myOutput.write(buffer,length);
}
myOutput.flush();
myOutput.close();
myInput.close();
}
public void open() throws sqlException {
String myPath = DB_PATH + DB_NAME;
db = sqliteDatabase.openDatabase(myPath,sqliteDatabase.OPEN_READONLY);
}
@Override
public synchronized void close() {
if (db != null)
db.close();
super.close();
}
@Override
public void onCreate(sqliteDatabase db) {
}
@Override
public void onUpgrade(sqliteDatabase db,int oldVersion,int newVersion) {
db.execsql("DROP TABLE IF EXISTS " + DB_TABLE);
onCreate(db);
}
public String[] getTH(long aLong) {
String[] columns = new String[] { KEY_YEAR,KEY_MONTHDAY,KEY_HD };
Cursor cursor = db.query(DB_TABLE,columns,KEY_HDATE + "=" + aLong,null);
if (cursor != null) {
cursor.moveToFirst();
String hpToday[] = new String[3];
hapToday[0] = cursor.getString(0);
hapToday[1] = cursor.getString(1);
hapToday[2] = cursor.getString(2);
cursor.close();
this.db.close();
return hpToday;
}
return null;
}
public String[] getFirstRandomAnswer(int randomNum1) {
String[] columns = new String[] { KEY_YEAR,null);
if (cursor != null) {
cursor.moveToPosition(randomNum1);
String r1Str[] = new String[3];
r1Str[0] = cursor.getString(0);
r1Str[1] = cursor.getString(1);
r1Str[2] = cursor.getString(2);
cursor.close();
this.db.close();
return r1Str;
}
return null;
}
public String[] getSecondRandomAnswer(int randomNum2) {
String[] columns = new String[] { KEY_YEAR,null);
if (cursor != null) {
cursor.moveToPosition(randomNum2);
String r2Str[] = new String[3];
r2Str[0] = cursor.getString(0);
r2Str[1] = cursor.getString(1);
r2Str[2] = cursor.getString(2);
cursor.close();
this.db.close();
return r2Str;
}
return null;
}
}
主要活动:
import java.io.IOException;
import java.util.Locale;
import java.util.Date;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import android.os.Bundle;
import android.text.Html;
import android.widget.TextView;
import android.app.Activity;
import android.database.sqlException;
public class MainActivity extends Activity {
private DBAdapter dba;
TextView hiddenDBdatetv,todayIstv,optionAtv;
String MMdStr;
String[] todayArray;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
hiddenDBdatetv = (TextView) findViewById(R.id.hiddenDBdate_TV);
todayIstv = (TextView) findViewById(R.id.todayIs_TV);
optionAtv = (TextView) findViewById(R.id.optionA_TV);
dba = new DBAdapter(this);
try {
dba.createDataBase();
} catch (IOException ioe) {
throw new Error("Unable to create database");
}
try {
dba.open();
} catch (sqlException sqle) {
throw sqle;
}
getMMdDate();
getTH();
}
private void getMMdDate() {
Date anotherCurDate = new Date();
SimpleDateFormat formatter = new SimpleDateFormat("MMd",Locale.US);
MMdStr = formatter.format(anotherCurDate);
SimpleDateFormat dateFormat = new SimpleDateFormat("MMd");
Date myDate = null;
try {
myDate = dateFormat.parse(MMdStr);
} catch (ParseException e) {
e.printStackTrace();
}
SimpleDateFormat timeFormat = new SimpleDateFormat("MMMMMMMMMM d");
String finalDate = timeFormat.format(myDate);
}
private void getTH() {
long aLong = Long.parseLong(MMdStr);
dba.open();
todayArray = dba.getTH(aLong);
dba.close();
optionAtv.setText(todayArray[2]);
}
@Override
protected void onDestroy() {
dba.close();
super.onDestroy();
}
}
最佳答案
原文链接:https://www.f2er.com/android/430736.html