我不知道为什么我自己的数据库无法打开。我已经将它包含在文件夹资产中并按照本网站上的步骤进行操作
在 android 应用程序中使用自己的 sqlite 数据库
我已经为此工作了很多天；不幸的是，我还是android的新手。有人可以帮我弄清楚出了什么问题吗？
数据库处理程序.java
package com.example.awesome;
/*
* DatabaseHandler.java
* Version 11
* Add sorting list
*/
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.List;
import android.content.ContentValues;
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;
//import android.util.Log;
public class DatabaseHandler extends SQLiteOpenHelper {
// All Static variables
// Database Version
private static final int DATABASE_VERSION = 1;
private static String DB_PATH = "data/data/com.example.awesome/databases/";
private static String DB_NAME = "AcademicLocation";
private SQLiteDatabase myDataBase;
private final Context myContext;
// All tables name
private static final String TABLE_UKMLOCATION = "UKM_Location";
// All Table Columns names
private static final String KEY_ID = "_id";
private static final String KEY_NAME = "Name";
private static final String KEY_ALAMAT = "Alamat";
private static final String KEY_NOTEL = "No_tel";
private static final String KEY_FAX = "Fax";
private static final String KEY_EMAIL = "Email";
private static final String KEY_TRANSPORT = "Transport";
private static final String KEY_LANDMARK = "Landmark";
private static final String KEY_WEBSITE = "Website";
private static final String KEY_CATEGORY = "Category";
public DatabaseHandler(Context context) {
super(context, DB_NAME, null, DATABASE_VERSION);
this.myContext = context;
}
/**
* Creates a empty database on the system and rewrites it with your own database.
* */
public void createDataBase() throws IOException {
boolean dbExist = checkDataBase();
if(dbExist) {
//do nothing - database already exist
}
else {
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, null, 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{
//Open your local db as the input stream
InputStream myInput = myContext.getAssets().open(DB_NAME);
// Path to the just created empty db
String outFileName = DB_PATH + DB_NAME;
//Open the empty db as the output stream
OutputStream myOutput = new FileOutputStream(outFileName);
//transfer bytes from the inputfile to the outputfile
byte[] buffer = new byte[1024];
int length;
while ((length = myInput.read(buffer))>0){
myOutput.write(buffer, 0, length);
}
//Close the streams
myOutput.flush();
myOutput.close();
myInput.close();
}
public void openDataBase() throws SQLException{
//Open the database
String myPath = DB_PATH + DB_NAME;
myDataBase = SQLiteDatabase.openDatabase(myPath, null, SQLiteDatabase.OPEN_READONLY);
}
@Override
public synchronized void close() {
if(myDataBase != null)
myDataBase.close();
super.close();
}
// Creating Tables
@Override
public void onCreate(SQLiteDatabase db) {
}
// Upgrading database
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
}
/**
* All CRUD(Create, Read, Update, Delete) Operations
*/
/*
* --------------------------------------------------------
* UKM_Location
* --------------------------------------------------------
*/
// Adding new Poi
public void addUkmLocation(UkmLocation UKM_Location) {
SQLiteDatabase db = this.getWritableDatabase();
ContentValues values = new ContentValues();
values.put(KEY_ID, UKM_Location.getID()); // ID
values.put(KEY_NAME, UKM_Location.getName()); // Name
values.put(KEY_ALAMAT, UKM_Location.getAlamat()); // Addr
values.put(KEY_NOTEL, UKM_Location.getNotel()); // Phone
values.put(KEY_FAX, UKM_Location.getFax()); // Fax
values.put(KEY_EMAIL, UKM_Location.getEmail()); // Emel
values.put(KEY_TRANSPORT, UKM_Location.getTransport()); // Transport
values.put(KEY_LANDMARK, UKM_Location.getLandmark()); // Landmark
values.put(KEY_WEBSITE, UKM_Location.getWebsite()); // Website
values.put(KEY_CATEGORY, UKM_Location.getCategory()); // Category
// Inserting Row
db.insert(TABLE_UKMLOCATION, null, values);
db.close(); // Closing database connection
}
// Getting single Poi
public UkmLocation getUkmLocation(String _id) {
SQLiteDatabase db = this.getReadableDatabase();
Cursor cursor = db.query(TABLE_UKMLOCATION,
new String[] { KEY_ID, KEY_NAME, KEY_ALAMAT,KEY_NOTEL, KEY_FAX, KEY_EMAIL, KEY_TRANSPORT,
KEY_LANDMARK,KEY_WEBSITE, KEY_CATEGORY },
KEY_ID + "=?",
new String[] { String.valueOf( _id) }, null, null, null, null);
if (cursor != null)
cursor.moveToFirst();
UkmLocation poi = new UkmLocation(cursor.getString(0),
cursor.getString(1), cursor.getString(2), cursor.getString(3), cursor.getString(4),
cursor.getString(5), cursor.getString(6), cursor.getString(7), cursor.getString(8),
cursor.getString(9));
// return poi
return poi;
}
// Getting single Poi by Category
public UkmLocation getUkmLocationByCategory(String Category) {
SQLiteDatabase db = this.getReadableDatabase();
Cursor cursor = db.query(TABLE_UKMLOCATION,
new String[] { KEY_ID, KEY_NAME, KEY_ALAMAT,KEY_NOTEL, KEY_FAX, KEY_EMAIL, KEY_TRANSPORT,
KEY_LANDMARK,KEY_WEBSITE, KEY_CATEGORY },
KEY_CATEGORY + "=?",
new String[] { String.valueOf( Category) }, null, null, null, null);
if (cursor != null)
cursor.moveToFirst();
UkmLocation poi = new UkmLocation(cursor.getString(0),
cursor.getString(1), cursor.getString(2), cursor.getString(3), cursor.getString(4),
cursor.getString(5), cursor.getString(6), cursor.getString(7), cursor.getString(8),
cursor.getString(9));
// return poi
return poi;
}
// Getting single Poi by name
public UkmLocation getUkmLocationByName(String Name) {
SQLiteDatabase db = this.getReadableDatabase();
Cursor cursor = db.query(TABLE_UKMLOCATION,
new String[] { KEY_ID, KEY_NAME, KEY_ALAMAT,KEY_NOTEL, KEY_FAX, KEY_EMAIL, KEY_TRANSPORT,
KEY_LANDMARK,KEY_WEBSITE, KEY_CATEGORY },
KEY_NAME + "=?",
new String[] { String.valueOf(Name) }, null, null, null, null);
if (cursor != null)
cursor.moveToFirst();
UkmLocation poi = new UkmLocation(cursor.getString(0),
cursor.getString(1), cursor.getString(2), cursor.getString(3), cursor.getString(4),
cursor.getString(5), cursor.getString(6), cursor.getString(7), cursor.getString(8),
cursor.getString(9));
// return poi
return poi;
}
// Getting all Poi
public List<UkmLocation> getAllPoi() {
List<UkmLocation> locationList = new ArrayList<UkmLocation>();
//Select All Query
String selectQuery = "SELECT * FROM " + TABLE_UKMLOCATION;
SQLiteDatabase db = this.getReadableDatabase();
Cursor cursor = db.rawQuery(selectQuery, null);
//looping through all rows and adding to list
if (cursor.moveToFirst()) {
do {
UkmLocation poi = new UkmLocation();
poi.setID(cursor.getString(0));
poi.setName(cursor.getString(1));
poi.setAlamat(cursor.getString(2));
poi.setNotel(cursor.getString(3));
poi.setFax(cursor.getString(4));
poi.setEmail(cursor.getString(5));
poi.setTransport(cursor.getString(6));
poi.setLandmark(cursor.getString(7));
poi.setWebsite(cursor.getString(8));
poi.setCategory(cursor.getString(9));
//Adding poi to list
locationList.add(poi);
} while (cursor.moveToNext());
}
//sorting list
Collections.sort(locationList,new Comparator<UkmLocation>() {
public int compare(UkmLocation poi, UkmLocation otherPoi) {
return poi.getName().compareTo(otherPoi.getName());
}
});
// return Poi list
db.close();
return locationList;
}
//----
// Getting all Kategori
public List<UkmLocation> getCategoryFaculty() {
List<UkmLocation> kategoriList = new ArrayList<UkmLocation>();
//Select All Query
String selectQuery = "SELECT * FROM " + TABLE_UKMLOCATION + " WHERE " +
KEY_CATEGORY + "= 'Faculty'";
SQLiteDatabase db = this.getReadableDatabase();
Cursor cursor = db.rawQuery(selectQuery, null);
//looping through all rows and adding to list
if (cursor.moveToFirst()) {
do {
UkmLocation kategori = new UkmLocation();
kategori.setID(cursor.getString(0));
kategori.setName(cursor.getString(1));
kategori.setAlamat(cursor.getString(2));
kategori.setNotel(cursor.getString(3));
kategori.setFax(cursor.getString(4));
kategori.setEmail(cursor.getString(5));
kategori.setTransport(cursor.getString(6));
kategori.setLandmark(cursor.getString(7));
kategori.setWebsite(cursor.getString(8));
kategori.setCategory(cursor.getString(9));
//Adding kategori to list
kategoriList.add(kategori);
} while (cursor.moveToNext());
}
// return Kategori list
return kategoriList;
}
//----
// Updating single Poi
public int updatePoi(UkmLocation UKM_Location) {
SQLiteDatabase db = this.getWritableDatabase();
ContentValues values = new ContentValues();
values.put(KEY_NAME, UKM_Location.getName()); // Poi Name
values.put(KEY_ALAMAT, UKM_Location.getAlamat()); // Poi Addr
values.put(KEY_NOTEL, UKM_Location.getNotel()); // Phone
values.put(KEY_FAX, UKM_Location.getFax()); // Fax
values.put(KEY_EMAIL, UKM_Location.getEmail()); // Emel
values.put(KEY_TRANSPORT, UKM_Location.getTransport()); // Transport
values.put(KEY_LANDMARK, UKM_Location.getLandmark()); // Landmark
values.put(KEY_WEBSITE, UKM_Location.getWebsite()); // Website
values.put(KEY_CATEGORY, UKM_Location.getCategory()); // Category
// updating row
return db.update(TABLE_UKMLOCATION, values, KEY_ID + " = ?",
new String[] { String.valueOf(UKM_Location.getID()) });
}
// Deleting single Poi
public void deletePoi(UkmLocation UKM_Location) {
SQLiteDatabase db= this.getWritableDatabase();
db.delete(TABLE_UKMLOCATION, KEY_ID + " =?",
new String[] { String.valueOf(UKM_Location.getID()) });
db.close();
}
// Getting Poi Count
public int getUkmLocationCount() {
String countQuery = "SELECT * FROM " + TABLE_UKMLOCATION;
SQLiteDatabase db = this.getReadableDatabase();
Cursor cursor = db.rawQuery(countQuery, null);
// cursor.close();
// return count
return cursor.getCount();
}
// Delete all Poi
public void deleteAllPoi(){
SQLiteDatabase db= this.getWritableDatabase();
db.execSQL("DELETE FROM " + TABLE_UKMLOCATION);
db.close();
}
}