在将我的应用程序安装到Android设备时，数据库文件存储在SD卡根目录下。但是它应该放置在路径
以下是我的代码：
<SD Card_Root>\<Project_Name>\<dbfile>中。在从设备卸载应用程序后，包括项目文件夹在内的数据库文件也应该被删除。所以，请帮我解决以下两个问题：
1. 在将apk文件安装到设备后，应将数据库文件放置在路径<SD Card_Root>\<Project_Name>\<dbfile>中。
2. 卸载apk文件后，包括根文件夹在内的数据库文件应该自动删除。
请提供您的想法/链接来帮助我。以下是我的代码：
import java.io.BufferedInputStream;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.zip.ZipEntry;
import java.util.zip.ZipInputStream;
import android.os.Environment;
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 DataBaseHelper extends SQLiteOpenHelper{
private static String DB_PATH = Environment.getExternalStorageDirectory().getAbsolutePath() ;
private static String DB_NAME = "Database.db";
private SQLiteDatabase myDataBase;
private final Context myContext;
public DataBaseHelper(Context context) {
super(context, DB_NAME, null, 2);
this.myContext = context;
}
public void createDataBase() throws IOException
{
// boolean dbExist = checkDataBase();
DB_PATH = Environment.getExternalStorageDirectory().getAbsolutePath();
if (Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED))
{
File db = new File(DB_PATH, DB_NAME);
if(!db.exists())
{
db.createNewFile();
try {
copyFromZipFile();
} catch (IOException e) {
throw new Error("Error copying database",e);
}
}
}
}
private void copyFromZipFile() throws IOException{
InputStream is = myContext.getResources().openRawResource(R.raw.database);
// Path to the just created empty db
File outFile = new File(DB_PATH ,DB_NAME);
//Open the empty db as the output stream
OutputStream myOutput = new FileOutputStream(outFile.getAbsolutePath());
ZipInputStream zis = new ZipInputStream(new BufferedInputStream(is));
try {
ZipEntry ze = null;
while ((ze = zis.getNextEntry()) != null) {
ByteArrayOutputStream baos = new ByteArrayOutputStream();
byte[] buffer = new byte[24 * 1024];
int count;
while ((count = zis.read(buffer)) != -1) {
baos.write(buffer, 0, count);
//Log.d("", buffer.toString());
baos.writeTo(myOutput);
baos.reset();
}
baos.writeTo(myOutput);
}
}
catch (IOException e) {}
zis.close();
myOutput.flush();
myOutput.close();
is.close();
/*finally {
zis.close();
myOutput.flush();
myOutput.close();
is.close();
} */
}
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;
}
public void openDataBase() throws SQLException{
//Open the database
String myPath = DB_PATH + "/" + DB_NAME;
myDataBase = SQLiteDatabase.openDatabase(myPath, null, SQLiteDatabase.OPEN_READWRITE);
}
@Override
public synchronized void close() {
if(myDataBase != null)
myDataBase.close();
super.close();
}
@Override
public void onCreate(SQLiteDatabase db) {
String sql = "create table if not exists info(_id integer primary key autoincrement, Name text not null, firmName text not null);";
db.execSQL(sql);
sql = "create table if not exists Client(_id integer primary key autoincrement, Name text not null, clientName text not null);";
db.execSQL(sql);
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
db.execSQL("DROP TABLE IF EXISTS employee");
db.execSQL("DROP TABLE IF EXISTS info");
db.execSQL("DROP TABLE IF EXISTS Client");
onCreate(db);
}
public void onDestroy()
{
myDataBase.close();
}
public Cursor getView(String sql)
{
if(myDataBase != null) {
myDataBase.close();
}
openDataBase();
Cursor xcur = myDataBase.rawQuery(sql,null);
return xcur;
}
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();
}
}