我是Android开发的新手，想要使用Assets文件夹中的.sq3文件选择数据并预先填充SQLite数据库。但是在其路径上获取异常。 所以我该怎么做？ 这是我的代码。
package com.wiztech.wahab;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
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;
public class DataBaseManager extends SQLiteOpenHelper{
//The Android's default system path of your application database.
private static String DB_PATH = "/data/data/com.wiztech.wahab/databases/";
// private static String DB_NAME = "BlueConnect.sq3";
private static String DB_NAME = "database.sq3";
private SQLiteDatabase myDataBase;
private SQLiteDatabase myData;
private final Context myContext;
public DataBaseManager(Context context) {
super(context, DB_NAME, null, 1);
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{
CopyFiles();
}
}
private void CopyFiles()
{
try
{
InputStream is = myContext.getAssets().open(DB_NAME);
File outfile = new File(DB_PATH,DB_NAME);
outfile.getParentFile().mkdirs();
outfile.createNewFile();
if (is == null)
throw new RuntimeException("stream is null");
else
{
FileOutputStream out = new FileOutputStream(outfile);
// BufferedOutputStream out = new BufferedOutputStream( new FileOutputStream(outfile));
byte buf[] = new byte[128];
do {
int numread = is.read(buf);
if (numread <= 0)
break;
out.write(buf, 0, numread);
} while (true);
is.close();
out.close();
}
//AssetFileDescriptor af = am.openFd("world_treasure_hunter_deluxe.apk");
}
catch (IOException e)
{
throw new RuntimeException(e);
}
}
/**
* Check if the database already exist to avoid re-copying the file each time you open the application.
* @return true if it exists, false if it doesn't
*/
private boolean checkDataBase(){
SQLiteDatabase checkDB = null;
try{
String myPath = DB_PATH + DB_NAME;
checkDB = SQLiteDatabase.openDatabase(myPath, null, SQLiteDatabase.OPEN_READONLY);
}catch(SQLiteException e){
}
if(checkDB != null){
checkDB.close();
}
return checkDB != null ? true : false;
}
/**
* Copies your database from your local assets-folder to the just created empty database in the
* system folder, from where it can be accessed and handled.
* This is done by transfering bytestream.
* */
@SuppressWarnings("unused")
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();
}
@Override
public void onCreate(SQLiteDatabase db) {
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
}
//---retrieve records---
public Cursor selectQuery(String query) throws SQLException
{
String myPath = DB_PATH + DB_NAME;
//myData = SQLiteDatabase.openDatabase(myPath, null, SQLiteDatabase.OPEN_READWRITE);
myData = SQLiteDatabase.openDatabase(myPath,null, SQLiteDatabase.CREATE_IF_NECESSARY);
Cursor mCursor =myData.rawQuery(query, null);
mCursor.moveToFirst();
myData.close();
return mCursor;
}
////////// For Insert And Update Data ////////
public void insert_update(String query) throws SQLException
{
String myPath = DB_PATH + DB_NAME;
myData = SQLiteDatabase.openDatabase(myPath, null, SQLiteDatabase.OPEN_READWRITE);
myData.execSQL(query);
myData.close();
}
public boolean UpdateVote_Individual(String rowid,String value,String count) {
String myPath = DB_PATH + DB_NAME;
myData = SQLiteDatabase.openDatabase(myPath, null, SQLiteDatabase.OPEN_READWRITE);
ContentValues args = new ContentValues();
args.put("total_votes", count);
return myData.update("promotors", args,
"promoter_id='" + rowid+"'", null) > 0;
}
}
package com.wiztech.wahab;
import android.app.Activity;
import android.content.Intent;
import android.database.Cursor;
import android.graphics.Color;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.TextView;
public class Criteria_Activity extends Activity {
DataBaseManager db;
Cursor cur;
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
System.out.println("reached inside Criteria_Activity");
setContentView(R.layout.criteria);
db = new DataBaseManager(getBaseContext());
cur = db.selectQuery("select * from client_table1;");
if(cur.moveToFirst()) {
do {
String age = cur.getString(1);
String gender = cur.getString(2);
String prof = cur.getString(3);
String hobby = cur.getString(4);
String likes = cur.getString(5);
String dislikes = cur.getString(6);
TextView ag = (TextView) findViewById(R.id.age_value);
if(age.length()==0||age==""){
age="Not Saved";
ag.setTextSize(16);
ag.setTextColor(Color.GRAY);
}
ag.setText(age);
TextView gend = (TextView) findViewById(R.id.gender_value);
if(gender.length()==0||gender==""){
gender="Not Saved";
gend.setTextSize(16);
gend.setTextColor(Color.GRAY);
}
gend.setText(gender);
TextView pr = (TextView) findViewById(R.id.prof_value);
if(prof.length()==0||prof==""){
prof="Not Saved";
pr.setTextSize(16);
pr.setTextColor(Color.GRAY);
}
pr.setText(prof);
TextView hobbie = (TextView) findViewById(R.id.hobby_value);
if(hobby.length()==0||hobby==""){
hobby="Not Saved";
hobbie.setTextSize(16);
hobbie.setTextColor(Color.GRAY);
}
hobbie.setText(hobby);
TextView lykes = (TextView) findViewById(R.id.likes_value);
if(likes.length()==0||likes==""){
likes="Not Saved";
lykes.setTextSize(16);
lykes.setTextColor(Color.GRAY);
}
lykes.setText(likes);
TextView dislykes = (TextView) findViewById(R.id.dislikes_value);
if(dislikes.length()==0|| dislikes==""){
dislikes="Not Saved";
dislykes.setTextSize(16);
dislykes.setTextColor(Color.GRAY);
}
dislykes.setText(dislikes);
}while(cur.moveToNext());
cur.close();
}//end if(cur.moveToFirst..........
Button criteria_edit_btn = (Button) findViewById(R.id.cr_edit_btn);
criteria_edit_btn.setOnClickListener(new OnClickListener(){
public void onClick(View v) {
// TODO Auto-generated method stub
Intent update_criteria_intent = new Intent(getParent(), Edit_Criteria_Activity.class);
TabGroupActivity parentActivity = (TabGroupActivity)getParent();
parentActivity.startChildActivity("Edit_Criteria_Activity", update_criteria_intent);
}
});
}// end onCreate
}//end this.Activity
答案 0 :(得分：1)
好吧，只需阅读日志中的内容即可。您正在client_table1上进行选择，但该表不存在。首先必须创建表。
请阅读本教程，了解如何使用SQLiteOpenHelper类在Android上使用sqlite：