致命的异常与getWritableDatabase
问题描述：
我有一个数据库管理器类下面这是导致致命的异常。我很茫然，为什么并希望有人能告诉我什么即时做错了或者我怎么能解决这个问题..致命的异常与getWritableDatabase
的代码：
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.util.ArrayList;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.HttpStatus;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.entity.ByteArrayEntity;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.util.EntityUtils;
import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteStatement;
import android.database.sqlite.SQLiteOpenHelper;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.drawable.BitmapDrawable;
import android.graphics.drawable.Drawable;
import android.os.AsyncTask;
import android.util.Log;
public class DataBaseManager extends SQLiteOpenHelper{
Context mContext;
private static final String TAG = "DataBaseManager";
private static final int dbVersion = 1;// ++ for DB changes
static final String dbName ="LCInstore";
//Table Names
static final String allIcons = "Icons";
static final String allScreens = "Screens";
static final String isLookUp = "LookUp";
//Column Names - LookUp
static final String colIconID = "IconID";
static final String colScreenID = "ScreenID";
static final String colRank = "Rank"; // order
//Column Names shared by tables: Screens and Icons
static final String colID = "ID";
static final String colType = "Type";
static final String colName = "Name";
//Column Names - Icons
static final String colImage = "Image";
static final String colLabel = "Label";
static final String colIntent = "Intent";
static final String colIParams = "Params";
public DataBaseManager(Context context) {
super(context, dbName, null, dbVersion);
mContext = context;
Log.v(TAG, "Initaited");
// TODO Auto-generated constructor stub
}
@Override
public void onCreate(SQLiteDatabase db) {
// TODO Auto-generated method stub
Log.v(TAG, "on create called");
// Create Icon Table if does not exist
db.execSQL("CREATE TABLE "+ allIcons +"" +
"("+colID + " INTEGER PRIMARY KEY AUTOINCREMENT, "+
colName + " TEXT," +
colImage + " BLOB," +
colLabel + " TEXT," +
colIntent + " TEXT," +
colType + " TEXT)");
// Create Screens Table if does not exist
db.execSQL("CREATE TABLE IF NOT EXISTS " + allScreens +"" +
"("+colID + " INTEGER PRIMARY KEY AUTOINCREMENT, "+
colName + " TEXT," +
colType + " TEXT)");
//Create LookUp Table if does not exist
db.execSQL("CREATE TABLE IF NOT EXISTS " + isLookUp +"" +
"("+colIconID + " INTEGER, "+
colScreenID + " INTEGER," +
colRank + " INTEGER)");
InsertInitData(db);
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
// TODO Auto-generated method stub
Log.v(TAG, "on upgrade called");
db.execSQL("DROP TABLE IF EXISTS "+allIcons);
}
/*private void InsertInitScreens(SQLiteDatabase db) {
ContentValues cv=new ContentValues();
cv.put(colName, "DR_Home");
cv.put(colType, "dr_home");
db.insert(allScreens, colID, cv);
cv.put(colName, "DR_Sub");
cv.put(colType, "dr_sub");
db.insert(allScreens, colID, cv);
}*/
private void InsertInitData(SQLiteDatabase db) {
//all Icons
addIconFromWeb(this, "Icon1", "http://sapientboston.com/internal/elidd/red.png", "MY RED ICON", "someIntent", "generic");
addIconFromWeb(this, "Icon2", "http://sapientboston.com/internal/elidd/red.png", "MY RED ICON", "someIntent", "generic");
addIconFromWeb(this, "Icon3", "http://sapientboston.com/internal/elidd/red.png", "MY RED ICON", "someIntent", "generic");
addIconFromWeb(this, "Icon4", "http://sapientboston.com/internal/elidd/red.png", "MY RED ICON", "someIntent", "generic");
addIconFromWeb(this, "Icon5", "http://sapientboston.com/internal/elidd/red.png", "MY RED ICON", "someIntent", "generic");
addIconFromWeb(this, "Icon6", "http://sapientboston.com/internal/elidd/red.png", "MY RED ICON", "someIntent", "generic");
addIconFromRes(this, "Icon7", R.drawable.dr_tablet_icon, "MY RED ICON", "someIntent", "generic");
addIconFromWeb(this, "Icon8", "http://sapientboston.com/internal/elidd/red.png", "MY RED ICON", "someIntent", "generic");
addIconFromWeb(this, "Icon9", "http://sapientboston.com/internal/elidd/red.png", "MY RED ICON", "someIntent", "generic");
addIconFromWeb(this, "Icon10", "http://sapientboston.com/internal/elidd/red.png", "MY RED ICON", "someIntent", "generic");
addIconFromWeb(this, "Icon11", "http://sapientboston.com/internal/elidd/red.png", "MY RED ICON", "someIntent", "generic");
addIconFromWeb(this, "Icon12", "http://sapientboston.com/internal/elidd/red.png", "MY RED ICON", "someIntent", "generic");
ContentValues cv2=new ContentValues();
cv2.put(colName, "DR_Home");
cv2.put(colType, "dr_home");
db.insert(allScreens, colID, cv2);
cv2.put(colName, "DR_Sub");
cv2.put(colType, "dr_sub");
db.insert(allScreens, colID, cv2);
addIconToScreen(1, "DR_Sub");
addIconToScreen(2, "DR_Sub");
addIconToScreen(3, "DR_Sub");
addIconToScreen(4, "DR_Sub");
addIconToScreen(5, "DR_Sub");
addIconToScreen(6, "DR_Sub");
addIconToScreen(7, "DR_Sub");
addIconToScreen(8, "DR_Sub");
addIconToScreen(9, "DR_Sub");
addIconToScreen(10,"DR_Sub");
}
public byte[] getBlobFromRes(int d) {
byte[] blobData;
Bitmap bitmap = BitmapFactory.decodeResource(this.mContext.getResources(),
d);
ByteArrayOutputStream stream = new ByteArrayOutputStream();
bitmap.compress(Bitmap.CompressFormat.PNG, 100, stream);
blobData = stream.toByteArray();
return blobData;
}
public void addIconFromRes(DataBaseManager db,String name, int res, String label, String intent, String type) {
SQLiteDatabase mdb = db.getWritableDatabase();
ContentValues cv=new ContentValues();
cv.put(colName, "Icon7");
cv.put(colImage, getBlobFromRes(res));
cv.put(colLabel, "MY RED ICON 2");
cv.put(colIntent, "someIntent");
cv.put(colType, "generic");
mdb.insert(allIcons, colID, cv);
}
public void addIconFromWeb (DataBaseManager db,String name, String url, String label, String intent, String type) {
new DownLoadImageTask (db, name, url, label, intent, type).execute(url);
}
private class DownLoadImageTask extends AsyncTask <String, Void, byte[]> {
String pName;
String pLabel;
String pIntent;
String pType;
SQLiteDatabase mdb;
public DownLoadImageTask(DataBaseManager db, String name, String url, String label, String intent, String type){
pName = name;
pLabel = label;
pIntent = intent;
pType = type;
mdb = db.getWritableDatabase();
}
@Override
protected byte[] doInBackground(String... url) {
byte[] blobData = null;
DefaultHttpClient mHttpClient = new DefaultHttpClient();
HttpGet mHttpGet = new HttpGet(url[0]);
HttpResponse mHttpResponse;
try {
mHttpResponse = mHttpClient.execute(mHttpGet);
if (mHttpResponse.getStatusLine().getStatusCode() == HttpStatus.SC_OK) {
HttpEntity entity = mHttpResponse.getEntity();
if (entity != null) {
//ContentValues values = new ContentValues();
blobData = EntityUtils.toByteArray(entity);
//mContext.getContentResolver().insert(MyBaseColumn.MyTable.CONTENT_URI, values);
}
}
} catch (ClientProtocolException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return blobData;
}
@Override
protected void onPostExecute(byte[] result) {
ContentValues cv=new ContentValues();
cv.put(colName, pName);
cv.put(colImage, result);
cv.put(colLabel, pLabel);
cv.put(colIntent, pIntent);
cv.put(colType, pType);
mdb.insert(allIcons, colID, cv);
}
}
public void addIconToScreen(int id, String screenName){
SQLiteDatabase db=this.getWritableDatabase();
int hsID = getScreenID(screenName);
int hsTotal = getScreenTotal(hsID)+1;
Cursor c = db.rawQuery("select * from "+ isLookUp +" where " + colIconID + "=" +id + " and " + colScreenID +"=" +hsID, null);
int numFound = c.getCount();
if(numFound<1){
ContentValues cv= new ContentValues();
cv.put(colScreenID, hsID);
cv.put(colIconID, id);
cv.put(colRank, hsTotal);
db.insert(isLookUp, colID, cv);
}
// else do nothing
}
public int getScreenID(String name){
SQLiteDatabase db=this.getWritableDatabase();
int sID;
String selectQuery = "SELECT "+colID+ " FROM " + allScreens + " WHERE " +colName + "=" +name;
Cursor cursor = db.rawQuery(selectQuery, null);
sID = cursor.getInt(0);
return sID;
}
public int getScreenTotal (int sID){
SQLiteDatabase db=this.getReadableDatabase();
int rows = (int) db.compileStatement("SELECT COUNT(*) FROM " + isLookUp + " where " + colScreenID + "="+sID).simpleQueryForLong();
return rows;
}
public void DeleteScreenIcon (int screenID, int iconID){
SQLiteDatabase db=this.getWritableDatabase();
db.delete(isLookUp, colScreenID + "=" + screenID + " and " +colIconID+ "="+iconID, null);
db.close();
}
// GETTERS
public ArrayList<Integer> getScreenIcons(String screenName) {
int sID = getScreenID(screenName);
ArrayList<Integer> iconList = new ArrayList<Integer>();
// Select All Query
String selectQuery = "SELECT * FROM " + isLookUp + " where " + colScreenID + "=" +sID + " order by " + colRank;
SQLiteDatabase db = this.getReadableDatabase();
Cursor cursor = db.rawQuery(selectQuery, null);
// looping through all rows and adding to list
if (cursor.moveToFirst()) {
do {
iconList.add(Integer.parseInt(cursor.getString(0)));
} while (cursor.moveToNext());
}
Log.v(TAG, "List Created");
cursor.close();
db.close();
// return contact list
return iconList;
}
public String getIconLabel(int id){
String label;
String selectQuery = "SELECT "+colLabel+ " FROM " + allIcons + " WHERE " +colIconID + "="+id;
SQLiteDatabase db = this.getReadableDatabase();
Cursor cursor = db.rawQuery(selectQuery, null);
if(cursor != null)
{
cursor.moveToFirst();
label = cursor.getString(0);
}
else{
label ="";
}
cursor.close();
db.close();
return label;
}
public String getIconImage(int id){
String image;
String selectQuery = "SELECT "+colImage+ " FROM " + allIcons + " WHERE " +colIconID + "="+id;
SQLiteDatabase db = this.getReadableDatabase();
Cursor cursor = db.rawQuery(selectQuery, null);
if(cursor != null)
{
cursor.moveToFirst();
image = cursor.getString(0);
}
else{
image ="";
}
cursor.close();
db.close();
return image;
}
public int checkHomeScreen(Integer iD) {
// TODO Auto-generated method stub
int sID = getScreenID("DR_Home");
SQLiteDatabase db=this.getReadableDatabase();
int rows = (int) db.compileStatement("SELECT COUNT(*) FROM " + isLookUp + " where " + colScreenID + "="+ sID + " and "+ colIconID + "="+iD).simpleQueryForLong();
return rows;
}
}
和错误：
答
public void onCreate(SQLiteDatabase db) {
InsertInitData(db);
}
private void InsertInitData(SQLiteDatabase db) {
addIconFromWeb(this,..
}
public void addIconFromWeb (...
new DownLoadImageTask (db..
}
public DownLoadImageTask(DataBaseManager db
mdb = db.getWritableDatabase()
}
SQLiteOpenHelper.getWritableDatabase()触发器SQLiteOpenHelper.onCreate()如果你的数据库不存在。 （和它不会因为你仍然在onCreate()）
解决方法：使用附带的SQLiteDatabase db对象来完成所有的初始化（从网上下载的是恕我直言，在这里一个非常糟糕的主意），你必须这样做的唯一的事情就是用您的DataBaseManager db在该环境内，因为这将创建循环。一旦创建数据库，您就可以安全地使用它。
下载数据并将其放入数据库应该从SQLiteOpenHelper的外部环境中完成。通过那个班。
SQLiteOpenHelper的目的是帮助您打开一个包含需要使用的表的数据库。就是这样。你不应该在这门课里面做很多繁重的工作，因为现在需要很长时间才能打开（.getWritableDatabase()）你的数据库（或者你必须期待这一点，如果你愿意的话，你可以想办法解决这个限制）
答
最简单的修复方法它会改变你从这个DownLoadImageTask构造...
public DownLoadImageTask(DataBaseManager db, <other parameters omitted>){
...
mdb = db.getWritableDatabase();
}
...这个...
public DownLoadImageTask(SQLiteDatabase db, <other parameters omitted>){
...
mdb = db;
}
改变你从这个addIconFromWeb(...)方法...
public void addIconFromWeb(DataBaseManager db, <other parameters omitted>) {
new DownLoadImageTask (db, <other parameters omitted>).execute(url);
}
...这个...
public void addIconFromWeb(SQLiteDatabase db, <other parameters omitted>) {
new DownLoadImageTask (db, <other parameters omitted>).execute(url);
}
在InsertInitData(...)更改您的来电......
private void InsertInitData(SQLiteDatabase db) {
addIconFromWeb(db, <other parameters omitted>);
...
}