我正在尝试将图像存储到我在android应用程序中创建的表中。该表有八列（整数id，字符串名称，字符串摘要，字符串imdb，字符串poster1Url，位图poster1，字符串poster2Url，位图poster2）。
这是我的表格代码：
public class Favorite {
public static final String TABLE_NAME = "notes";
public static final String COLUMN_ID = "id";
public static final String COLUMN_NAME = "name";
public static final String COLUMN_SUMMARY = "summary";
public static final String COLUMN_IMDB = "imdb";
public static final String COLUMN_POSTER_MEDIUM_URL = "posterMediumUrl";
public static final String COLUMN_POSTER_MEDIUM = "posterMedium";
public static final String COLUMN_POSTER_ORIGINAL_URL = "posterOriginalUrl";
public static final String COLUMN_POSTER_ORIGINAL = "posterOriginal";
private int id;
private String name;
private String summary;
private String imdb;
private String posterMediumUrl;
private Bitmap posterMedium;
private String posterOriginalUrl;
private Bitmap posterOriginal;
// Create table SQL query
public static final String CREATE_TABLE =
"CREATE TABLE " + TABLE_NAME + "("
+ COLUMN_ID + " INTEGER PRIMARY KEY,"
+ COLUMN_NAME + " TEXT,"
+ COLUMN_SUMMARY + " TEXT,"
+ COLUMN_IMDB + " TEXT,"
+ COLUMN_POSTER_MEDIUM_URL + " TEXT,"
+ COLUMN_POSTER_MEDIUM + " blob,"
+ COLUMN_POSTER_ORIGINAL_URL + " TEXT,"
+ COLUMN_POSTER_ORIGINAL + " blob"
+ ")";
public Favorite() {
}
public Favorite(int id, String name, String summary, String imdb, String posterMediumUrl, Bitmap posterMedium, String posterOriginalUrl, Bitmap posterOriginal) {
this.id = id;
this.name = name;
this.summary = summary;
this.imdb = imdb;
this.posterMediumUrl = posterMediumUrl;
this.posterMedium = posterMedium;
this.posterOriginalUrl = posterOriginalUrl;
this.posterOriginal = posterOriginal;
}
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getSummary() {
return summary;
}
public void setSummary(String summary) {
this.summary = summary;
}
public String getImdb() {
return imdb;
}
public void setImdb(String imdb) {
this.imdb = imdb;
}
public String getPosterMediumUrl() {
return posterMediumUrl;
}
public void setPosterMediumUrl(String posterMediumUrl) {
this.posterMediumUrl = posterMediumUrl;
}
public Bitmap getPosterMedium() {
return posterMedium;
}
public void setPosterMedium(Bitmap posterMedium) {
this.posterMedium = posterMedium;
}
public String getPosterOriginalUrl() {
return posterOriginalUrl;
}
public void setPosterOriginalUrl(String posterOriginalUrl) {
this.posterOriginalUrl = posterOriginalUrl;
}
public Bitmap getPosterOriginal() {
return posterOriginal;
}
public void setPosterOriginal(Bitmap posterOriginal) {
this.posterOriginal = posterOriginal;
}
}
这是我的DataBaseHelper：
public class DatabaseHelper extends SQLiteOpenHelper {
// Database Version
private static final int DATABASE_VERSION = 1;
// Database Name
private static final String DATABASE_NAME = "favorites_db";
public DatabaseHelper(Context context) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
}
// Creating Tables
@Override
public void onCreate(SQLiteDatabase db) {
// create favorites table
db.execSQL(Favorite.CREATE_TABLE);
}
// Upgrading database
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
// Drop older table if existed
db.execSQL("DROP TABLE IF EXISTS " + Favorite.TABLE_NAME);
// Create tables again
onCreate(db);
}
public long insertFavorite(Favorite favorite) {
// get writable database as we want to write data
SQLiteDatabase db = this.getWritableDatabase();
ContentValues values = new ContentValues();
values.put(Favorite.COLUMN_ID, favorite.getId());
values.put(Favorite.COLUMN_NAME, favorite.getName());
values.put(Favorite.COLUMN_SUMMARY, favorite.getSummary());
values.put(Favorite.COLUMN_IMDB, favorite.getImdb());
values.put(Favorite.COLUMN_POSTER_MEDIUM_URL, favorite.getPosterMediumUrl());
values.put(Favorite.COLUMN_POSTER_MEDIUM, Utility.getPictureByteOfArray(favorite.getPosterMedium()));
values.put(Favorite.COLUMN_POSTER_ORIGINAL_URL, favorite.getPosterOriginalUrl());
values.put(Favorite.COLUMN_POSTER_ORIGINAL, Utility.getPictureByteOfArray(favorite.getPosterOriginal()));
// insert row
long id = db.insert(Favorite.TABLE_NAME, null, values);
// close db connection
db.close();
// return newly inserted row id
return id;
}
public Favorite getFavorite(long id) {
// get readable database as we are not inserting anything
SQLiteDatabase db = this.getReadableDatabase();
Cursor cursor = db.query(Favorite.TABLE_NAME,
new String[]{Favorite.COLUMN_ID, Favorite.COLUMN_NAME, Favorite.COLUMN_SUMMARY, Favorite.COLUMN_IMDB, Favorite.COLUMN_POSTER_MEDIUM_URL, Favorite.COLUMN_POSTER_MEDIUM, Favorite.COLUMN_POSTER_ORIGINAL_URL, Favorite.COLUMN_POSTER_ORIGINAL},
Favorite.COLUMN_ID + "=?",
new String[]{String.valueOf(id)}, null, null, null, null);
Favorite favorite = null;
if (cursor != null && cursor.moveToFirst()) {
// prepare favorite object
favorite = new Favorite(
cursor.getInt(cursor.getColumnIndex(Favorite.COLUMN_ID)),
cursor.getString(cursor.getColumnIndex(Favorite.COLUMN_NAME)),
cursor.getString(cursor.getColumnIndex(Favorite.COLUMN_SUMMARY)),
cursor.getString(cursor.getColumnIndex(Favorite.COLUMN_IMDB)),
cursor.getString(cursor.getColumnIndex(Favorite.COLUMN_POSTER_MEDIUM_URL)),
//null,
Utility.getBitmapFromByte(cursor.getBlob(cursor.getColumnIndex(Favorite.COLUMN_POSTER_MEDIUM))),
cursor.getString(cursor.getColumnIndex(Favorite.COLUMN_POSTER_ORIGINAL_URL)),
Utility.getBitmapFromByte(cursor.getBlob(cursor.getColumnIndex(Favorite.COLUMN_POSTER_ORIGINAL))));
//null);
// close the db connection
cursor.close();
}
return favorite;
}
public List<Favorite> getAllFavorites() {
List<Favorite> favorites = new ArrayList<>();
// Select All Query
String selectQuery = "SELECT * FROM " + Favorite.TABLE_NAME;
SQLiteDatabase db = this.getWritableDatabase();
Cursor cursor = db.rawQuery(selectQuery, null);
// looping through all rows and adding to list
if (cursor.moveToFirst()) {
do {
Favorite favorite = new Favorite();
favorite.setId(cursor.getInt(cursor.getColumnIndex(Favorite.COLUMN_ID)));
favorite.setName(cursor.getString(cursor.getColumnIndex(Favorite.COLUMN_NAME)));
favorite.setSummary(cursor.getString(cursor.getColumnIndex(Favorite.COLUMN_SUMMARY)));
favorite.setImdb(cursor.getString(cursor.getColumnIndex(Favorite.COLUMN_IMDB)));
favorite.setPosterMediumUrl(cursor.getString(cursor.getColumnIndex(Favorite.COLUMN_POSTER_MEDIUM_URL)));
favorite.setPosterMedium(Utility.getBitmapFromByte(cursor.getBlob(cursor.getColumnIndex(Favorite.COLUMN_NAME))));
favorite.setPosterOriginalUrl(cursor.getString(cursor.getColumnIndex(Favorite.COLUMN_POSTER_ORIGINAL_URL)));
favorite.setPosterOriginal(Utility.getBitmapFromByte(cursor.getBlob(cursor.getColumnIndex(Favorite.COLUMN_NAME))));
favorites.add(favorite);
} while (cursor.moveToNext());
}
// close db connection
db.close();
// return favorites list
return favorites;
}
public int getFavoritesCount() {
String countQuery = "SELECT * FROM " + Favorite.TABLE_NAME;
SQLiteDatabase db = this.getReadableDatabase();
Cursor cursor = db.rawQuery(countQuery, null);
int count = cursor.getCount();
cursor.close();
// return count
return count;
}
public void deleteFavorites(Favorite favorite) {
SQLiteDatabase db = this.getWritableDatabase();
db.delete(Favorite.TABLE_NAME, Favorite.COLUMN_ID + " = ?",
new String[]{String.valueOf(favorite.getId())});
db.close();
}
}
在我的适配器中，我将此AsyncTask命名为从URL获取图像，转换为Bitmap并插入到我的表中：
public class SaveIntoDatabase extends AsyncTask<Favorite,Void,Void> {
// can use UI thread here
@Override
protected void onPreExecute() {
super.onPreExecute();
}
// automatically done on worker thread (separate from UI thread)
@Override
protected Void doInBackground(Favorite... params) {
Favorite favorite = params[0];
System.out.println("Inicio");
try {
InputStream inputStream = new URL(favorite.getPosterMediumUrl()).openStream();
Bitmap bitmap = BitmapFactory.decodeStream(inputStream);
//set bitmap value to Picture
favorite.setPosterMedium(bitmap);
System.out.println(bitmap);
} catch (Exception e) {
e.printStackTrace();
}
try {
InputStream inputStream = new URL(favorite.getPosterOriginalUrl()).openStream();
Bitmap bitmap = BitmapFactory.decodeStream(inputStream);
//set bitmap value to Picture
favorite.setPosterOriginal(bitmap);
System.out.println(bitmap);
//add data to database
db.insertFavorite(favorite);
} catch (Exception e) {
e.printStackTrace();
}
System.out.println("Fim");
return null;
}
}
然后我使用以下代码调用该异步任务：
TvShow tvShow = tvShowList.get(position);
SaveIntoDatabase task = new SaveIntoDatabase();
task.execute(new Favorite(Integer.parseInt(tvShow.getId()), tvShow.getName(), tvShow.getSummary(), tvShow.getTvShowExternals().getImdb(), tvShow.getTvShowImage().getMedium(), null, tvShow.getTvShowImage().getOriginal(), null));
这是将blob转换为位图的方法：
public static Bitmap getBitmapFromByte(byte[] image) {
return BitmapFactory.decodeByteArray(image, 0, image.length);
}
这是将位图转换为blob的方式：
public static byte[] getPictureByteOfArray(Bitmap bitmap) {
ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
bitmap.compress(Bitmap.CompressFormat.PNG, 0, byteArrayOutputStream);
return byteArrayOutputStream.toByteArray();
}
对我来说，一切似乎都很好，但是当我尝试从表的结果中访问图片时，两张图片都显示“ null”。