Question

我想在我的数据库中插入图像，但图像不会插入数据库中，但文本会插入数据库中。我在JSON中从服务器获取数据但是添加了文本，但是当加载JSON时，图像没有添加到我想要的数据库中，然后imageurl存储在数据库中，并且在离线后我访问

我的代码是：

数据库

public class DataBasehelper extends SQLiteOpenHelper {
private static final int DB_VERSION = 1;
private static final String DB_NAME = "MyApp";
private static final String TABLE_TEXTS= "texts";
private static final String TABLE_IMAGES= "images";
private static final String TABLE_SPINNER = "spinners";
private static final String KEY_ID = "_id";
private static final String KEY_NAME = "_name";
private static final String KEY_SPIN = "_spin";
private static final String KEY_URL = "url";

 private static final String CREATE_TABLE_IMAGE = "CREATE TABLE "
    + TABLE_IMAGES
    + " ( "
    + KEY_ID + " INTEGER PRIMARY KEY, "
    + KEY_NAME + " TEXT, "
    + KEY_URL + " TEXT) ";

 public DataBasehelper(Context context) {

    super(context, DB_NAME, null, DB_VERSION);
 }

 @Override
 public void onCreate(SQLiteDatabase db) {

    db.execSQL(CREATE_TABLE_IMAGE);
    Log.e("table name","==>"+CREATE_TABLE_TEXTS);
    Log.e("table name","==>"+CREATE_TABLE_IMAGE);
 }

 @Override
 public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
      db.execSQL("DROP TABLE IF EXISTS "+TABLE_IMAGES);
     onCreate(db);
 }

 public void addImage(ImgModel model) {
    SQLiteDatabase db = this.getWritableDatabase();
    try{
        ContentValues values = new ContentValues();
        values.put(KEY_NAME, model.getName());
        values.put(KEY_URL, model.getImageUrl());
        db.insert(TABLE_TEXTS, null, values);
        Log.e("this db","value is"+values);
        db.close();
     }catch (Exception e){
        Log.e("problem",e+"");
     }
 }
 public List<ImgModel> getAllImage() {
    SQLiteDatabase db = this.getReadableDatabase();
    List<ImgModel> imageList = null;
    try{
        imageList = new ArrayList<ImgModel>();
        String QUERY = "SELECT * FROM "+TABLE_TEXTS;
        Cursor cursor = db.rawQuery(QUERY, null);
        if(!cursor.isLast())
        {
            while (cursor.moveToNext())
            {
                ImgModel image = new ImgModel();
                image.set_id(cursor.getInt(0));
                image.setName(cursor.getString(1));
                image.setImageUrl(cursor.getString(2));
                imageList.add(image);
            }
        }
        db.close();
     }catch (Exception e){
        Log.e("error",e+"");
     }
     return imageList;
 }

模型类

public class ImgModel {
private int _id;
private String imageUrl;
private String name;

//Getters and Setters
public String getImageUrl() {
    return imageUrl;
}

public void setImageUrl(String imageUrl) {
    this.imageUrl = imageUrl;
}

public String getName() {
    return name;
}

public void setName(String name) {
    this.name = name;
}

public int get_id() {
    return _id;
}

public void set_id(int _id) {
    this._id = _id;
 }
}

活动

检查互联网

  NetworkUtils utils = new NetworkUtils(getApplicationContext());
    if(utils.isConnectingToInternet())
    {
        getSpinnerData();
    }
    else
    {
        List<ImgModel> imageList = db.getAllImage();
        adapter = new ImageAdapter(imageList, this);
        recyclerView.setAdapter(adapter);
    }

在db

中添加图像

 private void parseData(JSONArray array) {
    for (int i = 0; i < array.length(); i++) {
        ImgModel model1 = new ImgModel();
        JSONObject json = null;
        try {
            json = array.getJSONObject(i);
            String link = json.getString(Config.TAG_IMAGE_URL);
            String imgname = json.getString(Config.TAG_NAME);
            model1.setImageUrl(link);
            model1.setName(imgname);
            db.addImage(model1);    // add data in database
            Log.e("urls","===>"+link);
          } catch (JSONException e) {
            e.printStackTrace();
        }
        listimg.add(model1);
    }

Answer 1

使用像Picasso，Glide或Fresco这样的图像库，它会为你缓存图像，你只需要存储你现在正在做的网址，它只会下载图像一次，之后它会获取图像来自缓存

为什么它不在数据库中插入图像

1 个答案: