android - 将 url 中的图像插入到 Sqlite 表中

Question

我正在尝试使用 blob 将图像插入到 sqlite 数据库中，我不想将图像存储在存储卡中并从中读取，因为我不希望用户有权访问它。我的表中有一行名为 image 。数据来自 mysql 数据库

package com.mall.our;

import java.io.ByteArrayOutputStream;
import java.util.ArrayList;
import java.util.HashMap;

import android.content.ContentValues;
import android.content.Context;
import android.content.SharedPreferences;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteException;
import android.database.sqlite.SQLiteOpenHelper;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.preference.PreferenceManager;
import android.util.Log;

public class DBTool extends SQLiteOpenHelper {
    private Context appContext;
     static final String firstname="firstname";
     static final String lastname="lastname";

    public DBTool(Context applicationContext){

        super(applicationContext, "friend.db", null, 1);
        this.appContext = applicationContext;

    }
    @Override
    public void onCreate(SQLiteDatabase database) {

                String query = "CREATE TABLE friends ( contactId INTEGER PRIMARY KEY, name TEXT, " +
                        "message TEXT, image BLOB)";
                database.execSQL(query);
    }

    @Override
    public void onUpgrade(SQLiteDatabase database, int oldVersion, int newVersion) {

        String query = "DROP TABLE IF EXISTS friends";

        database.execSQL(query);
        onCreate(database);

    }
    public void insertContact(HashMap<String, String> queryValues){

        SQLiteDatabase database = this.getWritableDatabase();

        ContentValues values = new ContentValues();

        values.put("name", queryValues.get("name"));
        values.put("message", queryValues.get("message"));
        values.put("image", queryValues.get("image"));
        database.insert("friends", null, values);

        database.close();

    }
public ArrayList<HashMap<String, String>> getAllContacts(){

        ArrayList<HashMap<String, String>> contactArrayList = new ArrayList<HashMap<String, String>>();

String selectQuery = "SELECT * FROM friends";

        SQLiteDatabase database = this.getWritableDatabase();

        Cursor cursor = database.rawQuery(selectQuery, null);

        if(cursor.moveToFirst()){

            do{

                HashMap<String, String> contactMap = new HashMap<String, String>();


                contactMap .put("name", cursor.getString(0));
                contactMap .put("message", cursor.getString(1));
                contactMap .put("image", cursor.getString(2));

                contactArrayList.add(contactMap);

            } while(cursor.moveToNext());

        }

        return contactArrayList;

    }
    public int updateContact(HashMap<String, String> queryValues){

        SQLiteDatabase database = this.getWritableDatabase();

        ContentValues values = new ContentValues();

        values.put("name", queryValues.get("name"));
        values.put("message", queryValues.get("message"));
        values.put("image", queryValues.get("image"));


        return database.update("friends", values, 
                "contactId" + " = ?", new String[] {queryValues.get("contactId") });

    }

    public void deleteContact(){

        SQLiteDatabase database = this.getWritableDatabase();

        String deleteQuery = "DELETE FROM friends ";

        database.execSQL(deleteQuery);

    }


    public HashMap<String, String> getContactInfo(String id){

        HashMap<String, String> contactMap = new HashMap<String, String>();

        SQLiteDatabase database = this.getReadableDatabase();

        String selectQuery = "SELECT * FROM friends WHERE contactId='" + id + "'";

        Cursor cursor = database.rawQuery(selectQuery, null);

        if(cursor.moveToFirst()){

            do{

                contactMap.put("name", cursor.getString(0));
                contactMap.put("message", cursor.getString(1));
                contactMap.put("image", cursor.getString(2));

            } while(cursor.moveToNext());

        }

        return contactMap;

    }

}

这是我的另一个类

package com.mall.our;

import java.io.IOException;

    import java.net.URL;
    import java.io.InputStream;
    import java.net.HttpURLConnection;
    import java.util.ArrayList;
    import java.util.HashMap;
    import java.util.List;
    import org.apache.http.NameValuePair;
    import org.apache.http.message.BasicNameValuePair;
    import org.json.JSONArray;
    import org.json.JSONObject;
    import android.app.ProgressDialog;
    import android.content.Intent;
    import android.content.SharedPreferences;
    import android.content.SharedPreferences.Editor;
    import android.graphics.Bitmap;
    import android.graphics.BitmapFactory;
    import android.os.AsyncTask;
    import android.os.Bundle;
    import android.preference.PreferenceManager;
    import android.view.LayoutInflater;
    import android.view.View;
    import android.view.ViewGroup;
    import android.widget.AdapterView;
    import android.widget.BaseAdapter;
    import android.widget.ImageView;
    import android.widget.ListView;
    import android.widget.AdapterView.OnItemClickListener;
    import android.widget.TextView;

    import com.actionbarsherlock.app.SherlockListFragment;

    import com.mall.first.JSONParser;
    import com.mall.first.R;


    public class Chat extends SherlockListFragment {
        JSONParser jsonParser = new JSONParser();
        private static final String TAG_POSTS = "posts";
        public static final String TAG_ID = "id";
        public static final String TAG_NAME = "name";
        public static final String TAG_pic = "pic";
        public static final String TAG_MESSAGE = "message";
        public static final String TAG_CATEGORIES_LOGO = "categories_logo";
        DBTool dbTool = new DBTool(getActivity());
        /*
      user details
        private static final String NAME = "name";
        private static final String AGE = "age";
        private static final String STATUS = "status";
        private static final String PIC = "pic";
        private static final String SEX = "sex"; String friendname,status;

        private static final String TAG_SUCCESS = "success";*/
            //user


        private static final String URL = "http://10.0.2.2/ochat/chattingname.php";
        private static final String URL_CATEGORY = "http://10.0.2.2/ochat/selectchat.php";

            private BaseAdapter mAdapter;
            private ListView lv;
            SharedPreferences sp ;
            Bundle bon = new Bundle();

        @Override
        public View onCreateView(LayoutInflater inflater, ViewGroup container,
                Bundle savedInstanceState) {
            View rootView = inflater.inflate(R.layout.friends, container, false);
            return rootView;
        }
         @Override 
            public void onActivityCreated(Bundle savedInstanceState) {  
                super.onActivityCreated(savedInstanceState);  
                new LoadComments().execute();


     }

         class LoadComments extends AsyncTask<Void, Void, ArrayList<HashMap<String,String>>> {
                private ProgressDialog pDialog;
                @Override
                protected void onPreExecute() {
                    super.onPreExecute();
                    pDialog = new ProgressDialog(getActivity());

                    pDialog.setIndeterminate(false);
                    pDialog.setCancelable(true);

                }

                @Override
                protected ArrayList<HashMap<String, String>> doInBackground(Void... arg0) {

                      ArrayList<HashMap<String, String>> categoryList = new ArrayList<HashMap<String, String>>();

                    SharedPreferences sp = PreferenceManager.getDefaultSharedPreferences(getActivity());
                  String username = sp.getString("username", "anon");
                        List<NameValuePair> params = new ArrayList<NameValuePair>();
                        params.add(new BasicNameValuePair("username", username));
                      JSONObject json = jsonParser.makeHttpRequest(URL_CATEGORY, "POST",
                                params);

                      try {

                          JSONArray categories = json.getJSONArray(TAG_POSTS);
                          for (int i = 0; i < categories.length(); i++) {
                              String id = categories.getJSONObject(i).getString("TAG_ID");
                               String name = categories.getJSONObject(i).getString("TAG_NAME");
                               String pic = categories.getJSONObject(i).getString("TAG_pic");
                               String message = categories.getJSONObject(i).getString("TAG_MESSAGE");

                            HashMap<String, String> queryValuesMap =  new  HashMap<String, String>();

                            queryValuesMap.put("name", name);
                            queryValuesMap.put("image", pic);
                            queryValuesMap.put("message",message);

                            dbTool.insertContact(queryValuesMap);


                          }
                      }catch (Throwable e){
                          e.printStackTrace();
                      }
                      return categoryList;
                  }

                @Override
                protected void onPostExecute(ArrayList<HashMap<String, String>> result) {
                    super.onPostExecute(result);


                }
            }

            }

我的问题是如何将 Chat.java 类中的“String pic”变量转换为图像数组或 url。我如何将其转换为位图，以便我可以将其插入表格中？

Answer 1

在此代码下方使用 ArrayList 并将每个图像 url 添加到其中。

ArrayList<String> list = new ArrayList<String>(); list.add(pic);

使用此代码将可绘制对象转换为位图。

ByteArrayOutputStream baos = new ByteArrayOutputStream();
    // converting drawable to bitmap
    _bitmapToInsert = ((BitmapDrawable) getResources().getDrawable(
            R.drawable.skholingua)).getBitmap();
    // compressing bitmap
    _bitmapToInsert.compress(Bitmap.CompressFormat.PNG, 100, baos);
    // converting bitmap to byte array
    _photoToInsert = baos.toByteArray();
    // inserting into to database
    _sqlLiteManger.insert(_photoToInsert);

更多信息请阅读:http://www.skholingua.com/android-basic/advance-topics/database-storage