如何往数据库中存储mp3,image等文件

转载自： http://www.android1.net/Topic.aspx?BoardID=11&TopicID=588 講義摘錄之25: 使用SQLite的Blob儲存*.mp3檔案 這是一個Android範例，茲說明如下： Step-1: 首先將.mp3檔案放入Project的/res/raw/裡，如下： 程式一開始執行，建立一個資料庫，含有BLOB欄位，如下之指令： sql = "create table mySong(" + "song_no text not null, " + "song_mp3 blob );"; try { db.execSQL(sql); } catch (SQLException e) { Log.e("ERROR", e.toString()); return; } Step-2: 從Project的/res/raw/讀取*.mp3歌曲，然後分段儲存到SQLite的BLOB裡，如下之指令： InputStream is = getResources().openRawResource(rid); int bufSize = 63*1024; byte[] buffer = new byte[bufSize]; try { int size = is.read(buffer); while(size >= 0){ ByteArrayOutputStream out = new ByteArrayOutputStream(size); out.write(buffer, 0, size); out.flush(); out.close(); cv.put("song_mp3", out.toByteArray()); db.insert("mySong", null, cv); size = is.read(buffer); } } catch (IOException e) { Log.e("ERROR", e.toString()); } Step-3: 從SQLite的BLOB裡，讀取歌曲並存入 /data/data/com.misoo.SQ01/files/song.mp3， 如下之指令： FileOutputStream os = null; try{ os = openFileOutput("song.mp3", MODE_WORLD_READABLE); } catch(FileNotFoundException e){ Log.e("ERROR", e.toString()); } byte[] red_buf; //---------------------------------------- mOpenHelper = new DatabaseHelper(this); SQLiteDatabase db = mOpenHelper.getReadableDatabase(); String col[] = {"song_no", "song_mp3" }; cur = db.query("mySong", col, cond, null, null, null, null); int k =0; cur.moveToFirst(); try{ while(!cur.isAfterLast()){ red_buf = cur.getBlob(1); os.write(red_buf); k++; cur.moveToNext(); } os.flush(); os.close(); }catch(Exception e){ Log.e("ERROR", e.toString()); return; } Step-4: 使用MediaPlayer將 /data/data/com.misoo.SQ01/files/song.mp3， 播放出來，如下之指令： String path = "/data/data/com.misoo.SQ01/files/song.mp3"; mPlayer = new MediaPlayer(); try { mPlayer.setDataSource(path); mPlayer.prepare(); } catch (IOException e) { e.printStackTrace(); } mPlayer.start(); } 其實，BLOB欄位可儲存很大的資料量，在本範例裡，刻意將歌曲切成許多段，逐一存入資料庫裏。其目的只是為了舉例而已。 package com.misoo.SQ01; import java.io.ByteArrayOutputStream; import java.io.FileNotFoundException; import java.io.FileOutputStream; import java.io.IOException; import java.io.InputStream; import android.app.Activity; 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.SQLiteOpenHelper; import android.media.MediaPlayer; import android.os.Bundle; import android.util.Log; import android.view.View; import android.view.View.OnClickListener; import android.widget.Button; import android.widget.LinearLayout; public class ac01 extends Activity implements OnClickListener{ private static final String DB_NAME = "mp3Song.db"; private static final int DB_VERSION = 2; private Button btn, btn2, btn3; private Cursor cur; private MediaPlayer mPlayer; private static class DatabaseHelper extends SQLiteOpenHelper { DatabaseHelper(Context context) { super(context, DB_NAME, null, DB_VERSION); } @Override public void onCreate(SQLiteDatabase db) { } @Override public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) { } } @Override public void onCreate(Bundle icicle) { super.onCreate(icicle); LinearLayout layout = new LinearLayout(this); layout.setOrientation(LinearLayout.VERTICAL); btn = new Button(this); btn.setId(101); btn.setText("play"); btn.setBackgroundResource(R.drawable.heart); btn.setOnClickListener(this); LinearLayout.LayoutParams param = new LinearLayout.LayoutParams(80, 50); param.topMargin = 10; layout.addView(btn, param); btn2 = new Button(this); btn2.setId(102); btn2.setText("stop"); btn2.setBackgroundResource(R.drawable.heart); btn2.setOnClickListener(this); layout.addView(btn2, param); btn3 = new Button(this); btn3.setId(103); btn3.setText("exit"); btn3.setBackgroundResource(R.drawable.heart); btn3.setOnClickListener(this); layout.addView(btn3, param); setContentView(layout); setTitle("Saving into SQliteDB..."); //--------------------------------- init(); setTitle("Saved in SQliteDB."); } private DatabaseHelper mOpenHelper; public void init(){ mOpenHelper = new DatabaseHelper(this); SQLiteDatabase db = mOpenHelper.getWritableDatabase(); //----------------------------------- String sql = "drop table mySong"; try { db.execSQL(sql); } catch (SQLException e) { Log.e("ERROR", e.toString()); } //----------------------------------- sql = "create table mySong(" + "song_no text not null, " + "song_mp3 blob );"; try { db.execSQL(sql); } catch (SQLException e) { Log.e("ERROR", e.toString()); return; } //--------------------------------- SaveOneSong(db,"s01", R.raw.den_li_guing); } public void SaveOneSong(SQLiteDatabase db, String key, int rid){ ContentValues cv = new ContentValues(); cv.put("song_no", key); InputStream is = getResources().openRawResource(rid); int bufSize = 63*1024; byte[] buffer = new byte[bufSize]; try { int size = is.read(buffer); while(size >= 0){ ByteArrayOutputStream out = new ByteArrayOutputStream(size); out.write(buffer, 0, size); out.flush(); out.close(); cv.put("song_mp3", out.toByteArray()); db.insert("mySong", null, cv); size = is.read(buffer); } } catch (IOException e) { Log.e("ERROR", e.toString()); } } public void play(String cond){ FileOutputStream os = null; try{ os = openFileOutput("song.mp3", MODE_WORLD_READABLE); } catch(FileNotFoundException e){ Log.e("ERROR", e.toString()); } byte[] red_buf; //---------------------------------------- mOpenHelper = new DatabaseHelper(this); SQLiteDatabase db = mOpenHelper.getReadableDatabase(); String col[] = {"song_no", "song_mp3" }; cur = db.query("mySong", col, cond, null, null, null, null); int k =0; cur.moveToFirst(); try{ while(!cur.isAfterLast()){ red_buf = cur.getBlob(1); os.write(red_buf); k++; cur.moveToNext(); } os.flush(); os.close(); }catch(Exception e){ Log.e("ERROR", e.toString()); return; } String path = "/data/data/com.misoo.SQ01/files/song.mp3"; mPlayer = new MediaPlayer(); try { mPlayer.setDataSource(path); mPlayer.prepare(); } catch (IOException e) { e.printStackTrace(); } mPlayer.start(); } public void onClick(View v) { switch (v.getId()) { case 101: String cond = "song_no='s01'"; play(cond); break; case 102: stop(); break; case 103: stop(); finish(); break; } } public void stop() { if (mPlayer != null) { mPlayer.stop(); mPlayer.release(); mPlayer = null; } } }

 

转：http://xiaoxixi615.blog.sohu.com/142046454.html