package com.test.db;import java.io.File;import java.io.FileOutputStream;import java.io.InputStream;import java.io.OutputStream;import java.io.UnsupportedEncodingException;import android.app.Activity;import android.database.Cursor;import android.database.sqlite.SQLiteDatabase;import android.os.Bundle;public class DbtestActivity extends Activity { /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); // com.test.db 是程序的包名，請根據自己的程序調整 // /data/data/com.test.db/ // databases 目錄是準備放 SQLite 數據庫的地方，也是 Android 程序默認的數據庫存儲目錄 // 數據庫名為 test.db String DB_PATH = "/data/data/com.test.db/databases/"; String DB_NAME = "test.db"; // 檢查 SQLite 數據庫文件是否存在 if ((new File(DB_PATH + DB_NAME)).exists() == false) {  // 如 SQLite 數據庫文件不存在，再檢查一下 database 目錄是否存在  File f = new File(DB_PATH);  // 如 database 目錄不存在，新建該目錄  if (!f.exists()) {  f.mkdir();  }  try {  // 得到 assets 目錄下我們實現準備好的 SQLite 數據庫作為輸入流  InputStream is = getBaseContext().getAssets().open(DB_NAME);  // 輸出流  OutputStream os = new FileOutputStream(DB_PATH + DB_NAME);  // 文件寫入  byte[] buffer = new byte[1024];  int length;  while ((length = is.read(buffer)) > 0) {   os.write(buffer, 0, length);  }  // 關閉文件流  os.flush();  os.close();  is.close();  } catch (Exception e) {  e.printStackTrace();  } } // 下面測試 /data/data/com.test.db/databases/ 下的數據庫是否能正常工作 SQLiteDatabase database = SQLiteDatabase.openOrCreateDatabase(DB_PATH + DB_NAME, null); Cursor cursor = database.rawQuery("select * from test", null); if (cursor.getCount() > 0) {  cursor.moveToFirst();  try {  // 解決中文亂碼問題  byte test[] = cursor.getBlob(0);  String strtest = new String(test, "utf-8").trim();  // 看輸出的信息是否正確  System.out.println(strtest);  } catch (UnsupportedEncodingException e) {  // TODO Auto-generated catch block  e.printStackTrace();  } } cursor.close(); }}

package zcping.syan.DBDefinition;import java.io.File;import java.io.FileNotFoundException;import java.io.FileOutputStream;import java.io.IOException;import java.io.InputStream;import zcping.syan.DragonBaby.R;import android.content.Context;import android.database.sqlite.SQLiteDatabase;import android.util.Log;public class ReleaseDataBaseActivity{ /** Called when the activity is first created. */ //SD卡下的目錄 private final String DATABASE_PATH = android.os.Environment  .getExternalStorageDirectory().getAbsolutePath() + "/db_exam"; //數據庫名 private final String DATABASE_FILENAME = "db_exam.db"; //這個context是必需的，沒有context，怎么都不能實現數據庫的拷貝操作； private Context context; //構造函數必需傳入Context，數據庫的操作都帶有這個參數的傳入 public ReleaseDataBaseActivity(Context ctx) { this.context = ctx; } public SQLiteDatabase OpenDataBase() { try {  String databaseFilename = DATABASE_PATH + "/" + DATABASE_FILENAME;  File dir = new File(DATABASE_PATH);  //判斷SD卡下是否存在存放數據庫的目錄，如果不存在，新建目錄  if (!dir.exists()) {  dir.mkdir();  Log.i("ReleaseDataBaseActivity", "dir made:" + DATABASE_PATH);  } else {  Log.i("ReleaseDataBaseActivity", "dir exist:" + DATABASE_PATH);  }  try {  //如果數據庫已經在SD卡的目錄下存在，那么不需要重新創建，否則創建文件，并拷貝/res/raw下面的數據庫文件  if (!(new File(databaseFilename)).exists()) {   Log.i("ReleaseDataBaseActivity", "file not exist:"    + databaseFilename);   ///res/raw數據庫作為輸出流   InputStream is = this.context.getResources().openRawResource(    R.raw.db_exam);   //測試用   int size = is.available();   Log.i( "ReleaseDataBaseActivity", "DATABASE_SIZE:" + 1 );   Log.i("ReleaseDataBaseActivity", "count:" + 0);   //用于存放數據庫信息的數據流   FileOutputStream fos = new FileOutputStream(    databaseFilename);    byte[] buffer = new byte[8192];   int count = 0;   Log.i("ReleaseDataBaseActivity", "count:" + count);   //把數據寫入SD卡目錄下   while ((count = is.read(buffer)) > 0) {   fos.write(buffer, 0, count);   }   fos.flush();   fos.close();   is.close();  }  } catch (FileNotFoundException e) {  Log.e("Database", "File not found");  e.printStackTrace();  } catch (IOException e) {  Log.e("Database", "IO exception");  e.printStackTrace();  }  //實例化sd卡上得數據庫，database作為返回值，是后面所有插入，刪除，查詢操作的借口。  SQLiteDatabase database = SQLiteDatabase.openOrCreateDatabase(   databaseFilename, null);  return database; } catch (Exception e) { } return null; }}