1.如果資料庫檔案大於1M,就用Filesplit工具切割。先去下載這個軟體工具2.首先把已有的資料庫放到assets檔案夾下面,如果沒有這個檔案就先在android項目中建立這個檔案夾。代碼如下:import java.io.File; import java.io.FileOutputStream; import java.io.IOException; import java.io.InputStream; import java.io.OutputStream;import android.content.Context; import android.database.Cursor; import android.database.SQLException; import android.database.sqlite.SQLiteDatabase; import android.database.sqlite.SQLiteDatabase.CursorFactory; import android.database.sqlite.SQLiteException; import android.database.sqlite.SQLiteOpenHelper; * 將把assets下的資料庫檔案直接複製到DB_PATH,但資料庫檔案大小限制在1M以下 * 如果有超過1M的大檔案,則需要先分割為N個小檔案,然後使用copyBigDatabase()替換copyDatabase() */ public class DBManager extends SQLiteOpenHelper { //使用者資料庫檔案的版本 private static final int DB_VERSION = 1; //資料庫檔案目標存放路徑為系統預設位置,com.rys.lb 是你的包名 private static String DB_PATH = "/data/data/com.rys.lb/databases/"; //如果你想把資料庫檔案存放在SD卡的話 // private static String DB_PATH = android.os.Environment.getExternalStorageDirectory().getAbsolutePath() // + "/arthurcn/drivertest/packfiles/"; private static String DB_NAME = "data.db"; private static String ASSETS_NAME = "data.db"; private SQLiteDatabase myDataBase; private final Context myContext; /** * 如果資料庫檔案較大,使用FileSplit分割為小於1M的小檔案 * 此例中分割為 data.db.100 data.db.101 data.db.102.... */ //第一個檔案名稱尾碼 private static final int ASSETS_SUFFIX_BEGIN = 100; //最後一個檔案名稱尾碼 private static final int ASSETS_SUFFIX_END = 110; /** * 在SQLiteOpenHelper的子類當中,必須有該建構函式 * @param context 內容物件 * @param name 資料庫名稱 * @param factory 一般都是null * @param version 當前資料庫的版本,值必須是整數並且是遞增的狀態 */ public DBManager(Context context, String name, CursorFactory factory, int version) { //必須通過super調用父類當中的建構函式 super(context, name, null, version); this.myContext = context; } public DBManager(Context context, String name, int version){ this(context,name,null,version); } public DBManager(Context context, String name){ this(context,name,DB_VERSION); } public DBManager (Context context) { this(context, DB_PATH + DB_NAME); } public void createDataBase() throws IOException{ boolean dbExist = checkDataBase(); if(dbExist){ //資料庫已存在,do nothing. System.out.println("資料庫已經存在"); }else{ //建立資料庫 try { File dir = new File(DB_PATH); if(!dir.exists()){ dir.mkdirs(); } File dbf = new File(DB_PATH + DB_NAME); if(dbf.exists()){ dbf.delete(); } SQLiteDatabase.openOrCreateDatabase(dbf, null); // 複製asseets中的db檔案到DB_PATH下 //copyDataBase(); copyBigDataBase(); } catch (IOException e) { throw new Error("資料庫建立失敗"); } } } //檢查資料庫是否有效 private boolean checkDataBase(){ SQLiteDatabase checkDB = null; String myPath = DB_PATH + DB_NAME; try{ checkDB = SQLiteDatabase.openDatabase(myPath, null, SQLiteDatabase.OPEN_READONLY); }catch(SQLiteException e){ //database does't exist yet. } if(checkDB != null){ checkDB.close(); System.out.println("關閉"); } return checkDB != null ? true : false; } public DBManager open1(){ String myPath = DB_PATH + DB_NAME; System.out.println("資料庫已經..."); myDataBase = SQLiteDatabase.openDatabase(myPath, null, SQLiteDatabase.OPEN_READONLY); System.out.println("資料庫開啟"); return this; } /** * Copies your database from your local assets-folder to the just created empty database in the * system folder, from where it can be accessed and handled. * This is done by transfering bytestream. * */ private void copyDataBase() throws IOException{ //Open your local db as the input stream InputStream myInput = myContext.getAssets().open(ASSETS_NAME); // Path to the just created empty db String outFileName = DB_PATH + DB_NAME; //Open the empty db as the output stream OutputStream myOutput = new FileOutputStream(outFileName); //transfer bytes from the inputfile to the outputfile byte[] buffer = new byte[1024]; int length; while ((length = myInput.read(buffer))>0){ myOutput.write(buffer, 0, length); } //Close the streams myOutput.flush(); myOutput.close(); myInput.close(); } //複製assets下的大資料庫檔案時用這個 private void copyBigDataBase() throws IOException{ InputStream myInput; String outFileName = DB_PATH + DB_NAME; OutputStream myOutput = new FileOutputStream(outFileName); for (int i = ASSETS_SUFFIX_BEGIN; i < ASSETS_SUFFIX_END+1; i++) { myInput = myContext.getAssets().open(ASSETS_NAME + "." + i); byte[] buffer = new byte[1024]; int length; while ((length = myInput.read(buffer))>0){ myOutput.write(buffer, 0, length); } myOutput.flush(); myInput.close(); } myOutput.close(); System.out.println("資料庫已經複製"); } @Override public synchronized void close() { if(myDataBase != null){ myDataBase.close(); System.out.println("關閉成功1"); } super.close(); System.out.println("關閉成功2"); } /** * 該函數是在第一次建立的時候執行, * 實際上是第一次得到SQLiteDatabase對象的時候才會調用這個方法 */ @Override public void onCreate(SQLiteDatabase db) { } /** * 資料庫表結構有變化時採用 */ @Override public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) { } public void open(){ SQLiteDatabase DataBase=this.openOrCreateDatabase("data.db",null); }private SQLiteDatabase openOrCreateDatabase(String string, Object object) { // TODO Auto-generated method stub return null; }3.用SD卡要加許可權<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"></uses-permission> <uses-permission android:name="android.permission.MOUNT_UNMOUNT_FILESYSTEMS"></uses-permission> |