raw下db文件的使用

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[原]android 将.txt文件转化为.db并使用raw下的数据文件

2011-7-7阅读3663 评论1

在做城市搜索，此时，需要数据库，可数据源从何处获得？

1.新建一个.txt文件，以固定格式存储城市数据，如：

1||北京
2||天津
3|新疆|乌鲁木齐
4|新疆|奎屯
5|新疆|伊犁
6|新疆|库尔勒
7|新疆|阿克苏
8|青海省|西宁
9|河北省|石家庄
10|河北省|邯郸
11|河北省|保定

第一个字段为_id，第二个为provience，第三个字段为city

2.建数据库

public void onCreate(SQLiteDatabase db) {
               Log.d("DatabaseHelper","oncreat database-----------------------------------------");
               db.execSQL("CREATE TABLE "+ CITY_TABLE + " ("+
                       "_id INTEGER PRIMARY KEY , "+
                       "province TEXT, " +
                       "city TEXT);");

            }

到系统的/data/data目录下的对应包下查看一下是否数据库已建好。

3.将.txt数据导入到数据库下

将.txt文件放到应用程序对应的databases目录下
adb push ~/桌面/city.txt /data/data/com.android.weather/databases

# cd /data/data/com.android.weather/databases
# ls
city.txt
city_search.db
# sqlite3 city_search.db
sqlite> .tables
android_metadata citytable
sqlite> .import city.txt citytable
adb pull /data/data/com.android.weather/databases/city_search.db ~/桌面

现在已经获取了一个city_search.db的文件在桌面上。

4.使用

package com.android.weather.db;import java.io.File;import java.io.FileOutputStream;import java.io.InputStream;import android.content.ContentProvider;import android.content.ContentValues;import android.content.Context;import android.content.UriMatcher;import android.database.Cursor;import android.database.sqlite.SQLiteDatabase;import android.database.sqlite.SQLiteOpenHelper;import android.net.Uri;import android.util.Log;import com.android.weather.R;public class CityDataProvider extends ContentProvider {private static final String TAG = "CityDataProvider";private static final String AUTHORITY = "com.android.weather.db.city";private DatabaseHelper mDatabase;public static final Uri CONTENT_URI = Uri.parse("content://"+AUTHORITY+"/city");private final static String dataBaseDesDir =  "/data/data/com.android.weather/databases";@Overridepublic Cursor query(Uri uri, String[] projection, String selection,String[] selectionArgs, String sortOrder) {Log.d(TAG,"query");SQLiteDatabase db = mDatabase.getReadableDatabase();return db.query(DatabaseHelper.CITY_TABLE, projection, selection, selectionArgs, null, null, null);}public boolean onCreate() {        mDatabase = DatabaseHelper.getInstance(getContext());        onCreateDatabaseDir();        return true;}public int update(Uri uri, ContentValues values, String selection,String[] selectionArgs) {return 0;}public int delete(Uri uri, String selection, String[] selectionArgs) {return 0;}public String getType(Uri uri) {return null;}public Uri insert(Uri uri, ContentValues values) {return null;} private static  class DatabaseHelper extends SQLiteOpenHelper {        private static final String DATABASE_NAME = "city_search.db";        private static final String CITY_TABLE = "citytable";        private static final int DATABASE_VERSION =4;    static synchronized DatabaseHelper getInstance(Context context) {    return new DatabaseHelper(context);        }        public DatabaseHelper(Context context) {            super(context, DATABASE_NAME, null, DATABASE_VERSION);        }        public void onCreate(SQLiteDatabase db) {        Log.d("DatabaseHelper","oncreat database-----------------------------------------");//        db.execSQL("CREATE TABLE "+ CITY_TABLE + " ("+//    "_id INTEGER PRIMARY KEY , "+//    "province TEXT, " +//    "city TEXT);");                                        }            public void onUpgrade(SQLiteDatabase db, int oldVersion, int currentVersion) {//        db.execSQL("DROP TABLE IF EXISTS "+CITY_TABLE);//    onCreate(db);        }    }  private  void onCreateDatabaseDir() {File dir = new File(dataBaseDesDir);if (!dir.exists()) {try {dir.mkdir();} catch (Exception e) {e.printStackTrace();}}copyDatabaseFile(dataBaseDesDir);}private  void copyDatabaseFile(String destDir) {File dest = new File(destDir+"/"+DatabaseHelper.DATABASE_NAME);       if(dest.exists()){return ;}try {Log.d(TAG,"the database is not exit,then copy it---------------------");InputStream in = CityDataProvider.this.getContext().getResources().openRawResource(R.raw.city_search);int size = in.available();byte buf[] = new byte[size];in.read(buf);in.close();FileOutputStream out = new FileOutputStream(dest);out.write(buf);out.close();} catch (Exception e) {e.printStackTrace();}}}

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1楼huangzcy2011-12-28 11:19
能问下你的程序好像是把txt文件读取进数据库吗？？？

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