android 将.txt或者内容文件转化为.db并使用raw下的数据文件

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。

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";

@Override

public 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();

}

}

}