读取本地已有的.db数据库

浏览数：22 / 时间：2015年06月12日

先在项目中导入已有的xxx.db

下面新建DBManager .java和SQLiteActivity.java

package android.sqlite;

import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

import android.content.Context;
import android.database.SQLException;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteException;
import android.database.sqlite.SQLiteOpenHelper;
import android.database.sqlite.SQLiteDatabase.CursorFactory;
import android.util.Log;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
 
import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.os.Environment;
import android.util.Log;
 
public class DBManager {
    private final int BUFFER_SIZE = 400000;
    public static final String DB_NAME = "health.db"; //保存的数据库文件名
    public static final String PACKAGE_NAME = "android.sqlite";
    public static final String DB_PATH = "/data"
            + Environment.getDataDirectory().getAbsolutePath() + "/"
            + PACKAGE_NAME;  //在手机里存放数据库的位置
 
    private SQLiteDatabase database;
    private Context context;
 
    DBManager(Context context) {
        this.context = context;
    }
 
    public void openDatabase() {
        this.database = this.openDatabase(DB_PATH + "/" + DB_NAME);
    }
 
    private SQLiteDatabase openDatabase(String dbfile) {
        try {
            if (!(new File(dbfile).exists())) {//判断数据库文件是否存在，若不存在则执行导入，否则直接打开数据库
                InputStream is = this.context.getResources().openRawResource(
                        R.raw.health); //欲导入的数据库
                FileOutputStream fos = new FileOutputStream(dbfile);
                byte[] buffer = new byte[BUFFER_SIZE];
                int count = 0;
                while ((count = is.read(buffer)) > 0) {
                    fos.write(buffer, 0, count);
                }
                fos.close();
                is.close();
            }
            SQLiteDatabase db = SQLiteDatabase.openOrCreateDatabase(dbfile,
                    null);
            return db;
        } catch (FileNotFoundException e) {
            Log.e("Database", "File not found");
            e.printStackTrace();
        } catch (IOException e) {
            Log.e("Database", "IO exception");
            e.printStackTrace();
        }
        return null;
    }
    public void closeDatabase() {
        this.database.close();
    }
}

package android.sqlite;

import android.app.Activity;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.os.Bundle;
import android.widget.Button;

public class SQLiteActivity extends Activity {
    /** Called when the activity is first created. */
    
    public DBManager dbHelper;
     private SQLiteDatabase database;
   

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        
        dbHelper = new DBManager(this);
        dbHelper.openDatabase();
        dbHelper.closeDatabase();
        database = SQLiteDatabase.openOrCreateDatabase(DBManager.DB_PATH + "/" + DBManager.DB_NAME, null);        
         getdata();
        database.close();
        
    }

    

    private void getdata() {
        // TODO Auto-generated method stub
         
        Cursor cur = database.rawQuery("SELECT * FROM ctbx", null);
         
        if (cur != null) {
            int NUM_CITY = cur.getCount();
        
            if (cur.moveToFirst()) {
                do {
                    String id = cur.getString(cur.getColumnIndex("id"));
                    String code = cur.getString(cur.getColumnIndex("code"));
                    String name = cur.getString(cur.getColumnIndex("name"));
                    System.out.println(id+" "+code+" "+name);  //额外添加一句，把select到的信息输出到Logcat
                    
                } while (cur.moveToNext());
            }
           
        } else {
            return;
        }
    }

    
}

main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    >
<TextView  
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content" 
    android:text="@string/hello"
    />
</LinearLayout>