android导入外部数据库

public class DatabaseUtils {
    public static String data_path="" ;
    public  File dataFile=null;
    public Context context;
    public static final String DB_NAME="english.db";
    public DatabaseUtils(Context context) {
        this.context=context;
        data_path="/data"+ Environment.getDataDirectory().getAbsolutePath() + "/"+context.getPackageName()+"/databases/";
        dataFile=new File(data_path);
    }

    public  void outPutDatabase() throws IOException {
        if (!dataFile.exists()) {//包下面的databases有可能不存在
            dataFile.mkdirs();
        }
        File dbFile=new File(dataFile, DB_NAME);
        if (!dbFile.exists()) {
            Log.i("MainActivity", "数据库文件不存在,准备导入 ");
            //获取数据库文件的输入流
            InputStream inputStream=context.getAssets().open("english.db");
            FileOutputStream fileOutputStream=new FileOutputStream(dbFile);
            byte[] buffer=new byte[400000];
            int count=0;
            while ((count=inputStream.read())>0) {
                    fileOutputStream.write(buffer,0,count);
                    Log.i("MainActivity", "正在输出");
            }
            fileOutputStream.flush();
            fileOutputStream.close();
            inputStream.close();
            Toast.makeText(context, "导入数据库文件成功", Toast.LENGTH_LONG).show();

        }else {
            Toast.makeText(context, "数据库已经存在", Toast.LENGTH_LONG).show();
            Log.i("MainActivity", "数据库已经存在");
        }
    }
}

之前报了有这么一个错误

09-10 00:34:25.254: W/System.err(9596): java.io.FileNotFoundException: /data/data/com.kangda.app/databases/english.db: open failed: EISDIR (Is a directory)

其实原因就是databases这个目录是不存在的,然而,我却直接使用/data/data/com.kangda.app/databases/english.db去打开输出流,应该先创建好不存在的databases。

上面那个代码有点问题现在更正,上面inputStream.read()没有传入buffer:

public class DatabaseUtils {
    public static String data_path="" ;
    public  File dataFile=null;
    public Context context;
    public static final String DB_NAME="english.db";
    public DatabaseUtils(Context context) {
        this.context=context;
        data_path="/data"+ Environment.getDataDirectory().getAbsolutePath() + "/"+context.getPackageName()+"/databases/";
        dataFile=new File(data_path);
    }

    public  SQLiteDatabase outPutDatabase() throws IOException {
        SQLiteDatabase db=null;
        if (!dataFile.exists()) {//包下面的databases有可能不存在
            dataFile.mkdirs();
        }
        File dbFile=new File(dataFile, DB_NAME);
        if (!dbFile.exists()) {
            Log.i("MainActivity", "数据库文件不存在,准备导入 ");
            //获取数据库文件的输入流
            InputStream inputStream=context.getResources().openRawResource(R.raw.english);
            FileOutputStream fileOutputStream=new FileOutputStream(dbFile);
            byte[] buffer=new byte[1024];
            int count=-1;
            while ((count=inputStream.read(buffer))!=-1) {
                    fileOutputStream.write(buffer,0,count);
                    Log.i("MainActivity", "正在输出");
            }
            fileOutputStream.flush();
            fileOutputStream.close();
            inputStream.close();
            Toast.makeText(context, "导入数据库文件成功", Toast.LENGTH_LONG).show();
//           db = SQLiteDatabase.openDatabase(dbFile.getAbsolutePath(), null, Context.MODE_PRIVATE);
        }else {
            Toast.makeText(context, "数据库已经存在", Toast.LENGTH_LONG).show();
            Log.i("MainActivity", "数据库已经存在");
        }
        return db;
    }
}
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原文地址:https://www.cnblogs.com/zengmianhui/p/12634084.html