/**
     * 是否完成初始化
     */
    private static boolean isInit = false;

/**
     * 初始化数据库
     * @param context
     */
    synchronized public static void init(Context context)
    {
        if(isInit)
            return;
        // 输出路径
        String outFileName = DATABASE_PATH + DATABASE_NAME;

//检测是否已经创建
        File dir = new File(outFileName);
        if(dir.exists())
            return;

// 检测/创建数据库的文件夹
        dir = new File(DATABASE_PATH);

if (!dir.exists())
            dir.mkdir();

InputStream input = null;
        OutputStream output = null;
        // 从资源中读取数据库流
        input = context.getResources().openRawResource(R.raw.db);

try {
            output = new FileOutputStream(outFileName);

// 拷贝到输出流
            byte[] buffer = new byte[2048];
            int length;
            while ((length = input.read(buffer)) > 0) {
                output.write(buffer, 0, length);
            }
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            // 关闭输出流
            try {
                output.flush();
                output.close();
            } catch (IOException e) {
            }
            // 关闭输入流
            try {
                input.close();
            } catch (IOException e) {
            }
        }
        isInit = true;
    }