标签：
public class DataBaseUtils { // 当前数据库地址 private String DB_PATH; // 备份后数据库保存地址 private String DB_BACKUP_PATH; private Context context; private MessageShow ms; // 备份成功状态 private final int BACKUP_OK = 1; // 备份失败状态 private final int BACKUP_FAIL = -1; // 恢复成功状态 private final int RECOVER_OK = 2; // 恢复失败状态 private final int RECOVER_FAIL = -2; public interface MessageShow{ public void onPepare(); public void onSuccess(); public void onFail(); } public DataBaseUtils(Context context) { this.context = context; } /** * @Title: doDataBackUp * @Description: TODO(数据备份) * @param * @return void 返回类型 * @author fenglei015@deppon.com/273219 * @throws */ public void doDataBackUp(String DB_PATH, String DB_BACKUP_PATH,MessageShow ms) { this.DB_PATH = DB_PATH; this.DB_BACKUP_PATH = DB_BACKUP_PATH; this.ms=ms; new BackUpTask().execute(); } /** * @ClassName: BackUpTask * @Description: TODO(数据库备份异步任务) * @author fenglei015@deppon.com/273219 * @date 2015-12-25 上午11:10:58 * */ @TargetApi(Build.VERSION_CODES.CUPCAKE) class BackUpTask extends AsyncTask<String, Void, Integer> { @Override protected void onPreExecute() { // TODO Auto-generated method stub super.onPreExecute(); if(ms!=null) { ms.onPepare(); } } @Override protected Integer doInBackground(String... params) { // TODO Auto-generated method stub // 默认路径 /data/data/(包名)/databases/*.db File dbFile = context.getDatabasePath(DB_PATH); File exportDir = new File(DB_BACKUP_PATH); int result = 0; if (!exportDir.exists()) { exportDir.mkdirs(); } File backup = new File(exportDir, dbFile.getName()); try { backup.createNewFile(); fileCopy(dbFile, backup); result = BACKUP_OK; } catch (Exception e) { Log.e("backup_error", e.getMessage()); result = BACKUP_FAIL; } return result; } @Override protected void onPostExecute(Integer result) { // TODO Auto-generated method stub super.onPostExecute(result); switch (result) { case BACKUP_OK: if(ms!=null) { ms.onSuccess(); } break; case BACKUP_FAIL: if(ms!=null) { ms.onFail(); } break; } } } /** * @Title: fileCopy * @Description: TODO(文件拷贝方法) * @param @param dbFile * @param @param backup * @param @throws IOException 设定文件 * @return void 返回类型 * @author fenglei015@deppon.com/273219 * @throws */ private void fileCopy(File dbFile, File backup) throws IOException { // TODO Auto-generated method stub FileChannel inChannel = new FileInputStream(dbFile).getChannel(); FileChannel outChannel = new FileOutputStream(backup).getChannel(); try { inChannel.transferTo(0, inChannel.size(), outChannel); } catch (IOException e) { // TODO Auto-generated catch block Log.e("fileCopy_error", e.getMessage()); } finally { if (inChannel != null) { inChannel.close(); } if (outChannel != null) { outChannel.close(); } } } }
调用DataBaseUtils中的doDataBackUp(String DB_PATH, String DB_BACKUP_PATH,MessageShow ms) 方法
public class MainActivity extends Activity { private String DB_BACKUP_PATH=Environment.getExternalStorageDirectory()+"/feng_contactsBackup"; private String DATABASE_PATH=Environment.getExternalStorageDirectory() + "/ttttest.db"; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main);
DatabaseUtils bru=new DatabaseUtils(MainActivity.this); bru.doDataBackUp(DB_PATH, DB_BACKUP_PATH,new MessageShow() { @Override public void onSuccess() { // TODO Auto-generated method stub Toast.makeText(MainActivity.this,"success", Toast.LENGTH_LONG).show(); } @Override public void onPepare() { // TODO Auto-generated method stub Toast.makeText(MainActivity.this,"Pepare", Toast.LENGTH_LONG).show(); } @Override public void onFail() { // TODO Auto-generated method stub Toast.makeText(MainActivity.this,"Fail", Toast.LENGTH_LONG).show(); } }); } catch (Exception e) { // TODO Auto-generated catch block e.printStackTrace(); Log.e("DB_ERROR", "Get bean dao error cause by " + e.getMessage()); } } }
对整个异步回调使用的理解：
1.class A,class B
2.class A实现接口callback
3.class B拥有一个参数为callback接口类型的函数bMethod(callback cb)
4.class A运行时调用class B中的函数bMethod(callback cb),以自身传入参数
5.class B已取得A，就可以随时回调A所实现的callback接口中的方法
标签：
原文地址：http://www.cnblogs.com/waterhorse/p/5148491.html
