Sharepreference (storage)

public class MainActivity extends ActionBarActivity {
	EditText et_yh;
	EditText et_mm;
	Button bt_dl;
	Button bt_qx;
	CheckBox cb;
	SharedPreferences spf;
	Editor editor;
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		//SharedPreferences sp=PreferenceManager.getDefaultSharedPreferences(this);
//		SharedPreferences sp=getSharedPreferences("mysp", MODE_PRIVATE);
//		Editor editor=sp.edit();
//		editor.putString("name", " Zhang San ");
//		editor.putInt("age", 18);
//		editor.putLong("time", System.currentTimeMillis());
//		editor.putBoolean("default", true);
//		editor.commit();
//		editor.remove("time");
//		editor.commit();
//		System.out.println(sp.getString("name", ""));
//		editor.commit();
		et_yh=(EditText) findViewById(R.id.et_yonghu);
		et_mm=(EditText) findViewById(R.id.et_mima);
		cb=(CheckBox) findViewById(R.id.checkBox1);
		spf=getSharedPreferences("UserInfo", MODE_PRIVATE);
		editor=spf.edit();
		String name=spf.getString("Username","");
		Log.i("info", name);
		if(name=="") 
		{
			
			cb.setChecked(false);
		}else{
			
			cb.setChecked(true);
			et_yh.setText(name);
		}
	}
	public void doClick(View v) {
		// TODO Auto-generated method stub
		switch(v.getId())
		{
		case R.id.button1:
			String name=et_yh.getText().toString().trim();
			String pass=et_mm.getText().toString().trim();
			if("liuxin".equals(name)&&"123456".equals(pass))
			{
			if(cb.isChecked())
			{
				editor.putString("Username", name);
				editor.commit();
			}else{
				editor.remove("Username");
				editor.commit();
				//Log.i("info", "22");
			}
			Toast.makeText(this, " Login successful ", Toast.LENGTH_SHORT).show();
			}else{
				Toast.makeText(this, " Login failed , Incorrect password or user name ", Toast.LENGTH_SHORT).show();
			}
			break;
			default:
			break;
		}

	}

}

Reopen after launching the program