SharedPreferences

package com.example.administrator.mytestapp.SP;

import android.content.SharedPreferences;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;

import com.example.administrator.mytestapp.R;

public class TestSP extends AppCompatActivity {
private static final String TAG="SharedPreferencesDemo";
    private static final String LOGIN_DATA="LoginData";
    private EditText nameFiled,pwdFiled;
    private Button loginBtn;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_test_sp);
        nameFiled= (EditText) findViewById(R.id.name);
        pwdFiled= (EditText) findViewById(R.id.password);
        loginBtn= (Button) findViewById(R.id.login);
        loginBtn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                setTitle("Name:"+nameFiled.getText().toString()+"&Password"+pwdFiled.getText().toString());
            }
        });
        SharedPreferences loginData=getSharedPreferences(LOGIN_DATA,0);
        String name=loginData.getString("Name","");
        String password=loginData.getString("Password","");
        nameFiled.setText(name);
        pwdFiled.setText(password);
    }

    @Override
    protected void onStop() {
        SharedPreferences loginData=getSharedPreferences(LOGIN_DATA,0);
        SharedPreferences.Editor mEditor=loginData.edit();
        mEditor.putString("Name",nameFiled.getText().toString());
        mEditor.putString("Password",pwdFiled.getText().toString());
        mEditor.commit();
        super.onStop();
    }
}

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context="com.example.administrator.mytestapp.SP.TestSP">
<EditText
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:id="@+id/name"
    android:hint="姓名"/>
    <EditText
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="密码"
       android:id="@+id/password"/>
    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="login"
        android:id="@+id/login"/>
</LinearLayout>