Android如何实现文件存储

这篇文章主要讲解了"Android如何实现文件存储"，文中的讲解内容简单清晰，易于学习与理解，下面请大家跟着小编的思路慢慢深入，一起来研究和学习"Android如何实现文件存储"吧！

1、文件存储案例

public class TestActivity extends AppCompatActivity {    private EditText mFileEdit;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_test);        initView();    }    private void initView() {        mFileEdit = findViewById(R.id.fileEdit);        String inputText = load();        if (!TextUtils.isEmpty(inputText)) {            mFileEdit.setText(inputText);            mFileEdit.setSelection(inputText.length());            Toast.makeText(this, "Restoring succeeded", Toast.LENGTH_SHORT).show();        }    }    @Override    protected void onDestroy() {        super.onDestroy();        String inputText = mFileEdit.getText().toString();        save(inputText);    }    //    从文件中读取数据    public void save(String inputText) {        FileOutputStream outputStream = null;        BufferedWriter writer = null;        try {            outputStream = openFileOutput("data", Context.MODE_PRIVATE);            writer = new BufferedWriter(new OutputStreamWriter(outputStream));            writer.write(inputText);        } catch (IOException e) {            e.printStackTrace();        } finally {            try {                if (writer != null) {                    writer.close();                }            } catch (IOException e) {                e.printStackTrace();            }        }    }    //    将文件存储到文件中    public String load() {        FileInputStream inputStream = null;        BufferedReader reader = null;        StringBuilder builder = new StringBuilder();        try {            inputStream = openFileInput("data");            reader = new BufferedReader(new InputStreamReader(inputStream));            String line = "";            while ((line = reader.readLine()) != null) {                builder.append(line);            }        } catch (IOException e) {            e.printStackTrace();        } finally {            if (reader != null) {                try {                    reader.close();                } catch (IOException e) {                    e.printStackTrace();                }            }        }        return builder.toString();    }}

运行结果，Pass

2、SharePreferences存储案例

public class SharePfsActivity extends AppCompatActivity implements View.OnClickListener {    private static final String TAG = "SharePfsActivity";    private Button mSharedData;    private Button mRestoreData;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_shared_pfs);        initView();    }    private void initView() {        mSharedData = findViewById(R.id.sharedBtn);        mSharedData.setOnClickListener(this);        mRestoreData = findViewById(R.id.restoreBtn);        mRestoreData.setOnClickListener(this);    }    @Override    public void onClick(View view) {        switch (view.getId()) {            case R.id.sharedBtn:                sharedData();                break;            case R.id.restoreBtn:                restoreData();                break;            default:                break;        }    }    private void sharedData() {        SharedPreferences.Editor editor = getSharedPreferences("shareData", MODE_PRIVATE).edit();        editor.putString("name", "功勋");        editor.putString("type", "电影");        editor.apply();    }    private void restoreData() {        SharedPreferences preferences = getSharedPreferences("shareData", MODE_PRIVATE);        String name = preferences.getString("name", "");        String type = preferences.getString("type", "");        Log.d(TAG, "名称：" + name + "，类型：" + type);    }}

运行结果，Pass

3、登录页面，实现记住username和pwd功能

activity_login.xml文件

LoginActivity .class

public class LoginActivity extends AppCompatActivity {    private static final String TAG = "LoginActivity";    private Button mLogin;    private CheckBox mRemember;    private EditText mUsername;    private EditText mPwd;    private SharedPreferences mSharedPs;    private SharedPreferences.Editor mEditor;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_login);        initView();    }    private void initView() {        mSharedPs = PreferenceManager.getDefaultSharedPreferences(this);        mUsername = findViewById(R.id.username);        mPwd = findViewById(R.id.pwd);        mRemember = findViewById(R.id.remember);        mLogin = findViewById(R.id.login);        boolean isRemember = mSharedPs.getBoolean("remember_pwd", false);        if (isRemember) {            // 将账号和密码都设置到文本框中            mUsername.setText(mSharedPs.getString("username", ""));            mPwd.setText(mSharedPs.getString("pwd", ""));            mRemember.setChecked(true);        }        mLogin.setOnClickListener(new View.OnClickListener() {            @Override            public void onClick(View v) {                String username = mUsername.getText().toString();                String pwd = mPwd.getText().toString();                // 如果账号：admin，密码：123456，就认为登录成功                if (username.equals("admin") && pwd.equals("123456")) {                    mEditor = mSharedPs.edit();                    // 检查复选框是否被选中                    if (mRemember.isChecked()) {                        mEditor.putString("username", username);                        mEditor.putString("pwd", pwd);                        mEditor.putBoolean("remember_pwd", true);                    } else {                        mEditor.clear();                    }                    mEditor.apply();                    Intent intent = new Intent(LoginActivity.this, MainActivity.class);                    startActivity(intent);                    finish();                } else {                    Log.d(TAG, "用户名或密码输入错误，请重新输入");                }            }        });    }}

运行结果，Pass

感谢各位的阅读，以上就是"Android如何实现文件存储"的内容了，经过本文的学习后，相信大家对Android如何实现文件存储这一问题有了更深刻的体会，具体使用情况还需要大家实践验证。这里是，小编将为大家推送更多相关知识点的文章，欢迎关注！