implementation 'com.google.android.gms:play-services-basement:17.0.0'
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
import android.content.Context;
import android.util.Log;
import com.google.android.gms.common.util.IOUtils;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
public class DataPersistence {
private static final String TAG = "DataPersistence";
private static final String FILE_NAME = "data.txt";
public static boolean saveData(Context context, String data) {
try {
File file = new File(context.getExternalFilesDir(null), FILE_NAME);
FileOutputStream outputStream = new FileOutputStream(file);
outputStream.write(data.getBytes());
outputStream.close();
return true;
} catch (IOException e) {
Log.e(TAG, "Failed to save data: " + e.getMessage());
return false;
}
}
public static String loadData(Context context) {
try {
File file = new File(context.getExternalFilesDir(null), FILE_NAME);
FileInputStream inputStream = new FileInputStream(file);
byte[] buffer = new byte[(int) file.length()];
inputStream.read(buffer);
inputStream.close();
return new String(buffer);
} catch (IOException e) {
Log.e(TAG, "Failed to load data: " + e.getMessage());
return null;
}
}
}
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;
public class MainActivity extends AppCompatActivity {
private EditText editText;
private Button saveButton;
private Button loadButton;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
editText = findViewById(R.id.edit_text);
saveButton = findViewById(R.id.save_button);
loadButton = findViewById(R.id.load_button);
saveButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
String data = editText.getText().toString();
if (DataPersistence.saveData(MainActivity.this, data)) {
Toast.makeText(MainActivity.this, "Data saved", Toast.LENGTH_SHORT).show();
} else {
Toast.makeText(MainActivity.this, "Failed to save data", Toast.LENGTH_SHORT).show();
}
}
});
loadButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
String data = DataPersistence.loadData(MainActivity.this);
if (data != null) {
editText.setText(data);
Toast.makeText(MainActivity.this, "Data loaded", Toast.LENGTH_SHORT).show();
} else {
Toast.makeText(MainActivity.this, "Failed to load data", Toast.LENGTH_SHORT).show();
}
}
});
}
}
