數(shù)據(jù)保存到文件中就是使用java流將數(shù)據(jù)寫入文件中烧董。
android封裝了獲取輸入輸出流的兩個(gè)方法openFileInput和openFileOutput。
完整的代碼如下：
public class SaveInFileActivity extends AppCompatActivity {
private EditText et;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_save_in_file);
et = (EditText) findViewById(R.id.et_saveInFile);
String string=read();
if (!TextUtils.isEmpty(string)){
et.setText(string);
et.setSelection(string.length());
}
}
@Override
protected void onDestroy() {
super.onDestroy();
save();
}
private void save(){
FileOutputStream fileOutputStream;
BufferedWriter writer=null;
try {
fileOutputStream = openFileOutput("data", Context.MODE_PRIVATE);
writer= new BufferedWriter(new OutputStreamWriter(fileOutputStream));
writer.write(et.getText().toString());
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}finally {
if (writer!=null){
try {
writer.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
private String read(){
BufferedReader reader=null;
StringBuffer stringBuffer =new StringBuffer();
stringBuffer.append("");
try {
FileInputStream fileInputStream = openFileInput("data");
reader=new BufferedReader(new InputStreamReader(fileInputStream));
String line="";
while ((line=reader.readLine())!=null){
stringBuffer.append(line);
}
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}finally {
if (reader!=null){
try {
reader.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
return stringBuffer.toString();
}
}
