我创建了一个文件,当我运行程序时,数据被写入文件,但是当我再次运行程序时,新数据覆盖旧数据。我需要一旦程序运行并收集数据,这些数据就可以彼此级联写入文件,而不会覆盖文件中的先前数据。
这段代码运行成功,但是当我再次运行程序时,会发生我不需要的覆盖,我需要将以前的数据保存在文件中,并很快在它旁边写入新数据。编辑此代码后,它看起来像:
public class MainActivity extends Activity {
File file;
File sdCard;
FileOutputStream fos;
OutputStreamWriter myOutWriter;
String FileName = "Output3.txt";
String eol;
OutputStream fos1;
FileWriter fw ;
BufferedWriter writer;
BufferedWriter bw ;
PrintWriter out;
EditText txtData;
Button btnWriteSDFile;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
sdCard =getExternalFilesDir(null);
file = new File(sdCard,FileName);
txtData = (EditText) findViewById(R.id.editText1);
btnWriteSDFile = (Button) findViewById(R.id.button1);
btnWriteSDFile.setOnClickListener(new OnClickListener()
{
public void onClick(View v)
{
try {
fos = new FileOutputStream(file);
myOutWriter =new OutputStreamWriter(fos);
eol = System.getProperty("line.separator");
writer = new BufferedWriter(myOutWriter);
writer.append(txtData.getText() + eol);// write this text.
writer.flush();
fos.close();
Toast.makeText(v.getContext(),"Done writing SD 'Output.txt'", Toast.LENGTH_SHORT).show();
txtData.setText("");
} catch (Exception e) {
// e.printStackTrace();
Toast.makeText(v.getContext(), e.getMessage(),Toast.LENGTH_SHORT).show();
}
finally{
try {
fos.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
});
}
please,can any one answer me?