我想一次随机显示一个在txt文件中的数据库数据，并且不能重复数据。
private void question() {
// TODO Auto-generated method stub
InputStreamReader inputStream = new InputStreamReader
(getResources().openRawResource(R.raw.question1));
BufferedReader br = new BufferedReader(inputStream);
//number of lines in the database numLines
int numLines= 10;
Random r = new Random();
int desiredLine = r.nextInt(numLines);
String theLine="";
int lineCtr = 0;
try {
while ((theLine = br.readLine()) != null) {
if (lineCtr == desiredLine) {
StringTokenizer st = new StringTokenizer(theLine,",");
while(st.hasMoreTokens())
{
//reading and getting data from the database","
String a = st.nextToken();
String b = st.nextToken();
String c = st.nextToken();
String d = st.nextToken();
String e = st.nextToken();
String f = st.nextToken();
//button setText
question.setText(a);
ca.setText(f);
firstbutton.setText(e);
secondbutton.setText(d);
thirdbutton.setText(b);
fourthbutton.setText(c);
//assigning
firstholder =e;
secondholder =d;
thirdholder=b;
fourthholder =c;
break;
}
}
lineCtr++;
}
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}