[英]Error reading multiple lines of integers using BufferedReader
我收到此異常:
Exception in thread "main" java.lang.NumberFormatException: For input string: "55 45 65 88 "
at java.lang.NumberFormatException.forInputString(Unknown Source)
at java.lang.Integer.parseInt(Unknown Source)
at java.lang.Integer.valueOf(Unknown Source)
在使用此代碼時:
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
String line = br.readLine();
int noOfStudents = Integer.parseInt(line); //firstline contains 1 integer.
ArrayList <Integer> marks = new ArrayList<Integer>();
line = br.readLine(); //second line contains a line of integers
StringTokenizer tokens = new StringTokenizer(line, "\\s+");
// to break the line into tokens
while (tokens.hasMoreTokens())
{
marks.add(Integer.valueOf(tokens.nextToken())); //error here
//when I am converting tokens into integers its giving error
}
輸入樣例:
4
55 45 65 88(在這里,當我按Enter鍵時,會出現上述錯誤)
StringTokenizer
不支持正則表達式。
StringTokenizer tokens = new StringTokenizer(line, "\\s+");
// This will look for literal "\s+" string as the token.
改用這個
StringTokenizer tokens = new StringTokenizer(line, " "); // Just a space.
編輯:正如@MasterOdin指出的那樣, StringTokenizer
的默認定界符為空格" "
。 因此,以下內容也將以相同的方式工作,
StringTokenizer tokens = new StringTokenizer(line);
您可以使用以下簡單方法:
String []m=br.readLine().split(" "); // split the line delimited with space as array of string.
for(int i=0;i<m.length;i++){
marks.add(Integer.valueOf(m[i])); // add to the marks array list
}
編輯:按照TG
for (String s : br.readLine().split("\\s+")) {
marks.add(Integer.valueOf(s));
}
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