Java-解析具有整数和字符串的文本文件

Question

I have a text file with the following contents (delimiter is a single space):

1231 2134 143 wqfdfv -89 rwq f 8 qer q2
sl;akfj salfj 3 sl 123

My objective is to read the integers and strings seperately. Once I know how to parse them, I will create another output file to save them (but my question is only to know how to parse this text file).

I tried using Scanner and I am NOT able to get beyond the first inetger:

Scanner s = new Scanner (new File ("a.txt")).useDelimiter("");
while (s.hasNext()){
System.out.print(s.nextInt());}

and the output is

1231

How can I also get other integers from both the lines?

My desired outout is:

1231 
2134 
143
-89
8
3 
123

Answer 1

When reading data from file, read all as string types. Then test whether it is number by parsing it using Integer.parseInt() . If it throws an exception then it is a string, otherwise it is a number.

while (s.hasNext()) {
    String str = s.next();
    try { 
        b = Integer.parseInt(str); 
    } catch (NumberFormatException e) { // only catch specific exception
        // its a string, do what you need to do with it here
        continue;
    }
    // its a number
 } 

Answer 2

The delimiter should be something else like at least one whitespace or more

Scanner s = new Scanner (new File ("a.txt")).useDelimiter("\\s+");
while (s.hasNext()) {
    if (s.hasNextInt()) { // check if next token is an int
        System.out.print(s.nextInt()); // display the found integer
    } else {
        s.next(); // else read the next token
    }
}

and i have to admit that the solution from gotuskar is the better one in this simple case.