我想将最大数字从一个文件复制到另一个文件？但是，输入数字时遇到一些问题

Question

Whenever I try to write the Numbers like this-

(1
2
3
4
56)

It takes only the first number.What is wrong with my code.This is my code.

BufferedReader out = new BufferedReader(new FileReader("Nos for finding highest.txt"));
PrintWriter in = new PrintWriter(new FileWriter("third.txt"));
String str = " ";
str = out.readLine();
String[] numbers = str.split("\n");
int[] array = new int[numbers.length];
int count = 0;
for (String strs : numbers) {
    array[count++] = Integer.parseInt(strs);
}
int max = array[0];
for (int c : array) {
    if (c > max)
        max = c;
}

in.println(new Integer(max).toString());

in.close();

out.close();

If I take while((str = out.readLine()) != null) in the above code then it printouts all the numbers instead of printing max(Largest Number) .

Answer 1

If you input the numbers are on on the same line then split the input using space:

String[] numbers = str.split(" ");

If your numbers in the file are each in new line then use

String[] numbers = str.split("\n"); 

Answer 2

I'll expand on my comment for formatting reasons: Assuming your file has one number per line you'll want to first read them all into a list:

List<Integer> list = new LinkedList<>();
while((str = out.readLine()) != null) {
  //assuming the line is not empty and contains a valid integer
  list.add( Integer.valueOf(str) ); 
}

Then iterate and look for the highest number:

for( Integer i : list ) {
  //check for max here
}