java - 使用java在文件中的每个整数后面添加空格

Question

我正在尝试编写一段代码，它接受一个文件作为输入，并输出一个文件，如果没有整数，则每个整数后面都有空格。

示例:

输入文件包含:3 0001 输出文件应为:3 0 0 0 1

问题是，0001 被检测为 1，我的输出为

3 1

下面是我尝试的第一个代码

Scanner scanner = new Scanner(new File(inputPath));
ArrayList<Integer> integerArrayList = new ArrayList<Integer>();
while (scanner.hasNextInt()) integerArrayList.add(scanner.nextInt());
System.out.println(integerArrayList.toString());
scanner.close();

输出 - [3, 1]

尝试以角色的形式阅读

FileInputStream fin = new FileInputStream(new File(inputPath));
ArrayList<Integer> integerArrayList = new ArrayList<Integer>();
while (fin.available() > 0) integerArrayList.add(Integer.valueOf(fin.read()));
System.out.println(integerArrayList.toString());
fin.close();

现在输出是 - [51, 32, 48, 48, 48, 49]

Answer 1

尝试此代码并仔细阅读注释。

Scanner inp=new Scanner(new File(inputPath));
ArrayList<Integer> integerArrayList = new ArrayList<Integer>();
//looking for next string
while(inp.hasNext()){
   String my_string=inp.next();//taking the string
   for(int i=0;i<my_string.length();i++){//adding every character of string
    try {//if a integer found add to list
        integerArrayList.add(Integer.parseInt(String.valueOf(my_string.charAt(i))));
        } catch (Exception ex) {
          //exception occurs if an integer not found and do nothing 
        }
   }
}

//printing values and here you can use your code to write in another file but use a space(" ") after every integer to get your desired output
for(int i=0;i<integerArrayList.size();i++){
   System.out.print(integerArrayList.get(i)+" ");
}