似乎您想要的单词被空格分开了。在这种情况下，只需逐行阅读文件，然后使用即可获得所需的字词String.split(" ")。这是我可能想到的：

public class FileSplitter {

    public static void main(String[] args) throws IOException {
        File file = new File("input_file.txt");
        LinkedList<String> words = new LinkedList<String>();
        int i = 0;

        Files.lines(file.toPath()).
        forEachOrdered(line -> words.
                addAll(Arrays.asList(line.split(" "))));

        for(String word:words){
            if(word.trim().length() > 0){
                System.out.print(word.trim() + " ");
                if(i++ >= 3){
                    System.out.println();
                    i = 0;
                }
            }
        }
    }
}

对于您的示例，它返回以下内容：

sys_clock_gettime sys_poll sys_poll sys_clock_gettime 
sys_poll sys_poll sys_poll sys_clock_gettime 
sys_poll sys_clock_gettime sys_poll sys_poll 
sys_poll sys_poll sys_poll sys_poll
sys_poll sys_poll sys_socketcall