It seems like your desired words are divided by space. In that case just read your file line by line, and then get your words using String.split(" ").
Here is the one i might think of:
public class FileSplitter {
public static void main(String[] args) throws IOException {
File file = new File("input_file.txt");
LinkedList words = new LinkedList();
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;
}
}
}
}
}
For your example it returns this:
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