如何优化编写多行输出？

Question

Is there a better solution than writing a System.out.println in this way?

String nl = System.getProperty("line.separator");

for (k=0; k<=ds.size()-counter-1; k=k+counter){
            System.out.println (metric+" "+ds.get(k)+" "+ds.get(k+2)+" sensor=A cell="+ cellName + nl +
            metric+" "+ds.get(k)+" "+ds.get(k+3)+" sensor=B cell="+ cellName + nl + 
            metric+" "+ds.get(k)+" "+ds.get(k+4)+" sensor=C cell="+ cellName + nl + 
            metric+" "+ds.get(k)+" "+ds.get(k+5)+" sensor=D cell="+ cellName + nl +
            metric+" "+ds.get(k)+" "+ds.get(k+6)+" sensor=E cell="+ cellName + nl + 
            metric+" "+ds.get(k)+" "+ds.get(k+7)+" sensor=F cell="+ cellName + nl + 
            metric+" "+ds.get(k)+" "+ds.get(k+8)+" sensor=G cell="+ cellName + nl + 
            metric+" "+ds.get(k)+" "+ds.get(k+9)+" sensor=H cell="+ cellName + nl +
            metric+" "+ds.get(k)+" "+ds.get(k+10)+" sensor=I cell="+ cellName + nl +    
            metric+" "+ds.get(k)+" "+ds.get(k+11)+" sensor=L cell="+ cellName + nl +    
            metric+" "+ds.get(k)+" "+ds.get(k+12)+" sensor=M cell="+ cellName + nl +
            metric+" "+ds.get(k)+" "+ds.get(k+13)+" sensor=N cell="+ cellName); 
            }   

Answer 1

Create a StringBuilder, append your Strings to the StringBuilder, and then print it in one System.out.println call.

Oh, and you can easily nest two for loops and make your code much more readable.

eg,

  StringBuilder stringBuilder = new StringBuilder();
  Formatter formatter = new Formatter(stringBuilder);
  int maxSomething = 12;
  String template = metric + " %s %s sensor=%c cell=" + cellName + nl;
  for (int i = 0; i < ds.size()-counter-1; i = i + counter) {
     for (int j = 0; j < maxSomething; j++) {
        formatter.format(template, ds.get(i), ds.get(i + j + 2), (char)('A' + j));
     }
  }
  // the toString() below isn't necessary but is present for clarity
  System.out.println(stringBuilder.toString());
  formatter.close();

• Note: code not compiled nor tested.
• Note 2: code as written risks trying to extract items beyond the size of the ds list. You will want to set maxSomething based on the size of your ds list