OnJava8-Examples/arrays/CompType.java

// arrays/CompType.java
// <20>2016 MindView LLC: see Copyright.txt
// Implementing Comparable in a class.
import java.util.*;
import java.util.function.*;
import onjava.*;

public class CompType implements Comparable<CompType> {
  int i;
  int j;
  private static int count = 1;
  public CompType(int n1, int n2) {
    i = n1;
    j = n2;
  }
  @Override
  public String toString() {
    String result = "[i = " + i + ", j = " + j + "]";
    if(count++ % 3 == 0)
      result += "\n";
    return result;
  }
  @Override
  public int compareTo(CompType rv) {
    return (i < rv.i ? -1 : (i == rv.i ? 0 : 1));
  }
  private static Random r = new Random(47);
  public static Supplier<CompType> generator() {
    return () ->
      new CompType(r.nextInt(100), r.nextInt(100));
  }
  public static void main(String[] args) {
    CompType[] a =
      Generated.array(new CompType[12], generator());
    System.out.println("before sorting:");
    System.out.println(Arrays.toString(a));
    Arrays.sort(a);
    System.out.println("after sorting:");
    System.out.println(Arrays.toString(a));
  }
}
/* Output:
before sorting:
[[i = 58, j = 55], [i = 93, j = 61], [i = 61, j = 29]
, [i = 68, j = 0], [i = 22, j = 7], [i = 88, j = 28]
, [i = 51, j = 89], [i = 9, j = 78], [i = 98, j = 61]
, [i = 20, j = 58], [i = 16, j = 40], [i = 11, j = 22]
]
after sorting:
[[i = 9, j = 78], [i = 11, j = 22], [i = 16, j = 40]
, [i = 20, j = 58], [i = 22, j = 7], [i = 51, j = 89]
, [i = 58, j = 55], [i = 61, j = 29], [i = 68, j = 0]
, [i = 88, j = 28], [i = 93, j = 61], [i = 98, j = 61]
]
*/