OnJava8-Examples/arrays/CompType.java

// arrays/CompType.java
// (c)2016 MindView LLC: see Copyright.txt
// We make no guarantees that this code is fit for any purpose.
// Visit http://OnJava8.com for more book information.
// Implementing Comparable in a class
import java.util.*;
import java.util.function.*;
import onjava.*;
import static onjava.ArrayShow.*;

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 SplittableRandom r =
    new SplittableRandom(47);
  public static CompType get() {
    return new CompType(r.nextInt(100), r.nextInt(100));
  }
  public static void main(String[] args) {
    CompType[] a = new CompType[12];
    Arrays.setAll(a, n -> get());
    show("Before sorting", a);
    Arrays.sort(a);
    show("After sorting", a);
  }
}
/* Output:
Before sorting: [[i = 35, j = 37], [i = 41, j = 20], [i =
77, j = 79]
, [i = 56, j = 68], [i = 48, j = 93], [i = 70, j = 7]
, [i = 0, j = 25], [i = 62, j = 34], [i = 50, j = 82]
, [i = 31, j = 67], [i = 66, j = 54], [i = 21, j = 6]
]
After sorting: [[i = 0, j = 25], [i = 21, j = 6], [i = 31,
j = 67]
, [i = 35, j = 37], [i = 41, j = 20], [i = 48, j = 93]
, [i = 50, j = 82], [i = 56, j = 68], [i = 62, j = 34]
, [i = 66, j = 54], [i = 70, j = 7], [i = 77, j = 79]
]
*/