Re: Converting a HashMap<String, Thing> into a sorted array

qu0ll,

There are lots of ways to do this depending on your actual goal.

As a HashMap has keys and values, is your end goal to have an array of
{something} in the order that the keys are sorted or based on how the
{something}'s should be ordered on their own?

If its the later, you probably want to create a Comparator for each
{something} you want to sort.

Here is a simple example - not sure if its exactly what you want but
hopefully it helps.

/* Begin qu0ll.java */
import java.util.*;

public class qu0ll {
  public static void main(String args[]) {
    qu0llSomethingComparator c = new qu0llSomethingComparator();
    qu0llSomething[] myArray = new qu0llSomething[args.length];

    for (int i = 0; i < args.length; i ++) {
      myArray[i] = new qu0llSomething(args[i]);
    }

    Arrays.sort(myArray, c);

    for (qu0llSomething q : myArray) {
      System.out.println(q);
    }
  }
}
/* Begin qu0llSomethingComparator.java */
import java.util.*;

public class qu0llSomethingComparator implements
Comparator<qu0llSomething> {
  public int compare(qu0llSomething q1, qu0llSomething q2) {
    // Specialized rules for ordering go here

    if (q1.getLength() < q2.getLength()) {
      return -1;
    }
    else if (q1.getLength() == q2.getLength()) {
      if (q1.hashCode() < q2.hashCode()) {
        return -1;
      }
      else if (q1.hashCode() > q2.hashCode()) {
        return 1;
      }
      else {
        return 0;
      }
    }
    else {
      return 1;
    }
  }

  public boolean equals(Object o) {
    return (o == this);
  }
}
/* Begin qu0llSomething.java */
public class qu0llSomething {
  private String value;

  public qu0llSomething(String value) {
    this.value = value;
  }

  // Will throw NullPointerException if value is null
  public int getLength() {
    return value.length();
  }

  public String getValue() {
    return value;
  }

  public String toString() {
    return getValue();
  }
}

--

Let me know if I can assist further.

-kavaj

qu0ll wrote: