---

Category.java

package gov.nasa.arc.ase.util;

import java.util.Vector;

public class Category implements Comparable {
  private String[] categories;
  private int length;
  private int delta;

  public Category() {
    categories = new String[0];
    length = 0;
    delta = 1;
  }  
  public Category(int size) {
    if(size < 0) throw new IllegalArgumentException("size < 0");

    categories = new String[size];
    length = 0;
    delta = 1;
  }  
  public Category(int size, int delta) {
    if(size < 0) throw new IllegalArgumentException("size < 0");
    if(delta <= 0) throw new IllegalArgumentException("delta <= 0");

    categories = new String[size];
    length = 0;
    this.delta = delta;
  }  
  public Category(Category c) {
    int l = c.categories.length;
    categories = new String[l];
    System.arraycopy(c.categories, 0, categories, 0, l);
    length = l;
    delta = 1;
  }  
  public Category(Category c, int delta) {
    if(delta <= 0) throw new IllegalArgumentException("delta <= 0");

    int l = c.categories.length;
    categories = new String[l];
    System.arraycopy(c.categories, 0, categories, 0, l);
    length = l;
    this.delta = delta;
  }  
  public Category(String s) {
    parseFromString(s);
  }  
  public int compareTo(Object o) {
    Category c = (Category)o;
    Comparable[] o1 = categories;
    Comparable[] o2 = c.categories;
    int l1 = o1.length;
    int l2 = o2.length;
    for(int i = 0; i < l1 & i < l2; i++) {
      int r = o1[i].compareTo(o2[i]);
      if(r != 0) return r;
    }
    return l1 - l2;
  }  
  public void down(String o) {
    if(length >= categories.length)
      grow();

    categories[length++] = o;
  }  
  public boolean equals(Object o) {
    Category c = (Category)o;
    String[] o1 = categories;
    String[] o2 = c.categories;
    int l1 = o1.length;
    int l2 = o2.length;
    for(int i = 0; i < l1 & i < l2; i++)
      if(!o1[i].equals(o2[i])) return false;

    return true;
  }  
  protected void grow() {
    String[] copy = new String[length + delta];
    System.arraycopy(categories, 0, copy, 0, length);
    categories = copy;
  }  
  public int hashCode() {
    int hashcode = 0;

    for(int i = 0; i < length; i++)
      hashcode = hashcode + categories[i].hashCode();

    return hashcode;
  }  
  protected void parseFromString(String s) {
    if (!s.startsWith("/")) throw new IllegalArgumentException("category should start with /");

    int si = 1, len = s.length();
    Vector strings = new Vector();

    while(si < len) {
      int ei = s.indexOf('/', si);
      if (ei == -1) ei = len;

      strings.add(s.substring(si, ei));

      si = ei + 1;
    }

    length = strings.size();
    categories = new String[length];
    strings.toArray(categories);
    delta = 1;
  }  
  public void print(Category last) {
    boolean started = false;

    if(length == 0) {
      Debug.print(Debug.WARNING, "/");
      return;
    }

    for(int i = 0; i < length; i++) {
      if(i == length-1) {
    for(int j = 0; j < i; j++)
      Debug.print(Debug.WARNING, "  ");
    Debug.print(Debug.WARNING, categories[i].toString());
      } else if(started || last == null) {
    for(int j = 0; j < i; j++)
      Debug.print(Debug.WARNING, "  ");
    Debug.println(Debug.WARNING, categories[i].toString());
      } else if(!categories[i].equals(last.categories[i])) {
    started = true;
    for(int j = 0; j < i; j++)
      Debug.print(Debug.WARNING, "  ");
    Debug.println(Debug.WARNING, categories[i].toString());
      }
    }
  }  
  public void save(java.io.PrintStream out, Category last) {
    boolean started = false;

    if(length == 0) {
      out.print("/");
      return;
    }

    for(int i = 0; i < length; i++) {
      if(i == length-1) {
    for(int j = 0; j < i; j++)
      out.print("  ");
    out.print(categories[i].toString());
      } else if(started || last == null) {
    for(int j = 0; j < i; j++)
      out.print("  ");
    out.println(categories[i].toString());
      } else if(i >= last.length || !categories[i].equals(last.categories[i])) {
    started = true;
    for(int j = 0; j < i; j++)
      out.print("  ");
    out.println(categories[i].toString());
      }
    }
  }  
  public String toString() {
    if(length == 0) return "/";

    StringBuffer sb = new StringBuffer();
    for(int i = 0; i < length; i++) {
      sb.append("/");
      sb.append(categories[i]);
    }

    return sb.toString();
  }  
  public String up() {
    if(length == 0) throw new IndexOutOfBoundsException("length == 0");

    return categories[--length];
  }  
}

---