樹圖似乎是刪除條目

Question

我正在嘗試使用無符號長比較器的樹形圖。然而，樹形圖的看起來似乎是刪除entires。沒有比較器，它工作得很好，但我似乎無法弄清楚比較器有什麼問題。下面的實施例的代碼：

公共類主要{

public static void main(String args[]) { 

    class UnsignComparator implements Comparator<Long> { 

     @Override 
     public int compare(Long o1, Long o2) { 
      if (isLessThanUnsigned(o1, o2)) { 
       return -1; 
      } else if (o1.equals(o2)) { 
       return 0; 
      } else { 
       return -1; 
      } 
     } 

    } 

    TreeMap<Long, String> consistent = new TreeMap<Long, String>(
      new UnsignComparator()); 

    System.out.println("Treemap with comparator"); 
    consistent.put(1L, "a"); 
    System.out.println("1L: " + consistent.containsKey(1L)); 
    consistent.put(2L, "b"); 
    System.out.println("1L: " + consistent.containsKey(1L)); 
    System.out.println("2L: " + consistent.containsKey(2L)); 
    consistent.put(3L, "c"); 
    System.out.println("1L: " + consistent.containsKey(1L)); 
    System.out.println("2L: " + consistent.containsKey(2L)); 
    System.out.println("3L: " + consistent.containsKey(3L)); 

    System.out.println("Treemap with comparator keyset"); 
    for (long keys : consistent.keySet()) { 
     System.out.println(keys); 

    } 

    System.out.println("Treemap without comparator"); 
    TreeMap<Long, String> treemap = new TreeMap<Long, String>(); 
    treemap.put(1L, "a"); 
    System.out.println("1L: " + treemap.containsKey(1L)); 
    treemap.put(2L, "b"); 
    System.out.println("1L: " + treemap.containsKey(1L)); 
    System.out.println("2L: " + treemap.containsKey(2L)); 
    treemap.put(3L, "c"); 
    System.out.println("1L: " + treemap.containsKey(1L)); 
    System.out.println("2L: " + treemap.containsKey(2L)); 
    System.out.println("3L: " + treemap.containsKey(3L)); 

} 

//from http://www.javamex.com/java_equivalents/unsigned_arithmetic.shtml 
private static boolean isLessThanUnsigned(long n1, long n2) { 
    return (n1 < n2)^((n1 < 0) != (n2 < 0)); 
} 

}

結果如下：

Treemap with comparator 
    1L: true 
    1L: true 
    2L: true 
    1L: false //expected true 
    2L: true 
    3L: true 
    Treemap with comparator keyset 
    3 
    2 
    1 
    Treemap without comparator 
    1L: true 
    1L: true 
    2L: true 
    1L: true 
    2L: true 
    3L: true 

Answer 1

的else分支應返回1，不-1：

@Override 
public int compare(Long o1, Long o2) { 
    if (isLessThanUnsigned(o1, o2)) { 
     return -1; 
    } else if (o1.equals(o2)) { 
     return 0; 
    } else { 
     return 1; // <<== HERE: 1, not -1 
    } 
}