java代码中绑定异常错误的数组索引

Question

我写了一段代码，它应该能够创建整数的子集。

import java.util.Iterator; 
    import java.util.NoSuchElementException; 

    public class FixedRangeIntegerSet implements Iterable<Integer> { 

     private boolean[] elementFlags; 
     private int size; 
     private int lowerBound; 
     private int upperBound; 

     public FixedRangeIntegerSet(int lowerBound, int upperBound) { 
      this.lowerBound = lowerBound; 
      this.upperBound = upperBound; 
      int size = upperBound - lowerBound + 1; 
      elementFlags = new boolean[size + 1]; 
      this.size = size; 
     } 

     public FixedRangeIntegerSet(int lowerBound, int upperBound, Iterable<Integer> elements) { 
      int sizeCopy = size; 
      for (Integer element : elements) { 
       if (sizeCopy > 0) { 
        add(element); 
        sizeCopy--; 
       } 
      } 
     } 

     public FixedRangeIntegerSet(int lowerBound, int upperBound, Integer... elements) { 
      for (int i = 0; i < elements.length; i++) { 
       add(elements[i]); 
      } 
     } 

     public boolean add(Integer element) { 
      if (elementFlags[element - lowerBound] == true) { 
       return false; 
      } 
      elementFlags[element - lowerBound] = true; 
      return true; 
     } 

     public boolean containsElement(Integer element) { 
      if (element < lowerBound || element > upperBound) { 
       return false; 
      } 
      if (elementFlags[element - lowerBound] == true) { 
       return true; 
      } else 
       return false; 
     } 

     public int getSize() { 
      int size = 0; 
      for (Boolean i : elementFlags) { 
       if (i == true) { 
        size++; 
       } 
      } 
      return size; 
     } 

     public int getLowerBound() { 
      return lowerBound; 
     } 

     public int getUpperBound() { 
      return upperBound; 
     } 

     public boolean remove(Integer element) { 
      if (elementFlags[element - lowerBound] == false) { 
       return false; 
      } else { 
       elementFlags[element - lowerBound] = false; 
       return true; 
      } 
     } 

     @Override 
     public Iterator<Integer> iterator() { 
      return new RangeIter(); 
     } 

     private class RangeIter implements Iterator<Integer> { 

      private int currentIndex = 0; 

      @Override 
      public boolean hasNext() { 
       return currentIndex < size - 1; 
currentIndex < size 


      } 

      @Override 
      public Integer next() { 
       if (!hasNext()) { 
        throw new NoSuchElementException("No elements more!"); 
       } 
       Integer element = currentIndex; 
       while (elementFlags[currentIndex] == false && currentIndex <=size) { 
        currentIndex++; 
       } 
       return currentIndex++ + lowerBound; 
      } 
     } 
    } 

我在这一行取得数组索引例外：

while (elementFlags[currentIndex] == false && currentIndex <= size) { 

我认为问题是与迭代器。 你能帮我解决这段代码吗？ 非常感谢！

Answer 1

你或许应该这样做：

while (currentIndex <= size && elementFlags[currentIndex] == false) { 

你想先检查大小。如果currentIndex不是<=size那么它甚至不会尝试elementFlags[currentIndex]。