我試圖將點添加到鏈接列表中,以便跟蹤每個數據條目的頻率。每次我運行這段代碼,它都會給我一個NullPointerException。我不明白爲什麼,對我來說,似乎在它增加了它造成的差距之後,但我似乎無法修復它。鏈接列表,不斷獲取NullPointerException
if(firstNode == null)
{
addPair = new Pair(aData, 1);
firstNode = new Node(null, addPair, null);
lastNode = firstNode;
currentNode = firstNode;
numberOfNodes++;
}
else
{
currentNode=firstNode;
for(int count = 0; count<numberOfNodes; count++)
{
if(currentNode.data.fst().equals(aData))
{
addPair = new Pair(aData,currentNode.data.freq()+1);
if(count==0)
firstNode= new Node(currentNode,addPair,null);
currentNode = new Node(currentNode,addPair,null);
break;
}
if(count == (numberOfNodes-1) && currentNode.data.fst() !=(aData))
{
addPair = new Pair(aData,1);
Node newNode = new Node(currentNode, addPair, null);
currentNode.next = newNode;
lastNode = newNode;
numberOfNodes++;
break;
}
currentNode = currentNode.next;
}
}
numberOfEntries++;
private class Node
{
private Node previous;
private Pair data;
private Node next;
private Node(Node previousNode, Pair<T,Integer> addPair, Node nextNode)
{
previous = previousNode;
data = addPair;
next = nextNode;
}
}
能否請您分享您的堆棧跟蹤? – Mureinik 2015-02-08 21:10:58
如何向我們展示'Node'類?基本上,我們要求我們在乾草堆裏找到一根針,但只給我們一小堆乾草堆頂上的乾草,看看。 – 2015-02-08 21:13:10
添加節點類 – AHxRazr 2015-02-08 21:20:28