为什么/我在哪里陷入无限循环

Question

我目前正在尝试获取文本文件,并将文本文件分解为单词.然后我尝试将每个单词存储为二叉树中的节点.这样做后,我也尝试打印二叉树.出于某种原因,当我运行我的代码时,我现在陷入无限循环,但我不明白在哪里或为什么这是如果你可以看到我被抓到哪里将是一个很大的帮助谢谢

public class Tester {

public static void main(String[] args) throws FileNotFoundException {

    Tester run = new Tester();
    run.it();

}

public void it() throws FileNotFoundException { 

    BTree theTree = new BTree();

    String str = this.readInFile();

    int position = 0;

    String newWord = this.breakIntoWords(str, position);

    while(newWord != null){

        theTree.add(newWord);

        newWord = this.breakIntoWords(str, position);

    }

    theTree.print();

}

public String readInFile() throws FileNotFoundException {


    String myFile = "";
    int numWords = 0;

    Scanner myScan = new Scanner(new File("Dracula.txt"));

    while(myScan.hasNext() == true) {

        myFile += myScan.nextLine() + " ";

    }

    return myFile;

}

public String breakIntoWords(String myFile, int position) {

    String nextWord = null;

    char next = myFile.charAt(position);
    next = Character.toLowerCase(next);

    // First trim beginning
    while (((next < 'a') || (next > 'z')) && !Character.isDigit(next)) {

        position++;
        next = myFile.charAt(position);
        next = Character.toLowerCase(next);

    }

    // Now pull only letters or numbers until we hit a space
    while(!Character.isWhitespace(next)) {

        if (Character.isLetterOrDigit(next)) {

            nextWord += myFile.charAt(position);

        }

        position++; 
        next = myFile.charAt(position);

    }

    return nextWord;

}

public class BTree {

private BTNode root;
private int nodeCount;


public boolean add(String word){

    BTNode myNode = new BTNode(word);

    if(root == null){

        root = myNode;
        nodeCount++;
        return true;

    }

    if(findNode(word)){

        int tmp = myNode.getNumInstance();
        tmp++;
        myNode.setNumInstance(tmp);
        return false;

    }

    BTNode temp = root;

    while(temp != null){

        if(word.compareTo(temp.getMyWord()) < 0) {

            if(temp.getRightChild() == null){

                temp.setLeftChild(myNode);
                nodeCount++;
                return true;

            } else {

                temp = temp.getRightChild();

            }

        } else {

                if(temp.getLeftChild() == null){

                    temp.setLeftChild(myNode);
                    nodeCount++;
                    return true;

                } else {

                    temp = temp.getLeftChild();

                }

        }

    }

    return false;

}

public boolean findNode(String word) {
    return mySearch(root, word);
}

private boolean mySearch(BTNode root, String word) {
    if (root == null) {
        return false;
    }

    if ((root.getMyWord().compareTo(word) < 0)) {
        return true;
    } else {
        if (word.compareTo(root.getMyWord()) > 0) {
            return mySearch(root.getLeftChild(), word);
        } else {
            return mySearch(root.getRightChild(), word);
        }
    }
}

public void print() {
    printTree(root);
}

private void printTree(BTNode root) {
    if (root == null) {
        System.out.print(".");
        return;
    }

    printTree(root.getLeftChild());
    System.out.print(root.getMyWord());
    printTree(root.getRightChild());

}

public int wordCount() {

    return nodeCount;

}

Answer 1

您反复调用this.breakIntoWords(str, position),str并position使用其返回值来决定何时停止.由于从一次迭代到下一次迭代没有任何变化,循环永远不会终止.