if else statement

Question

我有几个if/else语句的代码。然而，每当抛出'else'情况时，所有后续语句也会导致'else'。这里是代码，我很感激一些帮助，请!

public List<Integer> htmlHelper(String arg) throws IOException,
        XPatherException, ParserConfigurationException,
        XPathExpressionException {
    CleanerProperties props = new CleanerProperties();
    props.setTranslateSpecialEntities(true);
    props.setTransResCharsToNCR(true);
    props.setOmitComments(true);
    HtmlCleaner cleaner = new HtmlCleaner(props);
    rootNode = cleaner.clean(arg);

    TagNode tagNode = new HtmlCleaner(props).clean(new URL(
            "http://www.athletics.psu.edu/psustrength/index_rec.asp"));
    org.w3c.dom.Document doc = (org.w3c.dom.Document) new DomSerializer(
            new CleanerProperties()).createDOM(tagNode);
    XPath jpath = XPathFactory.newInstance().newXPath();
    String recinfo = (String) jpath
            .evaluate(
"/html/body/div/div[1]/div/div/table/tbody/tr[3]/td[2]/p[2]/text()",
                    doc, XPathConstants.STRING);
    String recnum = recinfo.replaceAll("\D+", "");
    if (recnum != null && recnum.length() == 0) {
        recnumint = 500;
        grec = 0;
    } else {
        recnumint = Integer.parseInt(recnum);
        grec = recnumint;
    }
    XPath ipath = XPathFactory.newInstance().newXPath();
    String iminfo = (String) ipath
            .evaluate(
"/html/body/div/div[3]/div/div/table/tbody/tr[2]/td[2]/p[2]/text()",
                    doc, XPathConstants.STRING);
    String imnum = iminfo.replaceAll("\D+", "");
    if (imnum != null && recnum.length() == 0) {
        imint = 400;
        gim = 0;
    } else {
        imint = Integer.parseInt(imnum);
        gim = imint;
    }
    XPath xpath = XPathFactory.newInstance().newXPath();
    String whiteinfo = (String) xpath
            .evaluate(
"/html/body/div/div[3]/div/div/table/tbody/tr[1]/td[2]/p[2]/text()",
                    doc, XPathConstants.STRING);
    String whitenum = whiteinfo.replaceAll("\D+", "");
    if (whitenum != null && recnum.length() == 0) {
        whitenumint = 450;
        gwhite = 0;
    } else {
        whitenumint = Integer.parseInt(whitenum);
        gwhite = whitenumint;
    }
    XPath fpath = XPathFactory.newInstance().newXPath();
    String fitinfo = (String) fpath
            .evaluate(
"/html/body/div/div[3]/div/div/table/tbody/tr[4]/td[2]/p[2]/text()",
                    doc, XPathConstants.STRING);
    String fitnum = fitinfo.replaceAll("\D+", "");
    if (fitnum != null && recnum.length() == 0) {
        fitint = 470;
        gfit = 0;
    } else {
        fitint = Integer.parseInt(fitnum);
        gfit = fitint;
    }

    List<Integer> list = new ArrayList<Integer>();
    list.add(recnumint);
    list.add(whitenumint);
    list.add(imint);
    list.add(fitint);
    return list;
}
}

如前所述，当抛出第一个'else'语句时发生问题。如果第一种情况是' If '，第二种情况是'else'，那么第三种和第四种情况也是'else'

Answer 1

你所有的if都有相同的第二个条件，也许这就是原因吧?

你是说

if (imnum != null && imnum .length() == 0) {
                     ^^^^^^

代替

if (imnum != null && recnum.length() == 0) {

同样

if (whitenum != null && whitenum.length() == 0) {
                        ^^^^^^^^^

当然还有…

if (fitnum != null && fitnum.length() == 0) {
                      ^^^^^^

Answer 2

请记住NOT (A AND B)与(NOT A) OR (NOT B)是相同的。使用调试器来找出哪个条件失败。