Android indexoutofboundsexception

本文关键字：indexoutofboundsexception Android | 更新日期: 2023-09-27 18:01:37

大家好，我在用正则表达式。我有indexoutofboundexception这是我的来源

public String ExtractYoutubeURLFromHTML(String html) throws UnsupportedEncodingException
{
     Pattern pattern = Pattern.compile(this.extractionExpression);

     Matcher matcher = pattern.matcher(html);
     List<String> matches = new ArrayList<String>();
     while(matcher.find()){
         matches.add(matcher.group());
     }

    String vid0 = matches.get(0).toString();

    vid0 = vid0.replace ("''''u0026", "&");
    vid0 = vid0.replace ("''''''", "");

    vid0=URLDecoder.decode(vid0,"UTF-8");

    return vid0;
}

我调试，我有indexoutofboundexception无效索引异常

错误在这部分代码

 List<String> matches = new ArrayList<String>();
     while(matcher.find()){
         matches.add(matcher.group());
     }

    String vid0 = matches.get(0).toString();

我也有c#工作代码，我想在java代码中重写c#代码这是c#中的工作代码

public string ExtractYoutubeURLFromHTML(string html)
    {
        Regex rx = new Regex (this.extractionExpression);

        var video = rx.Matches (html);
        var vid0 = video [0].ToString ();
        vid0 = vid0.Replace ("''''u0026", "&");
        vid0 = vid0.Replace ("''''''", "");
        vid0 = System.Net.WebUtility.UrlDecode (vid0);

        return vid0;
    }

Android indexoutofboundsexception

如果matches为空，则matches.get(0).toString();将给出ArrayIndexOutOfBoundsException。

最好检查一下

if(matches.size()>0)
  String vid0 = matches.get(0).toString();

替换这个

String vid0 = matches.get(0).toString();

if(matches.size() > 0){
    String vid0 = matches.get(0).toString();
} else {
    return ""   // or you can also return null;
}