Can anybody tell me what’s wrong with this code?

Question

I am getting the compile time error.

import java.util.regex.Matcher;
import java.util.regex.Pattern;

class gfile
 {
  public static void main(String args[]) {
    // create a Pattern
    Pattern p = Pattern.compile("<div class="dinner">(.*?)</div>");//some prob with this line


    // create a Matcher and use the Matcher.group() method
  String can="<tr>"+
                          "<td class="summaryinfo">"+

                                "<div class="dinner">1,000</div>" +
                                "<div style="margin-top:5px " +
                                 "font-weight:bold">times</div>"+
                            "</td>"+
                        "</tr>";

    Matcher matcher = p.matcher(can);
    // extract the group

    if(matcher.find())
     {
    System.out.println(matcher.group());
     }
  else
     System.out.println("could not find");
  }
}

Answer 1

But, your Regex is matching (.*?) "Any character, any number of repetitions, as few as possible"

Meaning, it matches nothing...and everything.

...or the fact that your quotes aren't escaped.

Answer 2

(.*?) might need to be (.*)?

Answer 3

You have unescaped quotes inside your call to Pattern.compile.

Change:

Pattern p = Pattern.compile("<div class="dinner">(.*?)</div>");

To:

Pattern p = Pattern.compile("<div class=\"dinner\">(.*?)</div>");

Note: I just saw the same problem in your String can.

Change it to:

  String can="<tr>"+
                      "<td class=\"summaryinfo\">"+

                            "<div class=\"dinner\">1,000</div>" +
                            "<div style=\"margin-top:5px " +
                             "font-weight:bold\">times</div>"+
                        "</td>"+
                    "</tr>";

I don't know if this fixes it, but it will at least compile now.

Answer 4

You should use an HTML parser to parse and process HTML - not a regular expression.

Answer 5

As already pointed out, you'll need to escape the double quotes inside all of your strings.

And, if you want to have "1,000" as result, you'll need to use group(1), else you'll get the complete match of the pattern.

Resulting code:

import java.util.regex.Matcher;
import java.util.regex.Pattern;

class gfile
 {
  public static void main(String args[]) {
    // create a Pattern
    Pattern p = Pattern.compile("<div class=\"dinner\">(.*?)</div>");

    // create a Matcher and use the Matcher.group() method
    String can="<tr>"+
                          "<td class=\"summaryinfo\">"+

                                "<div class=\"dinner\">1,000</div>" +
                                "<div style=\"margin-top:5px " +
                                 "font-weight:bold\">times</div>"+
                            "</td>"+
                        "</tr>";

    Matcher matcher = p.matcher(can);

    if(matcher.find())
    {
       System.out.println(matcher.group(1));
    }
    else
       System.out.println("could not find");
  }
}