what is regular expression and how to load html content using regular expressions android

I would use something like that:

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

class SimpleRegexExample {
    //TODO: Load your html content from file
    protected String html = "<html>\n"
            + "<head>\n"
            + "  <meta http-equiv=\"Content-Type\" content=\"text/html; charset=utf-8\">\n"
            + " <meta http-equiv=\"Content-Style-Type\" content=\"text/css\">\n"
            + "  <title></title>\n"
            + "   <meta name=\"Generator\" content=\"Cocoa HTML Writer\">\n"
            + "   <meta name=\"CocoaVersion\" content=\"1038.36\">\n"
            + "    <style type=\"text/css\">\n"
            + "        p.p1 {margin: 0.0px 0.0px 0.0px 0.0px; font: 26.0px Helvetica}\n"
            + "        p.p2 {margin: 0.0px 0.0px 0.0px 0.0px; font: 19.0px Helvetica}\n"
            + "        p.p3 {margin: 0.0px 0.0px 0.0px 0.0px; font: 12.0px Helvetica; min-height: 14.0px}\n"
            + "        p.p4 {margin: 0.0px 0.0px 0.0px 0.0px; font: 19.0px Helvetica; min-height: 23.0px}\n"
            + "        p.p5 {margin: 0.0px 0.0px 0.0px 0.0px; font: 12.0px Helvetica}\n"
            + "    </style>\n"
            + "</head>\n"
            + "\n"
            + "    <body>\n"
            + "      <p class=\"p1\"><b>{{BookName}}</b></p>\n"
            + "      <p class=\"p2\">by {{AuthorName}}</p>\n"
            + "      <p class=\"p3\"><br></p>\n"
            + "      <p class=\"p3\"><br></p>\n"
            + "      <p class=\"p4\"><span class=\"Apple-converted-space\"> </span></p>\n"
            + "      <p class=\"p5\">{{AuthorBio}}</p>\n"
            + "      <p class=\"p3\"><br></p>\n"
            + "      <p class=\"p3\"><br></p>\n"
            + "      <p class=\"p5\">{{Credits}}</p>\n"
            + "      <p class=\"p3\"><br></p>\n"
            + "      <p class=\"p3\"><br></p>\n"
            + "   </body>\n"
            + "</html>\n";

    public SimpleRegexExample() {
        // Split the html text into single lines
        StringTokenizer st = new StringTokenizer(html, "\n");

        // Initialize the regex
        String regex = "\\{\\{(.*?)\\}\\}";
        Pattern p = Pattern.compile(regex);

        // Parses each line
        while (st.hasMoreTokens()) {
            String token = st.nextToken();
            Matcher m = p.matcher(token);

            // Searches for matches
            while (m.find()) {
                if (m.group(1) != null) {
                    // TODO: Set here your replacement
                    html = html.replace("{{" + m.group(1) + "}}", m.group(1));
                }
            }
        }

        // Prints the result
        System.out.println(html);
    }

    public static void main(String[] args) {
        new SimpleRegexExample();
    }
}

Answers

A regular expressions is used to define and search for a pattern of text within a string.

Just check below link, a stackoverflow question with good explanation about Regular Expression usage.

How to use a regular expression and assign the result to variables in Android?

I hope it may help you.

Answers

to get content from xml/html the best way possible is XPath you can direct have a query to get the Element in DOM which contain your required data.

If the HTML is your content then i will suggest u to have an attribute which specify that it is book name.

you can use the XPath query like this

//p[@class='p1']/b

Condition for XPath is that the HTML file should have a proper closing Tag.

But if you want to use Regular Expression then use this

.+<p class=\"p1">

This expression will the match for class p1 and u need to get the end index for this expression to get the position of the b tag after p tag.

U can try your expression at

http://www.gskinner.com/RegExr/