How can I parse a CSS file in Java, extracting specific rules based on selectors and retrieving their styles?

CSS Parsing in Java

In search of a CSS parser for Java, you may consider the W3C SAC interface and its implementations. However, finding tutorials and examples for these can be challenging.

Recommendation and Code Sample

I highly recommend using CSSParser, known for its excellent error feedback. Below is a modified sample code based on CSSParser:

<code class="java">import com.steadystate.css.parser.CSSOMParser;
import org.w3c.css.sac.InputSource;
import org.w3c.dom.css.CSSStyleSheet;
import org.w3c.dom.css.CSSRuleList;
import org.w3c.dom.css.CSSRule;
import org.w3c.dom.css.CSSStyleRule;
import org.w3c.dom.css.CSSStyleDeclaration;
import java.io.*;


public class CSSParserTest {

    protected static CSSParserTest oParser;

    public static void main(String[] args) {
        oParser = new CSSParserTest();
        if (oParser.Parse("design.css")) {
            System.out.println("Parsing completed OK");
        } else {
            System.out.println("Unable to parse CSS");
        }
    }

    public boolean Parse(String cssfile) {
        FileOutputStream out = null;
        PrintStream ps = null;
        boolean rtn = false;

        try {
            // Access CSS file as a resource (must be in package)
            InputStream stream = oParser.getClass().getResourceAsStream(cssfile);
            // Overwrite existing file contents
            out = new FileOutputStream("log.txt");

            if (out != null) {
                // Log file
                ps = new PrintStream(out);
                System.setErr(ps);
            } else {
                return rtn;
            }

            InputSource source = new InputSource(new InputStreamReader(stream));
            CSSOMParser parser = new CSSOMParser();
            CSSStyleSheet stylesheet = parser.parseStyleSheet(source, null, null);

            // Iterate through DOM and inspect
            CSSRuleList ruleList = stylesheet.getCssRules();
            ps.println("Number of rules: " + ruleList.getLength());

            for (int i = 0; i <p>This code allows you to parse a CSS file, access specific rules based on selectors, and retrieve their styles from the CSSStyleDeclaration object.</p></code>

The above is the detailed content of How can I parse a CSS file in Java, extracting specific rules based on selectors and retrieving their styles?. For more information, please follow other related articles on the PHP Chinese website!