MainClass.java Source code

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Here is the source code for MainClass.java

Source

import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.Writer;
import java.net.URL;

import javax.swing.text.MutableAttributeSet;
import javax.swing.text.html.HTML;
import javax.swing.text.html.HTMLEditorKit;

public class MainClass {
    private static void parse(URL url, String encoding) throws IOException {
        ParserGetter kit = new ParserGetter();
        HTMLEditorKit.Parser parser = kit.getParser();
        InputStream in = url.openStream();
        InputStreamReader r = new InputStreamReader(in, encoding);
        HTMLEditorKit.ParserCallback callback = new Outliner(new OutputStreamWriter(System.out));
        parser.parse(r, callback, true);
    }

    public static void main(String[] args) throws Exception {

        ParserGetter kit = new ParserGetter();
        HTMLEditorKit.Parser parser = kit.getParser();

        String encoding = "ISO-8859-1";
        URL url = new URL("http://www.java2s.com");
        InputStream in = url.openStream();
        InputStreamReader r = new InputStreamReader(in, encoding);
        // parse once just to detect the encoding
        HTMLEditorKit.ParserCallback doNothing = new HTMLEditorKit.ParserCallback();
        parser.parse(r, doNothing, false);

        parse(url, encoding);
    }

}

class Outliner extends HTMLEditorKit.ParserCallback {

    private Writer out;

    private int level = 0;

    private boolean inHeader = false;

    private static String lineSeparator = System.getProperty("line.separator", "\r\n");

    public Outliner(Writer out) {
        this.out = out;
    }

    public void handleStartTag(HTML.Tag tag, MutableAttributeSet attributes, int position) {

        int newLevel = 0;
        if (tag == HTML.Tag.H1)
            newLevel = 1;
        else if (tag == HTML.Tag.H2)
            newLevel = 2;
        else if (tag == HTML.Tag.H3)
            newLevel = 3;
        else if (tag == HTML.Tag.H4)
            newLevel = 4;
        else if (tag == HTML.Tag.H5)
            newLevel = 5;
        else if (tag == HTML.Tag.H6)
            newLevel = 6;
        else
            return;

        this.inHeader = true;
        try {
            if (newLevel > this.level) {
                for (int i = 0; i < newLevel - this.level; i++) {
                    out.write("<ul>" + lineSeparator + "<li>");
                }
            } else if (newLevel < this.level) {
                for (int i = 0; i < this.level - newLevel; i++) {
                    out.write(lineSeparator + "</ul>" + lineSeparator);
                }
                out.write(lineSeparator + "<li>");
            } else {
                out.write(lineSeparator + "<li>");
            }
            this.level = newLevel;
            out.flush();
        } catch (IOException ex) {
            System.err.println(ex);
        }

    }

    public void handleEndTag(HTML.Tag tag, int position) {

        if (tag == HTML.Tag.H1 || tag == HTML.Tag.H2 || tag == HTML.Tag.H3 || tag == HTML.Tag.H4
                || tag == HTML.Tag.H5 || tag == HTML.Tag.H6) {
            inHeader = false;
        }

        // work around bug in the parser that fails to call flush
        if (tag == HTML.Tag.HTML)
            this.flush();

    }

    public void handleText(char[] text, int position) {

        if (inHeader) {
            try {
                out.write(text);
                out.flush();
            } catch (IOException ex) {
                System.err.println(ex);
            }
        }

    }

    public void flush() {
        try {
            while (this.level-- > 0) {
                out.write(lineSeparator + "</ul>");
            }
            out.flush();
        } catch (IOException e) {
            System.err.println(e);
        }
    }

    private static void parse(URL url, String encoding) throws IOException {
        ParserGetter kit = new ParserGetter();
        HTMLEditorKit.Parser parser = kit.getParser();
        InputStream in = url.openStream();
        InputStreamReader r = new InputStreamReader(in, encoding);
        HTMLEditorKit.ParserCallback callback = new Outliner(new OutputStreamWriter(System.out));
        parser.parse(r, callback, true);
    }

}

class ParserGetter extends HTMLEditorKit {
    public HTMLEditorKit.Parser getParser() {
        return super.getParser();
    }
}