Dimanaux/HtmlParser.java

## HtmlParser.java
import java.util.ArrayList;
import java.util.List;

class Main {
    public static void main(String[] args) {
        System.out.println(
                tokenize(
                        ("<html>\n" +
                                "  <h1>content1</h1>\n" +
                                "  <div>\n" +
                                "    <h2>content2</h2>\n" +
                                "  </div>\n" +
                                "</html>").replaceAll("\\s*", "")
                )
        );
    }

    static List<Token> tokenize(String html) {
        List<Token> tokens = new ArrayList<>();
        StringBuilder currentToken = new StringBuilder();
        for (int i = 0; i < html.length(); i++) {
            char symbol = html.charAt(i);
            if (symbol == '<') {
                if (currentToken.length() != 0) {
                    tokens.add(Token.text(currentToken.toString()));
                }
                currentToken = new StringBuilder();
            } else if (symbol == '>') {
                tokens.add(Token.tag(currentToken.toString()));
                currentToken = new StringBuilder();
            } else {
                currentToken.append(symbol);
            }
        }
        if (currentToken.length() != 0) {
            tokens.add(Token.text(currentToken.toString()));
        }
        return tokens;
    }
}

interface Token {
    static Token tag(String tag) {
        return tag.startsWith("/") ?
                new ClosingTag(tag.substring(1)) :
                new OpeningTag(tag);
    }

    static Token text(String text) {
        return new Text(text);
    }

    class Text implements Token {
        private final String value;

        public Text(String value) {
            this.value = value;
        }

        @Override
        public String toString() {
            return "(Text " + value + ")";
        }
    }

    class ClosingTag implements Token {
        private final String tag;

        public ClosingTag(String tag) {
            this.tag = tag;
        }

        @Override
        public String toString() {
            return "(Tag /" + tag + ")";
        }
    }

    class OpeningTag implements Token {
        private final String tag;

        public OpeningTag(String tag) {
            this.tag = tag;
        }

        @Override
        public String toString() {
            return "(Tag " + tag + ")";
        }
    }
}
	import java.util.ArrayList;
	import java.util.List;

	class Main {
	public static void main(String[] args) {
	System.out.println(
	tokenize(
	("<html>\n" +
	" <h1>content1</h1>\n" +
	" <div>\n" +
	" <h2>content2</h2>\n" +
	" </div>\n" +
	"</html>").replaceAll("\\s*", "")
	)
	);
	}

	static List<Token> tokenize(String html) {
	List<Token> tokens = new ArrayList<>();
	StringBuilder currentToken = new StringBuilder();
	for (int i = 0; i < html.length(); i++) {
	char symbol = html.charAt(i);
	if (symbol == '<') {
	if (currentToken.length() != 0) {
	tokens.add(Token.text(currentToken.toString()));
	}
	currentToken = new StringBuilder();
	} else if (symbol == '>') {
	tokens.add(Token.tag(currentToken.toString()));
	currentToken = new StringBuilder();
	} else {
	currentToken.append(symbol);
	}
	}
	if (currentToken.length() != 0) {
	tokens.add(Token.text(currentToken.toString()));
	}
	return tokens;
	}
	}

	interface Token {
	static Token tag(String tag) {
	return tag.startsWith("/") ?
	new ClosingTag(tag.substring(1)) :
	new OpeningTag(tag);
	}

	static Token text(String text) {
	return new Text(text);
	}

	class Text implements Token {
	private final String value;

	public Text(String value) {
	this.value = value;
	}

	@Override
	public String toString() {
	return "(Text " + value + ")";
	}
	}

	class ClosingTag implements Token {
	private final String tag;

	public ClosingTag(String tag) {
	this.tag = tag;
	}

	@Override
	public String toString() {
	return "(Tag /" + tag + ")";
	}
	}

	class OpeningTag implements Token {
	private final String tag;

	public OpeningTag(String tag) {
	this.tag = tag;
	}

	@Override
	public String toString() {
	return "(Tag " + tag + ")";
	}
	}
	}