[TIKA-1904] Tika 2.0 - Create Proxy Parser and Detectors

• Type: Improvement
• Status: In Progress
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: 2.0.0
• Assignee: Bob Paulin
• Reporter: Bob Paulin
• Created: 19/Mar/16 20:07
• Updated: 12/Apr/21 12:59

Description

There are several parsers and detectors that instantiate parsers and detectors that live in different modules in tika 2.0. As of now these modules have are dependent on other modules this includes:
tika-parser-office-module -> tika-parser-web-module, tika-parser-text-module, tika-parser-package-module
tika-parser-ebook-module -> tika-parser-text-module
tika-parser-journal-module -> tika-parser-pdf-module

May of these dependencies could be made optional by introducing the concept of proxy parser and detectors that would enable functionality if all the dependencies are included in the project but not throw a ClassNotFoundException if the dependent module was not include( ex. parse function would do nothing).

EX
Currently
ChmParser

private void parsePage(byte[] byteObject, ContentHandler xhtml) throws TikaException {// throws IOException
        InputStream stream = null;
        Metadata metadata = new Metadata();
        HtmlParser htmlParser = new HtmlParser();
        ContentHandler handler = new EmbeddedContentHandler(new BodyContentHandler(xhtml));// -1
        ParseContext parser = new ParseContext();
        try {
            stream = new ByteArrayInputStream(byteObject);
            htmlParser.parse(stream, handler, metadata, parser);
        } catch (SAXException e) {
            throw new RuntimeException(e);
        } catch (IOException e) {
            // Pushback overflow from tagsoup
        }
    }

Instead the HtmlParser could be Proxyed in the constructor

private final Parser htmlProxyParser;
    
    public ChmParser() {
        this.htmlProxyParser = new ParserProxy("org.apache.tika.parser.html.HtmlParser");
    }

And

private void parsePage(byte[] byteObject, ContentHandler xhtml) throws TikaException {// throws IOException
        InputStream stream = null;
        Metadata metadata = new Metadata();
        ContentHandler handler = new EmbeddedContentHandler(new BodyContentHandler(xhtml));// -1
        ParseContext parser = new ParseContext();
        try {
            stream = new ByteArrayInputStream(byteObject);
            htmlProxyParser.parse(stream, handler, metadata, parser);
        } catch (SAXException e) {
            throw new RuntimeException(e);
        } catch (IOException e) {
            // Pushback overflow from tagsoup
        }
    }