Using the Rome Java API to access metadata fields

Question

I've been using the Rome API to parse data from an XML feed pretty successfully so for, but have run in to a bit of a snag.

Given the following snippet of XML:

<entry>
<id>uniqueId</id>
<updated>2008-11-05T01:32:35Z</updated>
<mm:status xmlns:mm="http://contentprovider.com&amp;quot; available="true"/>
<title>Title</title>
...
...
</entry>

Using the SyndEntryImpl class I'm able to use its standard methods (getTitle, getPublishedDate, etc) to pull the title, id, updated date, etc, but havent figured out a way to get the metadata tag (<mm:status ...).

Getting a string representation of the feed entry would be an acceptable solution as I'd be able to use string functions to retrieve the information, but even with that I havent found an easy method.

Has anyone run in to this in the past?

Thanks.

Answer 1

If you're not already using it, v1.0RC1 has several parsing fixes. Maybe try upgrading?

Answer 2

Here is the raw classes for our code without much explanation (but it is late here!). This parses elements:

import com.sun.syndication.io.ModuleGenerator;
import com.sun.syndication.io.impl.DateParser;
import com.sun.syndication.feed.module.Module;

import java.util.Collections;
import java.util.Set;
import java.util.HashSet;

import org.jdom.Element;
import org.jdom.Namespace;

/**
 * Generates amplafi content in atom.
 */
public class AmplafiModuleGenerator implements ModuleGenerator {

    private static final Namespace NAMESPACE = Namespace.getNamespace("amplafi", AmplafiModule.URI);
    private static final Set<Namespace> NAMESPACES;

    static {
        Set<Namespace> namespaces = new HashSet<Namespace>();
        namespaces.add(NAMESPACE);
        NAMESPACES = Collections.unmodifiableSet(namespaces);
    }

    public String getNamespaceUri() {
        return AmplafiModule.URI;
    }

    public Set<Namespace> getNamespaces() {
        return NAMESPACES;
    }

    public void generate(Module module, Element element) {
        AmplafiModule myModule = (AmplafiModule) module;
        if (myModule.getStartDate() != null) {
            Element myElement = new Element("startDate", NAMESPACE);
            myElement.setText(DateParser.formatW3CDateTime(myModule.getStartDate()));
            element.addContent(myElement);
        }
        if (myModule.getEndDate() != null) {
            Element myElement = new Element("endDate", NAMESPACE);
            myElement.setText(DateParser.formatW3CDateTime(myModule.getEndDate()));
            element.addContent(myElement);
        }
    }
}

import com.sun.syndication.feed.module.Module;

import java.util.Date;

/**
 * Module for amplafi atom extension.
 */
public interface AmplafiModule extends Module {
    public static final String URI = "http://www.amplafi.com/namespace";

    public Date getStartDate();
    public void setStartDate(Date date);

    public Date getEndDate();
    public void setEndDate(Date date);
}

public class AmplafiModuleImpl extends ModuleImpl implements AmplafiModule {

    private Date startDate;
    private Date endDate;

    public AmplafiModuleImpl() {
        super(AmplafiModule.class, AmplafiModule.URI);
    }

    @Override
    public Class getInterface() {
        return AmplafiModule.class;
    }

    @Override
    public void copyFrom(Object obj) {
        AmplafiModule module = (AmplafiModule) obj;
        setStartDate(module.getStartDate());
        setEndDate(module.getEndDate());
    }

    @Override
    public Date getStartDate() {
        return startDate;
    }

    @Override
    public void setStartDate(Date date) {
        startDate = date;
    }

    @Override
    public Date getEndDate() {
        return endDate;
    }

    @Override
    public void setEndDate(Date date) {
        endDate = date;
    }

    @Override
    public String toString() {
        return "AmplafiModuleImpl{" +
                "startDate=" + startDate +
                ", endDate=" + endDate +
                '}';
    }
}

package com.amplafi.core.iomanagement.contentanalyzers.modules;

import java.util.Date;

import org.jdom.Element;
import org.jdom.Namespace;

import com.sun.syndication.feed.module.Module;
import com.sun.syndication.io.ModuleParser;
import com.sun.syndication.io.impl.DateParser;

/**
 * Parses amplafi content from atom.
 */
public class AmplafiModuleParser implements ModuleParser {

    public String getNamespaceUri() {
        return AmplafiModule.URI;
    }

    public Module parse(Element element) {
        Namespace myNamespace = Namespace.getNamespace(AmplafiModule.URI);
        AmplafiModule module = null;
        Date start = null;
        Date end = null;
        final Element startChild = element.getChild("startDate", myNamespace);
        if (startChild!=null) {
            start = DateParser.parseDate(startChild.getText());
        }
        final Element endChild = element.getChild("endDate", myNamespace);
        if (endChild!=null) {
            end = DateParser.parseDate(endChild.getText());
        }

        if (start!=null || end!=null) {
            module = new AmplafiModuleImpl();
            module.setStartDate(start);
            module.setEndDate(end);
        }
        return module;
    }
}

rome.properties:

atom_1.0.item.ModuleParser.classes=\
com.amplafi.core.iomanagement.contentanalyzers.modules.AmplafiModuleParser

atom_1.0.item.ModuleGenerator.classes=\
com.amplafi.core.iomanagement.contentanalyzers.modules.AmplafiModuleGenerator