Groovy example source code file (BloglinesClient.groovy)

This example Groovy source code file (BloglinesClient.groovy) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Groovy tags/keywords

awt, bloglines, bloglines, defaultmutabletreenode, defaultmutabletreenode, email, error, exception, feed, feed, gui, item, item, jtree, log, my, string, swing, tree

The Groovy BloglinesClient.groovy source code

/*
 * BloglinesClient.groovy - an example of the Bloglines Web Services
 *
 * Written by Marc Hedlund <marc@precipice.org>, September 2004.
 * 
 * Mangled by John Wilson September 2004
 *
 * Small adaptions to JSR Version by Dierk Koenig, June 2005
 *
 * Used in Marc's article at:
 *    http://www.oreillynet.com/pub/a/network/2004/09/28/bloglines.html
 *
 * Requirements:
 *   - install Groovy as detailed at <http://groovy.codehaus.org/>.
 *   - put commons-httpclient-3.0-rc3.jar into GROOVY_HOME/lib
 *       see <http://jakarta.apache.org/commons/httpclient/>.
 *       note: this is currently designed for HttpClient2.x and not HttpClient3.x
 *
 * To Launch:
 *   groovy BloglinesClient.groovy
 *
 * This work is licensed under the Creative Commons Attribution
 * License. To view a copy of this license, visit
 * <http://creativecommons.org/licenses/by/2.0/> or send a letter to
 * Creative Commons, 559 Nathan Abbott Way, Stanford, California 94305, USA.
 */

import groovy.swing.SwingBuilder
import java.awt.BorderLayout
import javax.swing.JOptionPane
import javax.swing.JSplitPane
import javax.swing.JTree
import javax.swing.ListSelectionModel
import javax.swing.WindowConstants
import javax.swing.tree.DefaultMutableTreeNode
import javax.swing.tree.TreeSelectionModel
import org.apache.commons.httpclient.HttpClient
import org.apache.commons.httpclient.UsernamePasswordCredentials
import org.apache.commons.httpclient.methods.GetMethod

//Set up global variables and data types
server = 'rpc.bloglines.com'

class Feed {
    def name;
    def id;
    def unread;

    String toString() { (unread == "0" ? name : "${name} (${unread})") }
}

class Item {
    def title;
    def description;

    String toString() { title }
}

// Ask the user for account information (using simple dialogs)
email = JOptionPane.showInputDialog(null, "Email address:", "Log in to Bloglines",
        JOptionPane.QUESTION_MESSAGE)
password = JOptionPane.showInputDialog(null, "Password:", "Log in to Bloglines",
        JOptionPane.QUESTION_MESSAGE)

//Use HTTPClient for web requests since the server requires authentication
client = new HttpClient()
credentials = new UsernamePasswordCredentials(email, password)
client.state.setCredentials("Bloglines RPC", server, credentials)

abstractCallBloglines = { method, parameters ->
    url = "http://${server}/${method}${parameters}"
    try {
        get = new GetMethod(url)
        get.doAuthentication = true
        client.executeMethod(get)
        return get.responseBodyAsStream
    } catch (Exception e) {
        println "Error retrieving <${url}>: ${e}"
    }
}

callBloglinesListsub = abstractCallBloglines.curry('listsubs', '')
callBloglinesGetItems = abstractCallBloglines.curry('getitems')

//Get the list of subscriptions and parse it into a GPath structure
opml = new XmlSlurper().parse(callBloglinesListsub())

//Descend into the subscription outline, adding to the feed tree as we go
treeTop = new DefaultMutableTreeNode("My Feeds")
parseOutline(opml.body.outline.outline, treeTop)

def parseOutline(parsedXml, treeLevel) {
    parsedXml.each { outline ->
        if (outline['@xmlUrl'] != null) {  // this is an individual feed
            feed = new Feed(name: outline['@title'], id: outline['@BloglinesSubId'],
                    unread: outline['@BloglinesUnread'])
            treeLevel.add(new DefaultMutableTreeNode(feed))
        } else {  // this is a folder of feeds
            folder = new DefaultMutableTreeNode(outline['@title'])
            parseOutline(outline.outline, folder)
            treeLevel.add(folder)
        }
    }
}

//Build the base user interface objects and configure them
swing = new SwingBuilder()
feedTree = new JTree(treeTop)
itemList = swing.list()
itemText = swing.textPane(contentType: 'text/html', editable: false)
model = feedTree.selectionModel
model.selectionMode = TreeSelectionModel.SINGLE_TREE_SELECTION
itemList.selectionMode = ListSelectionModel.SINGLE_SELECTION

//Set up the action closures that will react to user selections
listItems = { feed ->
    rssStream = callBloglinesGetItems("?s=${feed.id}&n=0")
    if (rssStream != null) {
        try {
            rss = new XmlSlurper().parse(rssStream)
            itemList.listData = rss.channel.item.collect(new Vector()) {
                new Item(title: it.title, description: it.description)
            }
            feed.unread = "0"  // update the unread item count in the feed list
        } catch (Exception e) {
            println "Error during <${feed.name}> RSS parse: ${e}"
        }
    }
}

feedTree.valueChanged = { event ->
    itemText.text = ""  // clear any old item text
    node = (DefaultMutableTreeNode) feedTree.getLastSelectedPathComponent()
    if (node != null) {
        feed = node.userObject
        if (feed instanceof Feed && feed.unread != "0") {
            listItems(feed)
        }
    }
}

itemList.valueChanged = { event ->
    item = event.source.selectedValue
    if (item instanceof Item && item?.description != null) {
        itemText.text = "<html>${item.description}"
    }
}

//Put the user interface together and display it
gui = swing.frame(title: 'Bloglines Client', location: [100, 100], size: [800, 600],
        defaultCloseOperation: WindowConstants.EXIT_ON_CLOSE) {
    panel(layout: new BorderLayout()) {
        splitPane(orientation: JSplitPane.HORIZONTAL_SPLIT, dividerLocation: 200) {
            scrollPane {
                widget(feedTree)
            }
            splitPane(orientation: JSplitPane.VERTICAL_SPLIT, dividerLocation: 150) {
                scrollPane(constraints: BorderLayout.CENTER) {
                    widget(itemList)
                }
                scrollPane(constraints: BorderLayout.CENTER) {
                    widget(itemText)
                }
            }
        }
    }
}

gui.show()