Using GeoRss

I started using Marc’s GeoRss module as part of a webapp that needed to send geometries to an OpenLayers (JavaScript) client. Here are the steps I took to get GeoRss working.

* Read the documentation at http://georss.geonames.org/

* Used the following maven command to setup a basic project.

[sourcecode language=”bash”]
#!/bin/bash

PROJECT=twotrack

mvn archetype:generate \
-DarchetypeGroupId=org.apache.maven.archetypes \
-DarchetypeArtifactId=maven-archetype-profiles \
-Dversion=1.0.0-SNAPSHOT \
-DartifactId=$PROJECT-georss \
-DgroupId=net.fnarg.$PROJECT
[/sourcecode]

* Added GeoRss dependencies to the maven generated pom.xml

[sourcecode language=”xml”]
<dependency>
<groupId>rome</groupId>
<artifactId>rome</artifactId>
<version>0.9</version>
</dependency>
<dependency>
<groupId>org.geonames</groupId>
<artifactId>georss-rome</artifactId>
<version>0.9.8</version>
</dependency>
[/sourcecode]

* Grabbed the jars for Eclipse

[sourcecode language=”xml”]
mvn eclipse:eclipse
[/sourcecode]

* Extended Marc’s examples by wrapping some setters and getters for Spring

[sourcecode lanuage=”java”]
package net.fnarg.twotrack;

import java.net.URL;
import java.util.ArrayList;
import java.util.List;

import com.sun.syndication.io.XmlReader;
import com.sun.syndication.io.SyndFeedInput;
import com.sun.syndication.io.SyndFeedOutput;

import com.sun.syndication.feed.synd.SyndEntry;
import com.sun.syndication.feed.synd.SyndEntryImpl;
import com.sun.syndication.feed.synd.SyndFeed;
import com.sun.syndication.feed.synd.SyndFeedImpl;

import com.sun.syndication.feed.module.georss.GeoRSSUtils;
import com.sun.syndication.feed.module.georss.GeoRSSModule;
import com.sun.syndication.feed.module.georss.W3CGeoModuleImpl;
import com.sun.syndication.feed.module.georss.geometries.Position;

public class GeoRssFeed {
private SyndFeed feed;

public GeoRssFeed() {
feed = new SyndFeedImpl();
}

public GeoRssFeed(String url) throws Exception {
feed = new SyndFeedImpl();
this.setEntries(url);
}

public String getFeed() throws Exception {
return new SyndFeedOutput().outputString(feed);
}

public void setFeed() throws Exception {
feed.setFeedType("rss_2.0");
feed.setTitle("Two Track");
feed.setDescription("A tool for modelling toy train tracks");
feed.setLink("http://www.fnarg.net/twotrack/");
}

public void setEntries(String url) throws Exception {
SyndFeedInput input = new SyndFeedInput();
feed = input.build(new XmlReader(new URL(url)));
}

public List<SyndEntry> getEntries() {
return feed.getEntries();
}

public void setEntries(List<Position> positions) {
List<SyndEntry> entries = new ArrayList<SyndEntry>();
for (Position p : positions) {
SyndEntry entry = new SyndEntryImpl();
GeoRSSModule geoRSSModule = new W3CGeoModuleImpl();
geoRSSModule.setPosition(p);
entry.getModules().add(geoRSSModule);
entries.add(entry);
}
feed.setEntries(entries);
}
}
[/sourcecode]

* Wrote a test class to verify inputs/outputs

[sourcecode language=”java”]
package net.fnarg.twotrack;

import java.util.ArrayList;
import java.util.List;

import com.sun.syndication.feed.module.georss.GeoRSSModule;
import com.sun.syndication.feed.module.georss.GeoRSSUtils;
import com.sun.syndication.feed.module.georss.geometries.Position;
import com.sun.syndication.feed.synd.SyndEntry;

public class TestGeoRssReadWriter {

private static GeoRssFeed geoRssFeed;

/**
* Tester for the GeoRssFeed class
* @author gavin
*/
public static void main(String[] args) throws Exception {
// load XML file into memory
geoRssFeed = new GeoRssFeed("http://www.openlayers.org/dev/examples/xml/track1.xml");
// get and display the geometries
List<SyndEntry> entries = geoRssFeed.getEntries();
for (SyndEntry entry : entries) {
GeoRSSModule geoRSSModule = GeoRSSUtils.getGeoRSS(entry);
System.out.println(entry.getTitle() + " : lat="
+ geoRSSModule.getPosition().getLatitude() + ",lng="
+ geoRSSModule.getPosition().getLongitude() + ", desc="
+ entry.getDescription().getValue() + "; time="
+ entry.getPublishedDate());
}
// set mandatory XML fields with our Two Track headers
geoRssFeed.setFeed();
// output
System.out.println(geoRssFeed.getFeed());
// update the feed
Position p1 = new Position(54.2, 12.4);
Position p2 = new Position(55.2, 13.4);
List<Position> newEntries = new ArrayList<Position>();
newEntries.add(p1);
newEntries.add(p2);
// replace the geometries
geoRssFeed.setEntries(newEntries);
// check new output
System.out.println(geoRssFeed.getFeed());
}
}
[/sourcecode]

Maven refusing to compile Spring project due to annotations

The fix for the following issue is here http://maven.40175.n5.nabble.com/Maven-refusing-to-compile-Spring-project-due-to-annotations-tp4309204p4309211.html. Duh!


I’m running Eclipse and Maven on a Mac. Here’s my version of Maven

[sourcecode language=”bash”]
$ mvn -version
Apache Maven 2.2.1 (r801777; 2009-08-06 20:16:01+0100)
Java version: 1.6.0_22
Java home: /System/Library/Java/JavaVirtualMachines/1.6.0.jdk/Contents/Home
Default locale: en_US, platform encoding: MacRoman
OS name: "mac os x" version: "10.5.8" arch: "x86_64" Family: "mac"
[/sourcecode]

What I’m trying to do is use Maven to compile my Spring project (it builds fine in Eclipse) so I can deploy the war to a Tomcat. I setup my pom.xml (see below) and asked mvn to create the package. The build failed with the following error:

[sourcecode]
Compilation failure
/path/to/WelcomeController.java:[7,1] annotations are not supported in -source 1.3
(use -source 5 or higher to enable annotations)
@Controller
[/sourcecode]

Doing mvn compile gives the same error. Google showed me that this was a known problem with Maven with the fix explained here:

http://maven.apache.org/plugins/maven-compiler-plugin/howto.html

I can’t see why the fix isn’t working for me. In desparation I followed these instructions:

http://pwong-tipsandtricks.blogspot.com/2009/02/install-and-test-maven-on-centos-52.html and put a fresh maven on my Linux box. The build failed with the same error, so it seems that my pom.xml is the culprit. But how? Here’s the pom.

[sourcecode language=”xml”]
<project xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0
http://maven.apache.org/maven-v4_0_0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>net.fnarg.twotrack</groupId>
<artifactId>twotrack-webapp</artifactId>
<packaging>war</packaging>
<version>1.0-SNAPSHOT</version>
<name>Twotrack Webapp</name>
<url>http://maven.apache.org</url>

<properties>
<spring.version>3.0.5.RELEASE</spring.version>
<appName>twotrack</appName>
<tomcatPackageName>apache-tomcat-twotrack</tomcatPackageName>
<runas.username>twotrack</runas.username>
<runas.group>twotrack</runas.group>
</properties>

<repositories>
<repository>
<id>com.springsource.repository.bundles.release</id>
<name>SpringSource Enterprise Bundle Repository – SpringSource Bundle
Releases</name>
<url>http://repository.springsource.com/maven/bundles/milestone</url>
</repository>
<repository>
<id>com.springsource.repository.bundles.external</id>
<name>SpringSource Enterprise Bundle Repository – External Bundle
Releases</name>
<url>http://repository.springsource.com/maven/bundles/external</url>
</repository>
</repositories>

<dependencies>
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>jstl</artifactId>
<version>1.2</version>
</dependency>
<dependency>
<groupId>javax.el</groupId>
<artifactId>el-api</artifactId>
<version>1.0</version>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>org.apache.taglibs</groupId>
<artifactId>com.springsource.org.apache.taglibs.standard</artifactId>
<version>1.1.2</version>
</dependency>
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>servlet-api</artifactId>
<version>2.5</version>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-context</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-web</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-webmvc</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>3.8.1</version>
<scope>test</scope>
</dependency>
</dependencies>

<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-eclipse-plugin</artifactId>
<configuration>
<source>1.6</source>
<target>1.6</target>
</configuration>
</plugin>
</plugins>
<finalName>twotrack</finalName>
<resources>
<resource>
<directory>src/main/resources</directory>
<filtering>true</filtering>
</resource>
<resource>
<directory>src/main/webapp</directory>
<filtering>true</filtering>
</resource>
</resources>
</build>
</project>
[/sourcecode]

Install Apache and make a web page

To make a web page you need both a web server and a text editor. The webserver we’re going to use is Apache. There are lots of choices for a text editor but many web developers use Text Pad.

  • Install Text Pad from here
  • http://www.textpad.com/

  • Apache is bit more complicated
  • The full instructions are here, but they are fairly detailed.
    http://httpd.apache.org/docs/2.1/platform/windows.html

  • These are probably a friendlier place to start.
  • http://webdesign.about.com/cs/apache/a/aainstapachewin.htm

    We’re going to run Apache on localhost. This is a special name for a computer that let’s us access our own machine as if it were a server. On localhost Apache can only send pages to one computer, but that’s ok because it’s all we need for development.

  • Install Apache as above, then type
  • http://localhost/ in your browser

    Once our website is built the files will be transferred to another Apache that will serve the page onto the Internet.

    Rayburns don’t burn (properly)

    In response to the completely rubbish performance of the most single major investment I’ve made in the last ten years I did this.
    the inside of my rayburn cooker

    See, it’s been cleaned. Completely and absolutely free of any carbon. If you see even a speck of carbon, login and comment. The cooker has brand new wicks and should now burn for twelve months without further ado .. let’s fold arms, stand back and wait.