ToStringBuilder.reflectionToString in the apache commons library gives this functionality.

e.g.

@Override
public String toString() {
    return ToStringBuilder.reflectionToString(this);
}

We are currently starting to use Guava as a Utility library and the class Objects.ToStringHelper provides nice utilities for printing out an objects values but unfortunately doesn’t support reflection yet. The support for reflection is discussed here

We decided to create a maven plugin to allow these tasks to be setup quickly on the command line (rather than having a collection of batch scripts to do this).

Our maven project is a multi module project with a layout similar to this:

• parent
  • web
    • core
    • producta
    • productb
    • webapp

The plugin was included in the parent pom, so that the environment setup commands could be easily excused from the parent folder.

However, the task was running multiple times. In fact, on closer inspection it was running 6 times which is exactly how many modules we have in our project.

A quick read of the Mojo API Specification pointed me to the javadoc annotation @requiresProject, setting this value to false (the default is true) prevents the goal being run for each module.

/**
 * <p>
 * Description of MOJO.
 * </p>
 *
 * @goal some-goalname
 * @requiresProject false
 *
 */
public class MyMojoThatDoesntRunManyTimes extends AbstractMojo
....

I recently had to upgrade some developers from docflex-re 1.8.0 to 1.8.5, this migration went fine.

For some reason it didn’t on my machine.

I received the following error:

java.lang.NoClassDefFoundError: org/apache/xml/resolver/CatalogManager

Anyway to cut a long story short it transpired that about a year ago whilst working on another project I had changed the jdk’s xerces jar by placing

• xalan.jar
• xercesImpl.jar
• xml-apis.jar
• serializer.jar

in the jre/lib/endorsed directory and completely forgot about it.

Removing these jars (which were probably older versions and I didn’t need in there anyway) and everything works fine.

I’d imagine putting a new version of xerces in endorsed would probably fix this as well….

When I ran the build it failed

With the message

Failed to execute goal org.apache.maven.plugins:maven-site-plugin:3.0-beta-3:site
(default-site) on project webapp: failed to get Reports: Could not find goal
'index' in plugin org.jvnet.mcvp:maven-css-validator-plugin:1.0.0-SNAPSHOT
among available goals report, validate -> [Help 1]

The plugin I was using (a version of the maven css validation plugin that I have modified to generate reports) was defined in the maven 3 build as follows

....
<plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-site-plugin</artifactId>
    <version>3.0-beta-3</version>
    <configuration>
        <reportPlugins>
         ....
            <plugin>
                <groupId>org.jvnet.mcvp</groupId>
                <artifactId>maven-css-validator-plugin</artifactId>
                <version>1.0.0-SNAPSHOT</version>
            </plugin>
         .....
        </reportPlugins>
   </configuration>
    ....
</plugin>

When the plugin was configured under maven 2 (using the legacy reporting i.e. being in a <reporting> tag) it ran fine.

The fix

The last part of the exception states: among available goals report, validate

The “report” goal creates the report therefore modifiynig the pom so it specifies the “report” goal in a report set seems to work.

....
<plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-site-plugin</artifactId>
    <version>3.0-beta-3</version>
    <configuration>
        <reportPlugins>
         ....
            <plugin>
                <groupId>org.jvnet.mcvp</groupId>
                <artifactId>maven-css-validator-plugin</artifactId>
                <version>1.0.0-SNAPSHOT</version>
                <reportSets>
                    <reportSet>
                            <reports>
                                <report>report</report>
                            </reports>
                    </reportSet>
                </reportSets>
            </plugin>
         .....
        </reportPlugins>
   </configuration>
    ....
</plugin>

I assume that the Could not find goal ‘index’ portion of the error means that if I set the name of the goal to index perhaps the reportsets are not necessary?

Update: Changing the goal to “index” does indeed remove the need for the reportsets, however for legacy plugins you may not be able to modify the source code!

Another thing to note is that this plugin uses the Maven Anno Mojo

e.g.

@MojoGoal("index")
@MojoPhase("site")
public class CssReportingMojo extends AbstractMavenReport {

But I dont think this has anything to do with error.

I hope this is useful to anyone upgrading as I couldn’t find any info on this exception out there

Using the maven xml-maven-plugin we can force the build to break when xml documents aren’t welformed.

Currently we are only doing it for facelets files (with a .xhtml extension): The xml snippet below shows the configuration of the plugin for xhtml files.

Add this to the plugins element in the build section.

<plugin>
	<groupId>org.codehaus.mojo</groupId>
	<artifactId>xml-maven-plugin</artifactId>
	<executions>
		<execution>
			<goals>
				<goal>validate</goal>
			</goals>
		</execution>
	</executions>
	<configuration>
		<validationSets>
			<validationSet>
				<dir>src/main/webapp</dir>
				<includes>
					<include>**/*.xhtml</include>
				</includes>
			</validationSet>
		</validationSets>
	</configuration>
</plugin>

To Do:

Really we should be validating all xml files. Also we should investigate turning on schema validation, especially for facelets files.

It will be interesting to see if there is a significant speed increase, as it will be nice to reduce the time of our main nightly build which usually takes about 90-95 minutes.

Luckily, Hudson / Jenkins makes it easy to test out running builds using different versions of Maven, so there is no reason not to test it out. Remember that the reporting has changed significantly in Maven 3, so while your project may build successfully in Maven 3 without any changes to the pom, you will need to make changes to get the reporting working. This article on the Maven Site Plugin explains the changes and shows an example of the new configuration.

A very simple workaround for this is to take advantage of the skip parameter in the Checkstyle configuration. You can add the Checkstyle configuration into your build section of the pom and set the skip parameter to true. This will then prevent Checkstyle from running every time you build your project.

Example code to use in your pom.xml

<properties>
	<checkstylePluginVersion>2.6</checkstylePluginVersion>
</properties>
<build>
	<plugins>
		<plugin>
			<groupId>org.apache.maven.plugins</groupId>
			<artifactId>maven-checkstyle-plugin</artifactId>
			<version>${checkstylePluginVersion}</version>
			<executions>
				<execution>
					<goals>
						<goal>check</goal>
					</goals>
				</execution>
			</executions>
			<configuration>
				<skip>true</skip>
				<configLocation>customCheckstyle.xml</configLocation>
			</configuration>
			<dependencies>
				<dependency>
					<groupId>com.company.web</groupId>
					<artifactId>company-maven-resources</artifactId>
					<version>1.0.0-SNAPSHOT</version>
				</dependency>
			</dependencies>
		</plugin>
	</plugins>
</build>
<reporting>
	<plugins>
		<plugin>
			<groupId>org.apache.maven.plugins</groupId>
			<artifactId>maven-checkstyle-plugin</artifactId>
			<version>${checkstylePluginVersion}</version>
			<configuration>
				<skip>false</skip>
				<configLocation>customCheckstyle.xml</configLocation>
			</configuration>
        </plugin>
	</plugins>
</reporting>

In the above, we are also using a custom artifact as a dependency of the Checkstyle plugin. This artifact is a jar file which contains the customCheckstyle.xml file. We have also got the example code above in a parent pom file, which is in it’s own maven module with a packaging of pom, and artifactId of custom-super-pom. This way, any modules can specify custom-super-pom as their parent. Then when imported into Eclipse, they will automatically have Ckeckstyle configured, which will be referencing the customCheckstyle.xml file. Also, as these modules will inherit the reporting section from the custom-super-pom, they don’t need to have Checkstyle specified in them. This is great, since now all the configuration is in one single pom, making it much easier to maintain and update.

To change the customCheckstyle.xml file, all you would need to do is edit the file within the company-maven-resources artifact, and then install the artifact into your local repository. If you are also using a repository manager like Nexus, then deploy it there also. The following command takes care of it all:

mvn clean deploy

We have used a snapshot version for our super pom and custom maven resources modules so that when these are changed, we can just deploy new versions on top of the older ones. Then any modules that reference these snapshots should pick up the latest version of the artifcats the next time they are built.  You can also force the update to happen by passing in -U on the command line when building, if you find that it doesn’t seem to be checking for updates to snapshots automatically.

• eCobertura – Allows Cobertura code coverage to be run from the IDE directly
• eclipse-cs – Enforces coding standards using the CheckStyle tool
• PMD – Scans Java code and reports potential problems
• M2Eclipse – Maven integration from Sonatype
  • m2e-extensions – Works with version 0.10 of the M2Eclipse plugin. Can automatically setup Checkstyle and PMD configuration for Eclipse to match their configuration from the pom file if they are in it
  • m2e-code-quality – Same as m2e-extensions, except this one works with version 0.12 of the M2Eclipse plugin

Note: both m2e-extensions and m2e-code-quality only work if you have the pmd and checkstyle plugins configured in the build section of the pom. They do not currently work if you have pmd and checkstyle configured in the reporting section of the pom.

e.g. JSF h:selectOneRadio tag

<h:selectOneRadio id="aRadio">
	<f:selectItems value="#{radioOptions.items}" />
</h:selectOneRadio>

Code for #{radioOptions}

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

import javax.faces.model.SelectItem;

import org.jboss.seam.ScopeType;
import org.jboss.seam.annotations.Name;
import org.jboss.seam.annotations.Scope;

@Name("radioOptions")
@Scope(ScopeType.APPLICATION)
public class RadioOptions
{
	public List<SelectItem> items = new ArrayList<SelectItem>();

	public RadioOptions()
	{
		items.add(new SelectItem("1", "label 1"));
		items.add(new SelectItem("2", "label 2"));
		items.add(new SelectItem("3", "label 3"));
	}

	public List<SelectItem> getItems()
	{
		return items;
	}

	public void setItems(List<SelectItem> items)
	{
		this.items = items;
	}
}

Note: I’m using jboss seam in the example above, but you could easily remove the seam annotations and define the bean in using jsf managed beans or faces config etc. Also the examples here are a bit mickey mouse and could be better.

Under JSF 1.2 will be rendered as

<table id="myForm:aRadio">
	<tr>
		<td>
			<input type="radio" name="myForm:aRadio" id="myForm:aRadio:0" value="1" />
			<label for="myForm:aRadio:0">Label 1</label>
		</td>
		<td>
			<input type="radio" name="myForm:aRadio" id="myForm:aRadio:1" value="2" />
			<label for="myForm:aRadio:1">Label 2</label>
		</td>
		<td>
			<input type="radio" name="myForm:aRadio" id="myForm:aRadio:2" value="3" />
			<label for="myForm:aRadio:2">Label 3</label>
		</td>
	</tr>
</table>

Anyway this limitation is well known and as a result we’ve been using the apache tomahawk t:selectOneRadio (using the layout=”spread” attribute) and t:radio tags to provide more flexible layouts which can be styled by css.

Iterating through a list of select items

There are times when I want to render the radio buttons in a flexible fashion (offered by t:radio) using a loop tag such as t:dataList or a4j:repeat e.g.

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xmlns:ui="http://java.sun.com/jsf/facelets" xmlns:h="http://java.sun.com/jsf/html" xmlns:f="http://java.sun.com/jsf/core" xmlns:fn="http://java.sun.com/jsp/jstl/functions" xmlns:c="http://java.sun.com/jstl/core" xmlns:t="http://myfaces.apache.org/tomahawk" xmlns:a4j="https://ajax4jsf.dev.java.net/ajax">
<f:view>
<h:form id="myForm">
	<!-- radio button, layout spread  -->
	<t:selectOneRadio id="myRadio" forceId="true" layout="spread">
		<f:selectItems value="#{radioOptions.items}" />
	</t:selectOneRadio>

	<!-- data list, loops through all the radio button options -->
	<t:dataList var="helper" value="#{radioOptions.items}" rowIndexVar="idx">
		<!-- example html, not constrained to table layout -->
		<h1>Heading</h1>
		<t:radio for="myRadio" index="#{idx}"/>
		<h1>Another Heading</h1>
	</t:dataList>
</h:form>
</f:view>
</html>

Unfortunately this doesn’t work and throws:

java.lang.IllegalStateException: Could not find component 'myRadio' (calling findComponent on component 'myForm:j_id3:0:j_id5')

The Fix:

I almost always forget this which is why im blogging about it,

<t:radio for="myRadio" index="#{idx}"/>

needs to be replaced with

<t:radio for=":myForm:myRadio" index="#{idx}"/>

The tomahawk t:radio component must have the fully qualified component name of the t:selectOneRadio name otherwise it cannot find it.

Since the form is defined as:

<h:form id="myForm">

:myForm needs to be prefixed to the for attribute of the t:radio giving :myForm:myRadio

I take absolutely no credit for this because its explained here and on the Myfaces wiki this article is merely a note to self.

Btw, the above works with a4j:repeat as well as t:datalist

Currently tomahawk isn’t working in JSF 2.0 which is a shame as we are looking to upgrade very soon. Hopefully a decent radio button will become part of JSF 2 at some point.

The tomahawk component library now works with JSF 2.0

Update: Fully Qualified JSF Name

A bit of searching around on the web took me to Lincoln Baxter’s blog where he mentions rendering components outside of the form and explains that the first “:” tells JSF to start looking from the very top of the JSF View Root. Thanks for that!

org.apache.xerces.impl.dv.DVFactoryException:
DTD factory class org.apache.xerces.impl.dv.dtd.DTDDVFactoryImpl does not extend from DTDDVFactory.

This basically meant that an incompatible version of xerces was trying to be run. We have everything set to use Java 1.6, which ships with its own version of xerces. After some debugging, it was tracked down to the maven-site-plugin which we had recently upgraded to use version 2.1 of the plugin by specifying it in our pom file like so:

<pluginManagement>
	<plugins>
		<plugin>
			<groupId>org.apache.maven.plugins</groupId>
			<artifactId>maven-site-plugin</artifactId>
			<version>2.1</version>
		</plugin>
	</plugins>
</pluginManagement>

The maven-site-site plugin has the following dependency structure:

• org.apache.maven.plugins:maven-site-plugin:maven-plugin:2.1
  • org.apache.maven.doxia:doxia-module-xhtml:jar:1.1.2 (compile)
    • org.apache.maven.doxia:doxia-core:jar:1.1.2 (compile)
      • xerces:xercesImpl:jar:2.8.1 (compile)

It is the dependency of the xercesImpl jar 2.8.1 that is the problem. To get around this issue, you can tell the maven-site-plugin to exclude a particular dependency. This can be done like so:

<pluginManagement>
	<plugins>
		<plugin>
			<groupId>org.apache.maven.plugins</groupId>
			<artifactId>maven-site-plugin</artifactId>
			<version>2.1</version>
			<dependencies>
				<dependency>
					<groupId>org.apache.maven.doxia</groupId>
					<artifactId>doxia-core</artifactId>
					<version>1.1.2</version>
					<exclusions>
						<exclusion>
							<groupId>xerces</groupId>
							<artifactId>xercesImpl</artifactId>
						</exclusion>
					</exclusions>
				</dependency>
			</dependencies>
		</plugin>
	</plugins>
</pluginManagement>

There are a couple of maven reporting plugins that we found produced this exception when run with maven-site-plugin 2.1. These plugins are:

• DocFlex/XML Maven Plugin
• Canoo Webtest Maven Plugin

If you use an older version of the maven-site-plugin then the above mentioned reporting plugins should work ok. It is only when specifying a version of 2.1 or above that the exception occurs.

Some of the solutions suggested on the net didn’t work for us, like adding the xercesImpl jar as a dependency to the actual reporting plugin in question, so hopefully the solution mentioned in this post is helpful.