August 24, 2009

Firefox 3.5 brakes Eclipse 3.4

In mine previous blog I was writing about how to install Firefox 3.5 on Ubuntu 9.04, but that also had some unwanted side effect - it broke the Eclipse 3.4 installation!! Read more about http://hello-world-2-0.blogspot.com/2009/08/firefox-upgrade-broke-eclipse.html.

Configure Log4J DailyRollingFileAppender with custom PatternLayout

For some time I haven been planning to learn the mystic configuration of the org.apache.log4j.PatternLayout for Log4j and finally I have taken the time to do so.
  • c - The calling class name, if giving without precision is the fully qualified name returned.
  • C - The fully qualified class name.
  • d - The date of the logging request, can be formatted with java.text.SimpleDateFormat, i.e. %d{yyyy-MM-dd}
  • F - The name of the calling File.
  • l - The location information, same as %C%M(%F:%L). This can be slow.
  • L - The calling class line number
  • m - The logging message.
  • M - The calling class method.
  • n - The platform dependent line separator.
  • p - The logging Level.
  • r - The relative date in millisecond since application start.
  • t - The invoking thread.
  • [x|X] - the Message Diagnostic (MDC) information.

Now for some example. To be compliant with large open-source project such as Hibernate Annotation we use SLF4J as Logger interface. To use SLF4J, simply add the following to your Maven pom.xml
<dependency>

<groupId>org.slf4j</groupId>

<artifactId>slf4j-log4j12</artifactId>

<version>1.4.2</version>

</dependency>

And if we run 'mvn dependency:tree', we see that the artifact also contains the log4j.jar implementation.
[INFO] Scanning for projects...

[INFO] Searching repository for plugin with prefix: 'dependency'.

[INFO] ------------------------------------------------------------------------

[INFO] Building Log4J Test

[INFO]    task-segment: [dependency:tree]

[INFO] ------------------------------------------------------------------------

[INFO] [dependency:tree]

[INFO] se.msc.development:log4j-test:jar:1.0-SNAPSHOT

[INFO] +- org.slf4j:slf4j-log4j12:jar:1.4.2:compile

[INFO] |  +- org.slf4j:slf4j-api:jar:1.4.2:compile

[INFO] |  \- log4j:log4j:jar:1.2.13:compile

[INFO] +- javax.mail:mail:jar:1.4.1:compile

[INFO] |  \- javax.activation:activation:jar:1.1.1:compile

[INFO] \- junit:junit:jar:4.5:test

[INFO] ------------------------------------------------------------------------

[INFO] BUILD SUCCESSFUL

[INFO] ------------------------------------------------------------------------

[INFO] Total time: 4 seconds

[INFO] Finished at: Mon Aug 24 03:05:27 CEST 2009

[INFO] Final Memory: 12M/144M

[INFO] ------------------------------------------------------------------------

And here follows an example of how to use SLF4J in your code.
package se.msc.log4j;

import org.junit.Test;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class Log4JTest {
//import org.slf4j.Logger;
//import org.slf4j.LoggerFactory;
private static final Logger log = LoggerFactory.getLogger(Log4JTest.class);

//import org.apache.log4j.Logger;
//private static final Logger log = Logger.getLogger(Log4JTest.class);

@Test
public void testFoo() throws Exception {
log.info("Info log message.");
log.error("Fatal log message.", new NullPointerException("Null pointer exceptopn."));
}

}

An the log4j configuration file log4j.properties
# configure the root logger
log4j.rootLogger=INFO, STDOUT, DAILY

# configure the console appender
log4j.appender.STDOUT=org.apache.log4j.ConsoleAppender
log4j.appender.STDOUT.Target=System.out
log4j.appender.STDOUT.layout=org.apache.log4j.PatternLayout
log4j.appender.STDOUT.layout.conversionPattern=%d{yyyy-MM-dd HH:mm:ss.SSS} [%p] %c:%L - %m%n

# configure the daily rolling file appender
log4j.appender.DAILY=org.apache.log4j.DailyRollingFileAppender
log4j.appender.DAILY.File=/tmp/log4j/log4jtest.log
log4j.appender.DAILY.DatePattern='.'yyyy-MM-dd
log4j.appender.DAILY.layout=org.apache.log4j.PatternLayout
log4j.appender.DAILY.layout.conversionPattern=%d{yyyy-MM-dd HH:mm:ss.SSS} [%p] %c:%L - %m%n

and when running the JUnit test:
2009-08-24 03:00:47.775 [INFO] se.msc.log4j.Log4JTest:18 - Info log message.
2009-08-24 03:00:47.783 [ERROR] se.msc.log4j.Log4JTest:19 - Fatal log message.
java.lang.NullPointerException: Null pointer exceptopn.
at se.msc.log4j.Log4JTest.testFoo(Log4JTest.java:19)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:44)
at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:15)
at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:41)
at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:20)
at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:28)
at org.junit.internal.runners.statements.RunAfters.evaluate(RunAfters.java:31)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:73)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:46)
at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:180)
at org.junit.runners.ParentRunner.access$000(ParentRunner.java:41)
at org.junit.runners.ParentRunner$1.evaluate(ParentRunner.java:173)
at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:28)
at org.junit.internal.runners.statements.RunAfters.evaluate(RunAfters.java:31)
at org.junit.runners.ParentRunner.run(ParentRunner.java:220)
at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:45)
at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:460)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:673)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:386)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:196)

And now I final word about the DatePattern for the org.apache.log4j.DailyRollingFileAppender:
log4j.appender.DAILY.DatePattern='.'yyyy-MM-dd-a

Rolls over at midnight each day, as is the expected behaviour of a rolling log.

August 19, 2009

Bundle a Common Jar Into EJB Jar with Maven Plugin maven-ejb-plugin

Yesterday I had some problem with packing an EJB3 jar with Maven plugin maven-ejb-plugin. The problem seemed quite common. To bundle a common jar dependency into an EJB jar, but after reading the documentation for the maven-ejb-plugin at http://maven.apache.org/plugins/maven-ejb-plugin/, it seemed clear that the plugin lacked this capability. After several hour of failure I ran into a workaround . Instead of configure the maven-ejb-plugin I used the maven-dependency-plugin to copy the desired dependency jar into the target/classes directory and then configure maven-dependency-plugin to run before the package phase.
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-ejb-plugin</artifactId>
<configuration>
<generateClient>false</generateClient>
<ejbVersion>3.0</ejbVersion>
</configuration>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-dependency-plugin</artifactId>
<executions>
<execution>
<id>copy-dependencies</id>
<phase>process-classes</phase>
<goals>
<goal>copy-dependencies</goal>
</goals>
<configuration>
<includeGroupIds>se.msc.development</includeGroupIds>
<includeArtifactIds>common</includeArtifactIds>
<outputDirectory>${project.build.outputDirectory}</outputDirectory>
</configuration>
</execution>
</executions>
</plugin>

And if you need to add the common.jar to the classpath in the MANIFEST file add the following configuration to maven-ejb-plugin.
<archive>
<manifest>
<addclasspath>true</addclasspath>
</manifest>
<manifestfile>${project.build.outputDirectory}/META-INF/MANIFEST.MF</manifestfile>
</archive>

August 11, 2009

Installing Firefox 3.5 on Ubunut 9.04 – the Jaunty Jackalope

After several crashes with Firefox 3.0x I decided to install the new Firefox 3.5, since the new version is managed with Synaptic Package Manager everything went smoothly, but with one gotcha. Do not remove the old Firefox, otherwise will panel shortcut and menu item be removed and when clicking on html files will nothing happens. Instead do the following:
sudo apt-get install firefox-3.5 firefox-3.5-gnome-support

Redirect the firefox link to the new version:
sudo rm /usr/bin/firefox
sudo ln -s /usr/bin/firefox-3.5 /usr/bin/firefox