NoClassDefFoundError exception in your Maven project

After you have added a new dependency, you could have exception like this:

NetBeans error:

--- exec-maven-plugin:1.2.1:exec (default-cli) @ integration ---
java.lang.NoClassDefFoundError: path/to/the/class/ClassName
    at java.lang.Class.getDeclaredMethods0(Native Method)
    at java.lang.Class.privateGetDeclaredMethods(Class.java:2701)
    at java.lang.Class.privateGetMethodRecursive(Class.java:3048)
    at java.lang.Class.getMethod0(Class.java:3018)
    at java.lang.Class.getMethod(Class.java:1784)
    at sun.launcher.LauncherHelper.validateMainClass(LauncherHelper.java:544)
    at sun.launcher.LauncherHelper.checkAndLoadMain(LauncherHelper.java:526)
Caused by: java.lang.ClassNotFoundException: package.ClassName
    at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
    at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:331)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
    ... 7 more

IntellijIdea error:

static root folder for maven projects

Static files could be copied here:
<maven-project-root>\src\main\webapp\resources

They are accessed on server on URL:
<server_address>/resources

Example:
<maven-project-root>\src\main\webapp\resources\x.txt
could be accessed on
http://localhost:8080/resources/x.txt

In come cases, the content changes are actualized without server restart. For example with:
mvn jetty:run

Propagating java system properties to maven project code - issue solved

Issue description: I have got Hudson/Jenkins project. It is build via maven. Maven "Goals and options" is set to
test -DxxxApiConfigFile=config-xxxApi-client-jenkins

Starting console command "mvn test -DxxxApiConfigFile=config-xxxApi-client-jenkins" behaves correctly - the system property is set. But running

Solution: Maven field "Goals and options" has to be set to:
-DargLine="-DxxxApiConfigFile=config-xxxApi-client-jenkins" clean test

or even better:
-DxxxApiConfigFile=config-xxxApi-client-jenkins -DargLine="-DxxxApiConfigFile=config-xxxApi-client-jenkins" test


Source: http://www.cowtowncoder.com/blog/archives/2010/04/entry_385.html

maven - Uncompilable source code error

Caused by: java.lang.RuntimeException: Uncompilable source code - package xxxxxxx does not exist.

Searching in default maven repository

http://repo1.maven.org/maven2/ is the default repository for Maven 2 & 3, but many times it is hard to find the project artifactId, groupId and version in it.

log4j in maven project

Adding support for log4j is realized via maven dependency. You have to edit pom.xml file, and add these lines:

Client authentication with SSL certificates in Jetty in maven

Here is an example pom.xml fragment:

Adding external jar libraries to maven project

You have to add something like this in your pom.xml:
    <dependency>
        <groupId>com.xxx.yyy.messages</groupId>
        <artifactId>xxxyyyMessages2</artifactId>
        <version>2.0-SNAPSHOT</version>
        <scope>system</scope>
        <systemPath>${project.basedir}/../xxxyyyMessages2/target/xxxyyyMessages2-2.0-SNAPSHOT.jar</systemPath>
    </dependency>


Making jar with dependency jars incorporated with maven

I want to start my program from the clear console. Here is the code, which has to be placed in pom.xml:

java.lang.OutOfMemoryError: PermGen space - Cause and Solution

The error was (in maven):
java.lang.OutOfMemoryError: PermGen space

Solution:
If you build with maven:
MAVEN_OPTS="-Xms512m -Xmx768m -XX:PermSize=256m -XX:MaxPermSize=512m"
AND
JAVA_OPTS="-Xms512m -Xmx768m"

If you use other tools, check their OPTS configuration - may be there is analogue.

solved maven error "NoClassDefFoundError" ComponentLifecycleException


niskia:/xxyyzz# mvn jar:jar
Exception in thread "main" java.lang.NoClassDefFoundError: org/codehaus/plexus/component/repository/exception/ComponentLifecycleException
at java.lang.Class.getDeclaredMethods0(Native Method)
at java.lang.Class.privateGetDeclaredMethods(Class.java:2427)
at java.lang.Class.privateGetPublicMethods(Class.java:2547)
at java.lang.Class.getMethods(Class.java:1410)
at org.codehaus.classworlds.Launcher.getEnhancedMainMethod(Launcher.java:195)
at org.codehaus.classworlds.Launcher.launchEnhanced(Launcher.java:294)
at org.codehaus.classworlds.Launcher.launch(Launcher.java:255)
at org.codehaus.classworlds.Launcher.mainWithExitCode(Launcher.java:430)
at org.codehaus.classworlds.Launcher.main(Launcher.java:375)
Caused by: java.lang.ClassNotFoundException: org.codehaus.plexus.component.repository.exception.ComponentLifecycleException
at java.net.URLClassLoader$1.run(URLClassLoader.java:202)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:190)
at java.lang.ClassLoader.loadClass(ClassLoader.java:307)
at org.codehaus.classworlds.RealmClassLoader.loadClassDirect(RealmClassLoader.java:195)
at org.codehaus.classworlds.DefaultClassRealm.loadClass(DefaultClassRealm.java:255)
at org.codehaus.classworlds.RealmClassLoader.loadClass(RealmClassLoader.java:214)
at java.lang.ClassLoader.loadClass(ClassLoader.java:248)
... 9 more

The solution was reinstalling maven. For debian is done by:

apt-get remove maven2
apt-get install maven2


Adding JAXB / jxc support in maven

Put your schemas (*.xsd) and bindings (*.xjb) into the src/main/resources folder.
Correct pom.xml as you add:

<build>
 <plugins>
  <plugin>
   <groupId>org.jvnet.jaxb2.maven2</groupId>
   <artifactId>maven-jaxb2-plugin</artifactId>
   <executions>
    <execution>
     <goals>
      <goal>generate</goal>
     </goals>
     <configuration>
      <args>
       <arg>-nv</arg><!-- this disable strict schema validation -->
      </args>
     </configuration>
    </execution>
   </executions>
  </plugin>
  <plugin>
   <inherited>true</inherited>
   <groupId>org.apache.maven.plugins</groupId>
   <artifactId>maven-compiler-plugin</artifactId>
   <configuration>
    <source>1.5</source>
    <target>1.5</target>
   </configuration>
  </plugin>
 </plugins>
</build>