Develop Reference

SLF4J Incompatible magic value 3130930938

I am building a maven project where i faced this issue. Here is log trace
`Exception in thread "main" java.lang.ClassFormatError: Incompatible magic value 3130930938 in class file org/slf4j/LoggerFactory
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClass(ClassLoader.java:800)
at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
at java.net.URLClassLoader.defineClass(URLClassLoader.java:449)
at java.net.URLClassLoader.access$100(URLClassLoader.java:71)
at java.net.URLClassLoader$1.run(URLClassLoader.java:361)
at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:354)
at org.codehaus.plexus.classworlds.realm.ClassRealm.loadClassFromSelf(ClassRealm.java:386)
at org.codehaus.plexus.classworlds.strategy.SelfFirstStrategy.loadClass(SelfFirstStrategy.java:42)
at org.codehaus.plexus.classworlds.realm.ClassRealm.loadClass(ClassRealm.java:244)`
Here are my dependencies in pom.xml
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-api</artifactId>
<version>1.7.5</version>
</dependency>
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-simple</artifactId>
<version>1.6.4</version>
</dependency>
<dependency>
I already tried different options like clearing out java cache etc but didn't worked for me.
I appreciate any help. Thanks

All artifacts in the group org.slf4j must have the same version when used in the POM. Otherwise runtime errors are then result.

Thanks for all your help. I resolved this issue finally. Here is the culprit
Step 1: I converted the magic value into ascii and got the following output "??6?". I checked the slf4j api in my maven's m2 directory and found another version(1.5.6) of slf4j also present there. I removed the slf-4j (1.5.6).
Step 2:
I removed the slf4j bundle (which gave error) in eclipse/configuration/org.eclipse.osgi and retry with maven build command.
which is successfull.

ClassNotFoundException while using apache commons net

Getting the following while using Apache's commons-net library.
Caused by: java.lang.ClassNotFoundException: org.apache.commons.net.SocketFactory
at java.net.URLClassLoader$1.run(URLClassLoader.java:202)
at java.security.AccessController.doPrivileged(Native Method)
This class is loaded transitively by another one.
The environment is maven and commons-net has been loaded via the pom file.
<dependency>
<groupId>commons-net</groupId>
<artifactId>commons-net</artifactId>
<classifier>ftp</classifier>
<version>2.0</version>
</dependency>
There is no SSL connection. Do I need to specify using java.security ?

NoClassDefFoundError: DataAccessException using spring

I know this has been discussed a lot, but somehow none of the previously asked questions is applicable to my case.
When loading my application I get the following stacktrace:
Exception in thread "JavaFX Application Thread" java.lang.NoClassDefFoundError: org/springframework/dao/DataAccessException
at java.lang.Class.getDeclaredConstructors0(Native Method)
at java.lang.Class.privateGetDeclaredConstructors(Class.java:2663)
at java.lang.Class.getConstructor0(Class.java:3067)
at java.lang.Class.newInstance(Class.java:408)
at sun.reflect.misc.ReflectUtil.newInstance(ReflectUtil.java:51)
at javafx.fxml.FXMLLoader$ValueElement.processAttribute(FXMLLoader.java:923)
at javafx.fxml.FXMLLoader$InstanceDeclarationElement.processAttribute(FXMLLoader.java:967)
at javafx.fxml.FXMLLoader$Element.processStartElement(FXMLLoader.java:216)
at javafx.fxml.FXMLLoader$ValueElement.processStartElement(FXMLLoader.java:740)
at javafx.fxml.FXMLLoader.processStartElement(FXMLLoader.java:2701)
at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:2521)
at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:2435)
at javafx.fxml.FXMLLoader.load(FXMLLoader.java:2403)
at de.festo.rs.windows.FXApplStarter$1.run(FXApplStarter.java:29)
at com.sun.javafx.application.PlatformImpl.lambda$null$164(PlatformImpl.java:292)
at com.sun.javafx.application.PlatformImpl$$Lambda$55/29905907.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at com.sun.javafx.application.PlatformImpl.lambda$runLater$165(PlatformImpl.java:291)
at com.sun.javafx.application.PlatformImpl$$Lambda$54/20965065.run(Unknown Source)
at com.sun.glass.ui.InvokeLaterDispatcher$Future.run(InvokeLaterDispatcher.java:95)
at com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
at com.sun.glass.ui.win.WinApplication.lambda$null$141(WinApplication.java:102)
at com.sun.glass.ui.win.WinApplication$$Lambda$46/6575340.run(Unknown Source)
at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.ClassNotFoundException: org.springframework.dao.DataAccessException
at java.net.URLClassLoader$1.run(URLClassLoader.java:372)
at java.net.URLClassLoader$1.run(URLClassLoader.java:361)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:360)
at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)
at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
... 24 more
In most of the threads I read concerning similar errors people were indeed missing the spring-tx jar which I definately don´t.
It is declared in my maven dependencies along with the other spring jars neededd like this:
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-tx</artifactId>
<version>4.2.0.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-beans</artifactId>
<version>4.2.0.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-jdbc</artifactId>
<version>4.2.0.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-context</artifactId>
<version>4.2.0.RELEASE</version>
</dependency>
When investigating my deployed output the jars are there as well.
Nevertheless the mentioned error is thrown. I am really desperate with this.
Please note, that the application is not a WebApp but kind of a standalone application loaded from another program.
Funny thing is that my colleague can´t reproduce the error. For that reason I guess it´s some kind of race condition between my JavaFX loader loading the result of the spring-jdbc query into its datamodel. I don´t have any proof for this, it´s just kind of a gut instinct.
Any help or tipp would be really appreciated.
If further information is needed please let me know.

Class : org.springframework.dao.DataAccessException is defined in Spring-DAO. Check if have below dependency.
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-dao</artifactId>
<version>2.0.8</version>
</dependency>

to fix this issue i have just moved the application.java under the base package like i have created groupid demo.test.activemq and created the same package name in src folder and then restarted. it works for me.

Another posibility is, that you hide some dependencies through a scope like test:
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-tx</artifactId>
<scope>test</scope>
</dependency>
Just remove the scope (or set the default: compile)

ClassNotFoundException while executing mvn javadoc:javadoc

My build works fine except when doing a release (or more precisely mvn javadoc:javadoc).
I get the ClassNotFoundException below. Any hints as to how to provide the class would be deeply appreciated
Caused by: java.lang.NoClassDefFoundError: org/apache/http/HttpRequest
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClassCond(ClassLoader.java:631)
at java.lang.ClassLoader.defineClass(ClassLoader.java:615)
at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:141)
at java.net.URLClassLoader.defineClass(URLClassLoader.java:283)
at java.net.URLClassLoader.access$000(URLClassLoader.java:58)
at java.net.URLClassLoader$1.run(URLClassLoader.java:197)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:190)
at org.codehaus.plexus.classworlds.realm.ClassRealm.loadClassFromSelf(ClassRealm.java:386)
at org.codehaus.plexus.classworlds.strategy.SelfFirstStrategy.loadClass(SelfFirstStrategy.java:42)
at org.codehaus.plexus.classworlds.realm.ClassRealm.loadClass(ClassRealm.java:244)
at org.codehaus.plexus.classworlds.realm.ClassRealm.loadClass(ClassRealm.java:230)
at org.apache.maven.plugin.javadoc.AbstractJavadocMojo.buildJavadocOptions(AbstractJavadocMojo.java:5843)
at org.apache.maven.plugin.javadoc.AbstractJavadocMojo.executeReport(AbstractJavadocMojo.java:1857)
at org.apache.maven.plugin.javadoc.JavadocReport.generate(JavadocReport.java:130)
at org.apache.maven.plugin.javadoc.JavadocReport.execute(JavadocReport.java:315)
at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo(DefaultBuildPluginManager.java:101)
... 20 more
Caused by: java.lang.ClassNotFoundException: org.apache.http.HttpRequest
at org.codehaus.plexus.classworlds.strategy.SelfFirstStrategy.loadClass(SelfFirstStrategy.java:50)
at org.codehaus.plexus.classworlds.realm.ClassRealm.loadClass(ClassRealm.java:244)
at org.codehaus.plexus.classworlds.realm.ClassRealm.loadClass(ClassRealm.java:230)
... 38 more

It might be a problem of maven transitive dependencies conflict. Some dependencies are transitively depend on two different version of httpclient, try to exclude one with:
<dependency>
<groupId>groupId</groupId>
<artifactId>artifactId</artifactId>
<exclusions>
<exclusion>
<groupId>org.apache.httpcomponents</groupId>
<artifactId>httpclient</artifactId>
</exclusion>
</exclusions>
</dependency>

Chances are that the OP was running on Maven 2.x. So, the solution would be to use Maven 3.x if they want to work with recent versions of maven-javadoc-plugin (apparently 2.9+). After all the Maven 2 has reached its EOL, so there's no reason to continue to using it.
A combination of changes like the maven-javadoc-plugin upgrade to use a newer version of HttpClient and Maven moving from Plexus to Guice as IoC container may have caused this.
Here are a few ticket links that could help:
Required class missing: org/apache/http/HttpRequest
[Patch]
Port maven-javadoc-plugin from httpclient 3 to httpclient 4
Move
from Plexus to Guice as IoC container

ClassNotFoundException HttpRequestInterceptor

I am getting this weird exception on this line:
HttpSolrServer server = new HttpSolrServer("http://localhost:8080/solr/");
Stack trace:
Exception in thread "main" java.lang.NoClassDefFoundError: org/apache/http/HttpRequestInterceptor
at com.polgar.dipl.index.SolrIndex.init(SolrIndex.java:36)
at com.polgar.dipl.index.SolrIndex.getInstance(SolrIndex.java:30)
at com.polgar.dipl.main.ArticleIndexer.main(ArticleIndexer.java:44)
Caused by: java.lang.ClassNotFoundException: org.apache.http.HttpRequestInterceptor
at java.net.URLClassLoader$1.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
... 3 more

Getting the same problem. We both must be playing with Solr 3.6
I had to download the HttpClient jars from the HttpComponents project. They didn't seem to be included with Solr 3.6
http://hc.apache.org/downloads.cgi
3.6 Has a new version of the client that uses the new HttpComponents (4.0) stuff, not the old HttpClient (3.1) stuff. The old 3.1 jar is there, but not the new one.
Once I copied the jars over, it worked.
I copied the following (not all may be needed).
httpclient-4.1.3.jar
httpclient-cache-4.1.3.jar
httpcore-4.1.4.jar
httpmime-4.1.3.jar
works for me, now.

If you are using Maven to include SOLRJ, you'll also want the following phrases in your POM:
<dependency>
<groupId>org.apache.httpcomponents</groupId>
<artifactId>httpclient</artifactId>
<version>4.2.1</version>
</dependency>
<dependency>
<groupId>org.apache.httpcomponents</groupId>
<artifactId>httpmime</artifactId>
<version>4.2.1</version>
</dependency>

Looks like you are missing the HttpClient Jar file in your runtime classpath.

I was also facing this issue. To resolve this, I have done following:
Checked the versions available of http components in your "~.m2\repository\org\apache\httpcomponents" directory
Based on that add following entries in your pom.xml file and rebuild your project by running mvn clean install and mvn eclipse:eclipse command one by one.
(If you are behind the proxy, make sure you have provided essential configuration in your settings.xml file)
This should resolve the problem, It did for me. :)
<dependency>
<groupId>org.apache.httpcomponents</groupId>
<artifactId>httpclient</artifactId>
<version>4.2.3</version>
</dependency>
<dependency>
<groupId>org.apache.httpcomponents</groupId>
<artifactId>httpmime</artifactId>
<version>4.2.3</version>
</dependency>