java.lang.NoClassDefFoundError: Could not initialize class x - java

I'm new to tomcat and maven both, I created a project using IntelliJ IDEA.
there are some java classes in src directory, and the .class files is stored in target directory after building the project. It seems that tomcat cannot find where are the .class files to initialize classes.
here is the directory tree:
here is my pom.xml contetnt:
<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>IE</groupId>
<artifactId>IE</artifactId>
<packaging>war</packaging>
<version>1.0-SNAPSHOT</version>
<name>IE Maven Webapp</name>
<url>http://maven.apache.org</url>
<dependencies>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>3.8.1</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>javax.servlet.jsp</groupId>
<artifactId>javax.servlet.jsp-api</artifactId>
<version>2.3.1</version>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>javax.servlet-api</artifactId>
<version>4.0.0</version>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>org.json</groupId>
<artifactId>org.json</artifactId>
<version>chargebee-1.0</version>
</dependency>
</dependencies>
<build>
<sourceDirectory>src/main/javaClasses</sourceDirectory>
<finalName>IE</finalName>
<plugins>
<plugin>
<groupId>org.apache.tomcat.maven</groupId>
<artifactId>tomcat7-maven-plugin</artifactId>
<version>2.2</version>
<configuration>
<url>http://localhost:8080/manager/text</url>
<server>TomcatServer</server>
<path>/projectName</path>
</configuration>
</plugin>
</plugins>
</build>
</project>
can anybody help how can I tell the path of target file to find classes please? Now I can't instantiate any of my classes in my jsp files.


You haven't customized the configuration of the compiler plugin, therefore, it's incorrect to put your source files under src/main/javaClasses.
You should move your source packages/classes to src/main/java, and Maven should pick it up. This is where Maven expects them by default.
For more info, check standard directory layout page.

Related

Coverting Java project to a Maven project - can not find or load the main class

I have an old Java 1.8 project that I converted to Maven project in Eclipse.
After mvn eclipse:eclipse, the project structure changes so that Eclipse does not show packages, but a directories-like-structure. Now when I try to "Run as Java Application", Eclipse gives me a list of some weird classes to run - none of which are the Main class.
Now, if I run mvn eclipse:clean, the directory structure goes back to Package-like-view and I can choose the main class when I run the project as a Java Application, but I still get the main class not found along with error:
"Description Resource Path Location Type
The project was not built since its build path is incomplete. Cannot find the class file for java.lang.Object. Fix the build path then try building this project"
The build path should be okay after the mvn eclipse:eclipse. At least all the libraries are there and also jdk 1.8 library.
Maybe I am missing something, some kinda dependency missing from pom?
I am using Java version 1.8
My pom.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/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>myJavaApplication</groupId>
<artifactId>myJavaApplication</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>myJavaApplication</name>
<properties>
<java.version>1.8</java.version>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<maven.compiler.target>1.8</maven.compiler.target>
<maven.compiler.source>1.8</maven.compiler.source>
</properties>
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-jar-plugin</artifactId>
<configuration>
<archive>
<manifest>
<addClasspath>true</addClasspath>
<mainClass>my.java.application.main.Main</mainClass>
</manifest>
</archive>
</configuration>
</plugin>
</plugins>
</build>
<dependencies>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.12</version>
</dependency>
<dependency>
<groupId>itext</groupId>
<artifactId>itext</artifactId>
<version>1.3</version>
</dependency>
<dependency>
<groupId>commons-io</groupId>
<artifactId>commons-io</artifactId>
<version>2.4</version>
</dependency>
<dependency>
<groupId>org.codehaus.jackson</groupId>
<artifactId>jackson-mapper-asl</artifactId>
<version>1.8.5</version>
</dependency>
<dependency>
<groupId>org.codehaus.jackson</groupId>
<artifactId>jackson-core-lgpl</artifactId>
<version>1.8.5</version>
</dependency>
<dependency>
<groupId>javax.xml.bind</groupId>
<artifactId>jaxb-api</artifactId>
<version>2.3.1</version>
</dependency>
</dependencies>
</project>

Could not find or load main class error when adding maven dependency

I got a Maven project which is exported into a JAR and works fine.
As soon as I add Maven dependency (not using any class etc, just imported)
<dependency>
<groupId>technology.tabula</groupId>
<artifactId>tabula</artifactId>
<version>1.0.5</version>
</dependency>
the exported JAR throws the following error:
Error: Could not find or load main class main.MyMain
Any tips how to solve this problem?
I have to use this Lib, but the error already occurs when it's only imported, not used.
pom.xml
<?xml version="1.0" encoding="UTF-8"?>
<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/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>my.group</groupId>
<artifactId>my-art</artifactId>
<version>1.0</version>
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<configuration>
<source>8</source>
<target>8</target>
</configuration>
</plugin>
</plugins>
</build>
<dependencies>
<dependency>
<groupId>org.apache.poi</groupId>
<artifactId>poi-ooxml</artifactId>
<version>4.0.0</version>
</dependency>
<dependency>
<groupId>com.dropbox.core</groupId>
<artifactId>dropbox-core-sdk</artifactId>
<version>3.1.5</version>
</dependency>
<dependency>
<groupId>org.apache.httpcomponents</groupId>
<artifactId>httpclient</artifactId>
<version>4.5.10</version>
</dependency>
<dependency>
<groupId>org.jsoup</groupId>
<artifactId>jsoup</artifactId>
<version>1.13.1</version>
</dependency>
<!--<dependency>-->
<!--<groupId>technology.tabula</groupId>-->
<!--<artifactId>tabula</artifactId>-->
<!--<version>1.0.5</version>-->
<!--</dependency>-->
</dependencies>
</project>

The command I use from command line is "java -jar myapp.jar"
You need to specify the classpath for your app if you run it as a jar from the command line. See this post.

Troubleshooting compilation / .jar creation with Maven for Hadoop on Azure

I have .Jar file with only .class files in there without any .java files...
I cloned a git repository:
https://github.com/kaist-dmlab/k-Medoid/tree/master/MR-KMEDIAN
the repository has a .jar file as well, but no .pom file with the java code. So I created a Maven Project in Eclipse, created a package: com.parallel.WEIGHTED_KMEDIAN
and put the files in there. This is what the directory looks like:
I checked all the dependencies in the java files and looked them up on the maven website and added them. So my pom.xml file looks like this:
<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/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.parallel</groupId>
<artifactId>WEIGHTED_KMEDIAN</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>jar</packaging>
<name>WEIGHTED_KMEDIAN</name>
<url>http://maven.apache.org</url>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
</properties>
<dependencies>
<dependency>
<groupId>org.apache.hadoop</groupId>
<artifactId>hadoop-core</artifactId>
<version>1.2.1</version>
</dependency>
<dependency>
<groupId>org.apache.hadoop</groupId>
<artifactId>hadoop-mapreduce-client-core</artifactId>
<version>2.7.1</version>
</dependency>
<dependency>
<groupId>org.apache.hadoop</groupId>
<artifactId>hadoop-hdfs</artifactId>
<version>2.7.2</version>
</dependency>
<dependency>
<groupId>org.jpmml</groupId>
<artifactId>pmml-model</artifactId>
<version>1.0.0</version>
</dependency>
</dependencies>
<build>
<sourceDirectory>src/main/java</sourceDirectory>
<plugins>
<plugin>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.8.0</version>
<configuration>
<release>8</release>
</configuration>
</plugin>
</plugins>
</build>
</project>
When I run the .jar file on AZURE HDINSIGHTS I get an error:
When I compared the .jar file I created and the one in the project, I am missing all the .java files.
Is this the issue that azure doesn't like?
How can I add the .java files in the .jar file?
I created the jar file from eclipse going into run>maven build> clean install
files in my jar:
files in jar from git repo:
so far I have tried:
<sourceDirectory>src/main/java/com/parallel</sourceDirectory>
Updating MAVEN project
clean compile install

The solution was the project directory needed to be in a specific format, it should be under main/resources and then follow the path in the groupID specified in the POM.xml file:
POM.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/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.parallel</groupId>
<artifactId>WEIGHTED_KMEDIAN</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>jar</packaging>
<name>WEIGHTED_KMEDIAN</name>
<url>http://maven.apache.org</url>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
</properties>
<dependencies>
<dependency>
<groupId>org.apache.hadoop</groupId>
<artifactId>hadoop-core</artifactId>
<version>1.2.1</version>
</dependency>
<dependency>
<groupId>org.apache.hadoop</groupId>
<artifactId>hadoop-mapreduce-client-core</artifactId>
<version>2.7.1</version>
</dependency>
<dependency>
<groupId>org.apache.hadoop</groupId>
<artifactId>hadoop-hdfs</artifactId>
<version>2.7.2</version>
</dependency>
<dependency>
<groupId>org.jpmml</groupId>
<artifactId>pmml-model</artifactId>
<version>1.0.0</version>
</dependency>
</dependencies>
<build>
<sourceDirectory>src</sourceDirectory>
<plugins>
<plugin>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.8.0</version>
<configuration>
<release>8</release>
</configuration>
</plugin>
</plugins>
</build>
</project>
Dependencies:

maven build succeeds, but eclipse build fails

I have an Eclipse / Maven project: The build with Maven succeeds, but Eclipse does have compile-time errors and cannot build.
My Eclipse is Neon (4.6.3) and I am using the build-in Maven and JDK 1.8
Could you help me solve the problem?
My pom.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/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>seller</groupId>
<artifactId>home.digest</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>war</packaging>
<name>home.digest Maven Webapp</name>
<!-- FIXME change it to the project's website -->
<url>http://maven.apache.org</url>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<maven.compiler.source>1.8</maven.compiler.source>
<maven.compiler.target>1.8</maven.compiler.target>
</properties>
<dependencies>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.11</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.apache.httpcomponents</groupId>
<artifactId>httpclient</artifactId>
<version>4.5.8</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.apache.httpcomponents/httpcore -->
<dependency>
<groupId>org.apache.httpcomponents</groupId>
<artifactId>httpcore</artifactId>
<version>4.4.11</version>
</dependency>
<dependency>
<!-- jsoup HTML parser library # https://jsoup.org/ -->
<groupId>org.jsoup</groupId>
<artifactId>jsoup</artifactId>
<version>1.11.3</version>
</dependency>
</dependencies>
<build>
<finalName>home.digest</finalName>
<pluginManagement><!-- lock down plugins versions to avoid using Maven defaults (may be moved to parent pom) -->
<plugins>
<plugin>
<artifactId>maven-clean-plugin</artifactId>
<version>3.1.0</version>
</plugin>
<!-- see http://maven.apache.org/ref/current/maven-core/default-bindings.html#Plugin_bindings_for_war_packaging -->
<plugin>
<artifactId>maven-resources-plugin</artifactId>
<version>3.0.2</version>
</plugin>
<plugin>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.8.0</version>
</plugin>
<plugin>
<artifactId>maven-surefire-plugin</artifactId>
<version>2.22.1</version>
</plugin>
<plugin>
<artifactId>maven-war-plugin</artifactId>
<version>3.2.2</version>
</plugin>
<plugin>
<artifactId>maven-install-plugin</artifactId>
<version>2.5.2</version>
</plugin>
<plugin>
<artifactId>maven-deploy-plugin</artifactId>
<version>2.8.2</version>
</plugin>
</plugins>
</pluginManagement>
</build>
</project>
Eclipse fails to recognize the following imports in a class:
import org.apache.http.HttpEntity;
import org.apache.http.HttpHost;
import org.apache.http.protocol.HttpContext;
The Eclipse project has the following properties:

The problem was, that the jar file was corrupt:
[ERROR] error reading C:\Users\User.m2\repository\org\apache\httpcomponents\httpcore\4.4.11\httpcore-4.4.11.jar; invalid LOC header (bad signature)
I solved the problem by replacing the dependency
<dependency>
<groupId>org.apache.httpcomponents</groupId>
<artifactId>httpcore</artifactId>
<version>4.4.11</version>
</dependency>
by the dependency on an earlier version:
4.4.10

Hello
First of all, You should check to contain the apache jar file your maven local folder. Some version folder have in your local maven folder. But doesn't have jar file.
OR
this line code add to your pom.xml file.
<dependency>
<groupId>org.apache.httpcomponents</groupId>
<artifactId>httpclient</artifactId>
<version>4.5.6</version>
</dependency>

how convert a java project to maven

I want to convert to Maven a lot of java projects. I've tried to do: Right click on my project --> Configure --> Convert to Maven Project. but I only get: pom.xml (I put every depency that I need, plugins and etc).
My pom.xml contains:
<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/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>prueba</groupId>
<artifactId>prueba</artifactId>
<version>0.0.1-SNAPSHOT</version>
<build>
<sourceDirectory>src</sourceDirectory>
<plugins>
<plugin>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.1</version>
<configuration>
<source>1.8</source>
<target>1.8</target>
</configuration>
</plugin>
</plugins>
</build>
<dependencies>
<dependency>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.5.1</version>
<type>maven-plugin</type>
</dependency>
<!-- https://mvnrepository.com/artifact/org.primefaces/primefaces -->
<dependency>
<groupId>org.primefaces</groupId>
<artifactId>primefaces</artifactId>
<version>6.1</version>
</dependency>
<dependency>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-surefire-plugin</artifactId>
<version>2.19.1</version>
<type>maven-plugin</type>
</dependency>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.12</version>
</dependency>
<dependency>
<groupId>org.seleniumhq.selenium</groupId>
<artifactId>selenium-firefox-driver</artifactId>
<version>3.4.0</version>
</dependency>
<dependency>
<groupId>org.seleniumhq.selenium</groupId>
<artifactId>selenium-java</artifactId>
<version>3.4.0</version>
</dependency>
<dependency>
<groupId>org.testng</groupId>
<artifactId>testng</artifactId>
<version>6.11</version>
</dependency>
</dependencies>
</project>
But my java docs appears empty and the following code structure inside:
Structure
Content
But as you can see, it doesn't work because I don't have my original java code in "Maven format" and it doesn't build anything in the test.
How could I convert every java file to Maven to can execute in my TestNG.xml??
Thanks so much!!!

It seems your dependencies are not resolved or the project is not built.
Can you right click on your pom.xml and run maven install. Is your build successfull ?
Once your build is successfull.
Can you right click on project -> Maven -> Update project -> Check the Force update of snapshots/releases.
This will get all the dependencies in your classpath.
Build the code again and then it should work.
Best Regards,
Saurav

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