java cassandra connection java.lang.ClassNotFoundException: com.datastax.driver.core.Cluster

Question

I am trying to connect to Cassandra with datastax driver. So far I have just tried to run the SimpleClient app available in tutorials but I am having troubles.

Here is the Exception

Exception in thread "main" java.lang.NoClassDefFoundError: com/datastax/driver/core/Cluster
    at com.cass.App.connect(App.java:17)
    at com.cass.App.main(App.java:34)
Caused by: java.lang.ClassNotFoundException: com.datastax.driver.core.Cluster
    at java.net.URLClassLoader$1.run(URLClassLoader.java:366)
    at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.net.URLClassLoader.findClass(URLClassLoader.java:354)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:425)
    at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:358)
    ... 2 more

Here is my maven file

<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>com.cass</groupId>
  <artifactId>Connector</artifactId>
  <packaging>jar</packaging>
  <version>1.0-SNAPSHOT</version>
  <name>Connector</name>
  <url>http://maven.apache.org</url>
  <dependencies>
<dependency>
    <groupId>io.netty</groupId>
    <artifactId>netty-all</artifactId>
    <version>4.0.25.Final</version>
</dependency>
<dependency>
    <groupId>com.google.guava</groupId>
    <artifactId>guava</artifactId>
    <version>18.0</version>
</dependency>
<dependency>
    <groupId>com.yammer.metrics</groupId>
    <artifactId>metrics-core</artifactId>
    <version>2.2.0</version>
</dependency>
<dependency>
    <groupId>org.slf4j</groupId>
    <artifactId>slf4j-api</artifactId>
    <version>1.7.7</version>
</dependency>

    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>3.8.1</version>
      <scope>test</scope>
    </dependency>
<dependency>
  <groupId>com.datastax.cassandra</groupId>
  <artifactId>cassandra-driver-core</artifactId>
  <version>2.0.1</version>
</dependency>

  </dependencies>
<build>
      <plugins>
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-compiler-plugin</artifactId>
            <version>2.3.2</version>
            <configuration>
                <source>1.7</source>
                <target>1.7</target>
            </configuration>
        </plugin>
      </plugins>
    </build>
</project>

Here is my java file

package com.cass;

import com.datastax.driver.core.Cluster;
import com.datastax.driver.core.Host;
import com.datastax.driver.core.Metadata;

/**
 * Generate a unique number
 *
 */
public class App 
{

    private Cluster cluster;

public void connect(String node) {
      cluster = Cluster.builder()
            .addContactPoint(node).build();
      Metadata metadata = cluster.getMetadata();
      System.out.printf("Connected to cluster: %s\n", 
            metadata.getClusterName());
      for ( Host host : metadata.getAllHosts() ) {
         System.out.printf("Datatacenter: %s; Host: %s; Rack: %s\n",
               host.getDatacenter(), host.getAddress(), host.getRack());
      }
   }

   public void close() {
      cluster.close();
   }

   public static void main(String[] args) {
      App client = new App();
      client.connect("127.0.0.1");
      client.close();
   }
}

I am new to both Maven and Cassandra.

Edit - it was a stupid mistake of not including snapshot with dependencies in the cp java -cp target/CassandraTest2-1.0-SNAPSHOT-jar-with-dependencies.jar com.Test.App

did you solve it ? I had a similar problem. Could you update the question in case you solved? thanks — f_s, May 29 '21 at 15:01

score 2 · Answer 1 · edited May 23 '17 at 12:23

2

Ok the issue is that the required jar is not present in classpath or when you are running from command prompt, it is not able to locate those jars.

Separator ; is for windows. On Unix systems you should use :

please follow these two links, similar issues with answers.

java -cp jar1:jar2:jar3:dir1:. MyProgram

Link1 and link2

edited May 23 '17 at 12:23

Community

1
1

answered Jan 12 '15 at 04:28

Ankur Singhal

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Wouldn't maven handle the dependencies? – pJAEY Jan 12 '15 at 04:32
1

@pJAEY Maven will download the jars and dependent jars, but you need to referenced it in your classpath. – Ankur Singhal Jan 12 '15 at 04:33
I'd recommend looking into the maven assembly plugin and [jar-with-dependencies](http://maven.apache.org/plugins/maven-assembly-plugin/descriptor-refs.html#jar-with-dependencies) to build a jar that includes all dependencies. Another option is to use maven itself to run your main class using the [exec:java](http://mojo.codehaus.org/exec-maven-plugin/java-mojo.html) goal to run your main class. – Andy Tolbert Jan 12 '15 at 04:52
Didn't change anything. I fixed it by trying `java -cp target/CassandraTest2-1.0-SNAPSHOT-jar-with-dependencies.jar com.Test.App` – pJAEY Jan 12 '15 at 05:01
Good catch on the classpaths @ankur-singhal. thanks for the help :) – pJAEY Jan 12 '15 at 05:04

score 0 · Answer 2 · answered Aug 24 '16 at 19:29

I had the same issue. Only difference was datastax version was 2.1.1. Later i realized this version has an issue. My project started working after changing the version from 2.1.1 to 2.1.9 (In fact I tested your version too. it was working. Other that this version, it worked on all others. Strang!)

And for the maven. Yes, it does handle the dependency. Normally, if you put the dependency in pom file and run the class it handles. It did for me too.

java cassandra connection java.lang.ClassNotFoundException: com.datastax.driver.core.Cluster

2 Answers2