Netty dependency issue with ElasticSearch 6.3.2 - spring

Question

I'm using spring boot and trying to connect with Elasticsearch recent version 6.3.2 but couldn't Do we need to specify any appropriate jar version
Error:
Caused by: java.lang.NoClassDefFoundError: io/netty/util/internal/logging/InternalLoggerFactory
at java.lang.ClassLoader.defineClass1(Native Method) ~[na:1.8.0_161]
at java.lang.ClassLoader.defineClass(Unknown Source) ~[na:1.8.0_161]
at java.security.SecureClassLoader.defineClass(Unknown Source) ~[na:1.8.0_161]
at java.net.URLClassLoader.defineClass(Unknown Source) ~[na:1.8.0_161]
at java.net.URLClassLoader.access$100(Unknown Source) ~[na:1.8.0_161]
at java.net.URLClassLoader$1.run(Unknown Source) ~[na:1.8.0_161]
at java.net.URLClassLoader$1.run(Unknown Source) ~[na:1.8.0_161]
at java.security.AccessController.doPrivileged(Native Method) ~[na:1.8.0_161]
at java.net.URLClassLoader.findClass(Unknown Source) ~[na:1.8.0_161]
at java.lang.ClassLoader.loadClass(Unknown Source) ~[na:1.8.0_161]
at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source) ~[na:1.8.0_161]
at java.lang.ClassLoader.loadClass(Unknown Source) ~[na:1.8.0_161]
at org.elasticsearch.transport.netty4.Netty4Utils.<clinit>(Netty4Utils.java:49) ~[transport-netty4-client-6.3.2.jar:6.3.2]
at org.elasticsearch.transport.Netty4Plugin.<clinit>(Netty4Plugin.java:48) ~[transport-netty4-client-6.3.2.jar:6.3.2]
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) ~[na:1.8.0_161]
at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source) ~[na:1.8.0_161]
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source) ~[na:1.8.0_161]
at java.lang.reflect.Constructor.newInstance(Unknown Source) ~[na:1.8.0_161]
at org.elasticsearch.plugins.PluginsService.loadPlugin(PluginsService.java:696) ~[elasticsearch-6.3.2.jar:6.3.2]
at org.elasticsearch.plugins.PluginsService.<init>(PluginsService.java:114) ~[elasticsearch-6.3.2.jar:6.3.2]
at org.elasticsearch.client.transport.TransportClient.newPluginService(TransportClient.java:107) ~[elasticsearch-6.3.2.jar:6.3.2]
at org.elasticsearch.client.transport.TransportClient.buildTemplate(TransportClient.java:132) ~[elasticsearch-6.3.2.jar:6.3.2]
at org.elasticsearch.client.transport.TransportClient.<init>(TransportClient.java:280) ~[elasticsearch-6.3.2.jar:6.3.2]
at org.elasticsearch.transport.client.PreBuiltTransportClient.<init>(PreBuiltTransportClient.java:128) ~[transport-6.3.2.jar:6.3.2]
at org.elasticsearch.transport.client.PreBuiltTransportClient.<init>(PreBuiltTransportClient.java:114) ~[transport-6.3.2.jar:6.3.2]
at org.elasticsearch.transport.client.PreBuiltTransportClient.<init>(PreBuiltTransportClient.java:104) ~[transport-6.3.2.jar:6.3.2]
at com.techprimers.elastic.standaloneelasticexample.resource.UsersResource.<init>(UsersResource.java:32) ~[classes/:na]
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) ~[na:1.8.0_161]
at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source) ~[na:1.8.0_161]
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source) ~[na:1.8.0_161]
at java.lang.reflect.Constructor.newInstance(Unknown Source) ~[na:1.8.0_161]
at org.springframework.beans.BeanUtils.instantiateClass(BeanUtils.java:170) ~[spring-beans-5.0.5.RELEASE.jar:5.0.5.RELEASE]
... 19 common frames omitted
Caused by: java.lang.ClassNotFoundException: io.netty.util.internal.logging.InternalLoggerFactory
at java.net.URLClassLoader.findClass(Unknown Source) ~[na:1.8.0_161]
at java.lang.ClassLoader.loadClass(Unknown Source) ~[na:1.8.0_161]
at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source) ~[na:1.8.0_161]
at java.lang.ClassLoader.loadClass(Unknown Source) ~[na:1.8.0_161]
... 51 common frames omitted
The Java Code:
TransportClient client;
public UsersResource() throws UnknownHostException {
client = new PreBuiltTransportClient(Settings.EMPTY)
.addTransportAddress(new TransportAddress(InetAddress.getByName("localhost"), 9300));
//client.close();
}
Below I have given configuration of POM
<project>
<modelVersion>4.0.0</modelVersion>
<groupId>com.elastic</groupId>
<artifactId>standalone-elastic-example</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>jar</packaging>
<name>standalone-elastic-example</name>
<description>Demo project for Spring Boot</description>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.0.1.RELEASE</version>
<relativePath /> <!-- lookup parent from repository -->
</parent>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<java.version>1.8</java.version>
<elasticsearch.version>6.3.2</elasticsearch.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-elasticsearch</artifactId>
</dependency>
<dependency>
<groupId>org.elasticsearch</groupId>
<artifactId>elasticsearch</artifactId>
</dependency>
<dependency>
<groupId>org.elasticsearch.client</groupId>
<artifactId>transport</artifactId>
</dependency>
<dependency>
<groupId>org.apache.logging.log4j</groupId>
<artifactId>log4j-api</artifactId>
</dependency>
<dependency>
<groupId>org.apache.logging.log4j</groupId>
<artifactId>log4j-core</artifactId>
</dependency>
<dependency>
<groupId>org.apache.logging.log4j</groupId>
<artifactId>log4j-web</artifactId>
</dependency>
</dependencies>
Did I miss any dependency ?
What causing this issue not able to connect. Kindly let me know in case of any further information.
Thanks in Advance.

Answer 1

This might not solve your NoClassDefFoundError but you should probably start using "Java High Level REST Client" since elasticsearch is planning to deprecate the TransportClient in Elasticsearch 7.0 and removing it completely in 8.0.So, it's better to use Java High Level REST Client instead of transport client.
More details are available here.