Gradle build jar cannot find dependency at run time

I have below build.gradle file in which I have included json-simple dependency:

apply plugin: 'java'
repositories {
    mavenCentral()
}
 
dependencies {
    testImplementation('org.junit.jupiter:junit-jupiter-api:5.4.2')
    testRuntime('org.junit.jupiter:junit-jupiter-engine:5.4.2')
    compile 'com.googlecode.json-simple:json-simple:1.1.1'
}

test {
    useJUnitPlatform()
}
jar {
  manifest {
    attributes(
      'Main-Class': 'src.main.java.demo.Hello'
    )
  }
}

I have below class which uses json-simple:

package src.main.java.demo;

import org.json.simple.parser.JSONParser;
import org.json.simple.JSONObject;


public class Hello{
    public String hello(){
        try{String jsonString="{\"first\":\"Hello\",\"second\":\"world\"}";
        JSONParser jspa=new JSONParser();
        JSONObject job=(JSONObject)jspa.parse(jsonString);
        return (String)job.get("first");    }
        catch(Exception e){
            return "";
        }
    }
    public static void main(String[] args)
    {
        System.out.println(new Hello().hello());    
    } 
}

The project builds successfully but on running the created jar file of project, it says it cannot find JSONParser and JSONObject. It means that these dependencies are not added at runtime. What should I do to add them to the classpath?

Thank You!

You should create a fat jar. Change your build gradle like this

jar {
   manifest { 
      attributes "Main-Class": "src.main.java.demo.Hello"
   }  

  from {
     configurations.runtimeClasspath.collect { it.isDirectory() ? it : zipTree(it)}        
   }
}

for older Gradle you should use this

from {
configurations.compile.collect { it.isDirectory() ? it : zipTree(it) }
}