ApplicationEventMulticaster not initialized - call 'refresh' before multicasting events

Question

I am trying to implement ehcache for my application but when try invoking the server, getting the following error -

java.lang.IllegalStateException         


        

Answer 1

The idea behind spring-boot is that all the configurations are done automatically by spring.

In you case use the following POM.

 <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>1.2.3.RELEASE</version>
    </parent>

     <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

  <dependencies>
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>3.8.1</version>
      <scope>test</scope>
    </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
           <groupId>org.springframework</groupId>
           <artifactId>spring-context-support</artifactId>
        </dependency>
        <dependency>
           <groupId>org.springframework</groupId>
           <artifactId>spring-context-support</artifactId>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <scope>runtime</scope>
        </dependency>
        <dependency>
        <groupId>net.sf.ehcache</groupId>
        <artifactId>ehcache</artifactId>
        <version>2.9.0</version>
    </dependency>
    <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
        </dependency>
  </dependencies>

Add the following application.properties in your src/main/resources.

spring.datasource.url=jdbc:mysql://localhost:3306/soschema
spring.datasource.username=root
spring.datasource.password=root123
spring.datasource.driver-class-name=com.mysql.jdbc.Driver

# Specify the DBMS
spring.jpa.database = MYSQL

# Show or not log for each sql query
spring.jpa.show-sql = true

# Hibernate settings are prefixed with spring.jpa.hibernate.*
spring.jpa.hibernate.ddl-auto = update
spring.jpa.hibernate.dialect = org.hibernate.dialect.MySQL5Dialect
spring.jpa.hibernate.naming_strategy = org.hibernate.cfg.ImprovedNamingStrategy

Add the Appconfig file,

package org.arunm.ehcacheconfig;


import org.springframework.cache.CacheManager;
import org.springframework.cache.ehcache.EhCacheCacheManager;
import org.springframework.cache.ehcache.EhCacheManagerFactoryBean;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.io.ClassPathResource;


@Configuration
public class AppConfig {

    @Bean
    public CacheManager getEhCacheManager(){
            return  new EhCacheCacheManager(getEhCacheFactory().getObject());
    }
    @Bean
    public EhCacheManagerFactoryBean getEhCacheFactory(){
        EhCacheManagerFactoryBean factoryBean = new EhCacheManagerFactoryBean();
        factoryBean.setConfigLocation(new ClassPathResource("ehcache.xml"));
        factoryBean.setShared(true);
        return factoryBean;
    }

}

Add a top level class with the following code,

package org.ehcachetest;

import java.util.Arrays;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
import org.springframework.context.ApplicationContext;
import org.springframework.context.annotation.ComponentScan;

/**
 * Hello world!
 *
 */

@EnableAutoConfiguration
@ComponentScan
public class App 
{
    public static void main( String[] args )
    {
        ApplicationContext ctx = SpringApplication.run(App.class, args);

        String[] beanNames = ctx.getBeanDefinitionNames();
        Arrays.sort(beanNames);
        for (String beanName : beanNames) {
            System.out.println(beanName);
        }
    }
}

If you run App the main method you will find that spring has automatically created the sessionFactory, TransactionManager etc for you. There is no need for any manual configuration which means there is no need to add the dispatcherservlet, your hibernate config etc. Everything is managed by spring.

Answer 2

This is kinda stupid but my problem was that I had placed the @SpringBootApplication class (namely App, Application, WebApplication in most projects) inside the default package. Hence, everything was in total disarray.

I'm not sure why this exact error showed up, but moving the application class to a package sure fixed it.