问题
I am facing issues while using enum in my J2EE application. I am using enum in a switch case inside my stateless service bean.
During runtime I see following exception on switch statement:
Caused by: java.lang.NoClassDefFoundError: com/comp/service/TestServiceImpl$1
This issue has been extensively discussed on one of the thread on SO. But I do not see any solution mentioned to resolve this issue.
In my case I use JBOSS EAP6.1 server. JDK version is 1.7. Code is built using Maven in Eclipse IDE. And application is deployed as EAR archive. How do I add this extra generated class file in classpath inside my EAR archive? Is there any other way to resolve this issue?
Update 29 June 2014: I tried to build application from command line. Then this extra class file is generated. And I am able to deply and execute application successfully. It seems to be bug with eclipse then. Any idea how to resolve it?
pom.xml from EAR project:
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
<modelVersion>4.0.0</modelVersion>
<parent>
<artifactId>demo-maven</artifactId>
<groupId>com.comp.demo</groupId>
<version>0.0.1-SNAPSHOT</version>
</parent>
<artifactId>demo-ear</artifactId>
<packaging>ear</packaging>
<name>demo - ear</name>
<url>www.comp.com</url>
<licenses>
<license>
<name>Apache License, Version 2.0</name>
<distribution>repo</distribution>
<url>http://www.apache.org/licenses/LICENSE-2.0.html</url>
</license>
</licenses>
<dependencies>
<!-- Depend on the ejb module and war so that we can package them -->
<dependency>
<groupId>com.comp.demo</groupId>
<artifactId>demo-web</artifactId>
<type>war</type>
</dependency>
<dependency>
<groupId>com.comp.demo</groupId>
<artifactId>demo-service</artifactId>
<type>ejb</type>
</dependency>
</dependencies>
<build>
<finalName>${project.parent.artifactId}</finalName>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-ear-plugin</artifactId>
<version>${version.ear.plugin}</version>
<configuration>
<!-- Tell Maven we are using Java EE 6 -->
<version>6</version>
<!-- Use Java EE ear libraries as needed. Java EE ear libraries
are in easy way to package any libraries needed in the ear, and automatically
have any modules (EJB-JARs and WARs) use them -->
<defaultLibBundleDir>lib</defaultLibBundleDir>
<modules></modules>
<fileNameMapping>no-version</fileNameMapping>
</configuration>
</plugin>
<!-- The JBoss AS plugin deploys your ear to a local JBoss EAP container -->
<!-- Due to Maven's lack of intelligence with EARs we need to configure
the jboss-as maven plugin to skip deployment for all modules. We then enable
it specifically in the ear module. -->
<plugin>
<groupId>org.jboss.as.plugins</groupId>
<artifactId>jboss-as-maven-plugin</artifactId>
<configuration>
<skip>false</skip>
</configuration>
</plugin>
</plugins>
</build>
<profiles>
<profile>
<!-- When built in OpenShift the 'openshift' profile will be used when invoking mvn. -->
<!-- Use this profile for any OpenShift specific customization your app will need. -->
<!-- By default that is to put the resulting archive into the 'deployments' folder. -->
<!-- http://maven.apache.org/guides/mini/guide-building-for-different-environments.html -->
<id>openshift</id>
<build>
<plugins>
<plugin>
<artifactId>maven-ear-plugin</artifactId>
<version>${version.ear.plugin}</version>
<configuration>
<outputDirectory>deployments</outputDirectory>
</configuration>
</plugin>
</plugins>
</build>
</profile>
</profiles>
</project>
pom.xml from ejb project:
<?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/maven-v4_0_0.xsd">
<modelVersion>4.0.0</modelVersion>
<parent>
<artifactId>demo-maven</artifactId>
<groupId>com.comp.demo</groupId>
<version>0.0.1-SNAPSHOT</version>
</parent>
<artifactId>demo-service</artifactId>
<packaging>ejb</packaging>
<name>demo - service</name>
<url>www.comp.com</url>
<licenses>
<license>
<name>Apache License, Version 2.0</name>
<distribution>repo</distribution>
<url>http://www.apache.org/licenses/LICENSE-2.0.html</url>
</license>
</licenses>
<dependencies>
<!-- Declare the APIs we depend on and need for compilation. All of them
are provided by JBoss EAP 6 -->
<!-- Import the EJB API, we use provided scope as the API is included in
JBoss EAP 6 -->
<dependency>
<groupId>org.jboss.spec.javax.ejb</groupId>
<artifactId>jboss-ejb-api_3.1_spec</artifactId>
<scope>provided</scope>
</dependency>
<!-- Import the CDI API, we use provided scope as the API is included in
JBoss EAP 6 -->
<dependency>
<groupId>javax.enterprise</groupId>
<artifactId>cdi-api</artifactId>
<scope>provided</scope>
</dependency>
<!-- Import the JPA API, we use provided scope as the API is included in
JBoss EAP 6 -->
<dependency>
<groupId>org.hibernate.javax.persistence</groupId>
<artifactId>hibernate-jpa-2.0-api</artifactId>
<scope>provided</scope>
</dependency>
<!-- JSR-303 (Bean Validation) Implementation -->
<!-- Provides portable constraints such as @Email -->
<!-- Hibernate Validator is shipped in JBoss EAP 6 -->
<dependency>
<groupId>org.hibernate</groupId>
<artifactId>hibernate-validator</artifactId>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>org.jboss.ejb3</groupId>
<artifactId>jboss-ejb3-ext-api</artifactId>
<version>2.0.0-redhat-2</version>
<type>jar</type>
<scope>provided</scope>
</dependency>
<!-- Test scope dependencies -->
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.mockito</groupId>
<artifactId>mockito-all</artifactId>
<version>1.9.5</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.hibernate</groupId>
<artifactId>hibernate-entitymanager</artifactId>
<version>4.3.5.Final</version>
<scope>test</scope>
</dependency>
<!-- Optional, but highly recommended -->
<!-- Arquillian allows you to test enterprise code such as EJBs and Transactional(JTA)
JPA from JUnit/TestNG -->
<dependency>
<groupId>org.jboss.arquillian.junit</groupId>
<artifactId>arquillian-junit-container</artifactId>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.jboss.arquillian.protocol</groupId>
<artifactId>arquillian-protocol-servlet</artifactId>
<scope>test</scope>
</dependency>
<dependency>
<groupId>javax</groupId>
<artifactId>javaee-api</artifactId>
<version>6.0</version>
<type>jar</type>
<scope>provided</scope>
</dependency>
</dependencies>
<build>
<finalName>${project.artifactId}</finalName>
<plugins>
<plugin>
<artifactId>maven-ejb-plugin</artifactId>
<version>${version.ejb.plugin}</version>
<configuration>
<!-- Tell Maven we are using EJB 3.1 -->
<ejbVersion>3.1</ejbVersion>
</configuration>
</plugin>
</plugins>
</build>
<profiles>
<profile>
<!-- The default profile skips all tests, though you can tune it to run
just unit tests based on a custom pattern -->
<!-- Seperate profiles are provided for running all tests, including Arquillian
tests that execute in the specified container -->
<id>default</id>
<activation>
<activeByDefault>true</activeByDefault>
</activation>
<build>
<plugins>
<plugin>
<artifactId>maven-surefire-plugin</artifactId>
<version>${version.surefire.plugin}</version>
<configuration>
<skip>true</skip>
</configuration>
</plugin>
</plugins>
</build>
</profile>
<profile>
<!-- An optional Arquillian testing profile that executes tests in your
JBoss EAP instance -->
<!-- This profile will start a new JBoss EAP instance, and execute the
test, shutting it down when done -->
<!-- Run with: mvn clean test -Parq-jbossas-managed -->
<id>arq-jbossas-managed</id>
<dependencies>
<dependency>
<groupId>org.jboss.as</groupId>
<artifactId>jboss-as-arquillian-container-managed</artifactId>
<scope>test</scope>
</dependency>
</dependencies>
</profile>
<profile>
<!-- An optional Arquillian testing profile that executes tests in a remote
JBoss EAP instance -->
<!-- Run with: mvn clean test -Parq-jbossas-remote -->
<id>arq-jbossas-remote</id>
<dependencies>
<dependency>
<groupId>org.jboss.as</groupId>
<artifactId>jboss-as-arquillian-container-remote</artifactId>
<scope>test</scope>
</dependency>
</dependencies>
</profile>
</profiles>
</project>
回答1:
I have a project configuration quite similar to yours: eclipse, Maven, JDK 1.6, JBoss EAP6.2, and I have the same problem with a java.lang.NoClassDefFoundError when using an enum in a switch case.
I have found a workaround for it: generate an ear file (it is a war in my case) and install it manually from the JBoss administration console. I noticed the war includes the $1 needed classes and then you won't get the exception.
This is just a workaround, but it works for me. A good point of this workaround is that subsequent deployments done through eclipse work!
I will be listening to the answers to your question because I want a real solution.
回答2:
I ran into a similar issue, and the easy workaround was to define the Enum as public instead of private.
(Didn't have time to verify, but my hunch is that this causes the class to not be created as Name$1.class but rather something like Name$Enumname.class, which seemed to be the problem)
来源：https://stackoverflow.com/questions/24473247/java-enum-noclassdeffounderror