JavaEE 7 Heals Crippled Jars And java.lang.ClassFormatError 📎
JavaEE 6 APIs in Maven central were only usable for compiling. Any attempt to load the classes from
<dependency>
<groupId>javax</groupId>
<artifactId>javaee-web-api</artifactId>
<version>6.0</version>
<scope>provided</scope>
</dependency>
would result in:
java.lang.ClassFormatError: Absent Code attribute in method that is not native or abstract in class file javax/persistence/LockModeType
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClassCond(ClassLoader.java:632)
at java.lang.ClassLoader.defineClass(ClassLoader.java:616)
at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:141)
at java.net.URLClassLoader.defineClass(URLClassLoader.java:283)
at java.net.URLClassLoader.access$000(URLClassLoader.java:58)
at java.net.URLClassLoader$1.run(URLClassLoader.java:197)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:190)
The official Java EE 7 APIs do not have that problem any more:
<dependency>
<groupId>javax</groupId>
<artifactId>javaee-api</artifactId>
<version>7.0</version>
<scope>provided</scope>
</dependency>
If you are starting with JavaEE 7, just use the Essential Java EE 7 POM
When I spotted the "crippled" dependency in JavaEE 6 projects, I always asked "Do you write Unit Tests?". "Yes" answers were not honest. Now Java EE 7 killed my litmus tests :-)
The whole example with workaround was checked into http://kenai.com/projects/javaee-patterns The name of the project is: MavenUnitTestWithCrippledAPI. Just increase the dependency version to 7.0 and the unit tests should pass without any workarounds needed.
See you at Java EE Workshops at MUC Airport!