Why can't jdk 1.5 load a jar created with maven? (Bad version number)

Question

I'm using solaris, I created a maven app on jdk 1.6 but using the maven-compiler-plugin to specify the target as 1.5. Here is the snippet of my pom.xml:

  <plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-compiler-plugin</artifactId>
    <configuration>
      <source>1.5</source>
      <target>1.5</target>
    </configuration>
  </plugin>

Although when I try to run in the solaris box I get:

bash-2.05$ ./merchantInfoUpdate.sh 
Exception in thread "main" java.lang.UnsupportedClassVersionError: Bad version number in .class file
        at java.lang.ClassLoader.defineClass1(Native Method)
        at java.lang.ClassLoader.defineClass(ClassLoader.java:620)
        at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:124)
        at java.net.URLClassLoader.defineClass(URLClassLoader.java:260)
        at java.net.URLClassLoader.access$100(URLClassLoader.java:56)
        at java.net.URLClassLoader$1.run(URLClassLoader.java:195)
        at java.security.AccessController.doPrivileged(Native Method)
        at java.net.URLClassLoader.findClass(URLClassLoader.java:188)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:306)
        at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:268)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:251)
        at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:319)

And if I run the mvn install -X (with debug) and the compiler plugin tells me:

[DEBUG] Configuring mojo 'org.apache.maven.plugins:maven-compiler-plugin:2.0.2:compile' -->
[DEBUG]   (f) basedir = /home/emerson/newworkspace/java-batch-updater
[DEBUG]   (f) buildDirectory = /home/emerson/newworkspace/java-batch-updater/target
[DEBUG]   (f) classpathElements = [/home/emerson/newworkspace/java-batch-updater/target/classes, /home/emerson/.m2/repository/commons-logging/commons-logging/1.1.1/commons-logging-1.1.1.jar, /home/emerson/.m2/repository/log4j/log4j/1.2.12/log4j-1.2.12.jar]
[DEBUG]   (f) compileSourceRoots = [/home/emerson/newworkspace/java-batch-updater/src/main/java]
[DEBUG]   (f) compilerId = javac
[DEBUG]   (f) debug = true
[DEBUG]   (f) failOnError = true
[DEBUG]   (f) fork = false
[DEBUG]   (f) optimize = false
[DEBUG]   (f) outputDirectory = /home/emerson/newworkspace/java-batch-updater/target/classes
[DEBUG]   (f) outputFileName = com.company.ingestion.updater-2010.01
[DEBUG]   (f) projectArtifact = com.yell:com.company.ingestion.updater:jar:2010.01
[DEBUG]   (f) showDeprecation = false
[DEBUG]   (f) showWarnings = false
[DEBUG]   (f) source = 1.5
[DEBUG]   (f) staleMillis = 0
[DEBUG]   (f) target = 1.5
[DEBUG]   (f) verbose = false

emerson@emerson-desktop:~/newworkspace/java-batch-updater/target/expand$ file com/yell/ingestion/updater/ListingsManager.class

com/yell/ingestion/updater/ListingsManager.class: compiled Java class data, version 50.0 (Java 1.6)

Java version:

bash-2.05$ java -version
java version "1.5.0_05"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.5.0_05-b05)
Java HotSpot(TM) Server VM (build 1.5.0_05-b05, mixed mode)

Start script content:

bash-2.05$ more merchantInfoUpdate.sh 
LIB=lib

   CLASSPATH="."
   for i in `find $LIB  -name *.jar`; do CLASSPATH="$CLASSPATH:$i"; done;
    export CLASSPATH
   CLASSPATH=$CLASSPATH:resources/properties
java  $* -cp $CLASSPATH com.company.ingestion.updater.ListingsManager

I made sure it is actually the jar I'm building which is causing the problem, leaving it alone in the app classpath, and still I get the same error.

Any ideas?

Thanks

Thanks seanizer, I will make sure I will accept the best answers. — Emerson
Hi Janet, here it is: PATH=.:/usr/bin:/bin:/usr/sbin:/sbin:/usr/local/bin:/usr/openwin/bin:/usr/lbin::/oracle/app/oracle/product/9.2.0/bin:/bin:/usr/bin:/usr/ccs/bin:/home/user/ant/apache-ant-1.6.2/bin — Emerson
What do to get from "javac -version" (instead of java -version)? — Janek Bogucki

Michael Borgwardt Michael Borgwardt · Accepted Answer · 2010-08-19T11:11:28

Are you absolutely certain you're using Java 1.5 on the Solaris box, not 1.4? What's the output of java -version there? What does merchantInfoUpdate.sh contain? Does it put any other library JARs into the classpath, which may be compiled using the Java 1.6 class file format?

Why can't jdk 1.5 load a jar created with maven? (Bad version number)

2 Answers