According to the Maven release history, it should be possible to run any recent version of Maven (at the time of writing anyway) on JDK 7. However, when I try to do so on my Ubuntu 21.04 machine, I get an error: java.lang.UnsupportedClassVersionError: com/google/inject/Module : Unsupported major.minor version 52.0.
It happens even while running mvn without any parameters in a directory that doesn’t contain any Java files or pom.xml file.
Maven info:
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└─❯ mvn -versionApache Maven 3.6.3Maven home: /usr/share/mavenJava version: 1.7.0_80, vendor: Oracle Corporation, runtime: /home/jqno/.jabba/jdk/1.7.80-oracle/jreDefault locale: en_US, platform encoding: UTF-8OS name: "linux", version: "5.11.0-16-generic", arch: "amd64", family: "unix"(I also have a Zulu 1.7.292 and an OpenJDK installed; the behavior there is the same.)
Full stack trace:
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└─❯ mvn clean---------------------------------------------------constituent[0]: file:/usr/share/maven/conf/logging/constituent[1]: file:/usr/share/maven/lib/commons-lang3.jarconstituent[2]: file:/usr/share/maven/lib/sisu-plexus.jarconstituent[3]: file:/usr/share/maven/lib/maven-core-3.x.jarconstituent[4]: file:/usr/share/maven/lib/maven-shared-utils.jarconstituent[5]: file:/usr/share/maven/lib/sisu-inject.jarconstituent[6]: file:/usr/share/maven/lib/jansi.jarconstituent[7]: file:/usr/share/maven/lib/plexus-component-annotations.jarconstituent[8]: file:/usr/share/maven/lib/plexus-interpolation.jarconstituent[9]: file:/usr/share/maven/lib/maven-settings-builder-3.x.jarconstituent[10]: file:/usr/share/maven/lib/aopalliance.jarconstituent[11]: file:/usr/share/maven/lib/wagon-provider-api.jarconstituent[12]: file:/usr/share/maven/lib/jsr250-api.jarconstituent[13]: file:/usr/share/maven/lib/slf4j-api.jarconstituent[14]: file:/usr/share/maven/lib/plexus-cipher.jarconstituent[15]: file:/usr/share/maven/lib/maven-slf4j-provider-3.x.jarconstituent[16]: file:/usr/share/maven/lib/maven-resolver-transport-wagon.jarconstituent[17]: file:/usr/share/maven/lib/wagon-file.jarconstituent[18]: file:/usr/share/maven/lib/plexus-sec-dispatcher.jarconstituent[19]: file:/usr/share/maven/lib/maven-resolver-provider-3.x.jarconstituent[20]: file:/usr/share/maven/lib/jcl-over-slf4j.jarconstituent[21]: file:/usr/share/maven/lib/wagon-http-shaded.jarconstituent[22]: file:/usr/share/maven/lib/maven-compat-3.x.jarconstituent[23]: file:/usr/share/maven/lib/guice-no-aop.jarconstituent[24]: file:/usr/share/maven/lib/maven-artifact-3.x.jarconstituent[25]: file:/usr/share/maven/lib/guava.jarconstituent[26]: file:/usr/share/maven/lib/maven-resolver-connector-basic.jarconstituent[27]: file:/usr/share/maven/lib/commons-cli.jarconstituent[28]: file:/usr/share/maven/lib/maven-builder-support-3.x.jarconstituent[29]: file:/usr/share/maven/lib/maven-resolver-api.jarconstituent[30]: file:/usr/share/maven/lib/plexus-utils.jarconstituent[31]: file:/usr/share/maven/lib/maven-settings-3.x.jarconstituent[32]: file:/usr/share/maven/lib/maven-resolver-util.jarconstituent[33]: file:/usr/share/maven/lib/maven-resolver-impl.jarconstituent[34]: file:/usr/share/maven/lib/cdi-api.jarconstituent[35]: file:/usr/share/maven/lib/maven-resolver-spi.jarconstituent[36]: file:/usr/share/maven/lib/maven-embedder-3.x.jarconstituent[37]: file:/usr/share/maven/lib/maven-repository-metadata-3.x.jarconstituent[38]: file:/usr/share/maven/lib/commons-io.jarconstituent[39]: file:/usr/share/maven/lib/maven-model-builder-3.x.jarconstituent[40]: file:/usr/share/maven/lib/maven-plugin-api-3.x.jarconstituent[41]: file:/usr/share/maven/lib/maven-model-3.x.jarconstituent[42]: file:/usr/share/maven/lib/javax.inject.jar---------------------------------------------------Exception in thread "main" java.lang.UnsupportedClassVersionError: com/google/inject/Module : Unsupported major.minor version 52.0 at java.lang.ClassLoader.defineClass1(Native Method) at java.lang.ClassLoader.defineClass(ClassLoader.java:800) at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142) at java.net.URLClassLoader.defineClass(URLClassLoader.java:449) at java.net.URLClassLoader.access$100(URLClassLoader.java:71) at java.net.URLClassLoader$1.run(URLClassLoader.java:361) at java.net.URLClassLoader$1.run(URLClassLoader.java:355) at java.security.AccessController.doPrivileged(Native Method) at java.net.URLClassLoader.findClass(URLClassLoader.java:354) at org.codehaus.plexus.classworlds.realm.ClassRealm.loadClassFromSelf(ClassRealm.java:425) at org.codehaus.plexus.classworlds.strategy.SelfFirstStrategy.loadClass(SelfFirstStrategy.java:42) at org.codehaus.plexus.classworlds.realm.ClassRealm.unsynchronizedLoadClass(ClassRealm.java:271) at org.codehaus.plexus.classworlds.realm.ClassRealm.loadClass(ClassRealm.java:247) at org.codehaus.plexus.classworlds.realm.ClassRealm.loadClass(ClassRealm.java:239) at org.apache.maven.cli.MavenCli.container(MavenCli.java:636) at org.apache.maven.cli.MavenCli.doMain(MavenCli.java:282) at org.apache.maven.cli.MavenCli.main(MavenCli.java:193) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:606) at org.codehaus.plexus.classworlds.launcher.Launcher.launchEnhanced(Launcher.java:282) at org.codehaus.plexus.classworlds.launcher.Launcher.launch(Launcher.java:225) at org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode(Launcher.java:406) at org.codehaus.plexus.classworlds.launcher.Launcher.main(Launcher.java:347)It looks like somewhere, Maven tries to load a class that is compiled for JDK8, given that it complains about an unsupported class version of 52.0. But I don’t can’t find which class, or why Maven tries to load it in the first place. Everything I can find on Google seems unrelated.
What’s going on? How do I fix this?
UPDATE
I’ve unzipped the /usr/share/maven/lib/guice-no-aop.jar file and run javap -verbose com.google.inject.Module, and it indeed has version 52.0. I don’t know how that file got there (I would assume it was installed by apt install maven but I’m not sure).
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Answer
The problem here is that Ubuntu has repackaged Maven which in result produces the issue.
As shown here if you check the version via:
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mvn --versionApache Maven 3.6.3Maven home: /usr/share/mavenJava version: 1.7.0_80, vendor: Oracle Corporation, runtime: /home/jqno/.jabba/jdk/1.7.80-oracle/jreDefault locale: en_US, platform encoding: UTF-8OS name: "linux", version: "5.11.0-16-generic", arch: "amd64", family: "unix"This shows that you are NOT using Apache Maven.
If you do that on plain command line and install Apache Maven via https://maven.apache.org/download.cgi you will get an output like this:
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Apache Maven 3.6.3 (cecedd343002696d0abb50b32b541b8a6ba2883f)Maven home: /Users/XXX/tools/mavenJava version: 1.7.0_302, vendor: Azul Systems, Inc., runtime: /Users/khmarbaise/.sdkman/candidates/java/7.0.302-zulu/zulu-7.jdk/Contents/Home/jreDefault locale: en_GB, platform encoding: UTF-8OS name: "mac os x", version: "10.14.6", arch: "x86_64", family: "mac"The most important part is the first line:
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Apache Maven 3.6.3 (cecedd343002696d0abb50b32b541b8a6ba2883f)This is Apache Maven.
Second if you take careful look into the error output:
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constituent[0]: file:/usr/share/maven/conf/logging/constituent[1]: file:/usr/share/maven/lib/commons-lang3.jarconstituent[2]: file:/usr/share/maven/lib/sisu-plexus.jarconstituent[3]: file:/usr/share/maven/lib/maven-core-3.x.jarconstituent[4]: file:/usr/share/maven/lib/maven-shared-utils.jarconstituent[5]: file:/usr/share/maven/lib/sisu-inject.jarconstituent[6]: file:/usr/share/maven/lib/jansi.jarconstituent[7]: file:/usr/share/maven/lib/plexus-component-annotations.jarconstituent[8]: file:/usr/share/maven/lib/plexus-interpolation.jarconstituent[9]: file:/usr/share/maven/lib/maven-settings-builder-3.x.jarconstituent[10]: file:/usr/share/maven/lib/aopalliance.jarconstituent[11]: file:/usr/share/maven/lib/wagon-provider-api.jarconstituent[12]: file:/usr/share/maven/lib/jsr250-api.jarconstituent[13]: file:/usr/share/maven/lib/slf4j-api.jarconstituent[14]: file:/usr/share/maven/lib/plexus-cipher.jarconstituent[15]: file:/usr/share/maven/lib/maven-slf4j-provider-3.x.jarconstituent[16]: file:/usr/share/maven/lib/maven-resolver-transport-wagon.jarconstituent[17]: file:/usr/share/maven/lib/wagon-file.jarconstituent[18]: file:/usr/share/maven/lib/plexus-sec-dispatcher.jarconstituent[19]: file:/usr/share/maven/lib/maven-resolver-provider-3.x.jarconstituent[20]: file:/usr/share/maven/lib/jcl-over-slf4j.jarconstituent[21]: file:/usr/share/maven/lib/wagon-http-shaded.jarconstituent[22]: file:/usr/share/maven/lib/maven-compat-3.x.jarconstituent[23]: file:/usr/share/maven/lib/guice-no-aop.jarconstituent[24]: file:/usr/share/maven/lib/maven-artifact-3.x.jarconstituent[25]: file:/usr/share/maven/lib/guava.jarconstituent[26]: file:/usr/share/maven/lib/maven-resolver-connector-basic.jarconstituent[27]: file:/usr/share/maven/lib/commons-cli.jarconstituent[28]: file:/usr/share/maven/lib/maven-builder-support-3.x.jarconstituent[29]: file:/usr/share/maven/lib/maven-resolver-api.jarconstituent[30]: file:/usr/share/maven/lib/plexus-utils.jarconstituent[31]: file:/usr/share/maven/lib/maven-settings-3.x.jarconstituent[32]: file:/usr/share/maven/lib/maven-resolver-util.jarconstituent[33]: file:/usr/share/maven/lib/maven-resolver-impl.jarconstituent[34]: file:/usr/share/maven/lib/cdi-api.jarconstituent[35]: file:/usr/share/maven/lib/maven-resolver-spi.jarconstituent[36]: file:/usr/share/maven/lib/maven-embedder-3.x.jarconstituent[37]: file:/usr/share/maven/lib/maven-repository-metadata-3.x.jarconstituent[38]: file:/usr/share/maven/lib/commons-io.jarconstituent[39]: file:/usr/share/maven/lib/maven-model-builder-3.x.jarconstituent[40]: file:/usr/share/maven/lib/maven-plugin-api-3.x.jarconstituent[41]: file:/usr/share/maven/lib/maven-model-3.x.jarconstituent[42]: file:/usr/share/maven/lib/javax.inject.jarThan you can see things like this:
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constituent[3]: file:/usr/share/maven/lib/maven-core-3.x.jar..constituent[25]: file:/usr/share/maven/lib/guice-no-aop.jarIf you take a look into an original Apache Maven lib directory the files look like this:
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javaee (master *)$ ls -la ~/tools/apache-maven-3.6.3/lib/total 21000drwxr-xr-x 65 khmarbaise staff 2080 Nov 7 2019 .drwxr-xr-x 9 khmarbaise staff 288 Nov 21 2019 ..-rw-r--r-- 1 khmarbaise staff 44908 Nov 7 2019 cdi-api-1.0.jar-rw-r--r-- 1 khmarbaise staff 11560 Nov 7 2019 cdi-api.license-rw-r--r-- 1 khmarbaise staff 53820 Nov 7 2019 commons-cli-1.4.jar-rw-r--r-- 1 khmarbaise staff 11560 Nov 7 2019 commons-cli.license-rw-r--r-- 1 khmarbaise staff 208700 Nov 7 2019 commons-io-2.5.jar-rw-r--r-- 1 khmarbaise staff 11560 Nov 7 2019 commons-io.license-rw-r--r-- 1 khmarbaise staff 501879 Nov 7 2019 commons-lang3-3.8.1.jar-rw-r--r-- 1 khmarbaise staff 11560 Nov 7 2019 commons-lang3.licensedrwxr-xr-x 3 khmarbaise staff 96 Nov 7 2019 ext-rw-r--r-- 1 khmarbaise staff 2591373 Nov 7 2019 guava-25.1-android.jar-rw-r--r-- 1 khmarbaise staff 11560 Nov 7 2019 guava.license-rw-r--r-- 1 khmarbaise staff 520662 Nov 7 2019 guice-4.2.1-no_aop.jar-rw-r--r-- 1 khmarbaise staff 11560 Nov 7 2019 guice.license-rw-r--r-- 1 khmarbaise staff 283858 Nov 7 2019 jansi-1.17.1.jardrwxr-xr-x 10 khmarbaise staff 320 Nov 7 2019 jansi-native-rw-r--r-- 1 khmarbaise staff 11560 Nov 7 2019 jansi.license-rw-r--r-- 1 khmarbaise staff 2497 Nov 7 2019 javax.inject-1.jar-rw-r--r-- 1 khmarbaise staff 11560 Nov 7 2019 javax.inject.license-rw-r--r-- 1 khmarbaise staff 16539 Nov 7 2019 jcl-over-slf4j-1.7.29.jar-rw-r--r-- 1 khmarbaise staff 11560 Nov 7 2019 jcl-over-slf4j.license-rw-r--r-- 1 khmarbaise staff 397115 Nov 7 2019 jsoup-1.12.1.jar-rw-r--r-- 1 khmarbaise staff 1192 Nov 7 2019 jsoup.license-rw-r--r-- 1 khmarbaise staff 5848 Nov 7 2019 jsr250-api-1.0.jar-rw-r--r-- 1 khmarbaise staff 20545 Nov 7 2019 jsr250-api.license-rw-r--r-- 1 khmarbaise staff 57824 Nov 7 2019 maven-artifact-3.6.3.jar-rw-r--r-- 1 khmarbaise staff 14262 Nov 7 2019 maven-builder-support-3.6.3.jar-rw-r--r-- 1 khmarbaise staff 287955 Nov 7 2019 maven-compat-3.6.3.jar-rw-r--r-- 1 khmarbaise staff 633028 Nov 7 2019 maven-core-3.6.3.jar-rw-r--r-- 1 khmarbaise staff 98096 Nov 7 2019 maven-embedder-3.6.3.jar-rw-r--r-- 1 khmarbaise staff 215412 Nov 7 2019 maven-model-3.6.3.jar-rw-r--r-- 1 khmarbaise staff 192302 Nov 7 2019 maven-model-builder-3.6.3.jar-rw-r--r-- 1 khmarbaise staff 47035 Nov 7 2019 maven-plugin-api-3.6.3.jar-rw-r--r-- 1 khmarbaise staff 27158 Nov 7 2019 maven-repository-metadata-3.6.3.jar-rw-r--r-- 1 khmarbaise staff 148983 Nov 7 2019 maven-resolver-api-1.4.1.jar-rw-r--r-- 1 khmarbaise staff 44143 Nov 7 2019 maven-resolver-connector-basic-1.4.1.jar-rw-r--r-- 1 khmarbaise staff 180696 Nov 7 2019 maven-resolver-impl-1.4.1.jar-rw-r--r-- 1 khmarbaise staff 66242 Nov 7 2019 maven-resolver-provider-3.6.3.jar-rw-r--r-- 1 khmarbaise staff 36732 Nov 7 2019 maven-resolver-spi-1.4.1.jar-rw-r--r-- 1 khmarbaise staff 31013 Nov 7 2019 maven-resolver-transport-wagon-1.4.1.jar-rw-r--r-- 1 khmarbaise staff 167529 Nov 7 2019 maven-resolver-util-1.4.1.jar-rw-r--r-- 1 khmarbaise staff 44047 Nov 7 2019 maven-settings-3.6.3.jar-rw-r--r-- 1 khmarbaise staff 42090 Nov 7 2019 maven-settings-builder-3.6.3.jar-rw-r--r-- 1 khmarbaise staff 166562 Nov 7 2019 maven-shared-utils-3.2.1.jar-rw-r--r-- 1 khmarbaise staff 23815 Nov 7 2019 maven-slf4j-provider-3.6.3.jar-rw-r--r-- 1 khmarbaise staff 379197 Nov 7 2019 org.eclipse.sisu.inject-0.3.4.jar-rw-r--r-- 1 khmarbaise staff 11530 Nov 7 2019 org.eclipse.sisu.inject.license-rw-r--r-- 1 khmarbaise staff 205323 Nov 7 2019 org.eclipse.sisu.plexus-0.3.4.jar-rw-r--r-- 1 khmarbaise staff 11530 Nov 7 2019 org.eclipse.sisu.plexus.license-rw-r--r-- 1 khmarbaise staff 13350 Nov 7 2019 plexus-cipher-1.7.jar-rw-r--r-- 1 khmarbaise staff 11560 Nov 7 2019 plexus-cipher.license-rw-r--r-- 1 khmarbaise staff 4225 Nov 7 2019 plexus-component-annotations-2.1.0.jar-rw-r--r-- 1 khmarbaise staff 11560 Nov 7 2019 plexus-component-annotations.license-rw-r--r-- 1 khmarbaise staff 85327 Nov 7 2019 plexus-interpolation-1.25.jar-rw-r--r-- 1 khmarbaise staff 11560 Nov 7 2019 plexus-interpolation.license-rw-r--r-- 1 khmarbaise staff 27703 Nov 7 2019 plexus-sec-dispatcher-1.4.jar-rw-r--r-- 1 khmarbaise staff 11560 Nov 7 2019 plexus-sec-dispatcher.license-rw-r--r-- 1 khmarbaise staff 261801 Nov 7 2019 plexus-utils-3.2.1.jar-rw-r--r-- 1 khmarbaise staff 11560 Nov 7 2019 plexus-utils.license-rw-r--r-- 1 khmarbaise staff 41424 Nov 7 2019 slf4j-api-1.7.29.jar-rw-r--r-- 1 khmarbaise staff 1224 Nov 7 2019 slf4j-api.license-rw-r--r-- 1 khmarbaise staff 11586 Nov 7 2019 wagon-file-3.3.4.jar-rw-r--r-- 1 khmarbaise staff 2206349 Nov 7 2019 wagon-http-3.3.4-shaded.jar-rw-r--r-- 1 khmarbaise staff 55776 Nov 7 2019 wagon-provider-api-3.3.4.jarAll files which are like maven-core.. etc. are containing the version number of Maven (3.6.3) also the problematic
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-rw-r--r-- 1 khmarbaise staff 2591373 Nov 7 2019 guava-25.1-android.jar-rw-r--r-- 1 khmarbaise staff 11560 Nov 7 2019 guava.license-rw-r--r-- 1 khmarbaise staff 520662 Nov 7 2019 guice-4.2.1-no_aop.jar-rw-r--r-- 1 khmarbaise staff 11560 Nov 7 2019 guice.licenseYou see that this is in particular different to the given output you have where only file:/usr/share/maven/lib/guice-4.2.1-no_aop.jar apart from the missing version number of the other artifacts.
That means the problem is based on the usage of Ubuntu Maven and NOT using Apache Maven which is compatible with JDK 7 where as the repackaged version of Ubuntu is simply not.
The simplest solution is to remove the ubuntu Package of Maven and install the original Apache Maven https://maven.apache.org/download.cgi then the build with JDK 7 will work. (Download and check the checksums etc.)
Also you can download the Apache Maven and check the checksums of files against the ones of your distro (/usr/share/maven/lib/) I bet that all files are different.
The issue is based on the idea of distros to repackage Application (for example Maven) with their dependencies which are on their system which in reality means you have different versions of dependencies which results in such issues.