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Docker starts the springboot project and reports java version error

I use the following dockerfile to generate a image call userservice
FROM java:8-alpine
COPY ./userservice.jar /tmp/userservice.jar
ENTRYPOINT java -jar /tmp/userservice.jar
then I use the following command to run container
docker run --name userservice_container userservice
But the terminal prompts that the java version does not match，as follows:
Exception in thread "main" java.lang.UnsupportedClassVersionError: com/imortal/UserApplication has been compiled by a more recent version of the Java Runtime (class file version 55.0), this version of the Java Runtime only recognizes class file versions up to 52.0
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClass(ClassLoader.java:763)
at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
at java.net.URLClassLoader.defineClass(URLClassLoader.java:467)
at java.net.URLClassLoader.access$100(URLClassLoader.java:73)
at java.net.URLClassLoader$1.run(URLClassLoader.java:368)
at java.net.URLClassLoader$1.run(URLClassLoader.java:362)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:361)
at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
at org.springframework.boot.loader.LaunchedURLClassLoader.loadClass(LaunchedURLClassLoader.java:151)
at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:348)
at org.springframework.boot.loader.MainMethodRunner.run(MainMethodRunner.java:46)
at org.springframework.boot.loader.Launcher.launch(Launcher.java:107)
at org.springframework.boot.loader.Launcher.launch(Launcher.java:58)
at org.springframework.boot.loader.JarLauncher.main(JarLauncher.java:88)
So I went to check the compiled bytecode version, it is indeed 52, I don’t know why this error is still reported
javap -verbose .\UserApplication.class
public class com.imortal.UserApplication
minor version: 0
major version: 52
flags: (0x0021) ACC_PUBLIC, ACC_SUPER
this_class: #2 //
com/imortal/UserApplication
super_class: #4 // java/lang/Object
interfaces: 0, fields: 0, methods: 2, attributes: 2

Use a docker image that has a compatible jdk version, so that it doesn't create any conflict with all the microservices that you are having. This issue probably is occuring because one of your microservices is build on some other jdk version.

Can't run JAR files because of outdated JRE but updating it does nothing

I tried to open the jar with "java -jar blah.jar".
this is the outcome:
java -jar Desktop/lambertone2.jar
Exception in thread "main" java.lang.UnsupportedClassVersionError: main/Main has been compiled by a more recent version of the Java Runtime (class file version 54.0), this version of the Java Runtime only recognizes class file versions up to 52.0
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClass(ClassLoader.java:763)
at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
at java.net.URLClassLoader.defineClass(URLClassLoader.java:468)
at java.net.URLClassLoader.access$100(URLClassLoader.java:74)
at java.net.URLClassLoader$1.run(URLClassLoader.java:369)
at java.net.URLClassLoader$1.run(URLClassLoader.java:363)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:362)
at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:348)
at org.eclipse.jdt.internal.jarinjarloader.JarRsrcLoader.main(JarRsrcLoader.java:56) .
I went to Oracle site to download the latest JRE but it doesn't change anything.
All this happened some day ago where the update section of java told me to erase java because it was obsolete, so i removed it and reinstalled it.
if i use the command java --version it says me that the command is unsupported.
if i use javac --version it says that it is version 10.

maven version exception on mac

When I execute "mvn --version" I get this error:
Exception in thread "main" java.lang.UnsupportedClassVersionError: org/apache/maven/cli/MavenCli : Unsupported major.minor version 51.0
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClassCond(ClassLoader.java:637)
at java.lang.ClassLoader.defineClass(ClassLoader.java:621)
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)
at org.codehaus.plexus.classworlds.realm.ClassRealm.loadClassFromSelf(ClassRealm.java:401)
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:254)
at org.codehaus.plexus.classworlds.realm.ClassRealm.loadClass(ClassRealm.java:239)
at org.codehaus.plexus.classworlds.launcher.Launcher.getMainClass(Launcher.java:144)
at org.codehaus.plexus.classworlds.launcher.Launcher.launchEnhanced(Launcher.java:266)
at org.codehaus.plexus.classworlds.launcher.Launcher.launch(Launcher.java:229)
at org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode(Launcher.java:415)
at org.codehaus.plexus.classworlds.launcher.Launcher.main(Launcher.java:356)
Maven version I installed is maven 3.3.3
My java version is:
java version "1.8.0_65"
Java(TM) SE Runtime Environment (build 1.8.0_65-b17)
Java HotSpot(TM) 64-Bit Server VM (build 25.65-b01, mixed mode)
echo $PATH returns:
/Library/Maven/bin:/Library/Frameworks/Python.framework/Versions/3.5/bin:/usr/local/bin:/usr/bin:/bin:/usr/sbin:/sbin:/opt/X11/bin
How to solve the problem of Maven?

$JAVA_HOME should be pointing to 1.8.0_65 as in your case.
If you want it to permanently change the value of JAVA_HOME, you will have to add the command to your ~/.profile file. Below are instructions on how to accomplish this instead:
Open up Terminal.app (Applications → Utilities → Terminal)
Type:
emacs .profile
Add this to the end of the .profile file:
JAVA_HOME=/Library/Java/JavaVirtualMachines/jdk1.8.0_65.jdk/Contents/Home
export JAVA_HOME;
Note that JAVA_HOME should be the path of your JDK directory.
Save and exit emacs (ctrl-x, ctrl-s; ctrl-x, ctrl-c)
Open a new Terminal window (cmd-n) and type:
$JAVA_HOME/bin/java -version

mac-osx 10.9.4 Hadoop 2.7.1 Exception in thread "main" java.lang.UnsupportedClassVersionError: Unsupported major.minor version 51.0

When trying to run namenode -format, I am getting below error. Can anyone please suggest how to resolve it? ( On mac os x 10.9.4 version. Hadoop 2.7.1 version)
Pro:hadoop-2.7.1 hadoop$ bin/hdfs namenode -format
Exception in thread "main" java.lang.UnsupportedClassVersionError: org/apache/hadoop/hdfs/server/namenode/NameNode : Unsupported major.minor version 51.0
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClassCond(ClassLoader.java:637)
at java.lang.ClassLoader.defineClass(ClassLoader.java:621)
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$1.run(URLClassLoader.java:197)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:190)
at java.lang.ClassLoader.loadClass(ClassLoader.java:306)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:301)
at java.lang.ClassLoader.loadClass(ClassLoader.java:247)
Java Version is as below...
Pro:hadoop-2.7.1 hadoop$ java -version
java version "1.6.0_65"
Java(TM) SE Runtime Environment (build 1.6.0_65-b14-462-11M4609)
Java HotSpot(TM) 64-Bit Server VM (build 20.65-b04-462, mixed mode)
In hadoop-env.sh path given as
export JAVA_HOME=/System/Library/Java/JavaVirtualMachines/1.6.0.jdk/Contents/Home

51 Major version of Java class file format conforms to Java 7.
The Hadoop library in your version require Java 7, but you try to run it on Java 6 runtime which will not work.

Exception in thread "main" java.lang.NoClassDefFoundError: org/apache/hadoop/util/PlatformName

I know there have been many posts regarding this exception, but I am not able to fix this issue. Classpath has to be edited I think to resolve it.
I am trying to run a program called DistMap in hadoop infrastructure. This is the error I am getting.
Caused by: java.lang.ClassNotFoundException: org.apache.hadoop.util.PlatformName
at java.net.URLClassLoader$1.run(URLClassLoader.java:202)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:190)
at java.lang.ClassLoader.loadClass(ClassLoader.java:306)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:301)
at java.lang.ClassLoader.loadClass(ClassLoader.java:247)
Could not find the main class: org.apache.hadoop.util.PlatformName. Program will exit.
Exception in thread "main" java.lang.NoClassDefFoundError: org/apache/hadoop/fs/FsShell
Caused by: java.lang.ClassNotFoundException: org.apache.hadoop.fs.FsShell
at java.net.URLClassLoader$1.run(URLClassLoader.java:202)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:190)
at java.lang.ClassLoader.loadClass(ClassLoader.java:306)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:301)
at java.lang.ClassLoader.loadClass(ClassLoader.java:247)
Could not find the main class: org.apache.hadoop.fs.FsShell. Program will exit.
Exception in thread "main" java.lang.NoClassDefFoundError: org/apache/hadoop/util/PlatformName
Caused by: java.lang.ClassNotFoundException: org.apache.hadoop.util.PlatformName
at java.net.URLClassLoader$1.run(URLClassLoader.java:202)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:190)
at java.lang.ClassLoader.loadClass(ClassLoader.java:306)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:301)
at java.lang.ClassLoader.loadClass(ClassLoader.java:247)
Could not find the main class: org.apache.hadoop.util.PlatformName. Program will exit.
Exception in thread "main" java.lang.NoClassDefFoundError: org/apache/hadoop/fs/FsShell
Caused by: java.lang.ClassNotFoundException: org.apache.hadoop.fs.FsShell
at java.net.URLClassLoader$1.run(URLClassLoader.java:202)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:190)
at java.lang.ClassLoader.loadClass(ClassLoader.java:306)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:301)
at java.lang.ClassLoader.loadClass(ClassLoader.java:247)
Could not find the main class: org.apache.hadoop.fs.FsShell. Program will exit.
Error could not create input directory /distmap_output_input folder on hdfs file system
which java says
/usr/java/jdk1.6.0_32/bin/java
echo $CLASSPATH gives a blank line
cat ~/.bash_profile says
cat ~/.bash_profile
# .bash_profile
# Get the aliases and functions
if [ -f ~/.bashrc ]; then
. ~/.bashrc
fi
# User specific environment and startup programs
PATH=$PATH:$HOME/bin
export PATH
Update:
$HADOOP_HOME /usr/lib/hadoop
$HADOOP_CLASSPATH
/usr/lib/hadoop-0.20-mapreduce/hadoop-ant-2.0.0-mr1-cdh4.4.0.jar:/usr/lib/hadoop‌​-0.20-mapreduce/hadoop-ant.jar:/usr/lib/hadoop-0.20-mapreduce/hadoop-examples-2.0‌​.0-mr1-cdh4.4.0.jar:/usr/lib/hadoop-0.20-mapreduce/hadoop-examples.jar:/usr/lib/h‌​adoop-0.20-mapreduce/hadoop-core.jar:/usr/lib/hadoop-0.20-mapreduce/hadoop-core-2‌​.0.0-mr1-cdh4.4.0.jar:/usr/lib/hadoop-0.20-mapreduce/hadoop-test-2.0.0-mr1-cdh4.4‌​.0.jar:/usr/lib/hadoop-0.20-mapreduce/hadoop-test.jar:/usr/lib/hadoop-0.20-mapreduce/hadoop-tools-2.0.0-mr1-cdh4.4.0.jar:/usr/lib/hado‌​op-0.20-mapreduce/hadoop-tools.jar:/usr/lib/hadoop-0.20-mapreduce/lib/*jar:/usr/lib/hadoop/hadoop-common.jar:/usr/lib/hadoop/hadoop-common-2.0.0-cdh4.4.0.jar
The last 2 jar files have those classes PlatformName and FsShell. Still its not working.
Can anyone please help me fix this issue?
Thanks

hadoop-auth-2.2.0.jar should be there for hadoop2.2.0
Add hadoop auth jar for your version

If you are a maven user and faced this issue -
<dependency>
<groupId>org.apache.hadoop</groupId>
<artifactId>hadoop-client</artifactId>
<version>${hadoop.client.version}</version>
</dependency>
<dependency>
<groupId>org.apache.hadoop</groupId>
<artifactId>hadoop-common</artifactId>
<version>${hadoop.client.version}</version>
</dependency>
NOTE: :hadoop-client:2.5.2 alone didn't bring in all the required hadoop dependencies. That is why I added hadoop-common, which brought all the required deps.

Hadoop HADOOP_CLASSPATH issues
This would be helpful.
Thanks & Regards,
Alok Thaker

In my particular case, I am using Maven, and although I had hadoop-auth in both the POM and the classpath, I was still getting this exception.
What finally fixed it for me was changing the scope for the dependency in the POM from "provided" to "compile".